最新論文抄録


  • Neospora caninum infection in aborting bovines and lost fetuses: A systematic review and meta-analysis

    PLoS One. 2022 May 23;17(5):e0268903. doi: 10.1371/journal.pone.0268903. eCollection 2022.

    ABSTRACT

    BACKGROUND: Neospora caninum (N. caninum) is known to be a major cause of reproductive failure in cattle herds around the world. Therefore, the current comprehensive study was performed to estimate the global prevalence of N. caninum infection in bovines that had an abortion and aborted fetuses.

    METHODS: In this study, PubMed, ScienceDirect, Web of Science, Scopus, and ProQuest databases were systematically searched for relevant studies up until November 4, 2021. Pooled prevalence and corresponding 95% confidence intervals (CI) were estimated using a random effect model. Other analyzes performed on the data of this study include sensitivity analysis, publication bias test, and quality assessment.

    RESULTS: The final analyses included 71 studies conducted on 2965 abortive cattle and 4805 aborted fetuses. The overall prevalence rates of N. caninum infection in bovines that had an abortion were 47% and 1% using serological and molecular methods. Furthermore, overall prevalence rates of N. caninum infection in bovine aborted fetuses globally were 35% (95% CI: 8%-62%) and 43% (95% CI: 35%-52%) using serological and molecular methods.

    CONCLUSIONS: The results of this study showed the high prevalence of N. caninum infection in bovines that had an abortion and aborted fetuses. It is hoped that the results of this study will help prevent abortion in bovines around the world and encourage further studies to determine the impact of this parasite on the occurrence of abortion that may help reduce the economic damage caused by abortion worldwide.

    PMID:35604902 | PMC:PMC9126370 | DOI:10.1371/journal.pone.0268903

  • Inputs for optimizing selection platform for milk production traits of dairy Sahiwal cattle

    PLoS One. 2022 May 23;17(5):e0267800. doi: 10.1371/journal.pone.0267800. eCollection 2022.

    ABSTRACT

    The premises for the potential success of molecular breeding is the ability to identify major genes associated with important dairy related traits. The present study was taken up with the objectives to identify single nucleotide polymorphism (SNP) of bovine MASP2 and SIRT1 genes and its effect on estimated breeding values (EBVs) and to estimate genetic parameters for lactation milk yield (LMY), 305-day milk yield (305dMY), 305-day fat yield (305dFY), 305-day solid not fat yield (305dSNFY) and lactation length (LL) in Sahiwal dairy cattle to devise a promising improvement strategy. Genetic parameters and breeding values of milk production traits were estimated from 935 Sahiwal cattle population (1979-2019) reared at National Dairy Research Institute at Karnal, India. A total of 7 SNPs, where one SNP (g.499C>T) in exon 2 and four SNPs (g.576G>A, g.609T>C, g.684G>T and g.845A>G) in exon 3 region of MASP2 gene and 2 SNPs (g.-306T>C and g.-274G>C) in the promoter region of SIRT1 gene were identified in Sahiwal cattle population. Five of these identified SNPs were chosen for further genotyping by PCR-RFLP and association analysis. Association analysis was performed using estimated breeding values (n = 150) to test the effect of SNPs on LMY, 305dMY, 305dFY, 305dSNFY and LL. Association analysis revealed that, three SNP markers (g.499C>T, g.609T>C and g.-306T>C) were significantly associated with all milk yield traits. The estimates for heritability using repeatability model for LMY, 305dMY, 305dFY, 305dSNFY and LL were low, however the corresponding estimates from first parity were 0.20±0.08, 0.17±0.08, 0.13±0.09, 0.13±0.09 and 0.24, respectively. The repeatability estimates were moderate to high indicating consistency of performance over the parities and hence reliability of first lactation traits. Genetic correlations among the traits of first parity were high (0.55 to 0.99). From the results we could conclude that optimum strategy to improve the Sahiwal cattle further would be selecting the animals based on their first lactation 305dMY. Option top include the significant SNP in selection criteria can be explored. Taken together, a 2-stage selection approach, select Sahiwal animals early for the SNP and then on the basis of first lactation 305dMY will help to save resources.

    PMID:35604915 | PMC:PMC9126386 | DOI:10.1371/journal.pone.0267800

  • Bovine models for human ovarian diseases

    Prog Mol Biol Transl Sci. 2022;189(1):101-154. doi: 10.1016/bs.pmbts.2022.02.001. Epub 2022 Mar 25.

    ABSTRACT

    During early embryonic development, late fetal growth, puberty, adult reproductive years, and advanced aging, bovine and human ovaries closely share molecular pathways and hormonal signaling mechanisms. Other similarities between these species include the size of ovaries, length of gestation, ovarian follicular and luteal dynamics, and pathophysiology of ovarian diseases. As an economically important agriculture species, cattle are a foundational species in fertility research with decades of groundwork using physiologic, genetic, and therapeutic experimental techniques. Many technologies used in modern reproductive medicine, such as ovulation induction using hormonal therapy, were first used in cows before human trials. Human ovarian diseases with naturally occurring bovine correlates include premature ovary insufficiency (POI), polycystic ovarian syndrome (PCOS), and sex-cord stromal tumors (SCSTs). This article presents an overview of bovine ovary research related to causes of infertility, ovarian diseases, diagnostics, and therapeutics, emphasizing where the bovine model can offer advantages over other lab animals for translational applications.

    PMID:35595347 | DOI:10.1016/bs.pmbts.2022.02.001

  • Dietary wheat and reduced methane yield are linked to rumen microbiome changes in dairy cows

    PLoS One. 2022 May 19;17(5):e0268157. doi: 10.1371/journal.pone.0268157. eCollection 2022.

    ABSTRACT

    Fermentation of pasture grasses and grains in the rumen of dairy cows and other ruminants produces methane as a by-product, wasting energy and contributing to the atmospheric load of greenhouse gasses. Many feeding trials in farmed ruminants have tested the impact of dietary components on feed efficiency, productivity and methane yield (MeY). Such diets remodel the rumen microbiome, altering bacterial, archaeal, fungal and protozoan populations, with an altered fermentation outcome. In dairy cows, some dietary grains can reduce enteric methane production. This is especially true of wheat, in comparison to corn or barley. Using a feeding trial of cows fed rolled wheat, corn or barley grain, in combination with hay and canola, we identified wheat-associated changes in the ruminal microbiome. Ruminal methane production, pH and VFA concentration data together with 16S rRNA gene amplicon sequences were used to compare ruminal bacterial and archaeal populations across diets. Differential abundance analysis of clustered sequences (OTU) identified members of the bacterial families Lachnospiraceae, Acidaminococcaceae, Eubacteriaceae, Prevotellaceae, Selenomonadaceae, Anaerovoracaceae and Fibrobacteraceae having a strong preference for growth in wheat-fed cows. Within the methanogenic archaea, (at >99% 16S rRNA sequence identity) the growth of Methanobrevibacter millerae was favoured by the non-wheat diets, while Methanobrevibacter olleyae was unaffected. From the wheat-preferring bacteria, correlation analysis found OTU strongly linked to reduced MeY, reduced pH and raised propionic acid levels. OTU from the genera Shuttleworthia and Prevotella_7 and especially Selenomonadaceae had high anti-methane correlations. An OTU likely representing (100% sequence identity) the fumarate-reducing, hydrogen-utilising, rumen bacterium Mitsuokella jalaludinii, had an especially high negative correlation coefficient (-0.83) versus MeY and moderate correlation (-0.6) with rumen pH, strongly suggesting much of the MeY suppression is due to reduced hydrogen availablity. Other OTU, representing as yet unknown species from the Selenomonadaceae family and the genera Prevotella_7, Fibrobacter and Syntrophococcus also had high to moderate negative MeY correlations, but low correlation with pH. These latter likely represent bacterial species able to reduce MeY without causing greater ruminal acidity, making them excellent candidates, provided they can be isolated, for development as anti-methane probiotics.

    PMID:35587477 | PMC:PMC9119556 | DOI:10.1371/journal.pone.0268157

  • Sperm DNA methylation patterns at discrete CpGs and genes involved in embryonic development are related to bull fertility

    BMC Genomics. 2022 May 18;23(1):379. doi: 10.1186/s12864-022-08614-5.

    ABSTRACT

    BACKGROUND: Despite a multifactorial approach being taken for the evaluation of bull semen quality in many animal breeding centres worldwide, reliable prediction of bull fertility is still a challenge. Recently, attention has turned to molecular mechanisms, which could uncover potential biomarkers of fertility. One of these mechanisms is DNA methylation, which together with other epigenetic mechanisms is essential for the fertilising sperm to drive normal embryo development and establish a viable pregnancy. In this study, we hypothesised that bull sperm DNA methylation patterns are related to bull fertility. We therefore investigated DNA methylation patterns from bulls used in artificial insemination with contrasting fertility scores.

    RESULTS: The DNA methylation patterns were obtained by reduced representative bisulphite sequencing from 10 high-fertility bulls and 10 low-fertility bulls, having average fertility scores of – 6.6 and + 6.5%, respectively (mean of the population was zero). Hierarchical clustering analysis did not distinguish bulls based on fertility but did highlight individual differences. Despite this, using stringent criteria (DNA methylation difference ≥ 35% and a q-value < 0.001), we identified 661 differently methylated cytosines (DMCs). DMCs were preferentially located in intergenic regions, introns, gene downstream regions, repetitive elements, open sea, shores and shelves of CpG islands. We also identified 10 differently methylated regions, covered by 7 unique genes (SFRP1, STXBP4, BCR, PSMG4, ARSG, ATP11A, RXRA), which are involved in spermatogenesis and early embryonic development.

    CONCLUSION: This study demonstrated that at specific CpG sites, sperm DNA methylation status is related to bull fertility, and identified seven differently methylated genes in sperm of subfertile bulls that may lead to altered gene expression and potentially influence embryo development.

    PMID:35585482 | PMC:PMC9118845 | DOI:10.1186/s12864-022-08614-5

  • Formation of Blood Neutrophil Extracellular Traps Increases the Mastitis Risk of Dairy Cows During the Transition Period

    Front Immunol. 2022 Apr 27;13:880578. doi: 10.3389/fimmu.2022.880578. eCollection 2022.

    ABSTRACT

    The current study was conducted to analyze the functions of blood neutrophils in transition cows and their association with postpartum mastitis risk as indicated by somatic cell counts (SCCs) in milk. Seventy-six healthy Holstein dairy cows were monitored from Week 4 prepartum to Week 4 postpartum. Five dairy cows with low SCCs (38 ± 6.0 × 103/mL) and five with high SCCs (3,753 ± 570.0 × 103/mL) were selected based on milk SCCs during the first three weeks of lactation. At Week 1 pre- and postpartum, serum samples were obtained from each cow to measure neutrophil extracellular trap (NET)-related variables, and blood neutrophils were collected for transcriptome analysis by RNA sequencing. The serum concentration of NETs was significantly higher (P < 0.05) in cows with high SCCs than in cows with low SCCs (36.5 ± 2.92 vs. 18.4 ± 1.73 ng/mL). The transcriptomic analysis revealed that the transcriptome differences in neutrophils between high- and low-SCC cows were mainly in cell cycle-related pathways (42.6%), including the cell cycle, DNA damage, and chromosomal conformation, at Week 1 prepartum. The hub genes of these pathways were mainly involved in both the cell cycle and NETosis. These results indicated that the formation of NETs in the blood of transition dairy cows was different between cows with low and high SCCs, which may be used as a potential indicator for the prognosis of postpartum mastitis risk and management strategies of perinatal dairy cows.

    PMID:35572521 | PMC:PMC9092530 | DOI:10.3389/fimmu.2022.880578

  • Identification of Single Amino Acid Changes in the Rift Valley Fever Virus Polymerase Core Domain Contributing to Virus Attenuation <em>In Vivo</em>

    Front Cell Infect Microbiol. 2022 Apr 28;12:875539. doi: 10.3389/fcimb.2022.875539. eCollection 2022.

    ABSTRACT

    Rift Valley fever (RVF) is an arboviral zoonotic disease affecting many African countries with the potential to spread to other geographical areas. RVF affects sheep, goats, cattle and camels, causing a high rate of abortions and death of newborn lambs. Also, humans can be infected, developing a usually self-limiting disease that can turn into a more severe illness in a low percentage of cases. Although different veterinary vaccines are available in endemic areas in Africa, to date no human vaccine has been licensed. In previous works, we described the selection and characterization of a favipiravir-mutagenized RVFV variant, termed 40Fp8, with potential as a RVF vaccine candidate due to the strong attenuation shown in immunocompromised animal models. Compared to the parental South African 56/74 viral strain, 40Fp8 displayed 7 amino acid substitutions in the L-protein, three of them located in the central region corresponding to the catalytic core of the RNA-dependent RNA polymerase (RdRp). In this work, by means of a reverse genetics system, we have analyzed the effect on virulence of these amino acid changes, alone or combined, both in vitro and in vivo. We found that the simultaneous introduction of two changes (G924S and A1303T) in the heterologous ZH548-RVFV Egyptian strain conferred attenuated phenotypes to the rescued viruses as shown in infected mice without affecting virus immunogenicity. Our results suggest that both changes induce resistance to favipiravir likely associated to some fitness cost that could be the basis for the observed attenuation in vivo. Conversely, the third change, I1050V, appears to be a compensatory mutation increasing viral fitness. Altogether, these results provide relevant information for the safety improvement of novel live attenuated RVFV vaccines.

    PMID:35573791 | PMC:PMC9096444 | DOI:10.3389/fcimb.2022.875539

  • Immunohistochemical study on the development of cholinergic and nitrergic nerve structures in the bovine esophageal groove

    Pol J Vet Sci. 2022 Mar;25(1):165-174. doi: 10.24425/pjvs.2022.140853.

    ABSTRACT

    The proper functioning of the perinatal sucking reflex in calves is essential for the prevention of milk leakage into the rumen. The complex process behind its regulation is mediated at the gut level via multiple excitatory and inhibitory neurotransmitters, of which acetylcholine and nitric oxide are of fundamental importance. The aim of our study was to depict age-related alterations in the cholinergic and nitrergic innervation of the esophageal groove (EG) using immunohistochemistry and Real-Time PCR methods. We found out that the highest number of cholinergic nerve cells was present in the second trimester fetuses. From this developmental stage onward, their amount was gradually decreasing and reached the lowest value in 4-year-old cows. The same developmental pattern was observed for nitrergic nerve structures with the highest percentage of nitrergic neurons in the third trimester fetuses. Our observations prove that both neuronal populations are crucial for a proper closure of EG in calves. Therefore, their contribution to a general neuronal activity in the ENS diminishes with age as the high motility of a gastric groove is not necessarily required in older cattle.

    PMID:35575793 | DOI:10.24425/pjvs.2022.140853

  • Comparison of effect of parenteral and oral supplementation of Selenium and vitamin E on selected antioxidant parameters and udder health of dairy cows

    Pol J Vet Sci. 2022 Mar;25(1):155-164. doi: 10.24425/pjvs.2022.140852.

    ABSTRACT

    The aim of this study was to compare the effect of parenteral and oral supplementation of Selenium (Se) and vitamin E (VTE) on selected antioxidant parameters in blood and colostrum as well as their effect on the incidence of mastitis in dairy cows during the final phase of gravidity (6 weeks) and first two weeks after calving. For the practical part of the study 36 dairy cows of Slovak pied breed in the second to fourth lactation-gestation cycle were selected. The animals weredivided into three groups: the control (C) and two experimental groups (D1 and D2). The selected groups were treated as follows: in group D1 products containing Se (Selevit inj.) and vitamin E (Erevit sol. inj.) were administered intramuscularly twice, six and three weeks prior to parturition; in group D2 a vitamin-minerals supplement in the form of sodium selenite (Na2SeO3) and dl-α-tocopherol acetate were supplemented orally for six weeks calving. The blood samples were collected from the vena jugularis in dairy cows approximately 42 days before calving (control sampling), on parturition day, and the 14th day after calving. Higher concentrations of Se and VTE were found in the blood plasma samples of both experimental groups collected on the day of parturition. In addition, the orally supplemented group (D2) showed higher Se and α-tocopherol concentrations in blood plasma on the14th day after calving as well a reduction of occurrence of mastitis by about 25 % compared to the control group. The relationship between inflammatory response and oxidative stress was also confirmed. The concentrations of milk malondialdehyde indicating lipid peroxidation during mastitis were significantly higher in milk samples from infected cows than in milk samples from healthy animals in each monitored group. In order to prevent oxidative stress and moderate inflammatory response in dairy cows it is very important to optimally balance their nutritive needs with an appropriate ratio of Se and VTE supplements. Therefore we still recommend supplementation of the cows’ postpartum dietwith 0.5 mg of Se/kg dry matter (DM) and 102 mg of dl-α-tocopherol acetate/kg DM to stabilize their optimal blood levels, stimulate the activity of glutathione peroxidase and reduce the incidence of mastitis.

    PMID:35575868 | DOI:10.24425/pjvs.2022.140852

  • In-line near-infrared analysis of milk coupled with machine learning methods for the daily prediction of blood metabolic profile in dairy cattle

    Sci Rep. 2022 May 16;12(1):8058. doi: 10.1038/s41598-022-11799-0.

    ABSTRACT

    Precision livestock farming technologies are used to monitor animal health and welfare parameters continuously and in real time in order to optimize nutrition and productivity and to detect health issues at an early stage. The possibility of predicting blood metabolites from milk samples obtained during routine milking by means of infrared spectroscopy has become increasingly attractive. We developed, for the first time, prediction equations for a set of blood metabolites using diverse machine learning methods and milk near-infrared spectra collected by the AfiLab instrument. Our dataset was obtained from 385 Holstein Friesian dairy cows. Stacking ensemble and multi-layer feedforward artificial neural network outperformed the other machine learning methods tested, with a reduction in the root mean square error of between 3 and 6% in most blood parameters. We obtained moderate correlations (r) between the observed and predicted phenotypes for γ-glutamyl transferase (r = 0.58), alkaline phosphatase (0.54), haptoglobin (0.66), globulins (0.61), total reactive oxygen metabolites (0.60) and thiol groups (0.57). The AfiLab instrument has strong potential but may not yet be ready to predict the metabolic stress of dairy cows in practice. Further research is needed to find out methods that allow an improvement in accuracy of prediction equations.

    PMID:35577915 | PMC:PMC9110744 | DOI:10.1038/s41598-022-11799-0

  • Cumulative Effect of Subclinical Mastitis on Immunological and Biochemical Parameters in Cow Milk

    Arch Razi Inst. 2021 Dec 30;76(6):1629-1638. doi: 10.22092/ari.2021.356311.1819. eCollection 2021 Dec.

    ABSTRACT

    Mastitis is a complex and multifactorial disease that leads to chemical, physical, and bacteriological changes in milk, which is associated with great economic losses. This study was carried out on lactating cows to investigate the effect of subclinical mastitis (SCM) on milk production through the estimation of immunological and biochemical characteristics of milk. Therefore, a total of 200 apparently-healthy lactating cows were randomly selected from different areas in Baghdad and Maysan provinces in Iraq from April to July 2021, and 100 ml of fresh milk was directly collected from each cow. Milk samples were examined by the California mastitis test (CMT), and IgG concentration in milk was estimated by the ELISA method. Moreover, the changes in biochemical parameters and enzymatic parameters were analyzed to determine the prevalence of SCM. Based on the results of the CMT test, the prevalence of SCM was 41.5% with a significant increase in a mild degree of severity (61.45%). IgG antibodies increased significantly in positive cows (4.92± 0.21 µg/ml). Significant prevalence of infection was observed among cows ≥5 years old compared to those <5 years, crossbred ones compared to natives, and those with lower milk production without udder/milk abnormalities, compared to cows with normal milk production. However, a significant difference was observed between the two regions under investigation (i.e., Baghdad and Maysan provinces of Iraq). Results of biochemical and enzymatic parameters showed significant increases in the concentration of Cl, FFA, and Na, and a reduction in LAC and TP, though not in Ca and K. The pH of mastitis milk was significantly higher. Although no significant difference was observed in the values of ALT and LDH, AST was increased in mastitis milk. In conclusion, this study is one of the first reports on the estimated concentration of IgG in mastitis milk samples in Iraq. Increases in the concentration of SSCs and IgG in milk can apply to the detection of intra-mammary infections.

    PMID:35546972 | PMC:PMC9083874 | DOI:10.22092/ari.2021.356311.1819

  • Introduction of the Modern Methods of Assessing the Breeding Value of Cows in the Selection of Dairy Cattle in the Republic of Kazakhstan

    Arch Razi Inst. 2021 Dec 30;76(6):1715-1726. doi: 10.22092/ari.2021.356236.1810. eCollection 2021 Dec.

    ABSTRACT

    On the genetic improvement of animals, the need for decision-making takes place at the strategic, tactical, and operational levels. At the strategic level, this means defining a breeding goal, selecting a breeding system (selection or crossbreeding), as well as crossbreeding patterns, breeds, and lines. The current study aimed to analyze the breeding and genetic parameters of the dairy cattle in the Republic of Kazakhstan and introduce modern methods for assessing the breeding value of domestic and imported breeds of dairy cows. Research data were collected from primary zootechnical and breeding accounting (from the information and analytical system [IAS]), as well as experimental studies, visual assessment, measurements, and control milking of animals. In addition, biochemical studies of milk were conducted in this study. All animals were in the same conditions of feeding. The average milk yield per cow was 5,712±97 kg, with an average fat content of 3.83±0.02%, protein content of 3.28±0.01%, with the content of 339.6±54 thousand somatic cells. However, these data are obtained based on quarterly quality indicators of milk (fat content, protein, and the number of somatic cells), which raises doubts about the reliability of the results. It was found that the average index of the total estimated breeding value (EBV) for all breeds was 81. Among all breeds, the highest EBV was estimated at 84 in the Holstein cows (imported to the country).

    PMID:35546986 | PMC:PMC9083878 | DOI:10.22092/ari.2021.356236.1810

  • A comparison of logistic regression and classification tree to assess brucellosis associated risk factors in dairy cattle

    Prev Vet Med. 2022 Jun;203:105664. doi: 10.1016/j.prevetmed.2022.105664. Epub 2022 May 9.

    ABSTRACT

    Machine learning approaches have been increasingly utilized in the field of medicine. Brucellosis is one of the most common contagious zoonotic diseases with significant impacts on livestock health, reproduction, production, and public health worldwide. Therefore, our objective was to determine the seroprevalence and compare the logistic regression and Classification and Regression Tree (CART) data-mining analysis to assess risk factors associated with Brucella infection in the densest cattle populated Egyptian governorates. A cross-sectional study was conducted on 400 animals (383 cows, 17 bulls) distributed over four Governorates in Egypt’s Nile Delta in 2019. The randomly selected animals from studied geographical areas were serologically tested for Brucella using iELISA, and the animals’ information was obtained from the farm records or animal owners. Eight supposed risk factors (geographic location, gender, herd size, age, history of abortion, shared equipment, and disinfection post-calving) were evaluated using multiple stepwise logistic regression and CART machine-learning techniques. A total of 84 (21.0%; 95% CI 17.1-25.3) serum samples were serologically positive for Brucella. The highest seroprevalence of Brucella infection was reported among animals raised in herd size > 100 animals (65.5%), with no disinfection post-calving (61.7%), with a history of abortion (59.6%), and with shared equipment without thorough cleaning and disinfection (57.1%). The multiple stepwise logistic regression modeling identified herd size, history of abortion, and disinfection post-calving as important risk factors. However, CART modeling identified herd size, disinfection post-calving, history of abortion, and shared equipment as the most potential risk factors for Brucella infection. Comparing the two models, CART model showed a higher area under the receiver operating characteristic curve (AUROC = 0.98; 95% CI 0.95 – 1.00) than the binary logistic regression (AUROC = 0.89; 95% CI 0.73 – 0.92). Our findings strongly imply that Brucella infection is most likely to spread among animals raised in large herds (>100 animals) with a history of abortions and bad hygienic measures post-calving. The CART data-mining modeling provides an accurate technique to identify risk factors of Brucella infection in cattle.

    PMID:35550235 | DOI:10.1016/j.prevetmed.2022.105664

  • Effect of timing of paddock allocation in tropical grass on performance, nitrogen excretion, and enteric methane emissions from dairy cows

    Anim Sci J. 2022 Jan;93(1):e13734. doi: 10.1111/asj.13734.

    ABSTRACT

    The objective of this study was to investigate the influence of timing of paddock allocation (AM or PM) in tropical grass on nutritive value of the herbage, dry matter intake (DMI), milk yield and composition, ruminal fermentation, nitrogen excretion, and enteric CH4 emissions of dairy cows. Twenty cows were grouped in pairs and randomly distributed within pair to one of two treatments. PM herbage had greater contents of dry matter (DM), soluble carbohydrates, starch, and nonfibrous carbohydrate to protein ratio and lower contents of neutral detergent fiber and acid detergent fiber. There was no treatment effect on DMI, N excretion, milk yield, and CH4 emissions. However, milk protein and casein yields tended to be greater for PM than AM, while milk urea nitrogen concentration was lower for PM than AM. The increase in nutritive value of the afternoon relative to the morning herbage within the framework of this study was not large enough to increase DMI and milk yield or to decrease CH4 emission intensity by the dairy cows as hypothesized. The findings indicate that PM treatment can be a simple and useful grazing strategy that results in an herbage harvest with greater nutritional value and in lower excretion of urea N into milk.

    PMID:35537860 | DOI:10.1111/asj.13734

  • LincRNA#1 knockout alone does not affect polled phenotype in cattle heterozygous for the celtic POLLED allele

    Sci Rep. 2022 May 10;12(1):7627. doi: 10.1038/s41598-022-11669-9.

    ABSTRACT

    A long intergenic non-coding RNA (lincRNA#1) is overexpressed in the horn bud region of polled (hornless) bovine fetuses, suggesting a potential role in horn bud suppression. Genome editing was used to test whether the absence of this sequence was associated with the horned phenotype. Two gRNAs with high mutation efficiencies targeting the 5′ and the 3′ regions flanking the lincRNA#1 sequence were co-injected with Cas9 as ribonucleoprotein complexes into bovine zygotes (n = 121) 6 h post insemination. Of the resulting blastocysts (n = 31), 84% had the expected 3.7 kb deletion; of these embryos with the 3.7 kb deletions, 88% were biallelic knockouts. Thirty-nine presumptive edited 7-day blastocysts were transferred to 13 synchronized recipient cows resulting in ten pregnancies, five with embryos heterozygous for the dominant PC POLLED allele at the POLLED locus, and five with the recessive pp genotype. Eight (80%) of the resulting fetuses were biallelic lincRNA#1 knockouts, with the remaining two being mosaic. RT-qPCR analysis was used to confirm the absence of lincRNA#1 expression in knockout fetuses. Phenotypic and histological analysis of the genotypically (PCp) POLLED, lincRNA#1 knockout fetuses revealed similar morphology to non-edited, control polled fetuses, indicating the absence of lincRNA#1 alone does not result in a horned phenotype.

    PMID:35538091 | PMC:PMC9090918 | DOI:10.1038/s41598-022-11669-9

  • Genetic relationship between superovulatory response traits and carcass traits in Japanese Black cattle

    Anim Sci J. 2022 Jan;93(1):e13731. doi: 10.1111/asj.13731.

    ABSTRACT

    We estimated the genetic correlations between superovulatory response traits and carcass traits in Japanese Black cattle. As regards the superovulatory response traits in cows, we analyzed the phenotypic records of the total number of embryos and oocytes (TNE) and the number of good embryos (NGE) collected from 1532 donors between 2008 and 2018. As regards the carcass traits in fattened animals, we analyzed the phenotypic records for cold carcass weight, rib eye area, rib thickness, subcutaneous fat thickness, estimated yield percent, and marbling score for 1448 progenies derived from 596 donors and slaughtered between 2004 and 2020. Variance components were estimated using single-trait and two-trait animal models and the restricted maximum likelihood approach. The estimated genetic correlations with the carcass traits ranged from -0.05 to 0.04 for TNE and from -0.14 to 0.04 for NGE, and their standard errors ranged from 0.10 to 0.14. These results imply that the genetic relationship between the superovulatory response traits in Japanese Black donor cows and the carcass traits in their fattened progenies was weak to negligible. Therefore, we concluded that selecting donors with superior genetic ability for superovulatory responses would not have antagonistic effects on carcass performance in their fattened progenies.

    PMID:35537852 | DOI:10.1111/asj.13731

  • The transcriptome-wide N6-methyladenosine (m<sup>6</sup>A) map profiling reveals the regulatory role of m<sup>6</sup>A in the yak ovary

    BMC Genomics. 2022 May 11;23(1):358. doi: 10.1186/s12864-022-08585-7.

    ABSTRACT

    BACKGROUND AND AIM: Yak estrus is a seasonal phenomenon, probably involving epigenetic regulation of synthesis and secretion of sex hormones as well as growth and development of follicles. N6-methyladenosine (m6A) is the most common internal modification of the eukaryotic mRNA. However, there are no detailed reports on the m6A transcriptome map of yak ovary. Therefore, this study aimed to collected the yak ovarian tissues at three different states of anestrus (YO-A), estrus (YO-F), and pregnancy (YO-P), and obtained the full transcriptome m6A map in yak by MeRIP-seq.

    RESULTS: The HE staining revealed that the number of growing follicles and mature follicles in the ovary during the estrus period was relatively higher than those in the anestrus period and the pregnancy period. The RT-qPCR showed that the expression of METTL3, METTL14, FTO, YTHDC1 were significantly different across different periods in the ovaries, which suggests that m6A may play a regulatory role in ovarian activity. Next, we identified 20,174, 19,747 and 13,523 m6A peaks in the three ovarian samples of YO-A, YO-F and YO-P using the methylated RNA immunoprecipitation sequencing (MeRIP-seq). The m6A peaks are highly enriched in the coding sequence (CDS) region and 3’untranslated region (3’UTR) as well as the conserved sequence of “RRACH.” The GO, KEGG and GSEA analysis revealed the involvement of m6A in many physiological activities of the yak’s ovary during reproductive cycle. The association analysis found that some genes such as BNC1, HOMER1, BMP15, BMP6, GPX3, and WNT11 were related to ovarian functions.

    CONCLUSIONS: The comparison of the distribution patterns of methylation peaks in the ovarian tissues across different periods further explored the m6A markers related to the regulation of ovarian ovulation and follicular development in the yak ovary. This comprehensive map provides a solid foundation for revealing the potential function of the mRNA m6A modification in the yak ovary.

    PMID:35538402 | PMC:PMC9092806 | DOI:10.1186/s12864-022-08585-7

  • Performance and milk quality parameters of Jersey crossbreds in low-input dairy systems

    Sci Rep. 2022 May 9;12(1):7550. doi: 10.1038/s41598-022-10834-4.

    ABSTRACT

    Previous work has demonstrated some benefit from alternative breeds in low-input dairying, although there has been no systematic analysis of the simultaneous effect of Jersey crossbreeding on productivity, health, fertility parameters or milk nutritional quality. This work aimed to understand the effects of, and interactions/interrelations between, dairy cow genotypes (Holstein-Friesian (HF), Holstein-Friesian × Jersey crossbreds (HF × J)) and season (spring, summer, autumn) on milk yield; basic composition; feed efficiency, health, and fertility parameters; and milk fatty acid (FA) profiles. Milk samples (n = 219) and breed/diet data were collected from 74 cows in four UK low-input dairy farms between March and October 2012. HF × J cows produced milk with more fat (+ 3.2 g/kg milk), protein (+ 2.9 g/kg milk) and casein (+ 2.7 g/kg milk); and showed higher feed, fat, and protein efficiency (expressed as milk, fat and protein outputs per kg DMI) than HF cows. Milk from HF × J cows contained more C4:0 (+ 2.6 g/kg FA), C6:0 (+ 1.9 g/kg FA), C8:0 (+ 1.3 g/kg FA), C10:0 (+ 3.0 g/kg FA), C12:0 (+ 3.7 g/kg FA), C14:0 (+ 4.6 g/kg FA) and saturated FA (SFA; + 27.3 g/kg milk) and less monounsaturated FA (MUFA; -23.7 g/kg milk) and polyunsaturated FA (- 22.3 g/kg milk). There was no significant difference for most health and fertility parameters, but HF × J cows had shorter calving interval (by 39 days). The superior feed, fat and protein efficiency of HF × J cows, as well as shorter calving interval can be considered beneficial for the financial sustainability of low-input dairy farms; and using such alternative breeds in crossbreeding schemes may be recommended. Although statistically significant, it is difficult to determine if differences observed between HF and HF × J cows in fat composition are likely to impact human health, considering average population dairy fat intakes and the relatively small difference. Thus, the HF × J cow could be used in low-input dairying to improve efficiency and productivity without impacting milk nutritional properties.

    PMID:35534492 | PMC:PMC9085769 | DOI:10.1038/s41598-022-10834-4

  • Environmental transfer parameters of strontium for soil to cow milk pathway for tropical monsoonal climatic region of the Indian subcontinent

    Sci Rep. 2022 May 9;12(1):7528. doi: 10.1038/s41598-022-11388-1.

    ABSTRACT

    The radionuclide transfer between compartments is commonly described by transfer parameters representing the ratio of concentrations of an element in two compartments for equilibrium conditions. This is a comprehensive study on the soil-to-grass transfer factor (Fv) and grass-to-cow milk transfer coefficient (Fm) for stable strontium (Sr) for soil-grass (pasture)-cow (Bos taurus) milk environmental pathway under field conditions for a high rainfall tropical monsoonal climatic region of the Indian subcontinent. The study was conducted in the vicinity of the Kaiga nuclear power plant (NPP), situated ~ 58 km inland of the West Coast of the Indian subcontinent. A grass field was developed exclusively for this study, and two cows of the native breed were raised to graze on it. The soil, grass, and milk were analyzed to evaluate the Fv and the Fm values for the stable Sr. For comparison, several pasture lands and the cows raised by the villagers and a dairy farm were also studied. The Fv values were in the range 0.18-8.6, the geometric mean (GM) being 1.8. The correlations of Fv values with a range of physicochemical parameters are presented. The GM values for Fm were 2.2 × 10-3 d L-1 and 7.2 × 10-3 d L-1 for the two cows raised for this study, 2.6 × 10-3 d L-1 for those raised by the villagers, and 4.2 × 10-3 d L-1 for the dairy farm. The site-specific Fm value for the region was determined as 3.2 × 10-3 d L-1. The concentration ratio (CR), defined as the ratio of Sr concentration in milk to that in feed under equilibrium conditions, exhibited less variability (1.8 × 10-2-5.4 × 10-2) among the three categories of cows.

    PMID:35534517 | PMC:PMC9085734 | DOI:10.1038/s41598-022-11388-1

  • Metabotyping the Welsh population of badgers based on thoracic fluid

    Metabolomics. 2022 May 7;18(5):30. doi: 10.1007/s11306-022-01888-6.

    ABSTRACT

    INTRODUCTION: The European badger (Meles meles) is a known wildlife reservoir for bovine tuberculosis (bTB) and a better understanding of the epidemiology of bTB in this wildlife species is required for disease control in both wild and farmed animals. Flow infusion electrospray-high-resolution mass spectrometry (FIE-HRMS) may potentially identify novel metabolite biomarkers based on which new, rapid, and sensitive point of care tests for bTB infection could be developed.

    OBJECTIVES: In this foundational study, we engaged on assessing the baseline metabolomic variation in the non-bTB infected badger population (“metabotyping”) across Wales.

    METHODS: FIE-HRMS was applied on thoracic fluid samples obtained by post-mortem of bTB negative badgers (n = 285) which were part of the Welsh Government ‘All Wales Badger Found Dead’ study.

    RESULTS: Using principal component analysis and partial least squares-discriminant analyses, the major sources of variation were linked to sex, and to a much lesser extent age, as indicated by tooth wear. Within the female population, variation was seen between lactating and non-lactating individuals. No significant variation linked to the presence of bite wounds, obvious lymphatic lesions or geographical region of origin was observed.

    CONCLUSION: Future metabolomic work when making comparisons between bTB infected and non-infected badger samples will only need be sex-matched and could focus on males only, to avoid lactation bias.

    PMID:35524831 | PMC:PMC9079023 | DOI:10.1007/s11306-022-01888-6

  • Plasma essential amino acid concentration and profile are associated with performance of lactating dairy cows as revealed through meta-analysis and hierarchical clustering

    J Dairy Sci. 2022 Jun;105(6):5044-5061. doi: 10.3168/jds.2021-21028. Epub 2022 May 5.

    ABSTRACT

    Our aim was to explore whether changes in plasma essential AA (EAA) concentration ([EAA]p) or profile (defined here as the molar proportion of individual [EAA]p relative to the total [EAA]p) may serve as an indicator of the EAA status of a cow. We undertook a meta-analysis with the objectives to determine if different plasma EAA profiles exist among cows and to explore the association of [EAA]p or the profile of EAA with lactating cow performance and measures of N utilization. We hypothesized the existence of differences in [EAA]p and different plasma EAA profile for cows with greater milk output, feed efficiency, and greater N use efficiency (NUE; milk true protein-N:N intake) compared with cows with lower milk output, feed efficiency, and lower NUE. The data set included 22 feeding trials and 96 dietary treatments. First, a mixed-effect model analysis was used to predict [EAA]p in response to the categorical fixed effect of EAA, continuous fixed effect of National Research Council model-predicted metabolizable protein (MP) supply, continuous fixed effect of body weight, the fixed effect of EAA and MP supply interaction, the fixed effect of EAA and body weight interaction, and the random effect of study. Then, residuals of the model were standardized based on Z-score and clustered using the hierarchical method (Euclidean distance and Ward’s minimum variance method) resulting in 2 clusters. Finally, a fixed-effect model was used to evaluate the significance with which clusters were associated with [EAA]p, cow performance, feed efficiency, and NUE. The total concentration of [EAA]p was lower (784 vs. 983 µM) and the concentration of each EAA was on average 22 µM lower for cows in cluster 1 compared with cluster 2 with the smallest and greatest difference found for Met (4 µM) and Val (59 µM), respectively. The percentage difference in [EAA]p was the smallest for Thr (-5.3%) and the greatest for Leu (-37.1%). There was no difference between clusters for Arg, His, and Met molar proportions; however, cows in cluster 1 had a lower molar proportion of Leu and a tendency for lower molar proportion of Val compared with cows in cluster 2. Additionally, cows in cluster 1 had greater molar proportions of Ile, Lys, and Thr and a tendency for greater molar proportion of Phe compared with cows in cluster 2. The fixed-effect model analysis indicated that cows in cluster 1 had higher milk energy output (+3.2 Mcal/d), true protein yield (+87 g/d) and fat yield (+236 g/d), feed efficiency (milk Mcal:dry matter intake; +8% unit), and a tendency for greater MP efficiency (Milk true protein/MP supply; +2.3% unit) than cows in cluster 2. These results suggested greater use of EAA by the mammary gland (as reflected by greater milk protein synthesis) and lower hepatic catabolism of AA (as reflected by a tendency to greater MP efficiency) in cows of cluster 1 compared with cluster 2. Our findings should be evaluated further, including whether the relative molar proportions of plasma EAA might serve as a holistic indicator of the EAA status of cows as related to their productivity, feed efficiency and N utilization.

    PMID:35525617 | DOI:10.3168/jds.2021-21028

  • Actions of CSF2 and DKK1 on bovine embryo development and pregnancy outcomes are affected by composition of embryo culture medium

    Sci Rep. 2022 May 7;12(1):7503. doi: 10.1038/s41598-022-11447-7.

    ABSTRACT

    Procedures for in vitro embryo production in cattle have not been optimized. In the current experiment, we utilized a 3 × 3 factorial design to test whether the proportion of embryos becoming blastocysts in culture and the pregnancy rate after embryo transfer are affected by type of serum in the medium [no serum; 3% (v/v) KnockOut Serum Replacement (SR); 3% (v/v) fetal bovine serum (FBS)] and addition of specific embryokines [vehicle; 10 ng/mL colony stimulating factor 2 (CSF2); 100 ng/mL dickkopf related protein 1 (DKK1)] at day 5 of culture. Embryos were produced using abattoir-derived ovaries and Y-sorted semen from two Angus sires. The percent of putative zygotes and cleaved embryos becoming blastocysts was improved by SR and FBS. Pregnancy rate at day 30 was determined for 1426 Nelore recipients and calving rate for 266 recipients. In the absence of CSF2 or DKK1, pregnancy rates were lower for embryos cultured with SR or FBS. CSF2 and DKK1 reduced pregnancy rate for embryos cultured without serum but had no detrimental effect in the SR or FBS groups. Indeed, CSF2 blocked the negative effect of FBS on pregnancy rate. Data on birth weights were available for 67 bull calves. There were no effects of treatment. The sire used to produce embryos had significant and large effects on development to the blastocyst stage, pregnancy rate at day 30, calving rate and pregnancy loss between day 30 and calving. Results indicate that (1) SR and FBS can improve embryonic development in vitro while also compromising competence of embryos to survive after transfer, (2) actions of CSF2 and DKK1 depend upon other characteristics of the embryo production system, and (3) sire can have a large effect on embryonic development before and after transfer.

    PMID:35525843 | PMC:PMC9079070 | DOI:10.1038/s41598-022-11447-7

  • Effect of retained placenta and clinical mastitis on reproduction parameters, immune response, and steroidogenic receptors gene expression in postpartum crossbred dairy cows

    Trop Anim Health Prod. 2022 May 6;54(3):180. doi: 10.1007/s11250-022-03140-8.

    ABSTRACT

    The purpose of this study was to evaluate the effect of retained placenta (RP) and clinical mastitis (CM) on the reproductive efficiency of crossbred dairy cows during the postpartum period and the effect in some innate immune system indicators. For this, two experiments were carried out. In the first, a total of 232 cows were evaluated and divided as: healthy control (n = 184), RP (n = 22), and CM (n = 26) groups. The RP and CM was evaluated until 30 days postpartum (DPP) and reproductive rates were measured. In experiment 2, cows were divided in control (n = 10), RP (n = 10), and CM (n = 30) groups. Between 40 and 50 DPP, clinical, gynecological examination and endometrial cytobrush were performed to evaluate subclinical endometritis (SE) and gene expression of interleukins 1β (IL-1β) and 6 (IL-6), chemokine ligand 5 (CCL5), estrogen α (ESR1), and progesterone (PGR) receptors by qRT-PCR analysis. In experiment 1, the conception rate at 1st artificial insemination (AI) was lower in RP and CM groups and pregnancy rate at 150 days decreased in CM group. Calving-to-1st AI interval and days open were shorter in healthy cows. In experiment 2, the occurrence of SE was 26.7% and higher in RP and CM groups. The expression of IL-1β increased in RP and CM groups, while IL-6 was less expressed in RP group. The CCL5, ESR1, and PGR were similar between groups. In conclusion, cows with RP and CM had their reproductive efficiency negatively affected and had they initial pro-inflammatory response improved by the increase of IL-β.

    PMID:35522378 | DOI:10.1007/s11250-022-03140-8

  • PRD-Class Homeobox Genes in Bovine Early Embryos: Function, Evolution, and Overlapping Roles

    Mol Biol Evol. 2022 May 3;39(5):msac098. doi: 10.1093/molbev/msac098.

    ABSTRACT

    Eutherian Totipotent Cell Homeobox (ETCHbox) genes are mammalian-specific PRD-class homeobox genes with conserved expression in the preimplantation embryo but fast-evolving and highly divergent sequences. Here, we exploit an ectopic expression approach to examine the role of bovine ETCHbox genes and show that ARGFX and LEUTX homeodomain proteins upregulate genes normally expressed in the blastocyst; the identities of the regulated genes suggest that, in vivo, the ETCHbox genes play a role in coordinating the physical formation of the blastocyst structure. Both genes also downregulate genes expressed earlier during development and genes associated with an undifferentiated cell state, possibly via the JAK/STAT pathway. We find evidence that bovine ARGFX and LEUTX have overlapping functions, in contrast to their antagonistic roles in humans. Finally, we characterize a mutant bovine ARGFX allele which eliminates the homeodomain and show that homozygous mutants are viable. These data support the hypothesis of functional overlap between ETCHbox genes within a species, roles for ETCHbox genes in blastocyst formation and the change of their functions over evolutionary time.

    PMID:35512670 | PMC:PMC9117796 | DOI:10.1093/molbev/msac098

  • Cross-tissue single-cell transcriptomic landscape reveals the key cell subtypes and their potential roles in the nutrient absorption and metabolism in dairy cattle

    J Adv Res. 2021 Nov 24;37:1-18. doi: 10.1016/j.jare.2021.11.009. eCollection 2022 Mar.

    ABSTRACT

    INTRODUCTION: Dairy cattle are a vitally important ruminant in meeting the demands for high-quality animal protein production worldwide. The complicated biological process of converting human indigestible biomass into highly digestible and nutritious milk is orchestrated by various tissues. However, poorly understanding of the cellular composition and function of the key metabolic tissues hinders the improvement of health and performance of domestic ruminants.

    OBJECTIVES: The cellular heterogeneity, metabolic features, interactions across ten tissue types of lactating dairy cattle were studied at single-cell resolution in the current study.

    METHODS: Unbiased single-cell RNA-sequencing and analysis were performed on the rumen, reticulum, omasum, abomasum, ileum, rectum, liver, salivary gland, mammary gland, and peripheral blood of lactating dairy cattle. Immunofluorescences and fluorescence in situ hybridization were performed to verify cell identity.

    RESULTS: In this study, we constructed a single-cell landscape covering 88,013 high-quality (500 < genes < 4,000, UMI < 50, 000, and mitochondrial gene ratio < 40% or 15%) single cells and identified 55 major cell types in lactating dairy cattle. Our systematic survey of the gene expression profiles and metabolic features of epithelial cells related to nutrient transport revealed cell subtypes that have preferential absorption of different nutrients. Importantly, we found that T helper type 17 (Th17) cells (highly expressing CD4 and IL17A) were specifically enriched in the forestomach tissues and predominantly interacted with the epithelial cell subtypes with high potential uptake capacities of short-chain fatty acids through IL-17 signaling. Furthermore, the comparison between IL17RA high IL17RC high cells (epithelial cells with IL17RA and IL17RC expression levels both greater than 0.25) and other cells explained the importance of Th17 cells in regulating the epithelial cellular transcriptional response to nutrient transport in the forestomach.

    CONCLUSION: The findings enhance our understanding of the cellular biology of ruminants and open new avenues for improved animal production of dairy cattle.

    PMID:35499046 | PMC:PMC9039752 | DOI:10.1016/j.jare.2021.11.009

  • The Potential Role of MicroRNA-124-3p in Growth, Development, and Reproduction of <em>Schistosoma japonicum</em>

    Front Cell Infect Microbiol. 2022 Apr 13;12:862496. doi: 10.3389/fcimb.2022.862496. eCollection 2022.

    ABSTRACT

    The microRNA-124-3p plays an important role in regulating development and neurogenesis. Previous microRNA sequencing analyses of Schistosoma japonicum revealed sja-miR-124-3p differential expression patterns in schistosomes from different hosts and at different developmental stages. This study explores the regulatory role of sja-miR-124-3p in S. japonicum development and reproduction. Quantitative reverse-transcription PCR (qRT-PCR) showed that the expression level of sja-miR-124-3p in S. japonicum from resistant hosts, such as Microtus fortis, and unsuitable hosts, such as rats and water buffalo, was significantly higher than that in mice and yellow cattle at the same developmental stage. Overexpressing sja-miR-124-3p in infected mice led to a hepatic egg reduction rate of 36.97%, smaller egg granulomas in the livers, increased liver weight, subsided hepatocyte necrosis, and diminished inflammatory cell infiltration. The width of female worms increased but decreased in males. The vitelline cells were irregular, swollen, or fused. The teguments and ventral sucker of males and females were swollen and broken, but the morphological changes were particularly notable in males. qRT-PCR and dual-luciferase reporter assay system were used to confirm the in-silico-predicted target genes, S. japonicum DEAD-box ATP-dependent RNA helicase 1 (sjDDX1) and DNA polymerase II subunit 2 (sjPOLE2). Our results showed that RNA interference (RNAi)-mediated sjDDX1 silencing in mice provided a 24.55% worm reduction rate and an 18.36% egg reduction rate, but the difference was not significant (p > 0.05). Thus, our findings suggest that sja-miR-124-3p has an important role in growth, development, and reproduction in S. japonicum. All these results will greatly contribute toward providing important clues for searching vaccine candidates and new drug targets against schistosomiasis.

    PMID:35493736 | PMC:PMC9043613 | DOI:10.3389/fcimb.2022.862496

  • Evaluation of the efficacy of cow colostrum in the treatment and its effect on serum proteomes in calves with cryptosporidiosis

    Vet Immunol Immunopathol. 2022 Jun;248:110429. doi: 10.1016/j.vetimm.2022.110429. Epub 2022 Apr 26.

    ABSTRACT

    This study aimed to investigate the effect of using high-quality colostrum in addition to paromomycin on the treatment outcomes and serum proteomes of calves naturally affected by cryptosporidiosis. Thirty Holstein calves infected with only Cryptosporidium spp. were divided into three equal groups. Calves in the PC group received paromomycin orally at a dose of 100 mg/kg once daily for 5 days. Calves in PCOL and PBCOL groups received 250 ml colostrum 3 h after feeding twice a day for 3 days. The PBCOL group was also given 6 g of sodium bicarbonate 15 min before colostrum administration. While the fecal scores of all calves were evaluated daily for 10 days from the initiation of the treatment, fecal oocyst counts were determined on the 0, 1, 2, 3, 5, 7, and 10th days. Brix%, total protein (TP), immunoglobulin G (IgG), gamma-glutamyltransferase (GGT) levels, and proteomic analyses were performed on the 0 and 3rd days’ sera. Considering pretreatment values, fecal scores (8th, 2nd, and 2nd day), and fecal oocyst counts (10th, 3rd, and 2nd day) improved in a significantly (p < 0.05) shorter time in the colostrum groups than in the control group. By serum proteomic analysis, 99, 93, and 83 proteomes were detected in PC, PCOL, and PBCOL groups, respectively. Although the significant changes in any protein in Group PC were absent, significant changes were observed in Alpha-1B-glycoprotein (A1BG), Zinc transporterZIP11 (S39AB), Cathelicidin-1 (CTHL1), Actin_ cytoplasmic-1 (ACTB), and Apolipoprotein A-IV (APOA4) proteins in Group PCOL and Alpha-1-antiproteinase (A1AT), Serum amyloid A protein (SAA), Actin-cytoplasmic-2 (ACTG), Protein HP-20 homolog (HP20) proteins in Group PBCOL with colostral treatment, which indicated that the use of colostrum had an effect on calf serum proteomes. The more pronounced healing and shorter clinical improvement time in the colostrum groups especially colostrum with sodium bicarbonate revealed that these proteomes have positive effects in the treatment with their systemic and local effects in the intestines.

    PMID:35500421 | DOI:10.1016/j.vetimm.2022.110429

  • Nutritional and physicochemical quality of formulations based on colostrum and bovine whey

    PLoS One. 2022 May 2;17(5):e0267409. doi: 10.1371/journal.pone.0267409. eCollection 2022.

    ABSTRACT

    The objective of this study was to investigate the nutritional quality of bovine colostrum and whey mixtures. Five whey with bovine colostrum formulations were prepared (90:10; 80:20; 70:30; 60:40 and 50:50 whey:colostrum v:v) to be subjected to low-temperature pasteurization (63°C to 65°C for 30 minutes) and freeze-drying. The samples underwent chemical composition characterization, fatty acid profile analysis, determination of contamination by Enterobacteriaceae, pH, and Dornic acidity measurements before and after vat pasteurization. The amount of protein, fat, total solids, defatted dry extract, Brix and density increased as the bovine colostrum concentration increased. The level of saturated fatty acids and the thrombogenicity and atherogenicity indices reduced, while unsaturated fatty acids increased as the level of added bovine colostrum increased. The low-temperature pasteurization of the formulations was possible and effective, eliminating contamination by Enterobacteriaceae in the samples. Mixing bovine colostrum and whey reduced the colostrum viscosity, allowing a successful pasteurization procedure. Due to colostrum composition, the formulations yielded a higher nutritional value when compared to whey alone. The parameters applied in the formulation of mixtures of bovine colostrum and whey resulted in valuable ingredients for preparing novel dairy products.

    PMID:35500007 | PMC:PMC9060355 | DOI:10.1371/journal.pone.0267409

  • Predicting male fertility from the sperm methylome: application to 120 bulls with hundreds of artificial insemination records

    Clin Epigenetics. 2022 Apr 27;14(1):54. doi: 10.1186/s13148-022-01275-x.

    ABSTRACT

    BACKGROUND: Conflicting results regarding alterations to sperm DNA methylation in cases of spermatogenesis defects, male infertility and poor developmental outcomes have been reported in humans. Bulls used for artificial insemination represent a relevant model in this field, as the broad dissemination of bull semen considerably alleviates confounding factors and enables the precise assessment of male fertility. This study was therefore designed to assess the potential for sperm DNA methylation to predict bull fertility.

    RESULTS: A unique collection of 100 sperm samples was constituted by pooling 2-5 ejaculates per bull from 100 Montbéliarde bulls of comparable ages, assessed as fertile (n = 57) or subfertile (n = 43) based on non-return rates 56 days after insemination. The DNA methylation profiles of these samples were obtained using reduced representation bisulfite sequencing. After excluding putative sequence polymorphisms, 490 fertility-related differentially methylated cytosines (DMCs) were identified, most of which were hypermethylated in subfertile bulls. Interestingly, 46 genes targeted by DMCs are involved in embryonic and fetal development, sperm function and maturation, or have been related to fertility in genome-wide association studies; five of these were further analyzed by pyrosequencing. In order to evaluate the prognostic value of fertility-related DMCs, the sperm samples were split between training (n = 67) and testing (n = 33) sets. Using a Random Forest approach, a predictive model was built from the methylation values obtained on the training set. The predictive accuracy of this model was 72% on the testing set and 72% on individual ejaculates collected from an independent cohort of 20 bulls.

    CONCLUSION: This study, conducted on the largest set of bull sperm samples so far examined in epigenetic analyses, demonstrated that the sperm methylome is a valuable source of male fertility biomarkers. The next challenge is to combine these results with other data on the same sperm samples in order to improve the quality of the model and better understand the interplay between DNA methylation and other molecular features in the regulation of fertility. This research may have potential applications in human medicine, where infertility affects the interaction between a male and a female, thus making it difficult to isolate the male factor.

    PMID:35477426 | PMC:PMC9047354 | DOI:10.1186/s13148-022-01275-x

  • Subconjunctival bleedings in neonatal calves: a case series report

    BMC Vet Res. 2022 Apr 27;18(1):152. doi: 10.1186/s12917-022-03254-z.

    ABSTRACT

    BACKGROUND: In animals, only few reports exist about the occurrence and causes of subconjunctival bleedings, especially in newborn calves. Most case reports and studies showed that the major risk factors for subconjunctival bleedings in animals are traumatic events such as birth trauma and traffic accidents, respectively. In neonatal babies, it is suggested that compression of the thorax and abdomen during delivery or forces generated in utero during labor may raise venous pressure to conjunctival vessels and can cause subconjunctival bleedings.

    RESULTS: The incidence of bleedings in neonatal Holstein-Friesian calves was 2.4 per cent of 289 neonatal calves examined over a six-year period. In general, two types of subconjunctival bleedings were seen. One was usually in a semilunar fashion immediately outside the limbus of the eye. The other type was a stripe or macule of variable size at different positions of the sclera. The subconjunctival bleedings were not related to gestational time. In all cases, affected calves were born without assistance. Multiparous cows were more often involved in the calves with subconjunctival bleedings. Two calves examined haematologically did not show signs of anemia or thrombocytopenia.

    CONCLUSIONS: Subconjunctival bleedings in neonatal calves appear not to be incidental findings. Main causes or associated conditions of subconjunctival bleedings were not found.

    PMID:35477564 | PMC:PMC9044613 | DOI:10.1186/s12917-022-03254-z

  • Molecular detection of Brucella spp. in ruminant herds in Greece

    Trop Anim Health Prod. 2022 Apr 28;54(3):173. doi: 10.1007/s11250-022-03175-x.

    ABSTRACT

    Brucellosis is a worldwide distributed infectious disease. Ruminants and other animal species (swine, dogs, equids, etc.), as well as wild mammals, can be affected. The disease can be transmitted to humans through the food chain or by direct contact with infected animals. Because of the relatively high economic burden due to abortions within a herd, significant efforts have been employed and hence the disease in most European countries has been eradicated. Accordingly, Greece applies both control and eradication programs concerning small ruminants (sheep and goats) and bovines depending on the geographical area. Current challenges in the standard antibody-based laboratory methods used for Brucella detection are the failure to differentiate antibodies against the wild strain from the ones against the vaccine strain Rev1 and antibodies against B. melitensis from those against B. abortus. The aim of the study was to reexamine and combine previously published protocols based on PCR analysis and to generate a rapid, not expensive, and easy to perform diagnostic tool able to confirm the doubtful results delivered from serology. For this reason, 264 samples derived from 191 ruminants of the farm and divided in 2 groups (male/female) were examined with a modified DNA extraction and PCR protocol. Molecular examination revealed the presence of Brucella spp. in 39 out of 264 samples (derived from 30 animals). In addition, Brucella spp. was detected in infected tissues such as testicles, inguinal lymph nodes, fetal liver, and fetal stomach content.

    PMID:35482257 | DOI:10.1007/s11250-022-03175-x

  • Development of a letrozole-based synchronization protocol for fixed-time artificial insemination in beef cattle

    Anim Reprod Sci. 2022 May;240:106975. doi: 10.1016/j.anireprosci.2022.106975. Epub 2022 Apr 11.

    ABSTRACT

    Experiments were done to determine ovulation synchrony following a 4-day letrozole treatment (Exp 1), compare the efficacy of a letrozole-based protocol with other commonly used synchronization protocols for FTAI (Exp 2), and test a new intravaginal letrozole-releasing device (LRD) with and without pre-synchronization (Exp 3). In Exp 1, heifers and lactating cows at random stages of the estrous cycle were given an LRD for 4 days, PGF at LRD removal, and GnRH at 48 or 60 h after PGF, or no GnRH. In Exp 2, heifers and lactating cows were assigned to three FTAI groups: i) LRD, ii) estradiol+progesterone, iii) 5-d Co-synch+PRID. In Exp 3, heifers were pre-synchronized with PGF or not (control) 8 days before insertion of either an X-LRD or T-LRD for 3 days; FTAI was done 48 h after device removal. In Exp 1, the variation in interval to ovulation in cows, but not heifers, in the GnRH 48-h group was less than half that in other groups (P < 0.05). In Exp 2, the P/AI was lower (P < 0.001) in the LRD group compared to the other groups. In Experiment 3, the X-LRD increased (P < 0.0001) plasma letrozole concentrations compared to the T-LRD; the pregnancy rate was not affected by pre-synchronization or the type of LRD. Although ovulation synchrony was achieved following LRD treatment, the LRD group had the lowest P/AI compared to other protocols, perhaps because of too short an interval between LRD removal and GnRH/FTAI. Drug delivery was enhanced with the new X-LRD.

    PMID:35483319 | DOI:10.1016/j.anireprosci.2022.106975

  • Identifying pleiotropic variants and candidate genes for fertility and reproduction traits in Holstein cattle via association studies based on imputed whole-genome sequence genotypes

    BMC Genomics. 2022 Apr 28;23(1):331. doi: 10.1186/s12864-022-08555-z.

    ABSTRACT

    BACKGROUND: Genetic progress for fertility and reproduction traits in dairy cattle has been limited due to the low heritability of most indicator traits. Moreover, most of the quantitative trait loci (QTL) and candidate genes associated with these traits remain unknown. In this study, we used 5.6 million imputed DNA sequence variants (single nucleotide polymorphisms, SNPs) for genome-wide association studies (GWAS) of 18 fertility and reproduction traits in Holstein cattle. Aiming to identify pleiotropic variants and increase detection power, multiple-trait analyses were performed using a method to efficiently combine the estimated SNP effects of single-trait GWAS based on a chi-square statistic.

    RESULTS: There were 87, 72, and 84 significant SNPs identified for heifer, cow, and sire traits, respectively, which showed a wide and distinct distribution across the genome, suggesting that they have relatively distinct polygenic nature. The biological functions of immune response and fatty acid metabolism were significantly enriched for the 184 and 124 positional candidate genes identified for heifer and cow traits, respectively. No known biological function was significantly enriched for the 147 positional candidate genes found for sire traits. The most important chromosomes that had three or more significant QTL identified are BTA22 and BTA23 for heifer traits, BTA8 and BTA17 for cow traits, and BTA4, BTA7, BTA17, BTA22, BTA25, and BTA28 for sire traits. Several novel and biologically important positional candidate genes were strongly suggested for heifer (SOD2, WTAP, DLEC1, PFKFB4, TRIM27, HECW1, DNAH17, and ADAM3A), cow (ANXA1, PCSK5, SPESP1, and JMJD1C), and sire (ELMO1, CFAP70, SOX30, DGCR8, SEPTIN14, PAPOLB, JMJD1C, and NELL2) traits.

    CONCLUSIONS: These findings contribute to better understand the underlying biological mechanisms of fertility and reproduction traits measured in heifers, cows, and sires, which may contribute to improve genomic evaluation for these traits in dairy cattle.

    PMID:35484513 | PMC:PMC9052698 | DOI:10.1186/s12864-022-08555-z

  • Fatty acid profile characterization in colostrum, transition milk, and mature milk of primi- and multiparous cows during the first week of lactation

    J Dairy Sci. 2022 May;105(5):4692-4710. doi: 10.3168/jds.2022-20880a.

    ABSTRACT

    The specific fatty acid (FA) profile of colostrum may indicate a biological requirement for neonatal calves. The objective of this study was to characterize the FA profile and yields in colostrum, transition milk, and mature milk in primiparous (PP) and multiparous (MP) cows. Colostrum was milked from 10 PP and 10 MP Holstein cows fed the same pre- and postpartum rations. Milkings (M) 2 to 5 and 12 were respectively termed transition and mature milk. Overall, short-chain FA (C4:0 and C6:0) were 61 and 50% lower in colostrum than mature milk, respectively. A parity by milking interaction was also present, with higher C4:0 for PP cows at M2 and for MP cows at M12. Additionally, higher concentrations of C6:0 were present for PP cows at M2 through M4 and for MP cows at M12. Palmitic (C16:0) and myristic (C14:0) acids were 38% and 19% higher in colostrum than mature milk, respectively. However, total saturated FA remained relatively stable. Branched-chain FA were 13% lower in colostrum than mature milk and higher in PP than MP cows throughout the milking period. The proportion of trans-monounsaturated FA (MUFA) was 72% higher in PP cows throughout the milking period, as well as 13% lower in colostrum than mature milk. In contrast, cis-MUFA and total MUFA were not affected by milking nor parity. Linoleic acid (LA) was 25% higher in colostrum than transition and mature milks, but α-linolenic acid (ALA) did not differ. Consequently, the ratio of LA to ALA was 29% higher in colostrum than mature milk and 33% higher in MP cows. Linoleic acid was also 15% higher in MP cows, whereas ALA was 15% higher in PP cows. Conjugated linoleic acid (CLA, cis-9,trans-11) was 2.7-fold higher in PP cows, and no differences between colostrum and mature milk were detected. Overall, polyunsaturated FA (PUFA) from the n-6 and n-3 series were over 40% higher in colostrum compared with transition and mature milk. Milking by parity interactions were present for arachidonic acid (ARA), eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), docosahexaenoic acid (DHA), and total n-3 PUFA, translating to higher proportions in PP cows in M1 to M3, whereas proportions remained relatively stable throughout the milking period in MP cows. Despite increasing milk yields throughout the subsequent milkings, higher yields of EPA, ARA, DPA, and DHA were present in colostrum than in mature milk. Greater proportions and yields of n-3 and n-6 FA in colostrum may translate to specific requirements for newborn calves. Differences were also observed between PP and MP cows and may reflect different nutrient requirements and partitioning.

    PMID:35473965 | DOI:10.3168/jds.2022-20880a

  • Transition cow nutrition and management strategies of dairy herds in the northeastern United States: Part I-Herd description and performance characteristics

    J Dairy Sci. 2022 Jun;105(6):5327-5348. doi: 10.3168/jds.2021-20862. Epub 2022 Apr 22.

    ABSTRACT

    Our objective was to describe management and herd characteristics of the transition period on freestall dairy herds in the northeastern United States using an on-farm survey and prospective cohort design. Enrolled herds (n = 72) had a median of 900 milking cows (range: 345-2,900) and a rolling herd average of 12,674 kg (standard deviation ± 1,220 kg), and 87.2% (n = 82/94) of fresh pens were milked at least 3×/d. The prevalence of herds with ≥15% of sampled cows with elevated concentrations of nonesterified fatty acids prepartum (≥0.27 mmol/L, 2-14 d before parturition) and postpartum [primiparous: ≥0.60 mmol/L, multiparous: ≥0.70 mmol/L, 3-14 d in milk (DIM)], β-hydroxybutyrate postpartum (≥1.2 mmol/L, 3-14 DIM), and haptoglobin postpartum (≥1 g/L, 0-12 DIM) was 51%, 51%, 51%, and 57%, respectively. In most herds, cows were moved to a calving pen when showing signs of labor (73.6%; n = 53/72) instead of 0 to 3 d before expected calving (26.4%, n = 19/72). Cows remained in the calving or maternity pen for a median (range) time of 2 (0-24) h after parturition before moving to the next pen. Primiparous cows remained in the first pen moved to after parturition for a longer period than multiparous cows [median (range) days: 12 (1.5-25) vs. 6 (1.5-22)]. Approximately 20% of herds had routine vaccinations administered in the maternity or calving pen, first pen after parturition, or both. Almost all herds (n = 69/72) performed fresh cow health checks; however, only 53% (n = 38/72) locked up all fresh cows daily. More herds housed primiparous and multiparous cows in separate pens during the far-off dry (65.3%; n = 47/72) and high-lactation (81.9%; n = 59/72) periods compared with the close-up dry (31.9%; n = 23/72) and fresh periods (27.8%; n = 20/72). At least half of the pens observed during the far-off dry, close-up dry, and fresh periods had a stocking density <100%. Approximately one-third of pens observed during the far-off dry period had feed pushed up ≤4×/d compared with approximately 15 to 20% of pens observed during the close-up dry, fresh, and high-lactation periods. More than half of the total mixed ration samples acquired from the far-off and close-up dry period visits had greater than the recommended proportion of particles in the 19-mm screen of the Penn State Particle Separator. The results of this observational study illustrated the range of management practices used in freestall herds in this region and lay the groundwork for future hypothesis-driven studies using this sampled population.

    PMID:35469639 | DOI:10.3168/jds.2021-20862

  • Effects of breed, farm intensiveness, and cow productivity on infrared predicted milk urea

    J Dairy Sci. 2022 Jun;105(6):5084-5096. doi: 10.3168/jds.2021-21105. Epub 2022 Apr 22.

    ABSTRACT

    Milk urea content is receiving growing interest from science and industry as a tool to infer the protein adequacy of dairy cows’ diets, nitrogen excretion and its environmental impact, and efficiency of animals’ protein metabolism. Fourier-transform infrared (FTIR) prediction is a high-throughput method for rapidly and cheaply evaluating milk urea content at the population level. Existing knowledge of the major sources of variation (e.g., year, season, farming system, individual herd, and the cow’s breed, parity, stage of lactation, and productive potential) is fragmentary. The objective of this work was to study at the population level the simultaneous effects of all the major sources of variation and their most important interactions. Milk urea content in 1,759,706 test day milk samples collected from 291,129 lactations of 115,819 cows from 6,430 herds over 8 yr was predicted by FTIR. The milk urea content data (and also milk protein percentage, for comparison) were analyzed using a linear model that included the effects of parity, days in milk (DIM) class, year, month, herd intensiveness level, cow productivity level, breed, and herd intensiveness and cow productivity levels within breed. All sources of variation of milk urea content proved highly significant, the most important in terms of F-value being breed > year > herd intensiveness level > parity. The ranking for milk protein was very different (DIM class > herd intensiveness level > parity > breed). The patterns of the least squares means for urea and protein contents of milk were also very different and sometimes contrasting. The seasonal variation in urea was sinusoidal. Urea content increased during the first 4 mo of lactation and then remained almost stable before decreasing after 11 mo. Specialized dairy breeds had lower average milk urea content than dual-purpose breeds; in the former case it was lower in Holsteins than in Brown Swiss, and in the latter it was lower in Simmentals than in Alpine Greys. The effect of herd intensiveness level was much stronger than the effect of cow productivity level; the increase in milk urea with increasing herd average daily milk yield was almost linear in the case of dairy breeds but curvilinear in dual-purpose breeds. The large differences in breed and the modest relationships with the cow’s productive potential require further analysis at the genetic level to obtain information of potential use in genetic improvement of the dairy cow populations.

    PMID:35469641 | DOI:10.3168/jds.2021-21105

  • Transition cow nutrition and management strategies of dairy herds in the northeastern United States: Part II-Associations of metabolic- and inflammation-related analytes with health, milk yield, and reproduction

    J Dairy Sci. 2022 Jun;105(6):5349-5369. doi: 10.3168/jds.2021-20863. Epub 2022 Apr 22.

    ABSTRACT

    The objectives were as follows: (1) establish cow-level thresholds for prepartum nonesterified fatty acids (NEFA) and postpartum NEFA, β-hydroxybutyrate (BHB), and haptoglobin (Hp) concentrations associated with negative health events; (2) evaluate cow-level associations between biomarkers and 305-d mature equivalent milk at the fourth test day (ME305) and reproductive performance; and (3) identify herd-alarm levels (proportion of cows sampled above the critical threshold) for biomarkers that are associated with herd-level changes in disorder incidence (displaced abomasum and clinical ketosis), reproductive performance, and ME305. In a prospective cohort study, 1,473 cows from 72 farms were enrolled from the northeastern United States. Blood samples were collected from the same 11 to 24 cows per herd during the late-prepartum and early-postpartum periods. Whole blood was analyzed for postpartum BHB concentrations; plasma was analyzed for prepartum and postpartum NEFA and postpartum Hp concentrations. Critical thresholds for the biomarkers associated with health events for all cows were established using a receiver operating characteristic curve analysis. Poisson, linear mixed effects, and Cox proportional hazards models investigated the association of the biomarkers with health and performance. The prepartum NEFA and Hp threshold associated with culling was ≥0.17 mmol/L and 0.45 g/L, respectively. The postpartum NEFA and BHB thresholds associated with diagnosis of metritis, displaced abomasum, or clinical ketosis were ≥0.46 mmol/L and ≥0.9 mmol/L, respectively. Multiparous cows with prepartum NEFA concentration ≥0.17 mmol/L produced 479 kg less ME305. Multiparous and primiparous cows with postpartum NEFA concentration ≥0.46 mmol/L produced 280 kg less and 446 kg more ME305, respectively. Cows with BHB concentration ≥0.9 and ≥1.1 mmol/L produced 552 kg more ME305 and had a 20% decreased risk of pregnancy within 150 d in milk, respectively; however, multiparous cows with BHB concentration ≥1.5 mmol/L produced 376 kg less ME305. Cows with Hp concentration ≥0.45 g/L produced 492 kg less ME305 and had 28% decreased risk of pregnancy within 150 DIM. Cows with Hp concentration ≥0.45 g/L had 19% decreased pregnancy risk to first service (PRFS). Herds above the herd-alarm levels for prepartum NEFA had a 6.0-percentage unit increase in disorder incidence and a 6.0-percentage unit decrease in 21-d pregnancy rate (PR) for multiparous cows, a 3.9-percentage unit increase in PR and a 5.8-percentage unit increase in the probability of pregnancy for primiparous cows. Herds above the herd-alarm levels for postpartum NEFA had a 5.8- and 4.2-percentage unit increase in disorder incidence for multiparous and primiparous cows, respectively, a 789 kg decrease in ME305 for multiparous cows, and a 6.8- and 6.3-percentage unit decrease and increase in PR and PRFS for multiparous cows, respectively. Herds above the herd-alarm levels for BHB had an 8.5-percentage unit increase in disorder incidence, a 332 and 229 kg increase in ME305 for primiparous and multiparous cows, respectively, and a 3.2-, 5.2-, and 7.0-percentage unit decrease in PR, probability of pregnancy, and PRFS, respectively. Herds above the herd-alarm levels for postpartum Hp had a 5.3-percentage unit increase in disorder incidence. At the cow level and herd level, elevated biomarker concentrations were associated with an increased disorder risk and varied performance responses.

    PMID:35469642 | DOI:10.3168/jds.2021-20863

  • Relationship of parathyroid hormone-related protein and neonatal mineral metabolism in dairy cow placentas

    Anim Sci J. 2022 Jan;93(1):e13723. doi: 10.1111/asj.13723.

    ABSTRACT

    Parathyroid hormone-related protein (PTHrP) plays essential roles in placental calcium (Ca) transport, and it has been speculated that PTHrP in the placenta is regulated by calcium-sensing receptors (CaSR). This study clarified the relationship between PTHrP in the placenta of dairy cows and minerals in the fetal blood. Blood samples were obtained from 21 Holstein cows and 17 neonatal calves as well as 12 umbilical veins and arteries during cesarean section. After fetus removal, 13 caruncles and cotyledons were obtained. Concentrations of plasma PTHrP and serum minerals were measured. Real-time polymerase chain reaction (RT-qPCR) analyzed the gene expression of PTHrP and CaSR in the placenta. As a result, serum Ca and inorganic phosphorus concentrations in the neonate, umbilical vein, and artery were significantly higher than in the mother. Additionally, plasma PTHrP was detected in the bovine neonatal jugular vein, umbilical artery, and vein. PTHrP gene expression was significantly higher in the caruncles than in cotyledons; however, CaSR gene expression was higher in the cotyledons than in caruncles. These findings suggest that the PTHrP obtained from the placenta influences Ca homeostasis in the bovine fetus.

    PMID:35470917 | DOI:10.1111/asj.13723

  • Effects of wood kraft pulp as a partial replacement for roughage on rumen fermentation and productivity in dairy cows

    Anim Sci J. 2022 Jan;93(1):e13726. doi: 10.1111/asj.13726.

    ABSTRACT

    In this study, we evaluated the partial replacement of roughage with wood kraft pulp (KP) on rumen fermentation and productivity of dairy cows. Eighteen cows were divided into control and KP groups. The KP group started adaptation to KP 3 weeks before calving; after calving, they were fed a total mixed ration for 12 weeks, wherein 18% Timothy hay was replaced with KP. The dry matter intake, body weight, and milk yield and composition were similar in the control and KP groups. The average daily rumen pH was higher with KP feeding, and the average daily ruminal temperature remained lower at 16 days after calving (P < 0.05). The concentration of volatile fatty acids remained unaltered, the molar proportion of acetic acid decreased, and the molar proportion of propionic acid increased, indicating a low acetic acid:propionic acid ratio (P < 0.05). Lipopolysaccharide activity in the rumen fluid was higher in the KP group (P < 0.05); however, the rumen microbiota were unaffected. The digestibility of dry matter and neutral detergent fiber increased 12 weeks after calving, whereas excretion of urinary nitrogen decreased (P < 0.05). Partial replacement of roughage with KP did not suppress rumen fermentation and maintained postpartum productivity.

    PMID:35470929 | DOI:10.1111/asj.13726

  • Prevalence and associated factors of gastrointestinal helminthiasis of lactating cow and effect of strategic deworming on milk quantity, fat, and protein in Kucha, Ethiopia

    BMC Vet Res. 2022 Apr 25;18(1):150. doi: 10.1186/s12917-022-03251-2.

    ABSTRACT

    BACKGROUND: Gastrointestinal helminthiasis poses economic impacts on the dairy sector by reducing milk production. This study aimed at estimating the prevalence of gastrointestinal helminthiasis, the burden of helminths, and appraising potential factors associated with the prevalence in lactating cows. The study was also designed to elucidate the effects of anthelmintic treatment on milk yield, milk fat, and protein content in the Kucha district.

    METHODS: A cross-sectional and field clinical trial study designs were used. Standard parasitological techniques (floatation and sedimentation) were employed to detect cows’ infection status. McMaster and Stoll’s egg counting methods were used to estimate helminths’ burden. All putative factors that might have been linked with infection were recorded by field observations and farmers’ interviews. Sixty cows tested positive for the parasitic infection in the cross-sectional study design were randomly assigned into one of the two groups (dewormed Vs control). Milk yield, milk fat and protein contents were recorded in both groups on day zero and then on weekly basis. Descriptive statistics, binary logistic regression, and repeated measure ANOVA were used to analyze the data.

    RESULTS: Overall, of 422 examined cows, 150 (35.5%, 95% CI; 30.9-40.3%) were infected with at least one of the gastrointestinal helminth parasites. Strongyle nematode was the predominant type accounting for 52% of the total record. Analysis of fecal egg count (FEC) in infected cows depicts the highest record of Parampistomum egg, accounting 457.14 ± 275.45 Egg per gram (EPG) of feces. The prevalence of gastrointestinal helminthiasis in cow that had an average body condition score of 1.7 was over two fold higher (OR = 2.19, 95% CI = 1.17-4.17, P = 0.016) than in cows with 6.3 body condition score. A significant improvement in milk yield, milk fat, and milk protein was observed in dewormed cows over 28 days period.

    CONCLUSION: Gastrointestinal helminthiasis is threatening the welfare of lactating cows in Kucha, Ethiopia given its negative association with the body condition score. Gastrointestinal helminths are responsible for the reduction of milk yield and loss of milk fat and protein. However, an improvement in milk yield, milk fat, and milk protein after deworming using Tetrox® (Tetramisole and Oxyclozanide combination), a new drug to the area/ a drug used by relatively few farmers in the study area, proves the effectiveness of strategic deworming.

    PMID:35468823 | PMC:PMC9036821 | DOI:10.1186/s12917-022-03251-2

  • Invited review: Risk factors for transition period disease in intensive grazing and housed dairy cattle

    J Dairy Sci. 2022 Jun;105(6):4734-4748. doi: 10.3168/jds.2021-20649. Epub 2022 Apr 22.

    ABSTRACT

    Transition period (±3 wk around calving) diseases are prevalent in dairy systems. In this review we describe the physiological and behavioral changes experienced by cows during the transition period and during the dry period leading up to this. Our narrative review examines risk factors associated with these diseases in zero-grazing and grazing systems. The available research indicates that cows in these 2 systems experience similar incidences of transition diseases, and that low or high BCS and lameness are key manageable risks associated with both systems. Other cow- and herd-level risk factors identified in this review are parity, breed, and seasonal variability in disease incidence. Some risks appear to arise earlier in the dry period, outside what is normally considered the transition period; we recommend that future studies of transition period diseases should consider the entire dry period. We also encourage new work on measuring the effect of intervention strategies during late lactation on transition period diseases.

    PMID:35465987 | DOI:10.3168/jds.2021-20649

  • Adaptive immune response ranking is associated with reproductive phenotypes in grazing dairy cows divergent in genetic merit for fertility traits

    J Dairy Sci. 2022 Jun;105(6):5519-5533. doi: 10.3168/jds.2021-21538. Epub 2022 Apr 22.

    ABSTRACT

    A strong adaptive immune response has been reported to have positive effects on fertility; therefore, we investigated antibody- and cell-mediated adaptive immune responses (AMIR and CMIR, respectively) and their associations with reproductive phenotypes using a population of animals that differed in their estimated genetic merit for fertility traits (fertility breeding value; FertBV). Holstein-Friesian heifers (n = 528) grazed on pasture in 4 herds based on age. These herds included 277 heifers of positive (POS) FertBV and 251 of negative (NEG) FertBV. The adaptive immune response (IR) was evaluated before puberty at 7.5 mo of age and used to rank animals as high, average, or low for AMIR, CMIR, and overall IR (combined CMIR and AMIR). The animals were studied from 12 wk of age through to the end of their second lactation to measure growth, puberty, and timing and success of fertility phenotypes, including those related to ovulation and pregnancy. Initial analysis indicated no difference in fertility outcomes between cows ranked as high or average for AMIR (n = 55, n = 407, respectively), CMIR (n = 87, n = 354, respectively), and IR (n = 29, n = 470, respectively), so these groups were pooled as HiAv-IR. Proportions of heifers of POS FertBV were similar within HiAv and low categories across AMIR (0.52 and 0.58, respectively), CMIR (0.51 and 0.59, respectively), and IR (0.53 and 0.48, respectively). Heifers with HiAv-IR had a greater average daily weight gain from 13 to 52 wk of age (661 g, 95% confidence interval 652, 669 vs. 619 g, 95% confidence interval 591, 647) and tended to be younger at puberty (371 d, 95% confidence interval 366, 377 vs. 385 d, 95% confidence interval 369, 401) than low-IR heifers. Low-CMIR cows of a NEG FertBV had a >40 d longer calving to first ovulation interval during their first lactation compared with HiAv-CMIR NEG FertBV cows. Low-CMIR cows also had decreased pregnancy rates at both 3 wk (25% ± 7% vs. 42% ± 3%; least squares means ± standard error) and 6 wk (33% ± 7% vs. 54% ± 3%; least squares means ± standard error) into the seasonal breeding period during their first lactation, compared with HiAv-CMIR cows. In summary, although the number of POS and NEG FertBV cows was similar in each immune group; interaction effects between FertBV and immune ranking on reproductive phenotypes are evident when cows were ranked by the overall IR. There were also associations between dairy cows’ CMIR ranking and ability to return to estrus and become pregnant early in the breeding period, which will have benefits in seasonal breeding systems.

    PMID:35465990 | DOI:10.3168/jds.2021-21538

  • Evaluation of luteolysis, follicle size, and time to ovulation in Holstein heifers treated with two different analogs and doses of prostaglandin-F<sub>2α</sub>

    J Dairy Sci. 2022 Jun;105(6):5506-5518. doi: 10.3168/jds.2021-21487. Epub 2022 Apr 22.

    ABSTRACT

    Objectives were to evaluate the effect of 2 analogs of PGF (cloprostenol vs. dinoprost) and 2 doses (1 injection vs. 2 injections) on luteolysis, follicle diameter, hormonal concentrations, and time to ovulation in dairy heifers. Holstein heifers were fitted with automated estrus detection devices and had their estrous cycle synchronized using PGF and an intravaginal insert containing progesterone. Heifers detected in estrus were blocked by weight and randomly assigned to 1 of 4 treatments in a 2 × 2 factorial arrangement: cloprostenol on d 7 after estrus (CLOx1; n = 45), cloprostenol on d 7 and 8 after estrus (CLOx2; n = 41), dinoprost on d 7 after estrus (DINx1; n = 43), or dinoprost on d 7 and 8 after estrus (DINx2; n = 44). Treatment with the first injection of PGF was defined as experiment d 0. Area and blood flow of corpus luteum (CL) and diameter of follicles >5 mm were recorded every 12 h from d 0 to estrus and every 6 h thereafter until ovulation. Blood was sampled every 6 h from d 0 until ovulation. Heifers treated with cloprostenol had shorter interval to luteolysis (± SEM; CLOx1 = 23.5 ± 2.2, CLOx2 = 22.9 ± 2.2, DINx1 = 32.6 ± 2.7, DINx2 = 26.4 ± 2.1 h); however, time to ovulation was not affected by treatment. A smaller proportion of heifers treated with a single injection of PGF underwent luteolysis compared with heifers treated with 2 injections (CLOx1 = 84.6 ± 6.2, CLOx2 = 100.0 ± 0.0, DINx1 = 59.7 ± 9.8, DINx2 = 96.3 ± 2.7%). Proportion of heifers that ovulated was smaller for DINx1 compared with other treatments (CLOx1 = 88.8 ± 5.1, CLOx2 = 100.0 ± 0.0, DINx1 = 55.2 ± 9.7, DINx2 = 94.4 ± 3.4%). Ovulatory follicle diameter was larger for DINx1 (18.2 ± 2.7 mm) compared with DINx2 (17.4 ± 2.7 mm), whereas dose did not affect the diameter of the ovulatory follicle in heifers treated with cloprostenol (CLOx1 = 17.6 ± 2.7 vs. CLOx2 = 17.8 ± 2.8 mm). Among heifers that underwent luteolysis, progesterone concentrations from 18 to 36 h after treatment were lesser in heifers treated with cloprostenol compared with those treated with dinoprost. Type of PGF did not affect progesterone concentrations past 36 h from treatment; however, heifers treated with 2 PGF injections had lesser progesterone concentrations and CL blood flow from 36 to 72 h after treatment compared with heifers that received a single PGF injection.

    PMID:35465991 | DOI:10.3168/jds.2021-21487

  • Effects of an intensive experimental protocol on health, fertility, and production in transition dairy cows

    J Dairy Sci. 2022 Jun;105(6):5310-5326. doi: 10.3168/jds.2021-20673. Epub 2022 Apr 22.

    ABSTRACT

    Animal experimentation is required to investigate complex physiological relationships and facilitates development of evidence-based knowledge. However, experimental protocols can interfere with the daily routine of the animals, result in stress and pain, and have adverse effects on health and production. The goal of this study was to investigate the effects of an intensive experimental protocol on health traits and production in transition dairy cows. Eighty experimental dairy Holstein cows (EXP group) underwent serial protocol-based clinical and ultrasonographic examinations, puncture of the jugular vein for blood collection or drug application, and liver biopsy samples, 14 d before until 42 d after parturition. Controls (CTR group) included 206 cows from the same herd, which fulfilled the same inclusion criteria and were kept under the same production management but were not handled for the purpose of this study. Procedure-related effects with a potentially negative effect on health and production were recorded. Furthermore, production, fertility and culling traits of the 2 groups (CTR, EXP) were compared. Most procedure-related adverse effects were associated with transcutaneous liver biopsies and included diffuse inflammation of the skin incision in 11.9% (42 of 320), abscessation of the skin or subcutis in 4.6% (11 of 240), and increased liver echogenicity of the biopsy site in 10.4% (27 of 240). The experimental procedures had a negative effect on milk yield at the start [days in milk (DIM) 5-50, difference: 2.3 kg, standard error (SE): 0.8 kg] and end of lactation (DIM 251-300, difference: 2.0 kg, SE: 1.0 kg; DIM 301-350, difference: 2.3 kg, SE: 1.2 kg) resulting in a lower 305-d milk yield in the EXP group than in the CTR group (difference: 472 kg, SE 214 kg). The milk fat % was higher in the EXP group than in the CTR group from 251 DIM onward (DIM 251-300, difference: 0.20%, SE: 0.09%; DIM 301-350, difference: 0.41%, SE: 0.17%). Also, the somatic cell score was higher in the EXP group than in the CTR group, during early (5-50 DIM, difference: 0.43, SE: 0.22) and from mid-lactation onward (DIM 151-200, difference: 0.43, SE: 0.2; DIM 201-250, difference: 0.49, SE: 0.22; DIM 251-300, difference: 0.55, SE: 0.25; DIM 301-350, difference: 0.61, SE: 0.28). Experimental procedures had no effect on first service conception rate and time to pregnancy, but had a positive effect on stillbirth rate with fewer stillbirths in the CTR group (0%) than in the EXP group (3.9%). Furthermore, experimental handling had no effect on time to culling or type of culling, whereby poor production was a more frequent reason noted for culling in the EXP group. Procedure-associated impairment of production in dairy cows is rarely reported and allows the estimation of the effects of such a study protocol on animal health and production. As a limitation for the interpretation of the results, the number of animals included and conduction in one single herd have to be considered.

    PMID:35465993 | DOI:10.3168/jds.2021-20673

  • Osteopontin (OPN)/Secreted Phosphoprotein 1 (SPP1) Binds Integrins to Activate Transport of Ions Across the Porcine Placenta

    Front Biosci (Landmark Ed). 2022 Apr 1;27(4):117. doi: 10.31083/j.fbl2704117.

    ABSTRACT

    BACKGROUND: Fetal-placental development depends on a continuous and efficient supply of nutrients from maternal blood that are acquired by exchange through the placenta. However, the placenta is a low permeability barrier, and effective transport of substances depends on specific transport mechanisms. Active transport requires that ions or nutrients be moved against an electrical and/or concentration gradient. In pigs, active transport of ions occurs across the chorioallantois placenta to produce an electrochemical gradient that changes throughout gestation. The aim of this study was to utilize Ussing chambers to detect regulation of ion transport across the porcine chorioallantois by a factor(s) within the uterine-placental environment of pigs.

    METHODS: For the measurement of transchorioallantoic voltage potential as an index of ion transport across the placenta, pieces of chorioallantoic tissue from Day 60 of gestation were mounted into the cassettes of Ussing chambers, and treatments were added to the mucasal side of the tissue. Treatments included: (1) media incubated with Day 60 chorioallantois (placenta-conditioned media); (2) osteopontin/secreted phosphoprotein 1 (OPN/SPP1) purified from cow’s milk; (3) placenta-conditioned media from which OPN/SPP1 was removed; and (4) recombinant rat OPN with an intact RGD integrin binding sequence or a mutated RAD sequence. Ouabain was added to both sides of the chamber. Immunofluorescence was utilized to localize beta 3 integrin, aquaporin 8 and OPN/SPP1 in porcine placental tissues, and OPN/SPP1 within porcine lung, kidney and small intestine.

    RESULTS: Day 60 chorioallantoic membranes had greater transepithelial voltage in the presence of porcine placenta-conditioned media, indicating that a molecule(s) released from the placenta increased ion transport across the placenta. OPN/SPP1 purified from cow’s milk increased ion transport across the placenta. When OPN/SPP1 was removed from placenta-conditioned media, ion transport across the placenta did not increase. Recombinant rat OPN/SPP1 with a mutated RGD sequence that does not bind integrins (RAD) did not increase ion transport across the placenta. Ouabain, an inhibiter of the sodium-potassium ion pump, ablated ion transport across the placenta.

    CONCLUSIONS: The present study documents a novel pericellular matrix role for OPN/SPP1 to bind integrins and increase ion transport across the porcine chorioallantoic placenta.

    PMID:35468676 | DOI:10.31083/j.fbl2704117

  • Intrauterine infusion of blood serum of dromedary camel improves the uterine health and fertility in high producing dairy cows with subclinical endometritis

    Anim Reprod Sci. 2022 May;240:106973. doi: 10.1016/j.anireprosci.2022.106973. Epub 2022 Mar 29.

    ABSTRACT

    The blood serum of dromedary camels contains a unique type of antibodies with a high potency to neutralize toxins and to identify and inactivate some bacterial pathogens. The present study was designed to examine changes in the endometrial histology of cows with no subclinical endometritis (SE) (experiment 1) and changes in the uterine cytology and endometrial mRNA expression of COX2, IL-1β, IL-8, and iNOS following intrauterine administration of DCBS in cows with SE as compared to different common treatments (experiment 2). In addition, the effects of the intrauterine administration of DCBS were examined on the pregnancy rate in dairy cows with SE (experiment 3). DCBS did not induce any histological reactions in the bovine endometrium. The mean ( ± SE) percentage of PMNs after intrauterine infusion of Pen-Strep, DCBS and double DCBS in cows with SE differed as compared to cows treated with PGF2α and no treated cows with SE (1.47 ± 0.87; 1.43 ± 1.08 and 1.31 ± 0.23 vs 3.00 ± 0.43 and 3.5 ± 0.75, P < 0.05, respectively) in experiment 2. The mRNA expression of COX2, IL-1β, and iNOS was reduced (P < 0.05) after treatment with Pen-Strep, DCBS and double DCBS as compared with no treated-cows with SE. The pregnancy rate after the first AI was tended to be higher (49.2 vs 39.0%), while the overall pregnancy rate was greater (P < 0.05) in cows with SE when treated with DCBS as compared to the Pen-Strep group (76.9 vs 61.0%) in experiment 3. In conclusion, serum of dromedary camel, as a non-antibiotic preparation, can improve the uterine health and fertility when used for the treatment of bovine SE.

    PMID:35462321 | DOI:10.1016/j.anireprosci.2022.106973

  • The Foetal Origins of Allergy and Potential Nutritional Interventions to Prevent Disease

    Nutrients. 2022 Apr 12;14(8):1590. doi: 10.3390/nu14081590.

    ABSTRACT

    The first nine months from conception to birth involves greater changes than at any other time in life, affecting organogenesis, endocrine, metabolic and immune programming. It has led to the concept that the “first 1000 days” from conception to the second birthday are critical in establishing long term health or susceptibility to disease. Immune ontogeny is predominantly complete within that time and is influenced by the maternal genome, health, diet and environment pre-conception and during pregnancy and lactation. Components of the immunological protection of the pregnancy is the generation of Th-2 and T-regulatory cytokines with the consequence that neonatal adaptive responses are also biased towards Th-2 (allergy promoting) and T-regulatory (tolerance promoting) responses. Normally after birth Th-1 activity increases while Th-2 down-regulates and the evolving normal human microbiome likely plays a key role. This in turn will have been affected by maternal health, diet, exposure to antibiotics, mode of delivery, and breast or cow milk formula feeding. Complex gene/environment interactions affect outcomes. Many individual nutrients affect immune mechanisms and variations in levels have been associated with susceptibility to allergic disease. However, intervention trials employing single nutrient supplementation to prevent allergic disease have not achieved the expected outcomes suggested by observational studies. Investigation of overall dietary practices including fresh fruit and vegetables, fish, olive oil, lower meat intake and home cooked foods as seen in the Mediterranean and other healthy diets have been associated with reduced prevalence of allergic disease. This suggests that the “soup” of overall nutrition is more important than individual nutrients and requires further investigation both during pregnancy and after the infant has been weaned. Amongst all the potential factors affecting allergy outcomes, modification of maternal and infant nutrition and the microbiome are easier to employ than changing other aspects of the environment but require large controlled trials before recommending changes to current practice.

    PMID:35458152 | PMC:PMC9026316 | DOI:10.3390/nu14081590

  • Carry-over effects of dry period heat stress on the mammary gland proteome and phosphoproteome in the subsequent lactation of dairy cows

    Sci Rep. 2022 Apr 22;12(1):6637. doi: 10.1038/s41598-022-10461-z.

    ABSTRACT

    Exposure to heat stress during a cow’s dry period disrupts mammary gland remodeling, impairing mammary function and milk production during the subsequent lactation. Yet, proteomic changes in the mammary gland underlying these effects are not yet known. We investigated alterations in the mammary proteome and phosphoproteome during lactation as a result of dry period heat stress using an isobaric tag for relative and absolute quantitation (iTRAQ)-based approach. Cows were cooled (CL; n = 12) with fans and water soakers in a free stall setting or were heat stressed through lack of access to cooling devices (HT; n = 12) during the entire dry period (approximately 46 days). All cows were cooled postpartum. Mammary biopsies were harvested from a subset of cows (n = 4 per treatment) at 14, 42, and 84 days in milk. Overall, 251 proteins and 224 phosphorylated proteins were differentially abundant in the lactating mammary gland of HT compared to CL cows. Top functions of differentially abundant proteins and phosphoproteins affected were related to immune function and inflammation, amino acid metabolism, reactive oxygen species production and metabolism, tissue remodeling, and cell stress response. Patterns of protein expression and phosphorylation are indicative of increased oxidative stress, mammary gland restructuring, and immune dysregulation due to prior exposure to dry period heat stress. This study provides insights into the molecular underpinnings of disrupted mammary function and health during lactation arising from prior exposure to dry period heat stress, which might have led to lower milk yields.

    PMID:35459770 | PMC:PMC9033811 | DOI:10.1038/s41598-022-10461-z

  • Reproductive tract disease in Irish grazing dairy cows: Retrospective observational study examining its association with reproductive performance and accuracy of 2 diagnostic tests

    J Dairy Sci. 2022 Jun;105(6):5471-5492. doi: 10.3168/jds.2021-21404. Epub 2022 Apr 18.

    ABSTRACT

    The detection of reproductive tract disease (RTD) 3 wk postpartum is important because of its effect on subsequent reproductive outcomes. Numerous methods for the diagnosis of RTD are described, some of which are more practical and instantaneous in terms of diagnosis. Two of these methods involve identification of purulent vaginal discharge (PVD) and evidence of ultrasonographic uterine changes indicative of endometritis (UE). The objectives of our retrospective observational study were (1) to assess the association of PVD or UE score at the prebreeding examination (PBE) with the hazard of pregnancy within the subsequent breeding season; (2) to determine the test sensitivity (Se) and specificity (Sp) at the point of sampling of both tests using a Bayesian latent class model; and (3) to determine the effect of varying positivity thresholds on test accuracy. To achieve these objectives, we analyzed an initial data set of 5,049 PBE from 2,460 spring-calved cows in 8 herds between 2014 and 2018. Each PBE was conducted once between 25 and 86 d in milk. At each PBE, vaginal discharge was obtained with a Metricheck device (Simcro) whereas uterine contents were assessed using transrectal ultrasonography. Purulent vaginal discharge was scored on a scale of 0 to 3 depending on discharge character, and UE was scored on a scale of 0 to 4 depending on the presence and consistency of intraluminal fluid. Cows with scores of ≥2 in either test had received treatment. Fertility data were available from 4,756 PBE after data exclusion. The association between PVD or UE score at the PBE and subsequent hazard of pregnancy was analyzed using a Cox proportional hazards model. Cows with a PVD score of 2 or 3 were less likely to conceive than cows with a PVD score 0 [score 2 hazard ratio (HR) = 0.74; 95% confidence interval (CI): 0.59-0.94; score 3 HR = 0.65; 95% CI: 0.51-0.84]. Cows with a UE score of 1, 2, 3, or 4 were less likely to conceive than cows with a UE score of 0 (score 1 HR = 0.82; 95% CI: 0.73-0.93; score 2 HR = 0.79; 95% CI: 0.62-1.00; score 3 HR = 0.43; 95% CI: 0.43-0.90; score 4 HR = 0.39; 95% CI: 0.26-0.58). To determine the Se and Sp of PVD or UE score for diagnosis of RTD at the time of PBE, a Bayesian latent class model was fitted on 2,460 individual cow PBE. Flat priors were used for the Se and Sp of UE, whereas informative priors were used for PVD Se (mode = 65%, 5th percentile = 45%) and Sp (mode = 90%, 5th percentile = 80%) and RTD prevalence (mode = 20%, 5th percentile = 10%). Posterior estimates (median and 95% Bayesian probability intervals; BPI) were obtained using ‘rjags’ (R Studio). The optimal test thresholds (PVD and UE score ≥1) were selected by assessing the effect of different thresholds on test estimates and using a misclassification cost analysis. Based on these, median (95% BPI) Se for PVD and UE score ≥1 were 44% (29-60%) and 67% (33-100%), respectively. Median Sp for PVD and UE score ≥1 were 90% (86-93%) and 91% (86-93%), respectively. Higher scores in both tests were associated with impaired fertility, and UE scoring with a threshold of ≥1 had the highest test Se and Sp estimates although test Se was conditional on days in milk when the PBE occurred.

    PMID:35450719 | DOI:10.3168/jds.2021-21404

  • Genomic Prediction of Complex Traits in Animal Breeding with Long Breeding History, the Dairy Cattle Case

    Methods Mol Biol. 2022;2467:447-467. doi: 10.1007/978-1-0716-2205-6_16.

    ABSTRACT

    In accordance with the infinitesimal model for quantitative traits, a very large number of genes affect nearly all economic traits. In only two cases has the causative polymorphism been determined for genes affecting economic traits in dairy cattle. Most current methods for genomic evaluation are based on the “two-step” method. Genetic evaluations are computed by the individual animal model, and functions of the evaluations of progeny-tested sires are the dependent variable for estimation of marker effects. With the adoption of genomic evaluation in 2008, annual rates of genetic gain in the US increased from ∼50-100% for yield traits and from threefold to fourfold for lowly heritable traits, including female fertility, herd-life and somatic cell concentration. Gradual elimination of the progeny test scheme has led to a reduction in the number of sires with daughter records and less genetic ties between years. As genotyping costs decrease, the number of cows genotyped will continue to increase, and these records will become the basic data used to compute genomic evaluations, most likely via application of “single-step” methodologies. Less emphasis in selection goals will be placed on milk production traits, and more on health, reproduction, and efficiency traits and “environmentally friendly” production. Genetic variance for economic traits is maintained by increase in frequency of rare alleles, new mutations, and changes in selection goals and management.

    PMID:35451786 | DOI:10.1007/978-1-0716-2205-6_16


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