最新論文抄録

Comprehensive genetic analysis and predictive evaluation of milk electrical conductivity for subclinical mastitis in Chinese Holstein cows
BMC Genomics. 2024 Dec 20;25(1):1230. doi: 10.1186/s12864-024-11157-6.
ABSTRACT
BACKGROUND: Bovine mastitis significantly impacts the dairy industry, causing economic losses through reduced milk production, lower milk quality, and increased health risks, and early detection is critical for effective treatment. This study analyzed milk electrical conductivity data from 9,846 Chinese Holstein cows over a two-year period, collected during three daily milking sessions, alongside smart collar data and dairy herd improvement test results. The aim was to conduct a comprehensive genetic analysis and assess the potential of milk electrical conductivity as a biomarker for the early detection of bovine subclinical mastitis.
RESULTS: The results revealed significant phenotypic and strong genetic correlations (-0.286 to 0.457) between milk electrical conductivity, somatic cell score, milk yield, activity quantity, and milking speed. Logistic regression models yielded area under the curve values ranging from 0.636 to 0.697 and odds ratio values from 9.70 to 10.69, demonstrating a certain predictive capability of milk electrical conductivity for identifying subclinical mastitis. Various factors influencing milk electrical conductivity, including lactation stage, environmental conditions, age at first calving, parity, and body condition score, were identified. The random regression model demonstrated moderate to high heritability of milk electrical conductivity (0.458 to 0.487), particularly during the early to mid-lactation periods, with all estimates exceeding 0.35 However, after day 275 of lactation, the heritability decreased to below 0.2. Notably, shifts in genetic factors affecting milk components were observed around 60 and 270 days into lactation, with increased environmental sensitivity to milk electrical conductivity during these periods.
CONCLUSIONS: This study demonstrates that milk electrical conductivity is influenced by multiple factors, such as age at first calving, parity, and body condition score, and exhibits significant phenotypic associations with somatic cell score, milk yield, activity quantity, and milking speed. Although milk electrical conductivity showed moderate to high heritability and potential as a predictor for subclinical mastitis, its low genetic correlations with SCS limit its effectiveness as a standalone indicator. Future research should focus on combining EC with other indicators to improve the accuracy of mastitis detection.
PMID:39707191 | DOI:10.1186/s12864-024-11157-6
Early pregnancy diagnosis in cows using corpus luteum blood flow analysis based on colour Doppler ultrasonography and mRNA analysis
BMC Vet Res. 2024 Dec 20;20(1):572. doi: 10.1186/s12917-024-04438-5.
ABSTRACT
BACKGROUND: Reproductive efficiency is paramount in the dairy industry, where early pregnancy detection of dairy cows will allow to detect the non-pregnant animals early, thus enabling to re-synchronize them and getting them pregnant leading to decrease in calving interval, which, in turn, is critical for maximizing productivity and economic gain. The objective of this study was to evaluate the colour Doppler ultrasonography (CDUS) and peripheral blood leukocytes (PBLs)-based pregnancy-associated biomarker mRNAs expression for the earliest detection of pregnancy status in the dairy cows at post insemination. Intensively managed animals were ovulation synchronized and subjected to timed artificial insemination (TAI). On day 20, corpus luteum blood flow (CLBF) was evaluated using CDUS in 30 cows. The percentage of the incoming blood flow (as an area) of the corpus luteum (CL) was determined using an image analysis software. On day 35, the same operator performed a final pregnancy diagnosis using transrectal ultrasonography to confirm the pregnancy. Blood samples were collected on day 20 and 28 after TAI for biomarkers analysis. The mRNA expression levels of ISG15, MX1, MX2, and PAG9 genes in PBLs were determined by quantitative polymerase chain reaction (qPCR).
RESULTS: The identified CLBF cutoff point resulted 100% sensitivity and negative predictive value (NPV) in determining non-pregnant status on day 20 in the cows. Overall, MX2 and ISG15 mRNAs showed the most significant (P < 0.05) expression levels in pregnant animals on day 20 and 28 compared to non-pregnant animals. Among them, MX2 showed the highest expression levels on both days, ascertaining it as the better candidate biomarker for the earliest identification of pregnancy.
CONCLUSIONS: The CDUS-based CLBF analysis on day 20 after TAI can be potentially used for the early identification of non-pregnancy status in dairy cows and MX2 could be a potential mRNA candidate for the identification of pregnancy in cows. Further studies should be conducted in large scale to validate these findings due to the small sample number used in the current study.
PMID:39707361 | DOI:10.1186/s12917-024-04438-5
Genome-wide association studies and functional annotation of pre-weaning calf mortality and reproductive traits in Nellore cattle from experimental selection lines
BMC Genomics. 2024 Dec 18;25(1):1196. doi: 10.1186/s12864-024-11113-4.
ABSTRACT
BACKGROUND: Reproductive efficiency is crucial for the long-term economic sustainability of beef cattle production. Pregnancy loss and stillbirth are complex reproductive traits that do not yet have their genomic background fully understood, especially in zebu breeds (Bos taurus indicus). Hence, this study aimed to perform a genome-wide association study (GWAS) and functional annotation for conception success (CS), pregnancy loss (PL), stillbirth (SB), and pre-weaning calf mortality (PWM) in Nellore cattle. In this study, 3,728 cows with 17,094 reproductive records and 11,785 calves were evaluated. A total of 3,351 genotyped animals and 383,739 SNP markers were considered for GWAS analyses. SNP effects were estimated using the weighted single-step GWAS (WssGWAS), which considered two iterations. The top ten genomic windows with the highest contribution to the additive genetic variance of the traits were selected for gene annotation. Candidate genes were then analyzed for Gene Ontology terms (GO) and metabolic pathways.
RESULTS: The top ten genomic windows that explained the largest proportion of the direct additive genetic variance ([Formula: see text]) for CS, PL, SB, and PWM accounted for 17.03% (overlapping with 79 genes), 16.76% (57 genes), 11.71% (73 genes), and 12.03% (65 genes) of the total [Formula: see text], respectively. For CS, significant GO terms included Somitogenesis (GO:0001756), Somite Development (GO:0061053), and Chromosome Segregation (GO:0007059). Considering PL, the processes annotated were the Regulation of Hormone Secretion (GO:0046883), and Hormone Transport (GO:0009914), along with the Glucagon Signaling Pathway (bta04922). Embryonic Development (GO:0045995), and Cerebellum Development (GO:0021549) were the main biological processes found in the gene enrichment analysis for SB. For PWM, the Regulation of Glucose metabolic processes (GO:0010906), Zinc Ion Homeostasis (GO:0055069), Lactation (GO:0007595), and Regulation of Insulin Secretion (GO:0050796) were the most significant GO terms observed.
CONCLUSIONS: These findings provide valuable information on genomic regions, candidate genes, biological processes, and metabolic pathways that may significantly influence the expression of complex reproductive traits in Nellore cattle, offering potential contributions to breeding strategies and future genomic selection strategies.
PMID:39695361 | PMC:PMC11654436 | DOI:10.1186/s12864-024-11113-4
Current Status of Synthetic Mammalian Embryo Models
Int J Mol Sci. 2024 Nov 29;25(23):12862. doi: 10.3390/ijms252312862.
ABSTRACT
Advances in three-dimensional culture technologies have facilitated the development of synthetic embryo models, such as blastoids, through the co-culturing of diverse stem cell types. These in vitro models enable precise investigation of developmental processes, including gastrulation, neurulation, and lineage specification, thereby advancing our understanding of early embryogenesis. By providing controllable, ethically viable platforms, they help circumvent the limitations of in vivo mammalian embryo studies and contribute to developing regenerative medicine strategies. Nonetheless, ethical challenges, particularly regarding human applications, persist. Comparative studies across various species-such as mice, humans, non-human primates, and ungulates, like pigs and cattle-offer crucial insights into both species-specific and conserved developmental mechanisms. In this review, we outline the species-specific differences in embryonic development and discuss recent advancements in stem cell and synthetic embryo models. Specifically, we focus on the latest stem cell research involving ungulates, such as pigs and cattle, and provide a comprehensive overview of the improvements in synthetic embryo technology. These insights contribute to our understanding of species-specific developmental biology, help improve model efficiency, and guide the development of new models.
PMID:39684574 | PMC:PMC11641582 | DOI:10.3390/ijms252312862
Phenylalanine Regulates Milk Protein Synthesis via LAT1-mTOR Signaling Pathways in Bovine Mammary Epithelial Cells
Int J Mol Sci. 2024 Dec 6;25(23):13135. doi: 10.3390/ijms252313135.
ABSTRACT
Phenylalanine (Phe) is a potentially limiting amino acid for lactating cows. The mechanism by which Phe regulates milk protein synthesis remains unclear. The present study elucidates the mechanisms by which phenylalanine affects milk protein synthesis, amino acid utilization, and related signaling pathways in bovine mammary epithelial cells (BMECs). The BMECs were treated with five concentrations (0, 0.22, 0.44, 0.88, 1.76 mM, and serum free). Rapamycin inhibitors and RNA interference (RNAi) were used to inhibit the phosphorylation of the mammalian target of rapamycin (mTOR) signaling pathway and the expression of relevant amino acid transporters, respectively. The results showed that 4×Phe (0.88 mM) significantly increased (p < 0.05) both the mRNA and protein expression of α-casein (CSN1S1), β-casein (CSN2), and κ-casein (CSN3), as well as L-type amino acid transporter-1 (LAT1) mRNA expression. Protein expression and modification assays of mTOR-related proteins showed that 4×Phe could increase (p < 0.05) the expression of α-casein and eukaryotic initiation factor 4E-binding protein-1 (4EBP1) and tended to increase the expression of ribosomal protein S6 protein kinase (S6K1, p = 0.054). The general control nonderepressible 2 (GCN2) signaling pathway factor, eukaryotic initiation factor 2 (eIF2α), was downregulated by 4×Phe treatment (p < 0.05). The rapamycin inhibition test showed that Phe regulated casein synthesis via the mTOR signaling pathway. RNAi experiments showed that LAT1 mediated the entry of Phe into cells. Moreover, 4×Phe treatment tended to decrease (0.05 < p < 0.10) the consumption of valine, leucine, histidine, tyrosine, cysteine, alanine, asparagine, and serine in the medium. Collectively, phenylalanine enhanced α-casein synthesis by regulating the phosphorylation of 4EBP1 and eIF2α and promoting the formation of the mTOR-centered casein translation initiation complex.
PMID:39684845 | PMC:PMC11642424 | DOI:10.3390/ijms252313135
Transition cow health and management in pasture-based dairy herds: A farmers' survey
PLoS One. 2024 Dec 17;19(12):e0314987. doi: 10.1371/journal.pone.0314987. eCollection 2024.
ABSTRACT
Seasonal-calving pasture-based systems characterize Irish dairy production. During the dry period, cows are housed and offered predominantly grass silage, providing unique transition cow management opportunities. This study aimed to describe transition period disease incidence and management strategies reported by farmers, and to evaluate their associations with herd size and calving pattern to inform and guide research activities and national advisory. An online survey distributed amongst 3,899 Teagasc Technical Dairy Advisory clients yielded 525 responses suitable for analysis. Results are presented for all respondents, by herd size and by the two most common calving systems (spring- [84.3%; 439/521] and split-calving [12.9%; 67/521]). Disease incidence was reportedly highest in cows within their first 3 weeks postpartum (58%; 299/519), in cows calving at the end of the calving season (48%; 245/510) and in multiparous cows (52%; 266/513). Respondents reported treating >3% of their herd for milk fever (23%; 120/521) and retained placenta (13%; 68/518), and <1% of their herd for grass tetany (82.6%; 419/507) and ketosis (72.7%; 368/506). Regarding management, dry cow body condition monitoring (73%; 365/497), dry cow mineral supplementation (61%; 304/497), and Ca supplementation at calving (61%; 314/487) were most commonly reported. Other milk fever prevention strategies supported by research in other production systems were not commonly reported (low K [20%; 101/497] and negative dietary cation-anion difference diet [6%; 31/497]). The odds of reporting keeping records of antibiotic treatment for milk fever were higher (OR = 3.20) for farmers from small compared to large herds. In conclusion, responses to our survey suggest that milk fever is a transition cow health concern in Irish dairy farms. Efforts should be devoted to enhance farmers' uptake of existing research-supported prophylactic strategies for milk fever and to optimize commonly reported management strategies in the Irish dairy production context.
PMID:39689143 | DOI:10.1371/journal.pone.0314987
Livestock abortion surveillance in Tanzania reveals disease priorities and importance of timely collection of vaginal swab samples for attribution
Elife. 2024 Dec 16;13:RP95296. doi: 10.7554/eLife.95296.
ABSTRACT
Lack of data on the aetiology of livestock diseases constrains effective interventions to improve livelihoods, food security and public health. Livestock abortion is an important disease syndrome affecting productivity and public health. Several pathogens are associated with livestock abortions but across Africa surveillance data rarely include information from abortions, little is known about aetiology and impacts, and data are not available to inform interventions. This paper describes outcomes from a surveillance platform established in Tanzania spanning pastoral, agropastoral and smallholder systems to investigate causes and impacts of livestock abortion. Abortion events were reported by farmers to livestock field officers (LFO) and on to investigation teams. Events were included if the research team or LFO could attend within 72 hr. If so, samples and questionnaire data were collected to investigate (a) determinants of attribution; (b) patterns of events, including species and breed, previous abortion history, and seasonality; (c) determinants of reporting, investigation and attribution; (d) cases involving zoonotic pathogens. Between 2017-2019, 215 events in cattle (n=71), sheep (n=44), and goats (n=100) were investigated. Attribution, achieved for 19.5% of cases, was significantly affected by delays in obtaining samples. Histopathology proved less useful than PCR due to rapid deterioration of samples. Vaginal swabs provided practical and sensitive material for pathogen detection. Livestock abortion surveillance, even at a small scale, can generate valuable information on causes of disease outbreaks, reproductive losses and can identify pathogens not easily captured through other forms of livestock disease surveillance. This study demonstrated the feasibility of establishing a surveillance system, achieved through engagement of community-based field officers, establishment of practical sample collection and application of molecular diagnostic platforms.
PMID:39679912 | DOI:10.7554/eLife.95296
A Review on Reliable and Standardized Animal Models to Study the Pathogenesis of Schmallenberg Virus in Ruminant Natural Host Species
Methods Mol Biol. 2025;2893:207-222. doi: 10.1007/978-1-0716-4338-9_16.
ABSTRACT
In the late summer of 2011, the Netherlands reported a cluster of reduced milk yield, fever, and diarrhea in dairy cattle. In March 2012, congenital malformations appeared, and Schmallenberg virus (SBV) was identified, becoming one of the few orthobunyaviruses distributed in Europe. Initially, little was known about the pathogenesis and epidemiology of these viruses in the European context, so assumptions were largely extrapolated from related viruses and other regions worldwide. To study SBV’s pathogenesis and its ability to cross the placental barrier, standardized and repeatable models that mimic clinical signs observed in the field are essential. This review discusses some of the latest experimental designs for infectious disease challenges involving SBV, covering infectious doses, routes of infection, inoculum preparation, and origin. Special attention is given to the placental crossing associated with SBV.
PMID:39671040 | DOI:10.1007/978-1-0716-4338-9_16
Effect of maternal heat stress at different stages of pregnancy on the reproductive performance and antral follicle count of the progeny of Holstein cows
Anim Reprod Sci. 2025 Jan;272:107665. doi: 10.1016/j.anireprosci.2024.107665. Epub 2024 Dec 4.
ABSTRACT
The objective was to evaluate the effect of maternal exposure to heat stress conditions at different stages of pregnancy on the reproductive performance and antral follicle count of progeny. The study was conducted at five commercial dairy farms located in southeastern Brazil. Retrospective data (2002 and 2015) on reproductive indices of daughters of Holstein cows that were exposed to heat stress conditions in the first (n = 447), second (n = 729) or third (n = 746) trimester of pregnancy and daughters of cows not exposed to heat stress (n = 359) were analyzed. Antral follicle count (AFC) and ovarian size were determined in a subgroup of animals (n = 242) by transrectal ultrasound. Statistical analysis was performed using the SAS GLIMMIX procedure. The number of services after first calving was lower in daughters of cows not exposed to heat stress conditions than in those exposed during different trimesters of pregnancy (P = 0.03). The calving interval was longer for daughters of cows exposed to heat stress conditions in the second and third trimesters of pregnancy than for those not exposed to heat stress (P = 0.01). In addition, the probability of pregnancy at first AI, (P = 0.01) and the AFC (P = 0.001) were greater in daughters of cows not exposed to heat stress conditions than in those exposed during the different phases of the gestational period. These findings indicate that maternal heat stress in different stages of pregnancy negatively affect the future fertility and AFC of bovine offspring.
PMID:39667294 | DOI:10.1016/j.anireprosci.2024.107665
Identification of genomic regions affecting nitrogen excretion intensity in Brown Swiss dairy cows
Anim Biotechnol. 2024 Nov;35(1):2434097. doi: 10.1080/10495398.2024.2434097. Epub 2024 Dec 10.
ABSTRACT
Dairy cows with a lower nitrogen excretion intensity (N_exi) excrete less nitrogen, ammonia (NH₃) and nitrous oxide (N₂O), a highly potent greenhouse gas (GHG), per kg of milk produced and therefore represent a lower environmental impact while maintaining food security. To date, the genomics background of N_exi is unknown. Here we performed a genetic association study, overlap analysis and functional enrichment analysis for N_exi in 875 genotyped dairy cows with 2,147 lactations from 200 herds. We identified 1456 single nucleotide polymorphisms (SNPs) that significantly affect N_exi. We found 140 SNPs overlapping with 148 protein-coding genes. The MAN1A1 gene is a strong candidate gene for N_exi. Genotype CC of rs42786248, the most significantly associated SNP located in the MAN1A1 gene, had higher N_exi than genotypes AA (p < 0.001) and AC (p < 0.001). We identified 33 genes involved in biological processes related to nitrogen metabolism. Our results form the basis for further research on the genomics background of N_exi. The identified SNPs serve as potential targets for selective breeding programs, aimed at reducing N_exi and associated NH₃ and N₂O emissions in cattle production, thus contributing to more environmentally sustainable milk production.
PMID:39655902 | DOI:10.1080/10495398.2024.2434097
Alpha-Lipoic acid supplementation during in vitro culture of abattoir- and OPU-derived bovine oocytes improves embryonic quality
Anim Reprod Sci. 2025 Jan;272:107667. doi: 10.1016/j.anireprosci.2024.107667. Epub 2024 Dec 9.
ABSTRACT
The Ovum Pick-Up (OPU) technique offers a rapid path to genetic improvement. Embryonic genome activation (EGA) is crucial for successful embryonic development and occurs in two phases: minor EGA (MN_EGA) from 2-cell to 8-cell stages, and major EGA (MJ_EGA) from 8-cell to 16-cell stages. Supplementation with alpha-lipoic acid (ALA) during MN_EGA using abattoir derived-oocytes has been shown to enhance in vitro embryo production. Two experiments were carried out in the study at hand. Experiment I aimed to evaluate ALA effects on embryo development and quality during MJ_EGA using abattoir-derived oocytes. Oocytes were treated with either a Control in vitro culture (IVC) medium or 2.5 µM ALA during MJ_EGA. The ALA presented a trend to increase the blastocyst cell number on day 7 (P = 0.06), along with reducing ROS levels and increasing GSH levels (P ≤ 0.05). Experiment II aimed to verify whether the results from abattoir- derived oocytes could be extrapolated to OPU-derived oocytes. The treatments included a Control, 2.5 µM ALA during MN_EGA, and 2.5 µM ALA during MJ_EGA. The ALA supplementation during MJ_EGA improved the total blastocyst rate on day 8 (P = 0.04), with a trend towards increased blastocyst cell number on day 7 (P = 0.09). No improvements were observed in MN_EGA. Overall, ALA supplementation during MJ_EGA is more effective than during MN_EGA for improving the embryonic quality of OPU-derived oocytes.
PMID:39657512 | DOI:10.1016/j.anireprosci.2024.107667
Effects of heat stress on predicted energy balance, fat-to-protein ratio, and milk β-hydroxybutyrate in first-lactation Holstein cattle in Hokkaido, Japan
Anim Sci J. 2024 Jan-Dec;95(1):e70013. doi: 10.1111/asj.70013.
ABSTRACT
Heat stress (HS) reduces dry-matter intake and causes negative energy balance (EB) in Holstein cattle, with consequent deterioration in milk production and wellness. Therefore, the effects of HS can be detected more directly from imbalances in EB than from the consequent changes in production or health traits. EB can be monitored by metabolism-related traits such as predicted EB (PEB), the fat-to-protein ratio (FPR), or β-hydroxybutyrate (BHB) in milk. We examined the days on which HS effects on the test-day PEB, FPR, or milk BHB were the greatest in first lactation. We collected weather records and test-day records. We considered the fixed effects of herd-year, test month, calving age, days in milk, temperature-humidity index (THI) from any one of test day to 14 days prior (15 models per trait), and random effects of animal and residuals in the models and compared the deviance information criterion (DIC) between models for each trait. For PEB, FPR, and milk BHB, the model gave the lowest DIC when including the effect of THI 1, 1, and 0 day before the test day. We observed that HS caused a decrease in PEB and an increase in FPR and milk BHB.
PMID:39648137 | PMC:PMC11625659 | DOI:10.1111/asj.70013
Pre-conception nutrition estimated from milk composition characterises the sex ratio of offspring in cattle
Anim Reprod Sci. 2025 Jan;272:107650. doi: 10.1016/j.anireprosci.2024.107650. Epub 2024 Dec 6.
ABSTRACT
In livestock breeding, offspring of a particular sex are often favoured. Various biological mechanisms influence the offspring sex ratio (OSR). It has been hypothesised that maternal body condition/nutritional status influence OSR. We analysed the relationship between the nutritional status of the cow and OSR. The analysed dataset contained 40,913 milk recordings of 39,192 cows from 3625 farms. Nutritional status was estimated based on the fat-to-protein (F:P) ratio and urea content in milk in the seven to fourteen days prior to conception. Somatic cell count (SCC) was also considered. Cows with > 150,000 SSC were analysed separately. When SSC was normal (≤150,000), high urea with high F:P resulted in a higher probability of male offspring (61 %), with OSR significantly deviating towards male (1.47). Conversely, a high urea level and low F:P resulted in a higher probability of female offspring (57 %), with OSR significantly in favour of females (0.79). At normal or low milk urea, the sex of the offspring did not change within F:P classes. The sex ratio did not deviate from 1:1 when F:P and urea were in the normal range. When SCC was high, the probability of particular sex did not change significantly in either combination of F:P and urea, but OSR showed a tendency toward males (OSR>1) when F:P and urea were low or normal. Our results confirmed the influence of maternal nutritional status on the offspring sex. Thus, adjusting nutrition in the pre-insemination period seems to be a way to influence the sex ratio of offspring in dairy cows.
PMID:39644767 | DOI:10.1016/j.anireprosci.2024.107650
Strategies to increase circulating progesterone in late metestrus and early diestrus in recipient dairy heifers and cows: A focus on induction of accessory corpus luteum formation
Anim Reprod Sci. 2025 Jan;272:107652. doi: 10.1016/j.anireprosci.2024.107652. Epub 2024 Nov 22.
ABSTRACT
The capacity of recipients to support transferred embryos is a challenge for dairy cattle production systems. This review explores methods for increasing P4 to improve early pregnancy establishment in dairy cattle. A key aspect of P4 supplementation during the critical first weeks of pregnancy is its correlation with successful embryo elongation. Moreover, P4 was correlated to an increased chance of embryo survival after maternal recognition of pregnancy. Internal releasing devices increase circulating P4 concentrations but may negatively impact fertility possibly due to unwanted health pathologies such as vaginitis and the still undefined mechanism of haste luteolysis. The accessory corpus luteum (CL) induction in recipient dairy cattle increases endogenous P4 output increasing circulating P4 concentrations. Two ovulatory inducers are commonly used: gonadotropin-releasing hormone (GnRH) and human chorionic gonadotropin (hCG). Despite their distinct structures, GnRH and hCG are equally capable of inducing ovulation in cattle. The P4 supplementation by an accessory CL formation was widely used in fixed-time artificial insemination breeding programs, but still not exhaustively studied in embryo transfer (ET) programs. The induction of an accessory CL in ET programs has yielded inconsistent results depending on parity, embryo type production, embryo stage of development, and type of hormone used. Although maternal physiological mechanisms support the idea of increasing P4 for higher fertility and better embryo development, the actual results in creating a high-P4 maternal environment are still uncertain.
PMID:39644763 | DOI:10.1016/j.anireprosci.2024.107652
Transcriptomic analysis of luteal tissue supports the earlier onset of luteolysis in heifers with diminished ovarian reserve
Reprod Fertil Dev. 2024 Dec;36:RD24130. doi: 10.1071/RD24130.
ABSTRACT
Context Antral follicle count (AFC) is reflective of ovarian reserve and linked to reproductive performance in mammalian females. We previously demonstrated earlier upregulation of endometrial oxytocin receptor transcription in heifers with low AFC, indicating an earlier onset of luteolysis. Aims We aimed to support the earlier onset of luteolysis in non-pregnant heifers with a low number of antral ovarian follicles (Open Low AFC) and hypothesized a reduced abundance of luteinizing hormone/choriogonadotropin receptor (LH/CG-R ) and increased abundance of thrombospondin-1 (THBS1 ) in luteal tissue of those heifers. We further investigated if classical interferon stimulated genes (ISGs) are already upregulated in response to conceptus-derived interferon tau. Methods For 4years, 10 heifers with the highest (High AFC) and 10 heifers with the lowest AFC (Low AFC) of the population (n =120/year) were selected, synchronized and inseminated. On day 15 or 16 after insemination, reproductive tracts were collected, and pregnancy status was determined. Corpora lutea were isolated, weighed and underwent transcriptomic analysis. Key results Transcript abundance of LH/CG-R was lower in Open Low AFC heifers compared to all other subgroups. Transcript abundance of THBS1 was upregulated in Open vs Pregnant heifers and showed greater abundance in Low vs High AFC heifers. Luteal weights and abundance of ISGs did not differ between heifers of differing AFC groups or pregnancy status. Conclusions The patterns of luteal LH /CG-R and THBS1 abundance support the concept of earlier onset of luteolysis in Open heifers with diminished AFC. Implications This may result in a shorter window for maternal recognition of pregnancy and contribute to inferior reproductive performance.
PMID:39642042 | DOI:10.1071/RD24130
The influence of corpus luteum and first-wave dominant follicle location on conception rate after artificial insemination in Holstein cattle
Anim Sci J. 2024 Jan-Dec;95(1):e70012. doi: 10.1111/asj.70012.
ABSTRACT
The influence of post-ovulatory corpus luteum (CL) and first-wave dominant follicle (1DF) location on pregnancy establishment in cattle remains controversial. This study aimed to reveal the relationship between CL and 1DF positioning, pregnancy outcomes, and blood steroid hormone levels following artificial insemination (AI) in Holstein cattle. Data from heifers (n = 163) and cows (n = 69) with optimally timed AI, defined as ovulation within 24 h post-AI, were analyzed to determine associations between CL (left/right ovary) and 1DF (ipsilateral/contralateral to CL) locations and conception rates. Plasma progesterone (P₄) and estradiol-17β (E₂) concentrations were measured five days post-insemination. In heifers, neither CL (p = 0.24) nor 1DF location (p = 0.44) affected conception rates. Cows with left-sided CL tended to have higher conception rates than those with right-sided CL (p = 0.08). Relative 1DF location did not affect conception in cows. The location of CL and 1DF did not affect plasma P₄ and E₂ concentrations or the ratio of plasma E₂ to P₄ in heifers or cows. These findings suggest a trend towards improved conception rates in cows with CL located on the left ovary post-AI, regardless of 1DF location. The mechanism should not be associated with systemic ovarian hormones.
PMID:39632604 | DOI:10.1111/asj.70012
Single nucleotide polymorphisms of <em>GYS2</em> gene and its association with milk production traits of dairy cows
Anim Biotechnol. 2024 Nov;35(1):2432966. doi: 10.1080/10495398.2024.2432966. Epub 2024 Dec 4.
ABSTRACT
Glycogen synthase 2 (GYS2) encodes liver glycogen synthase, a rate limiting enzyme in glycogen metabolism. Our preliminary work suggested that GYS2 was a candidate gene affecting milk production traits by analyzing the liver proteome of dairy cows. Herein, this research identified single nucleotide polymorphisms (SNPs) of GYS2, analyzed their genetic effects on traits of dairy cattle, and speculated the pathogenic mechanism through functional prediction of key mutation sites. Seven SNPs were found by resequencing and the association analysis showed that these SNPs were significantly associated with 305-day milk yield, fat yield, protein yield or fat percentage (p-value ≤ 0.0488). Six SNPs among them formed two haplotype blocks and they were associated with 305-day milk yield, fat yield, protein yield or fat percentage (p-value ≤ 0.0349). Furthermore, 5:g.88602007G > A and 5:g.88602026G > A were predicted to change the transcription factor binding sites (TFBSs), which might regulate the expression of GYS2. The missense mutation site, 5:g.88602535G > T, changed the secondary structure of mRNA and the secondary and tertiary structure of protein. In summary, the GYS2 was proved to have genetic effect on milk production traits, and its valuable seven SNPs, could provide more useful genetic information for molecular breeding of dairy cows.
PMID:39629739 | DOI:10.1080/10495398.2024.2432966
Genetic characteristics of the coronet scores related to Holstein cattle hoof health in Japan
Anim Sci J. 2024 Jan-Dec;95(1):e70014. doi: 10.1111/asj.70014.
ABSTRACT
Hoof disorders are crucial factors leading to dairy cattle culling. These disorders are difficult to detect, diagnose, and record, causing animal health problems and serious economic losses. The coronet score is a new hoof health indicator developed by the Dairy Herd Improvement Program of Japan. This score is assigned on a 5-point scale and can easily be determined by examining the degree of redness and swelling around the hooves. To determine whether coronet scores can be used to genetically improve hoof health, we investigated non-genetic factors in the score, developed a genetic analysis model, and estimated genetic parameters. Coronet scores were collected from 1280 herds in 28 prefectures once a month from 2014 to 2021. Furthermore, 1,598,878 test-day records of 94,951 cows from the first- to third-parity and pedigree information of 216,416 individuals were used in the analysis. Results revealed that herd size, parity, age, test month, and lactation stage influenced the coronet score. Additionally, the heritability of the coronet score estimated via the herd-test-day model was 0.027, and genetic trends deteriorated in sires and cows. Overall, we demonstrated that coronet score is a heritable trait, suggesting that hoof health could be genetically improved by selection for coronet score.
PMID:39631409 | PMC:PMC11617061 | DOI:10.1111/asj.70014
Effects of calcium and buffer sources on lactational performance, ruminal fermentation, nutrient digestibility, and metabolism of dairy cows
J Dairy Sci. 2024 Dec;107(12):10680-10694. doi: 10.3168/jds.2024-25089.
ABSTRACT
The objective was to investigate the effects of calcium and rumen buffer sources on lactational performance, ruminal fermentation, enteric gas emissions, apparent total-tract digestibility of nutrients, and blood variables of lactating dairy cows. A replicated 3 × 3 Latin square design experiment was conducted with 9 primi- and 9 multiparous mid-lactation Holstein cows. Cows were fed the same basal diet, except for the inclusion (as % DMI) of the following minerals: (1) CON, 0.80% limestone and 0.55% NaCl; (2) BICARB, 0.80% limestone and 0.80% NaHCO₃; and (3) ARAG, 0.80% aragonite and 0.55% NaCl. Dry matter intake was decreased by ARAG compared with CON but not with BICARB. Treatments did not affect milk yield, ECM, or yields of milk components. Feed efficiency was increased by BICARB compared with CON but not with ARAG (i.e., 1.72, 1.64, and 1.70, respectively). Compared with CON, milk fat was increased by both BICARB and ARAG (3.32% vs. 3.58%, respectively). Milk protein concentration tended to be slightly decreased (i.e., 2%) by ARAG compared with CON but not with BICARB. Milk total solids and MUN concentrations were increased by BICARB and tended to be increased by ARAG, compared with CON. Treatments did not affect ruminal fermentation variables, except that ARAG increased butyrate molar proportion, compared with CON but not with BICARB. Additionally, ruminal NH₃ concentration was greater for ARAG than for BICARB. Enteric gas emission and apparent total-tract digestibility of nutrients were not affected by treatments in the current study. Blood pH was not affected by treatments, and blood ionized Ca concentration was greater for ARAG than for BICARB, but neither was different from CON. Treatments did not affect plasma haptoglobin, β-hydroxybutyrate, or urea N concentrations. Overall, rumen buffering capacity of ARAG appears to be similar to that of BICARB, which was supported by increased milk fat, compared with CON. Compared with BICARB, ARAG increased ionized Ca concentration because of decreased base excess and HCO₃^– concentrations in blood.
PMID:39623659 | DOI:10.3168/jds.2024-25089
Rumen-protected methionine supplementation improves lactation performance and alleviates inflammation during a subclinical mastitis challenge in lactating dairy cows
J Dairy Sci. 2024 Dec;107(12):10761-10775. doi: 10.1016/j.jods.2024.08.001.
ABSTRACT
This study aimed to evaluate the effects of rumen-protected Met on lactation performance, inflammation, and immune response, and liver glutathione of lactating dairy cows during a subclinical mastitis challenge (SMC). Thirty-two Holstein cows (145 ± 51 DIM) were enrolled in a randomized complete block design. At -21 d relative to the SMC, cows were assigned to dietary treatments, and data were collected before and during the SMC. Cows were blocked according to parity, DIM, and milk yield and received a basal diet (17.4% CP; Lys 7.01% MP and Met 2.14% MP) plus 100 g/d of ground corn (CON; n = 16) or a basal diet plus 100 g/d of ground corn and rumen-protected Met (SM, Smartamine M at 0.09% of dietary DM; n = 16), fed as a top-dress. At 0 d, the mammary gland’s rear right quarter was infused with 100,000 cfu of Streptococcus uberis (O140J). Milk yield was recorded twice daily from 0 until 3 d relative to SMC. Milk samples were collected during each milking from 0 to 3 d relative to SMC, blood samples were collected at 0, 6, 12, 24, 48, and 72 h relative to SMC. The mTOR pathway activation was assessed in immune cells in blood and milk samples by measuring quantity and phosphorylation status of mTOR-related proteins, including AKT, S6RP, and 4EBP1. For the ratio of phosphorylated to total AKT, S6RP, and 4EBP1, blood samples were collected at 0, 12, and 24 h, and milk samples at 24 h relative to SMC. Liver biopsies were performed at -10 d and 24 h relative to SMC for measurement of glutathione. Linear mixed models with repeated measures were used to analyze the results. There was a trend for greater milk yield per milking (+ 0.8 kg) and per day (+1.7 kg) after SMC in SM cows compared with CON. The DMI was not affected by dietary treatments. Reactive oxygen metabolites were lower in SM cows than in CON. Milk somatic cell linear score was not affected by dietary treatments, and a score >4 at 24 h confirmed subclinical mastitis. The SM cows had greater milk fat percentage at 24 and 36 h post SMC, resulting in overall greater milk fat. Milk protein tended to be greater in SM cows than in CON. We observed greater liver glutathione in SM cows than in CON. Among inflammation biomarkers, ceruloplasmin was lower for SM cows compared with CON. In milk, greater phosphorylated (p) AKT:AKT and pS6RP:S6RP ratios were observed in immune cell populations from SM cows compared with CON. Blood neutrophils had a greater p4EBP1:4EBP1 ratio in SM cows compared with CON. Overall, our results show that Met supplementation during an SMC positively affected milk performance, lowered the risk of oxidative stress, and attenuated inflammation partially by increasing liver glutathione and immune cells’ protein synthesis via mTOR signaling.
PMID:39623660 | DOI:10.1016/j.jods.2024.08.001
New approaches in bovine spermatozoa evaluation and their relationship with male fertility
Anim Reprod Sci. 2025 Jan;272:107656. doi: 10.1016/j.anireprosci.2024.107656. Epub 2024 Nov 26.
ABSTRACT
Male fertility potential depends on physical, endocrine, and genetic factors responsible for producing functional male gametes. Although the main function of the male gamete, the spermatozoon, is to deliver its genetic material to the oocyte, this premise has been modified over the past few years. It is believed that the spermatozoon provides essential factors for fertilization and pre-implantation embryo development. A viable/healthy spermatozoon has functional subcellular compartments (nucleus, acrosome, midpiece, and flagellum) due to the actions of proteins, transcripts, and epigenetic marks in the organelles present in them that have important roles in reproductive biology. Male fertility potential reflects viable spermatozoa with proper function. Therefore, new approaches to functional sperm analysis are essential. Additionally, intrinsic factors and sperm molecules constitute potential biomarkers of viable spermatozoa and male fertility. Among these factors are proteins, the genome, and coding and non-coding RNAs, such as microRNAs, that act during fertilization and early embryo development. Research has been seeking increasingly efficient tools to predict fertility and functional studies of these molecules through gene and protein expression. Thus, analytical tools are essential to identify and classify viable and functional spermatozoa, to evaluate assisted reproductive male potential.
PMID:39616724 | DOI:10.1016/j.anireprosci.2024.107656
Regulatory T cells in bovine fertility: Current understanding and future prospects
Anim Reprod Sci. 2025 Jan;272:107655. doi: 10.1016/j.anireprosci.2024.107655. Epub 2024 Nov 26.
ABSTRACT
Regulatory T cells (Tregs) have emerged as crucial players in maintaining maternal-fetal tolerance and promoting successful pregnancy outcomes. This review examines the importance of these cells in pregnancy, drawing on human and animal-based studies, with a focus on their role in bovine fertility. Tregs employ various mechanisms to mediate maternal-fetal tolerance, including regulation of effector T-cell responses, interactions with innate immune cells in the uterine microenvironment, and modulation of trophoblast function. In humans, Treg dynamics during normal pregnancy and alterations in pregnancy complications provide compelling evidence for their involvement in maintaining fetal-maternal harmony. Animal models, particularly mouse studies, have further elucidated the importance of Tregs in preventing fetal rejection and promoting successful pregnancy outcomes. The review also explores the characterization of bovine Tregs, highlighting their similarities and unique features compared to human and rodent counterparts. Recent studies have indicated the presence and potential significance of Tregs in the bovine uterine environment during early pregnancy. Translational applications of Treg research in livestock fertility are discussed, with a focus on immunomodulatory strategies for enhancing Treg function, such as antigen-specific tolerance induction, pharmacological targeting of Treg pathways, and cell-based therapies using autologous or allogeneic Tregs. The review concludes by emphasizing the potential impact of Treg-based strategies on the livestock industry and the broader implications for human reproductive health. Future research directions are outlined, underscoring the need for further investigations into the role of Tregs in bovine reproductive tissues and their relationship with fertility outcomes.
PMID:39616725 | DOI:10.1016/j.anireprosci.2024.107655
Sperm acrosome-associated 1 (SPACA1) mRNA and protein molecules deficiency indicate low fertility and semen quality of Bali bulls (Bos sondaicus)
Theriogenology. 2025 Feb;233:80-87. doi: 10.1016/j.theriogenology.2024.11.009. Epub 2024 Nov 17.
ABSTRACT
Molecular-based biomarkers are believed to be more accurate in determining bulls’ fertility and sperm’s various fertility characteristics. The sperm acrosome-associated 1 (SPACA1) molecule, located in the anterior acrosomal and equatorial segments of the sperm head, is thought to be related to the function of binding and fusion between sperm and oocyte. This study aims to analyze the association of SPACA1 mRNA and protein with the fertility rate and semen quality of Bali bulls (Bos sondaicus) and assess its potential as a potential molecular biomarker determining bull fertility and sperm quality. Frozen semen from 20 Bali bulls was used in the research, which was then divided into two groups: high (HF) and low fertility (LF). SPACA1 mRNA abundance was analyzed using qRT-PCR, and SPACA1 protein abundance was analyzed using EIA. The semen quality parameters analyzed were motility (CASA), plasma membrane integrity (HOS test), sperm head morphology abnormalities (William staining), sperm viability (SYBR 14-PI), sperm capacitation (CTC assay), and sperm acrosome integrity (FITC-PNA). The results showed that there was a significant difference (P < 0.05) between high fertility (HF) and low fertility (LF) bulls, both in the abundance of SPACA1 at the mRNA, protein, and semen quality levels. Overall, the correlation test results showed a close relationship (P < 0.01) between the abundance of SPACA1 mRNA and protein with field fertility and various semen quality parameters tested in the study. A low level of SPACA1 molecules indicates low fertility and semen quality in Bali bulls. The SPACA1 molecule has the potential to be developed through further research to become a biomarker for determining fertility and semen quality in bulls.
PMID:39613497 | DOI:10.1016/j.theriogenology.2024.11.009
MicroRNAs bta-novel-miR-117, bta-novel-miR-234 and bta-novel-miR-417 have adverse effects on blastocyst formation
Theriogenology. 2025 Feb;233:88-99. doi: 10.1016/j.theriogenology.2024.11.018. Epub 2024 Nov 23.
ABSTRACT
In a previous study we found that the levels of the novel microRNAs (miRNAs) bta-novel-miR-117 bta-novel-miR-234 and bta-novel-miR-417 (P < 0.001) are significantly up-regulated in extracellular vesicles (EVs) in the culture medium of degenerating embryos compared to blastocysts. Because the functions of these novel miRNAs are still unknown, we investigated their regulatory roles during bovine blastocyst development by adding their mimics and inhibitors to the culture medium. The addition of mimics for bta-novel-miR-117, bta-novel-miR-234 and bta-novel-miR-417 resulted in a decreased blastocyst rate, and supplementation of bta-novel-miR-234 inhibitors increased the cleavage rate significantly (P < 0.001). Low-input transcriptome analysis and RT-qPCR results revealed that bta-novel-miR-117, bta-novel-miR-234 and bta-novel-miR-417 co-target genes such as ANKEF1, HAND2 and SLC2A2, downregulated their expression significantly (P < 0.001). These genes associated with glucose transmembrane transport and plasma membrane raft metabolism play crucial roles in embryonic development. The results suggest that overexpressing of these three novel miRNAs impairs embryonic development, and they might serve as biomarkers to detect failing bovine embryos.
PMID:39613498 | DOI:10.1016/j.theriogenology.2024.11.018
Viromics-based precision diagnosis of reproductive abnormalities in cows reveals a reassortant Akabane disease virus
BMC Vet Res. 2024 Nov 29;20(1):539. doi: 10.1186/s12917-024-04400-5.
ABSTRACT
BACKGROUND: At the end of 2021, an epidemic of reproductive abnormalities in cows occurred in Jilin Province, China, posing an urgent need for a rapid diagnosis.
RESULTS: To identify the cause of the disease, a total of 172 samples were collected from 21 dead calves and 45 aborting or pregnant cows in 10 farms across the province. Routine PCR or RT-PCR detection did not find any common abortion-related agents. We then employed the viromics-based precision diagnosis method to analyze these samples, and the read-based annotation showed signals of an Akabane disease virus (AKAV) in some libraries. To further identify the virus, nested RT-PCR detection revealed that 52.3% (11/21) of dead calves and 26.6% (12/45) of cows were positive for the virus. Phylogenetic analysis of the partial fragments showed that the S segment of the virus was 100% identical to the Chinese strain TJ2016, but its M and L segments shared 94.3% and 96.5% identities with an Israeli strain.
CONCLUSIONS: The viromic and molecular results suggested that these animals were infected with a reassortant AKAV. Coupled with the clinical signs, the virus should be responsible for the epizootic, highlighting that molecular and serological surveys of the virus in cows during early pregnancy, as well as ecological investigation in its arthropod vectors, are necessary.
PMID:39614255 | PMC:PMC11606050 | DOI:10.1186/s12917-024-04400-5
Single-step genomic BLUP (ssGBLUP) effectively models small cattle populations: lessons from the Israeli-Holstein Herdbook
BMC Genomics. 2024 Nov 27;25(1):1147. doi: 10.1186/s12864-024-11074-8.
ABSTRACT
BACKGROUND: Routine genomic-estimated breeding values (gEBVs) are computed for the Israeli dairy cattle population by a two-step methodology in combination with the much larger Dutch population. Only sire genotypes are included. This work evaluated the contribution of cow genotypes obtained from the Israeli Holstein population to enhance gEBVs predictions via single-step genomic best-linear unbiased prediction (ssGBLUP). The gEBV values of 141 bulls with daughter information and high reliabilities for 305-day lactation yield of milk, fat, and protein were compared with the bulls’ predicted ssGBLUP-gEBVs using a truncated dataset omitting production data of the last five years. We investigated how these sire gEBVs were affected by varying polygenic weights in the genomic relationship matrices and by deleting old phenotypic or genotypic records.
RESULTS: The correlations of the predicted gEBVs for milk, fat and protein computed from the truncated data with the current gEBVs based also on daughter records of the last five years were 0.64, 0.57, and 0.56, respectively, for a polygenic weight of 0.5, similar to the values achieved by the current two-step methodology. The regressions of the current gEBVs on the predicted values were 0.9 for milk and 0.7 for fat and protein. Genotyping of 1.8-5 cows had the approximate statistical power of one additional bull depending on the trait. Omitting phenotype records earlier than 2000 resulted in similar gEBV values. Omitting genotypes before 1995 improved the regression coefficients. For all experiments, varying the polygenic weights over the range of 0.1 to 0.9 resulted in a trade-off between correlations and overestimation of gEBVs for young bulls.
CONCLUSIONS: The model suffers from overestimation of the predicted values for young bulls. The time interval used for inclusion of genotypic and phenotypic records and adjustment of the polygenic weight can improve gEBV predictions and should be tuned to fit the tested population. For relatively small populations, genotyping of cows can significantly increase the reliability of gEBVs computed by single-step methodology. By extrapolation of our results, records of ~ 13,000 genotyped cows should provide a sufficiently large training population to obtain reliable estimates of gEBVs using ssGBLUP.
PMID:39604830 | PMC:PMC11600912 | DOI:10.1186/s12864-024-11074-8
The extracellular vesicle tetraspanin CD63 journey from the testis through the epididymis to mature bull sperm
Sci Rep. 2024 Nov 27;14(1):29449. doi: 10.1038/s41598-024-81021-w.
ABSTRACT
The important role of extracellular vesicles, which are considered key mediators of intercellular communication under physiological and pathological conditions, in various cellular processes, including those crucial for mammalian reproduction, has been increasingly studied. Tetraspanins, including CD63, are widely used as markers of extracellular vesicles, but they may also play a role in their biogenesis, cargo selection, cell targeting, and uptake. This study aimed to map the journey of the extracellular vesicle protein tetraspanin CD63 from the testis through the epididymis into mature bull sperm via an approach that included immunohistochemistry (immunofluorescence and immunoperoxidase staining), Western blot analysis, and immunoprecipitation analysis. We described the presence of CD63 in bull testicular and epididymal tissues, extracellular vesicles produced in these organs and spermatozoa during epididymal transit and after ejaculation. In addition, we revealed the nonuniform distribution of potential CD63 partners, such as CD9, integrin αV and syntenin-1, in the sperm head and tail and in extracellular vesicles. These findings contribute to understanding the complex mechanisms underlying sperm maturation and point to the possible involvement of tetraspanins and their associated partners, either as part of extracellular vesicles or sperm membranes, in these processes.
PMID:39604592 | PMC:PMC11603341 | DOI:10.1038/s41598-024-81021-w
Factors influencing calving difficulty and gestation length in dairy cows inseminated with beef sires
Animal. 2024 Dec;18(12):101369. doi: 10.1016/j.animal.2024.101369. Epub 2024 Nov 7.
ABSTRACT
Producing calves with higher economic value by utilising semen from beef breeds in dairy herds (Beef-on-Dairy, BoD) has become more common in recent times. Such crossbreed calves promise better carcass conformation and higher consumer acceptance due to the better flavour, but the widespread adaptation of BoD requires careful consideration of the sire breed to maximise the benefits. In this regard, two major traits of interest are calving difficulty and gestation length due to associated costs. In this study, 3 966 BoD calves from crossing Holstein dams with beef sires of the breeds Angus (n = 811), Belgian Blue (n = 2841), Limousin (n = 169) and Wagyu (n = 145) from 122 farms were evaluated to determine differences in calving difficulty and gestation length using binary logit and linear regression models. Lowest calving difficulty was observed for Wagyu crossbreds while Limousin crossbreds had the highest calving difficulty incidences. Selected sires from Angus and Belgian Blue breeds were also compared using chi-square analysis for differences in calving difficulty. The risk of calving difficulty was 1.94 times higher for male calves. Heifers had a significantly higher risk for calving difficulty when compared with the multiparous cows in the study. Calves with higher birth weight and longer gestation length were more prone to calving problems. For gestation length, Angus crossbreds had the shortest gestation (280.2 d), while the longest gestation (287.6) was observed in Limousin crossbreds. To maximise the benefits of the BoD breeding strategy, selecting appropriate sire breeds and within-breed sire selection for economically important traits, such as birth weight, appropriate gestation length, and reduced calving difficulty, may provide a viable solution.
PMID:39608181 | DOI:10.1016/j.animal.2024.101369
Transcriptomic and Metabolomics Joint Analyses Reveal the Influence of Gene and Metabolite Expression in Blood on the Lactation Performance of Dual-Purpose Cattle (<em>Bos taurus</em>)
Int J Mol Sci. 2024 Nov 18;25(22):12375. doi: 10.3390/ijms252212375.
ABSTRACT
Blood is an important component for maintaining animal lives and synthesizing sugars, lipids, and proteins in organs. Revealing the relationship between genes and metabolite expression and milk somatic cell count (SCC), milk fat percentage, milk protein percentage, and lactose percentage in blood is helpful for understanding the molecular regulation mechanism of milk formation. Therefore, we separated the buffy coat and plasma from the blood of Xinjiang Brown cattle (XJBC) and Chinese Simmental cattle (CSC), which exhibit high and low SCC/milk fat percentage/milk protein percentage/lactose percentages, respectively. The expression of genes in blood and the metabolites in plasma was detected via RNA-Seq and LC-MS/MS, respectively. Based on the weighted gene coexpression network analysis (WGCNA) and functional enrichment analysis of differentially expressed genes (DEGs), we further found that the expression of genes in the blood mainly affected the SCC and milk fat percentage. Immune or inflammatory-response-related pathways were involved in the regulation of SCC, milk fat percentage, milk protein percentage, and lactose percentage. The joint analysis of the metabolome and transcriptome further indicated that, in blood, the metabolism pathways of purine, glutathione, glycerophospholipid, glycine, arginine, and proline are also associated with SCC, while lipid metabolism and amino-acid-related metabolism pathways are associated with milk fat percentage and milk protein percentage, respectively. Finally, related SCC, milk fat percentage, and milk protein percentage DEGs and DEMs were mainly identified in the blood.
PMID:39596441 | PMC:PMC11594596 | DOI:10.3390/ijms252212375
Effects of Moringa oleifera leaf powder supplementation on milk somatic cell scores and the plasma indexes of inflammation and antioxidant activity in dairy cows
Vet Res Commun. 2024 Nov 26;49(1):41. doi: 10.1007/s11259-024-10607-6.
ABSTRACT
The effects of Moringa oleifera (MO) leaf powder (MOLP) supplementation on milk somatic cell scores (SCS), plasma inflammation markers, and plasma antioxidants were studied in 18 multiparous Holstein cows, 10 in early lactation (days in milk; DIM < 100) and eight in mid- and late-lactation (DIM ≥ 100). Nine of these 18 cows (5 + 4 individuals for each lactation stage, respectively) were placed in the MO group and fed with MOLP at 0.3% of partial mixed ration (PMR) dry matter (DM) for 3 weeks, while the other nine represented the control group and were not fed any MOLP supplementation. Milk, blood, and rumen fluid samples were collected on weeks 0 and 3. The SCS and plasma acute phase protein (APP) concentrations in the early lactation cows in the control group increased markedly (P < 0.05) and milk yield decreased significantly, resulting in a difference (P < 0.05) between groups at the end of the experiment. In mid- and late-lactation cows, MOLP supplementation did not affect SCS, milk yields, and plasma APP concentrations. Plasma superoxide dismutase levels in the MO group at both lactation stages were higher (P < 0.05) than in the control group. In conclusion, feeding MOLP at 0.3% of PMR DM to dairy cows for 3 weeks controlled the increase in SCS in the early lactation individuals and the subsequent decrease in milk production as a response to inflammation. The results also suggested that MOLP supplementation was responsible for the increase in antioxidant activity during lactation.
PMID:39589675 | DOI:10.1007/s11259-024-10607-6
A portable microfluidic chip-based fluorescent and colorimetric aptasensor combining recombinase polymerase amplification for bovine pregnancy-associated glycoproteins detection
Biosens Bioelectron. 2025 Feb 15;270:116981. doi: 10.1016/j.bios.2024.116981. Epub 2024 Nov 21.
ABSTRACT
A portable dual-mode PDMS-based microfluidic chip aptasensor was developed to detect bovine pregnancy-associated glycoproteins (bPAG) in bovine milk. Reagents within the chip chambers underwent reactions driven by gravity, where pre-encoded rich C sequences on the complementary strand of the aptamer facilitated the generation of abundant G-quadruplexes via subsequent RPA reaction, which activated the chromogenic substrates and fluorogenic precursors in the chip, producing distinct colorimetric and fluorescent signals. These signals were captured by our developed smartphone application and converted into RGB values, further enabling the quantification of bPAG with detection limits of 0.079 ng/mL and 0.024 ng/mL for colorimetric and fluorescent modes, respectively, over a linear range of 0.1-100 ng/mL. Bovine milk and other animal source milk were evaluated in the proposed assay, accurate identification results were obtained, indicating significant potential in bovine milk monitoring. The work further provided a valuable reference for point-of-care testing of non-nucleic acid targets in food samples.
PMID:39586144 | DOI:10.1016/j.bios.2024.116981
Supplementation with L-kynurenine during in vitro maturation improves bovine oocytes developmental competence through its antioxidative action
Theriogenology. 2025 Feb;233:53-63. doi: 10.1016/j.theriogenology.2024.11.014. Epub 2024 Nov 20.
ABSTRACT
Oxidative stress impairs the developmental potential of oocytes during in vitro maturation (IVM). L-kynurenine (L-KYN), an endogenous metabolite, exhibits antioxidant, anti-inflammatory and neuroprotective effects. This work aimed to evaluate the potential effects of L-KYN on bovine oocyte IVM and its mechanisms. Different concentrations of L-KYN (0, 10, 50, 100, and 200 μmol/L) were supplemented to bovine oocyte IVM medium. Results shown a notable enhancement in the oocyte maturation rate and the subsequent zygote cleavage and blastocyst formation rate when the L-KYN concentration reached 100 μmol/L. Further analysis revealed that this treatment effectively down-regulated expression levels of genes to cumulus cell apoptosis (Bax and Caspase3), up-regulated expression levels of genes to cumulus cell expansion (HAS2, PTX3, and PTGS2) and oocyte antioxidant (GPX4 and CAT). L-KYN supplementation also effectively increased glutathione (GSH) levels, promoted oocytes mitochondrial activity, enhanced DNA repairability, deceased reactive oxygen species (ROS) levels, and reduced apoptosis. In conclusion, adding 100 μmol/L of L-KYN to IVM medium could enhance bovine oocyte quality and the subsequent embryonic development. L-KYN could be a potential antioxidant supplement for bovine oocyte maturation in vitro.
PMID:39579654 | DOI:10.1016/j.theriogenology.2024.11.014
Moon cycle influences calving frequency, gestation length and calf weight at birth, but not offspring sex proportion in tropical crossbred cattle
Chronobiol Int. 2024 Dec;41(12):1533-1544. doi: 10.1080/07420528.2024.2432437. Epub 2024 Nov 22.
ABSTRACT
Numerous studies have shown the influence of the moon cycle on biological functions in farm animals, suggesting that predicting calving distribution could enhance survival rates by improving management practices in animal production. This study builds on previous research by examining the impact of the lunar cycle on calving frequency, gestation length, birth weight, and calf sex in artificially inseminated cows. We analyzed 121,276 records from dual-purpose crossbred cows across 36 farms along the western margin of Lake Maracaibo basin, Venezuela. The lunar cycle was divided into 30 periods of 0.984 days each and further categorized into four phases: 1) 1.97 days around the new moon; 2) 12.8 days during the crescent phase; 3) 1.97 days around the full moon; and 4) 12.8 days during the waning phase. Data were analyzed using a logistic regression and the general linear model in SAS, comparing proportions and means with contrast and general linear model tests, respectively. There was no association between the lunar cycle and the sex of calves. However, calvings distribution across the lunar month showed notable peaks 2 days around both the new and full moons, a pattern consistent regardless of the number of calvings or gestation lengths. In addition, significant differences were observed between the days surrounding the new (1) and full (3) moons compared to the other lunar phases (2 and 4). Moon cycle also influenced gestation length and calf birth weight. This study expands previous findings and demonstrates that the lunar cycle consistently affects certain reproductive traits in inseminated dual-purpose cows, including gestation length, calf birth weight, and calving distribution, with practical implications for cattle operations.
PMID:39575857 | DOI:10.1080/07420528.2024.2432437
Harnessing the value of fertility biomarkers in bull sperm for buck sperm
Anim Reprod Sci. 2025 Jan;272:107643. doi: 10.1016/j.anireprosci.2024.107643. Epub 2024 Nov 14.
ABSTRACT
Efficient and sustainable reproduction and production of cattle and goats are vitally important for ensuring global food security. There is a need for potent biomarkers to accurately evaluate semen quality and predict male fertility. Although there is a reasonable set of biomarkers identified in bull sperm, there is a significant lack of such information in buck sperm along with a lack of transfer of proven technologies in goat reproductive biotechnology. These gaps are important problems because they are preventing advances in fundamental andrology and applied science of goat production. Both cattle and goats are ruminants, and they share significant similarities in their genetics and physiology although subtle differences do exist. This review harnesses the power of utilizing the knowledge developed in bull sperm to generate information on buck sperm fertility markers. These include genomic, functional genomic, epigenomic fertility markers. Revealing molecular underpinnings of such similarity and diversity using systems biology is expected to advance both fundamental and applied andrology of livestock and endangered species.
PMID:39577268 | DOI:10.1016/j.anireprosci.2024.107643
Perspectives in cattle reproduction for the next 20 years – A European context
Theriogenology. 2025 Feb;233:8-23. doi: 10.1016/j.theriogenology.2024.11.007. Epub 2024 Nov 14.
ABSTRACT
Following a significant increase in herd and farm sizes after the removal of milk quotas in Europe, the past 10 years have seen a slight yet steady decline in the population of cattle. This includes a reduction of approximately 5 % in dairy and beef cattle. This trend is driven by various factors, such as changing market demands, economic shifts, and sustainability challenges in the livestock sector. Despite this, technological advancements in reproductive management have continued to enhance efficiency and sustainability, particularly in dairy production. The main areas of rapid development, which will continue to grow for improving fertility and management, include: i) genetic selection (including improved phenotypes for use in breeding programs), ii) nutritional management (including transition cow management), iii) control of infectious disease, iv) rapid diagnostics of reproductive health, v) development of more efficient ovulation/estrous synchronization protocols, vi) assisted reproductive management (and automated systems to improve reproductive management), vii) increased implementation of sexed semen and embryo transfer, viii) more efficient handling of substantial volumes of data, ix) routine implementation of artificial intelligence technology for rapid decision-making at the farm level, x) climate change and sustainable cattle production awareness, xi) new (reproductive) strategies to improve cattle welfare, and xii) improved management and technology implementation for male fertility. This review addresses the current status and future outlook of key factors that influence cattle herd health and reproductive performance, with a special focus on dairy cattle. These insights are expected to contribute to improved performance, health, and fertility of ruminants in the next 20 years.
PMID:39577272 | DOI:10.1016/j.theriogenology.2024.11.007
Multiparameter growth-performance monitoring of Holstein dairy heifers fed on moderate- or high-energy feeding plans from birth to puberty
PLoS One. 2024 Nov 21;19(11):e0314015. doi: 10.1371/journal.pone.0314015. eCollection 2024.
ABSTRACT
Today, dairy cattle farmers are seeking to optimize expenditure and productivity throughout the lives of their animals by focusing on efficiency at all levels. One strategy for bringing forward the start of a dairy cow’s profitability phase is to advance the onset of puberty and reduce the animal’s age at their first calving. Thus, one objective of this study was to feed two groups of Holstein dairy heifers the same diet but in different quantities, with the aim of generating a growth differential of at least 200 g/day between the two groups. Thirty-eight heifer calves were followed from birth through puberty using body morphometric measurements and quantitative data collected by automatic feeders, which enabled the monitoring of both feed intake and growth for individual heifers. Routine ultrasonography was used to examine changes in the muscle and adipose tissue compartments, and x-ray tomography was used to monitor bone mineralization and rumen development. At 12 weeks of age, heifers in the optimized feeding (OPT) group had greater cortical bone thickness in the tibia compared with the control (CON) group. At 18 weeks of age, OPT heifers also had more trabecular cancellous bone. In contrast, the ruminal volumes of the heifers in the CON group were greater than those of the OPT heifers at 12 weeks. The OPT heifers had greater indices of general, skeletal, and muscular development at 9 weeks, 6 months, and 12 months. Among the circulating plasma indicators measured in this study, non-esterified fatty acids were highest in the CON calves at 6 and 12 months of age and at the onset of puberty, whereas IGF1 was highest in the OPT calves at all ages. The age at puberty of the OPT calves was 8.4 ± 0.6 months compared with 11.2 ± 1.1 months for the CON calves. The OPT heifers had an average daily weight gain of 1018 g/day from birth to the onset of puberty, which enabled them to achieve increased body fattening and to reach puberty 3 months earlier compared with the CON heifers; the average daily weight gain of the CON heifers was 780 g/day over the same period. Taken together, this study defines new reference values for a multitude of morphometric indicators, thereby enabling precise monitoring of the growth of Holstein heifers from birth to puberty.
PMID:39570837 | PMC:PMC11581270 | DOI:10.1371/journal.pone.0314015
Evaluation of GnRH- versus estradiol-based protocols for ovulation synchronization in postpartum Bos taurus grazing beef cows submitted to fixed-time artificial insemination
Theriogenology. 2025 Feb;233:1-7. doi: 10.1016/j.theriogenology.2024.11.008. Epub 2024 Nov 13.
ABSTRACT
This study compared the effect of a 7-day estradiol- and a 7-day GnRH-based FTAI protocol versus a presynchronized GnRH-based FTAI protocol (7 & 7 GnRH) on pregnancy per AI (P/AI) in multiparous postpartum Angus cows. Cows were blocked according to presence/absence of a CL, body condition score, and days postpartum and assigned randomly to one of three treatments: I) 7-day EB (n = 368), estradiol benzoate (EB) and intravaginal progesterone-(P4)-releasing device (IVPD) on Day -10, prostaglandin F_2α (PG), equine chorionic gonadotropin (eCG) and estradiol cypionate (ECP) at IVPD removal on Day -3 with FTAI done on Day -1 (54 ± 2 h after IVPD removal); II) 7-day GnRH (n = 367), GnRH at IVPD insertion on Day -10, PG and eCG at IVPD removal on Day -3 with GnRH and FTAI on Day 0 (66 ± 2 h after IVPD removal); and III) 7 & 7 GnRH (n = 361), PG at IVPD insertion on Day -17, GnRH on Day -10, IVPD removal, PG and eCG on Day -3 with GnRH and FTAI on Day 0 (66 ± 2 h after IVPD removal). Preovulatory follicle diameter, corpus luteum (CL) presence, CL area, and P4 concentration were determined at IVPD removal, as well as estrus expression at FTAI and P/AI between 35 and 40 days after FTAI. Plasma P4 concentrations at IVPD removal were greater (P < 0.05) in cows subjected to the 7-day GnRH or 7 & 7 GnRH protocols and a greater number of cows (P < 0.05) had at least one CL at IVPD removal compared to cows subjected to the 7-day EB protocol. However, the 7 & 7 GnRH protocol resulted in more cows with two CLs at IVPD removal compared to the other two protocols. Moreover, cows synchronized with the 7 & 7 GnRH protocol had larger preovulatory follicles (P < 0.05) and larger CL area at IVPD removal (P < 0.05), and a greater rate of estrus expression before FTAI (P < 0.05) than cows synchronized with the 7-day EB, whereas those variables were intermediate in cows synchronized with the 7-day GnRH. Pregnancy per AI was greater (P < 0.05) in cows treated with the 7 & 7 GnRH (63.5 %) treatment compared to the 7-day EB (51.4 %) and the 7-day GnRH (51.3 %) protocols. In summary, the 7 & 7 GnRH protocol enhanced circulating P4 before IVPD removal, increased estrus expression rate before FTAI, and improved P/AI in postpartum Bos taurus grazing beef cows.
PMID:39566176 | DOI:10.1016/j.theriogenology.2024.11.008
Nitrogen excretion and utilisation of dairy cows grazing temperate semi-natural grasslands
Animal. 2024 Dec;18(12):101358. doi: 10.1016/j.animal.2024.101358. Epub 2024 Oct 16.
ABSTRACT
Diets reliant on grazed, temperate herbage are prone to greater nitrogen (N) losses via urine than balanced stall-fed diets which poses a greater risk for N emissions. Measures for improving the N utilisation in grazing-based dairy cattle systems are predominantly investigated on homogenous clover-ryegrass pastures with high herbage yields and nutritional quality. In contrast, grazing-based systems reliant on less external inputs (e.g., synthetic fertilisers or concentrates) using semi-natural grassland as main feed source, such as in large parts of Central Europe, received less attention. The N utilisation and excretion of grazing cows in low-input dairy farms were, thus, investigated on nine commercial organic dairy farms in South Germany across one to four periods per farm. The dataset captured a diverse set of dairy production systems comprising 323 individual animal observations. A mean (± one SD) milk production, DM intake (DMI), and pasture DMI of 23.9 kg (± 5.35), 21.0 kg (± 3.21), and 11.3 kg/d (± 4.83), respectively, was determined. Feed intake was estimated using titanium dioxide and faecal CP concentration as markers of faecal excretion and diet digestibility, respectively. Milk N use efficiency (MNE; i.e., milk N secretion as share of N intake) averaged 24.7 g/100 g N intake (± 5.91), which is greater than observations in temperate, high-input grazing systems but lower than in cows receiving balanced diets in the barn. The MNE and another seven indicators of N utilisation and excretion displayed a wide range of values. The grazing management factors explaining this variation were, thus, identified via backward elimination. The supplementation strategy had the greatest potential for manipulating N utilisation and excretion of dairy cows. Increasing shares of fresh forages (i.e., meadow grass or clover-grass leys) as well as of hay in supplement DMI increased N utilisation (e.g., MNE) and decreased urinary N excretion (e.g., urinary N to creatinine ratio), while increasing shares of concentrates in supplement DMI are related to lower N losses via urine. At the same time, increases in total supplement DMI reduced N utilisation and increased urinary N excretion. Hence, full-time grazing combined with supplementation of fresh forage and hay in the barn is a viable option for low-input, grazing-based dairy operations with moderate levels of N losses.
PMID:39566364 | DOI:10.1016/j.animal.2024.101358
Modeling impact of improved forage cultivation on milk productivity and feed sufficiency in semiarid tropics of central India: A doubly robust analysis
Anim Sci J. 2024 Jan-Dec;95(1):e70009. doi: 10.1111/asj.70009.
ABSTRACT
The study using cross-sectional data collected from 300 dairy farmers has analyzed the factors affecting adoption of improved forage technologies and its impact on milk yield and feed sufficiency in central region. We used inverse-propensity-weighting regression adjustment (IPWRA) method as main technique for impact evaluation and checked the robustness of the results using matching methods. Our findings suggest that education status, adult cattle unit, animal breed type, off-farm income activities, farm size, and access to training and market significantly influence adoption of improved forage technologies and practices. Further, the adoption led to a significant increase in daily milk yield (1.07 to 1.34 L), total dry matter availability by over 27%, and green fodder availability by around 80%. Ration balancing has been identified as a significant concern in the study region. Consequently, the study suggests that adopting a comprehensive approach is necessary to address the issue of proper ration balancing and fully harness the production potential of dairy animals.
PMID:39558662 | DOI:10.1111/asj.70009
Comparative analysis of differentially expressed genes and transcripts in the ovary of yak in estrus and anestrus
Anim Biotechnol. 2024 Nov;35(1):2427757. doi: 10.1080/10495398.2024.2427757. Epub 2024 Nov 18.
ABSTRACT
Since most yaks have a long postpartum anestrus period, postpartum anestrus is the main factor affecting the reproductive efficiency of yaks. In this study, the third-generation sequencing technology was used to successfully screen differentially expressed genes (DEGs) and differentially expressed transcripts (DETs) in the ovarian tissues of yaks during estrus and anestrus. The functional references of DEGs and DETs were Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, and Clusters of Orthologous Genes database. A total of 1149 DEGs and 2294 DETs were successfully identified. These DEGs and DETs were mainly related to biological processes such as “reproduction”, “reproductive process”, “metabolic process” and “rhythmic process”. Kisspeptin-G protein-coupled receptor was found to be involved in regulating the reproductive cycle of yaks. DEGs and DETs were also related to gonadotropin-releasing hormone (GnRH) signaling pathways such as oocyte meiosis, estrogen signaling pathway, and progesterone-mediated induced oocyte maturation. The results showed that SIRT1, CSNK1A1, SLIT3, INHBA, INSL3, ZP2, Clock, BMP15, Bmal1, KISS1, and LCHGR regulate the postpartum quiescent state and the reproductive cycle of yaks. This study will help to further clarify the reproductive mechanism of yaks at the molecular level and provide certain assistance for the development of animal husbandry.
PMID:39558653 | DOI:10.1080/10495398.2024.2427757
Genetic parameters of functional longevity and associated traits in Italian Charolais and Limousine breeds
J Anim Sci. 2024 Jan 3;102:skae354. doi: 10.1093/jas/skae354.
ABSTRACT
This study aimed to estimate the genetic parameters of stayability (STAY) at different calvings using a single-step genomic best linear unbiased prediction (ssGBLUP) approach, comparing Gaussian-linear and threshold models in Italian Charolais and Limousine beef cattle. It also examined the genetic relationship between STAY and other traits to identify potential indicators of longevity and assessed the impact of STAY selection on economically important traits. STAY, a key trait for farm profitability, is defined as the probability of a cow surviving and remaining productive in the herd until a determined age. We evaluated STAY from the second to third calving and subsequent intervals (e.g., STAY23, STAY78), along with two fertility traits and several conformation traits. Data included 47,362 Limousine cows and 9,174 Charolais cows from 2,471 to 1,774 herds, respectively, born between 1977 and 2023. Analyses were performed fitting univariate threshold and Gaussian-linear animal models to estimate genetic parameters for STAY traits (STAY2 to STAY8) using ssGBLUP. Also, bivariate models were used to estimate genetic correlations between STAY and fertility and conformation traits. Heritabilities for STAY ranged from 0.13 to 0.11 and from 0.21 to 0.14 for Limousine, and from 0.14 to 0.11 and from 0.21 to 0.19 for Charolais, using Gaussian-linear and threshold models, respectively. Significant re-ranking of genotyped sires based on STAY traits was observed, particularly for more distant calvings (STAY8) compared to earlier ones (STAY3), indicating that STAY traits are genetically distinct. Genetic correlations were positive between STAY and conformation traits for Limousine. In Charolais, many traits were uncorrelated, but some conformation traits showed positive correlations, except for rump convexity, which had negative correlations with STAY. In conclusion, the heritability estimates of STAY suggests that genetic improvement for longevity in Limousine and Charolais herds is feasible. Selecting sires with consistently high genomic breeding values for STAY across early and late calvings highlights the importance of long-term longevity. Genetic correlations indicate that selection based on conformation traits could enhance herd survival by improving cow resilience for the Limousine. Instead for the Charolais some conformation traits showed positive correlations with STAY, while rump convexity had negative association, potentially affecting longevity.
PMID:39555595 | PMC:PMC11630839 | DOI:10.1093/jas/skae354
Use of Injectable Progesterone as a Pre-Synchronisation Strategy in a Timed Artificial Insemination Protocol Based on Gonadotropin-Releasing Hormone and Progesterone in Bos indicus Beef Cows in Anoestrous
Reprod Domest Anim. 2024 Nov;59(11):e14745. doi: 10.1111/rda.14745.
ABSTRACT
This study evaluated the effects of pre-synchronisation with injectable progesterone (P4) on the ovarian follicular dynamics of Bos taurus indicus cows in anoestrous treated with a timed artificial insemination (TAI) protocol. Multiparous Nelore females (n = 47) at 30-60 days postpartum were used in this study. 10 days before (D-10) the TAI protocol, antral follicle count (AFC; follicles ≥ 3 mm), ovarian condition and body condition score (BCS; 1-5) were assessed and were randomly allocated into two groups: Pre-sync (n = 25), which underwent pre-synchronisation with 150 mg of injectable P4 intramuscularly (i.m.), and control (n = 22), which received the same volume of NaCL 0.9%. On D0, the ovarian assessment was repeated, and TAI protocol was initiated in all animals, with the insertion of an intravaginal P4 device and administration of 10.5 μg of buserelin acetate (gonadotropin-releasing hormone-GnRH). On D7, the P4 device was removed, and 300 IU of equine chorionic gonadotropin, 150 μg of D-cloprostenol and 1 mg of estradiol cypionate were administered i.m. On the same day (D7), the presence of the corpus luteum (CL) was assessed, the dominant follicle was measured, and the tail was painted to evaluate estrous expression. On D9, the largest follicle was remeasured, and TAI was performed. Animals that were not detected in oestrous at the time of AI were administered 10.5 μg of GnRH i.m. Numerical data were analysed using the Mann-Whitney U test. Binary data were analysed using the Fisher’s exact test (5%). BCS, both at the beginning of pre-synchronisation (p = 0.45) and TAI protocol initiation (p = 0.20), and AFC (p = 0.36) did not differ between control and Pre-sync groups. The diameter of the largest follicle was similar between the control and Pre-sync groups on D-10 (p = 0.32), D0 (p = 0.33), D7 (p = 0.29) and D9 (p = 0.22). On D7 of the protocol, the Pre-sync group had a higher percentage of CL visible on transrectal ultrasonography (84.0%; p = 0.02) than the control group (54.5%); however, the expression during oestrous did not differ between groups (p = 0.59). The pregnancy rate was similar (p = 0.64) between groups and was not influenced by the CL rate on D7 (p = 0.48), oestrous expression (p = 0.20) or their interaction (p > 0.1). Pre-synchronisation effectively increased the proportion of cows with CL on D7 without altering the diameter of the largest follicle, oestrous expression or pregnancy rate in anoestrous cows treated with a GnRH/P4-based TAI protocol.
PMID:39548767 | DOI:10.1111/rda.14745
Characterizing pregnancy losses in lactating Holstein cows receiving a fixed-timed artificial insemination protocol
Anim Reprod Sci. 2025 Jan;272:107644. doi: 10.1016/j.anireprosci.2024.107644. Epub 2024 Nov 13.
ABSTRACT
This experiment assessed pregnancy losses from day 31 of gestation to calving in lactating Holstein cows reared in tropical conditions, and evaluated if serum concentrations of haptoglobin and pregnancy-associated glycoproteins (PAGs) during early gestation differs according to pregnancy losses. Cows (708 primiparous and 844 multiparous) were assigned to an ovulation synchronization + fixed-time artificial insemination (FTAI) protocol (day -11-0 of the experiment). Pregnancy status was verified using transrectal ultrasonography on days 31, 62, 120, and according to calf birth. Blood samples were collected from all cows on day 24, and from cows diagnosed as pregnant on day 31. Pregnancy losses were greater (P < 0.01) from day 31-62 (12.8 %) and day 120 to calving (12.1 %) compared with day 62-120 (6.42 %). Pregnancy losses were greater in multiparous compared with primiparous cows from day 31-62 (17.1 vs. 9.5 %) and from 120 to calving (15.4 vs. 7.7 %). Serum PAGs concentrations on day 31 were less (P ≤ 0.03) in cows that lost the pregnancy from day 31-62 (3.57 ng/mL) and from day 62-120 (4.40 ng/mL) compared to cows that maintained the pregnancy (5.57 and 5.66 ng/mL, respectively). Cows that experienced pregnancy loss from day 31-62 had greater (P = 0.05) serum haptoglobin concentrations on day 24 (0.414 mg/mL) compared with cows that maintained the pregnancy (0.271 mg/mL). Collectively, this experiment provides novel information about pregnancy losses after day 31 of gestation in lactating Holstein cows reared in tropical environments.
PMID:39549490 | DOI:10.1016/j.anireprosci.2024.107644
Curcuma longa essential oil as an acaricidal agent for the control of cattle ectoparasitic tick – Rhipicephalus (Boophilus) annulatus
Sci Rep. 2024 Nov 15;14(1):28138. doi: 10.1038/s41598-024-78716-5.
ABSTRACT
well known for its insecticidal, anti-inflammatory, antioxidant, anticancer, anti-rheumatic and antibiotic properties, Turmeric (Curcuma longa L.) Essential oil (EO), is effective in repelling and controlling many different pest species. The present study evaluates in vitro efficacy of turmeric EO against ectoparasitic tick, Rhipicephalus (Boophilus)annulatus collected from their natural host, domesticated cows. Repellency and toxicity of the EO on ectoparasitic ticks was analyzed with petri dish choice bioassay and AIT (Adult immersion test) against adult engorged females and nymphal stages of ticks. The Repellency Concentration (RC₅₀) and Lethal Concentration (LC₅₀) reproductive index, inhibition of oviposition and egg hatchability of treated ticks were estimated. GC-MS analysis identified Ar-turmerone as the major phytochemical, which induces adulticidal and repellant properties of EO. The nymphal stages of the ticks exhibited greater repellency on application of EO than the adult stage. Also, EO induced effective mortality in adult ticks. Further, this lethal concentration is capable of producing a decreased output in reproductive parameters namely, fecundity, % of oviposition and egg hatchability in surviving ticks thereby considerably reducing Rhipicephalus (Boophilus) R(B). annulatus population on its host. This study reveals the potency C. longa EO to be used as an effective pest control agent against R (B). annulatus infestation that can serve as an alternative to synthetic pesticides.
PMID:39548158 | PMC:PMC11568328 | DOI:10.1038/s41598-024-78716-5
Milk production and composition in warm-climate regions: a systematic review and meta-analysis
Trop Anim Health Prod. 2024 Nov 14;56(8):382. doi: 10.1007/s11250-024-04214-5.
ABSTRACT
Milk production is a key component of the agriculture sector in the tropics and subtropics, contributing 47.32% to global milk production. This study aimed to quantify milk production and composition (fat and protein) in warm-climate regions located between 30 degrees north and south of the equator. A meta-analysis was conducted using the standardized mean (SM) for milk production, fat percentage, and protein percentage, all adjusted for dry matter intake (DMI), focusing on lactating ruminants. A total of 42, 11, 15, and 16 research papers were selected for cows, buffalo, sheep, and goats, respectively, encompassing 2421 animal records from experiments published between 1992 and 2024. The SM for milk production was 10.38, 9.77, 0.79, and 1.13 kg/day/animal for cows, buffalo, sheep, and goats, respectively. Due to the significant variance between different cow breeds, the study divided the cows into three main groups based on breed type crossbreds, foreign, and local breeds. The SM for milk production per animal was 11.49 kg/day for crossbreds, 22.95 kg/day for foreign breeds, and 7.13 kg/day for local breeds. The effect of DMI on the SM of milk production for cows, sheep, and goats was highly significant. For milk fat, the SM was 3.95, 6.64, 4.70, and 3.56% for cows, buffalo, sheep, and goats, respectively. Regarding milk protein, the SM was 3.36, 3.91, 4.34, and 3.45% for cows, buffalo, sheep, and goats, respectively. The results of this meta-analysis highlight that warm-climate regions are significant contributors to global dairy production. Furthermore, improving ruminant milk production and quality in hot climates need further efforts.
PMID:39541054 | PMC:PMC11564219 | DOI:10.1007/s11250-024-04214-5
Influence of herbal supplementation on nutrient digestibility, blood biomarkers, milk yield, and quality in tropical crossbred cows
PLoS One. 2024 Nov 14;19(11):e0313419. doi: 10.1371/journal.pone.0313419. eCollection 2024.
ABSTRACT
Herbal supplements containing diverse phytochemicals have been proven to improve digestibility, beneficial serum metabolites, milk yield, and quality in cows. However, the temperature sensitivity of phytochemicals in herbs complicates their practical use as livestock supplements. In response, this study aimed to assess how shade-dried plantain, lemongrass, and their combination influence cow performance, digestibility, serum and milk antioxidants, and milk fatty acids. Forty multiparous mid-lactating Holstein-tropical crossbred cows were randomly assigned to four groups (n = 10) for 63 days in a completely randomized design with covariates adjustment. The control group received a basal diet (14.9% crude protein, 11.0 MJ metabolizable energy/kg dry matter (DM)) without herbs. The herbs-supplemented groups received shade-dried powder (per cow/day) of either 100 g plantain (plantain), 100 g lemongrass (lemongrass), or 50 g each of plantain and lemongrass (combined), along with the basal diet. Compared with the control, the plantain or lemongrass group presented improved performance, i.e., DM consumption (3-4%), milk (10-11%) and its components yield (p ≤ 0.05). Similar to the control, the combined group had no effect on performance or digestibility, whereas the digestibility of all nutrients in the plantain or lemongrass group substantially increased. Herbs-supplementation reduced serum bad-cholesterol and urea-nitrogen while increasing good-cholesterol and albumin compared with the control (p < 0.01). Notably, 4-8% serum and 8-23% milk antioxidants were greater in the herbs-supplemented groups than the control, while the lemongrass had the optimum milk β-carotene. Substantially, herbs-supplementation resulted in a 6-10% higher unsaturated fatty acids (USFAs), whereas the combined group presented a 3.56-fold greater n-3 fatty acids than the control. Significantly, the plantain or lemongrass group presented better benefit‒cost‒ratio than the combined and control. Therefore, shade-dried herbs-supplementation improved the beneficial serum metabolites, serum and milk antioxidants, and milk USFAs in cows. Additionally, shade-dried plantain or lemongrass enhanced cow DM consumption, digestibility, milk yield, and profitability.
PMID:39541370 | PMC:PMC11563391 | DOI:10.1371/journal.pone.0313419
Compatibility of dry incubator on in vitro production of bovine embryos
Theriogenology. 2025 Jan 15;232:117-123. doi: 10.1016/j.theriogenology.2024.11.005. Epub 2024 Nov 7.
ABSTRACT
Embryo culture is crucial to achieve successful outcomes in in vitro production-embryo transfer for cattle. This study explored the innovative use of dry incubators for bovine embryo culture, building on their advantages in human medicine, such as reduced contamination risk, stable temperature control, and lower gas consumption. In this study, we examined changes in osmotic pressure, the in vitro developmental potential of IVP embryos including the cleavage rate, blastocyst development rate, blastocyst diameter, and blastocyst cell number, morphokinetics, and the transcriptional profile of the blastocysts between humidified and dry incubators. Our research demonstrates the feasibility of this approach, showing that although the osmotic pressure gradually increases over the culture period (on day 8: 271.7 vs. 299.0, respectively; P = 0.09), it did not negatively affect the blastocyst formation rate (62.4 % vs. 69.8 %) and the morphological quality of blastocysts (diameter: 237.4 vs. 242.8, total cell number: 189.2 vs. 242.8). Embryos cultured in dry incubators exhibited morphokinetics comparable to those cultured in conventional humidified incubators. Furthermore, RNA-seq revealed that while a few genes showed changes, the transcriptomic profiles of blastocysts cultured in dry incubators were largely similar to those of blastocysts cultured in humidified incubators. These findings highlight the considerable potential of dry incubators for the in vitro production of bovine embryos.
PMID:39541606 | DOI:10.1016/j.theriogenology.2024.11.005
Incidence of puerperal metritis and associated risk factors in dairy cows in Hawassa, Southern Ethiopia
Res Vet Sci. 2024 Dec;181:105447. doi: 10.1016/j.rvsc.2024.105447. Epub 2024 Nov 7.
ABSTRACT
Metritis has considerable economic impact on dairy herd profitability due largely to reduced reproductive performance. Studies in Ethiopia only report prevalence, with no available data on the incidence of metritis. The present prospective cohort study aimed to estimate the incidence of puerperal metritis, identify risk factors, and isolate the causative bacteria in dairy cows in Hawassa. Daily follow-up of 120 dairy cows from parturition to 21 days postpartum was carried out from November 2019 to February 2021. Of these, 21 developed puerperal metritis with an incidence rate of 0.94 cases per 100 cow days at risk (95 % CI: 0.6-1.4). The cumulative incidence was found to be 17.5 % (95 % CI: 11.8-25.6). Over 90 % of the puerperal metritis occurred within the first 10 days of parturition. The mean day of occurrence of puerperal metritis was 7.7 days postpartum and the mean rectal temperature in metritic cows was 40.5 °C. Retained fetal membranes (RFM) (p < 0.001) emerged as the only predisposing factor for metritis in the final Cox regression model. Cows with RFM faced a 14.9 times higher risk of metritis compared to cows without RFM. A total of 52 bacterial isolates, belonging to 4 genera, were recovered from the aerobic culture of 21 uterine swab samples. E. coli and Staphylococcus spp. were the most frequently isolated bacteria, with recovery from 21 (100 %) and 20 (95.2 %) of the metritic uteri, respectively. Results of this study suggested the importance of reducing incidence of RFM to reduce incidence of metritis in dairy cows.
PMID:39541874 | DOI:10.1016/j.rvsc.2024.105447
Intergenerational effects of maternal rate of body weight gain on the multi-omics hepatic profiles of bovine fetuses
Gene. 2025 Feb 5;936:149082. doi: 10.1016/j.gene.2024.149082. Epub 2024 Nov 12.
ABSTRACT
Maternal periconceptual nutrition affects the growth trajectory of developing fetuses by modulating gene expression. The regulatory mechanisms and their role in fetal development remain underexplored in livestock models. Herein, we investigated the effects of maternal rate of body weight (BW) gain during early gestation on the DNA methylation, microRNA profiles, and their interaction with the hepatic gene expression in female fetuses. At breeding, 36 crossbred beef heifers (∼13 months of age) were randomly assigned to a nutritional plane to gain Low (0.28 kg/day; LG, n = 18) or Moderate (0.79 kg/day; MG, n = 18) BW through the first 83 days of gestation. A subset of pregnant heifers (n = 17) was selected, and fetal liver samples were collected on day 83 of gestation for DNA methylation and miRNA-Sequencing. After data quality control, miRDeep2 and Bismark tools were used to analyze miRNA and methylation data, respectively. The bta-miR-206 was the only differentially expressed miRNA (FDR = 0.02). Eight differentially methylated genes were identified (DMGs, FDR < 0.1). The over-represented pathways and biological processes (adj. p < 0.05) for bta-miR-206 targeted genes were associated with embryonic development, energy metabolism, and mineral transport, whereas the DMGs regulated anatomical structural development and transcriptional regulation. Our results show that key genes involved with liver metabolism, tissue structure, and function were regulated by DNA methylation and the miR-206. However, further investigation is warranted to determine physiological responses and long-term consequences on animal performance.
PMID:39536959 | DOI:10.1016/j.gene.2024.149082
Estimation of genetic and non-genetic effects on productive life of Iranian Holstein dairy cows
Anim Sci J. 2024 Jan-Dec;95(1):e70010. doi: 10.1111/asj.70010.
ABSTRACT
Understanding the factors that influence the lifespan of dairy cows is crucial for enhancing their productive life (PL). This study aimed to investigate the impact of genetic and environmental effects on the PL of Holstein cows. Data included 82,505 cows from 1952 sires that calved for the first time between 2001 and 2016. PL was defined from first calving to culling. Proportional hazard models, assuming a piecewise Weibull distribution of the baseline hazard function, were utilized to account for time-dependent effects, such as herd size variations, year-season, milk yield, fat and protein contents, and the time-independent fixed effect of age at first calving. Herd-year and sire effects were considered as random effects. All effects showed significant associations with PL (p < 0.001). The relative risk of culling was higher in heifers that calved at an older age and cows that calved during the cold season. Moreover, cows with lower production had a significantly shorter PL compared with high-producing cows. The effective heritability in the absence of censored data was estimated at 0.15. These findings suggest that greater attention should be paid to regular and accurate breeding programs, which are essential for enhancing profitability and the PL of Iranian dairy cows.
PMID:39537574 | DOI:10.1111/asj.70010

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