BACKGROUND: The maternal-offspring relationship, such as whether fetal sex influences maternal health, is essential to explore to advance prenatal and maternal health. While associations exist between fetal sex and maternal health outcomes, it is unclear whether these reflect a causal relationship.
OBJECTIVE: To demonstrate that fetal sex can be randomly assigned to test the causal effect of fetal sex on maternal outcomes.
METHODS: Holstein dairy cows were stratified and randomized using sealed opaque envelopes to be artificially inseminated with either X- or Y-sorted bull semen until 40 cows became pregnant. Monthly body weight measurements were recorded, and an intravenous glucose tolerance test was performed 30 days before the expected calving day. The primary outcome was insulin area under the curve (AUC), and secondary outcomes were clearance rate, half-life, and AUC for glucose, insulin, and non-esterified fatty acid concentrations. An intention-to-treat (ITT) approach using multiple imputation was employed for primary analysis, and an as-treated (AT) approach was used for secondary analysis.
RESULTS: We demonstrated that we could successfully randomize the assignment of fetal sex to dams and test for causal effects of fetal sex on glucoregulatory outcomes using dairy cows as a model. Insulin AUC was not statistically different between groups (ITT p = 0.857, AT p = 0.874), and other outcomes were also not statistically different (p > 0.05).
CONCLUSIONS: We demonstrated that causal effects of fetal sex on maternal outcomes can be causally tested in dairy cows. Our study did not provide statistical evidence to support an effect of fetal sex on maternal glucose-related outcomes.

Mastitis, a serious threat to the health and milk production function of dairy cows decreases milk quality. Blood from three healthy cows and three mastitis cows were collected in this study and their transcriptome was sequenced using the Illumina HiSeq platform. Differentially expressed genes (DEGs) were screened according to the |log2FoldChange| > 1 and P-value < 0.05 criteria. Pathway enrichment and functional annotation were performed through KEGG and GO analyses. Finally, the mechanism of the AMP-activated protein kinase (AMPK) mediation of (-)-epigallocatechin-3-gallate (EGCG) to promote lipid metabolism in mastitis cows was analyzed in bovine mammary epithelial cells (BMECs). Transcriptome analysis revealed a total of 825 DEGs, with 474 genes showing increased expression and 351 genes showing decreased expression. The KEGG analysis of DEGs revealed that they were mainly linked to tumour necrosis factor, nuclear factor-κB signalling pathway, and lipid metabolism-related signalling pathway, whereas GO functional annotation found that DEGs were enriched in threonine and methionine kinase activity, cellular metabolic processes, and cytoplasm. AMPK expression, which is involved in several lipid metabolism pathways, was downregulated in mastitis cows. The results of in vitro experiments showed that the inhibition of AMPK promoted the expression of lipid synthesis genes in lipopolysaccharide-induced BMECs and that EGCG could promote lipid synthesis by decreasing the expression of AMPK and downregulating the expression of inflammatory factors in inflammatory BMECs. In conclusion, our study demonstrated that AMPK mediated EGCG to inhabit of inflammatory responses and promote of lipid synthesis in inflammatory BMECs.

This study aimed to reveal the morphological characteristics of pure Holstein and Simmental skulls and to obtain reference values for morphometric analysis. Moreover, 54 skulls from 12- to 14-month-old male Holstein (n = 25) and Simmental (n = 29) cattle were collected from Turkey\'s Southeastern Anatolia Region between 2023 and 2024. Linear measurements indicated that Holsteins had longer skulls compared to Simmentals. Holsteins exhibited significantly higher values for the greatest length of nasals and the shortest skull length. The facial breadth was wider in Holsteins and statistically distinctive between the breeds. Holsteins had a more oval orbital bony roof, while Simmentals exhibited a wider orbital structure. The orbital index was higher in Holsteins, distinguishing between the two breeds. It was observed that Simmental cattle had a wider occipital region. This difference is likely due to the larger lateral appearance of the Simmental skull, which has more body weight and provides a larger surface area for muscle attachment. These differences not only aid in breed identification but also offer insights into the functional adaptations of each breed. Future research should explore the genetic and environmental factors contributing to these morphological traits, further enriching our knowledge of cattle morphology and its implications for breeding and conservation efforts.

We investigated the thermostability of four European avian influenza A(H5N1) viruses in whole and semi-skimmed milk and their replication in bovine kidney and lung cells amid the current influenza A(H5N1) dairy cattle outbreak in the United States. Results showed strain-dependent differences in thermal inactivation, particularly in whole milk, and variable replication efficacy in lung cells. These findings support assessing the inactivation of European H5N1 viruses in milk and their replication in bovine cells, aiding biosafety protocols and public health measures.

BACKGROUND: We recently identified ~ 10,000 correlated regions of systemic interindividual epigenetic variation (CoRSIVs) in the human genome. These methylation variants are amenable to population studies, as DNA methylation measurements in blood provide information on epigenetic regulation throughout the body. Moreover, establishment of DNA methylation at human CoRSIVs is labile to periconceptional influences such as nutrition. Here, we analyze publicly available whole-genome bisulfite sequencing data on multiple tissues of each of two Holstein cows to determine whether CoRSIVs exist in cattle.
RESULTS: Focusing on genomic blocks with ≥ 5 CpGs and a systemic interindividual variation index of at least 20, our approach identifies 217 cattle CoRSIVs, a subset of which we independently validate by bisulfite pyrosequencing. Similar to human CoRSIVs, those in cattle are strongly associated with genetic variation. Also as in humans, we show that establishment of DNA methylation at cattle CoRSIVs is particularly sensitive to early embryonic environment, in the context of embryo culture during assisted reproduction.
CONCLUSIONS: Our data indicate that CoRSIVs exist in cattle, as in humans, suggesting these systemic epigenetic variants may be common to mammals in general. To the extent that individual epigenetic variation at cattle CoRSIVs affects phenotypic outcomes, assessment of CoRSIV methylation at birth may become an important tool for optimizing agriculturally important traits. Moreover, adjusting embryo culture conditions during assisted reproduction may provide opportunities to tailor agricultural outcomes by engineering CoRSIV methylation profiles.

The fertilization of oocytes ovulated by pigs, sheep, cows, and horses is not considered a limiting factor in successful establishment of pregnancy. Pig, sheep, and cow embryos undergo cleavage to the blastocyst stage, hatch from the zona pellucida, and undergo central-type implantation. Hatched blastocysts of pigs, sheep, and cows transition from tubular to long filamentous forms to establish surface area for exchange of nutrients and gases with the uterus. The equine blastocyst, surrounded by external membranes, does not elongate but migrates throughout the uterine lumen before attaching to the uterine luminal epithelium (LE) to begin implantation. Pregnancy recognition signaling in pigs requires the trophectoderm to express interleukin 1 beta, estrogens, prostaglandin E2, and interferon gamma. Sheep and cow conceptus trophectoderm expresses interferon tau that induces interferon regulatory factor 2 that inhibits transcription of estrogen and oxytocin receptors by uterine epithelia. This prevents oxytocin-induced luteolytic pulses of prostaglandin F2-alpha from regressing the corpora lutea, as well as ensuring the secretion of progesterone required for maintenance of pregnancy. The pregnancy recognition signal produced by equine blastocysts is not known. Implantation in these species requires interactions between extracellular matrix (ECM) proteins and integrins as the conceptus undergoes apposition and firm attachment to the uterine LE. This review provides details with respect to early embryonic development and the transition from spherical to filamentous conceptuses in pigs, sheep, and cows, as well as pre-implantation development of equine blastocysts and implantation of the conceptuses.

BACKGROUND: Fatty liver in dairy cows is a common metabolic disease defined by triglyceride (TG) buildup in the hepatocyte. Clinical diagnosis of fatty liver is usually done by liver biopsy, causing considerable economic losses in the dairy industry owing to the lack of more effective diagnostic methods. Therefore, this study aimed to investigate the potential utility of blood biomarkers for the diagnosis and early warning of fatty liver in dairy cows.
RESULTS: A total of twenty-four lactating cows within 28 days after parturition were randomly selected as experimental animals and divided into healthy cows (liver biopsy tested, n = 12) and cows with fatty liver (liver biopsy tested, n = 12). Inductively coupled plasma mass spectrometry (ICP-MS) was used to determine the macroelements and microelements in the serum of two groups of cows. Compared to healthy cows (C), concentrations of calcium (Ca), potassium (K), magnesium (Mg), strontium (Sr), selenium (Se), manganese (Mn), boron (B) and molybdenum (Mo) were lower and copper (Cu) was higher in fatty liver cows (F). Meanwhile, the observed differences in macroelements and microelements were related to delivery time, with the greatest major disparity between C and F occurring 7 days after delivery. Multivariable analysis was used to test the correlation between nine serum macroelements, microelements and fatty liver. Based on variable importance projection and receiver operating characteristic (ROC) curve analysis, minerals Ca, Se, K, B and Mo were screened as the best diagnostic indicators of fatty liver in postpartum cows.
CONCLUSIONS: Our data suggested that serum levels of Ca, K, Mg, Se, B, Mo, Mn, and Sr were lower in F than in C. The most suitable period for an early-warning identification of fatty liver in cows was 7 days after delivery, and Ca, Se, K, B and Mo were the best diagnostic indicators of fatty liver in postpartum cows.

To compare the impact of nanoselenium and sodium selenite on the performance, blood indices, and milk metabolites of dairy cows during the peak lactation period, two groups of dairy cows under the same conditions were selected as the control group (CON group) and treatment group (NSe group) for a 38-day (10 days for adaptation and 28 days for sampling) experiment. The control group (CON) was provided a basal diet +3.3 g/d of sodium selenite (purity1%), whereas the nanoselenium group (NSe) was offered the same diet +10 mL/d of nanoselenium (selenium concentration 1,500 mg/L). The results showed that NSe significantly increased the milk yield, milk selenium content, and feed efficiency (p < 0.05), but had no significant effect on other milk components (p > 0.05). NSe significantly increased blood urea nitrogen (BUN) and alkaline phosphatase (ALP) (p < 0.05), but had no significant effects on malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), blood total antioxidant capacity (T-AOC), or blood selenium (p > 0.05). In addition, the nontargeted metabolomics of the milk was determined by LC-MS technology, and the differentially abundant metabolites and their enrichment pathways were screened. According to these findings, NSe considerably increased the contents of cetylmannoside, undecylenoic acid, 3-hydroxypentadecanoic acid, 16-hydroxypentadecanoic acid, threonic acid, etc., but decreased the contents of galactaric acid, mesaconic acid, CDP-glucose etc. Furthermore, the enriched metabolic pathways that were screened with an impact value greater than 0.1 included metabolism of niacin and niacinamide, pyruvate, citrate cycle, riboflavin, glycerophospholipid, butanoate and tyrosine. Pearson correlation analysis also revealed a relationship between different milk metabolites and blood selenium, as well as between milk selenium and blood biochemical indices. In conclusion, compared with sodium selenite, nanoselenium improves the milk yield, feed efficiency, and milk selenium content of dairy cows and regulates milk metabolites and related metabolic pathways in Holstein dairy cows during the peak lactation period, which has certain application prospects in dairy production.

Here we report the case of a cow with two ovaries that each exhibited hyperplasia but that otherwise had normal gross morphology. Both ovaries had a large number of tertiary follicles on the ovarian surface. Oocytes from one ovary were studied in more detail. The transcriptome was largely similar to other oocytes. Oocytes could undergo cleavage at a rate consistent with other oocytes and result in blastocyst-stage embryo formation after in vitro maturation and fertilization. Review of the literature from cattle and other species did not reveal reports of a similar type of spontaneous ovarian abnormality. Whole genome sequencing revealed many single nucleotide polymorphisms with predicted large effects on protein structure that could potentially be causative for the phenotype. The variant considered most likely to cause the observed alteration in ovarian function was a mutation in the glycoprotein-modifying enzyme MAN1A2.

The cervix is an important organ that has to dilate sufficiently at delivery to allow the foetus to transition to extrauterine life. Insufficient dilatation of the cervix (IDC) is a frequent cause of dystocia in cattle. The mechanisms underlying cervical opening and the pathogenesis of IDC are still widely unclear. Systematic studies on the relationship between IDC and steroid hormones have been limited and have yielded inconsistent findings. This study aimed to measure oestrogen and progesterone (P4) concentrations in intrapartum cows presented with dystocia due to IDC and in a comparison (C) group of cows with eutocic delivery. Before any obstetrical procedures, and right after the initial evaluation, blood samples were taken from IDC and C animals. Concentrations of P4, oestradiol-17β (E2), free total oestrogens (FTE) and conjugated total oestrogens (CTE) were measured by established radioimmunoassays. Concentrations of P4 (p = .538), FTE (p = .065) and CTE (p = .605) were not statistically different between C and IDC groups. However, E2 levels in group C were significantly lower when compared to those in the IDC group (p = .013), which is inconsistent with the function of oestrogens in cervical dilatation. The correlation analysis demonstrated significant positive correlations between the pairs P4 versus FTE, P4 versus E2 and FTE versus E2 in group C and between the pair FTE versus E2 in group IDC. In conclusion, the results suggest that local activities of steroids relevant to the aetiology of IDC are not reflected by concentrations in the systemic circulation or that other factors are clearly more important.