Dairy cow mastitis is a common and prevalent disease arose by various complicated pathogeny, which poses serious threat to the health of cows, safety of dairy product and economic benefits for pastures. Due to the high stealthiness and long incubation period, subclinical mastitis (SM) of cows causes enormous economic losses. Besides the infection by exogenous pathogenic microorganisms, previous studies demonstrated that gastrointestinal microbial dysbiosis is one of the crucial causes for occurrence and development of mastitis based on the theory of entero-mammary axis. Whereas, limited researches have been conducted on potential pathological metabolic mechanisms underlying the relationship between gut microbiota and SM in cows. The differences in blood parameters, gut microbiome, plasma and fecal metabolome between healthy and SM cows were compared by performing 16 S rDNA sequencing and non-targeted metabolomic analysis in the current study. The content of total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and activity of catalase (CAT), total antioxidant capacity(T-AOC) were significantly decreased, while malondialdehyde (MDA) concentration was dramatically increased in serum of SM cows in comparison with healthy cows. The gut of cows with SM harbored more abundant Cyanobacteria, Proteobacteria, Succinivibrio and Lactobacillus_iners. Moreover, the abundance of Paraprevotella, Coprococcus, Succiniclasticum, Desulfovibrio and Bifidobacterium_pseudolongum were observably reduced in the gut of SM cows. Furthermore, higher abundance of pro-inflammatory metabolites were observed in feces (9(S)-HPODE, 25-hydroxycholesterol, dodecanedioic acid, etc.) and plasma (9-hydroxy-10,12-octadecadienoic acid, 13,14-dihydro PGF1α, 5,6-dehydro arachidonic acid, myristic acid, histamine, etc.) of SM cows. The abundance of certain metabolites with anti-inflammatory and antioxidant properties (mandelic acid, gamma-tocotrienol, deoxycholic acid, etc.) were notably decreased in feces or plasma of cows with SM. The intestinal microbial composition and metabolic profiles of healthy and SM cows were significantly distinct, that were characterized by decreased abundance of intestinal symbiotic bacteria, potential probiotics and anti-inflammatory, antioxidant compounds, along with increased abundance of potential pro-inflammatory bacteria, lipid metabolites, and the occurrence of oxidative stress in cows suffered from SM. The results of this study further enriched our understanding of the correlations between gut microbiota and metabolic profiles and SM, which provided insight into the formulation of management strategies for SM in cows.

Hematology RIs help clinicians and researchers determine whether a hematology parameter is abnormal, which plays an important role in animal health surveillance. China is one of the largest dairy producers in the world, with millions of Holstein cows. However, there has been no published data on hematology RIs for dairy cows in China yet. Therefore, the aim of this study is to establish updated and accurate RIs for Holstein cows in southern China. To increase the accuracy of the RIs, we collected blood samples from 786 Holstein cows and analyzed 25 hematologic variables. The RIs for Holstein cows were established using the 95% percentile RIs according to the American Society of Veterinary Clinical Pathology guidelines. The effects of different ages, parities and lactation stages were also checked in this study. The data of 21, 22 and 19 out of 25 hematology parameters were significantly different between different ages, parities and lactation stages, respectively. Furthermore, the hematology RIs of separate subclasses according to different ages, parities and lactation stages were generated. Hematology RIs according to ages and lactation stages, as well as parities and lactation stages, were also assessed. Together, our results confirm that hematology RIs for cows vary by ages, parities and lactation stages. The present study helps to fill the gap in hematology RIs for Holstein cows in southern China, and our data may serve as a very useful tool for monitoring the health and welfare of dairy cattle in China.

This investigation provides a comprehensive analysis of genomic diversity and selection signatures in Zaobei beef cattle, an indigenous breed known for its adaptation to hot and humid climates and superior meat quality. Whole-genome resequencing was conducted on 23 Zaobei cattle, compared with 46 Simmental cattle to highlight genetic distinctions. Population structure analysis confirmed the genetic uniqueness of Zaobei cattle. Using methods such as DASDC v1.01, XPEHH, and θπ ratio, we identified 230, 232, and 221 genes through DASDC, including hard sweeps, soft sweeps, and linkage sweeps, respectively. Coincidentally, 109 genes were identified when using XPEHH and θπ ratio methods. Together, these analyses revealed eight positive selection genes (ARHGAP15, ZNF618, USH2A, PDZRN4, SPATA6, ROR2, KCNIP3, and VWA3B), which are linked to critical traits such as heat stress adaptation, fertility, and meat quality. Moreover, functional enrichment analyses showed pathways related to autophagy, immune response, energy metabolism, and muscle development. The comprehensive genomic insights gained from this study provide valuable knowledge for breeding programs aimed at enhancing the beneficial traits in Zaobei cattle.

Hubei indigenous cattle have adapted to diverse environmental conditions, exhibiting unique genetic traits associated with both economic and adaptive characteristics. Understanding their adaptive selection offers insight into their evolutionary history and genetic enhancements. In this study, we analyzed whole-genome sequencing (WGS) data from five Hubei indigenous cattle breeds to identify selection signals. Selective sweep analysis revealed the candidate genes (USH2A, TMTC2, ABCC12, and SUGT1) associated with sensory perception, backfat thickness, reproduction, and immune function. The further integration of cis-regulatory elements (CREs) and expression quantitative trait loci (eQTL) highlighted regulatory variants, influencing adaptive traits. Notably, positively selected genes such as RPS6KA2, CRLS1, MGST3, GPCPD1, and LDLRAP1 were associated with lipid metabolism, meat quality, and reproductive traits, influencing aldehyde volatile organic compounds (VOCs) and fat deposition. These findings highlight the understanding of the genetic basis of adaptation and production traits in Hubei indigenous cattle and provide valuable insights for their conservation and potential breeding strategies.

The genetic diversity of cattle plays a crucial role in adapting to environmental challenges and enhancing production traits. While research has predominantly focused on single nucleotide polymorphisms (SNPs), small indel and structural variants (SVs) also significantly contribute to genetic variation. This study investigates the distribution and functional impact of insertions and deletions in five Hubei indigenous cattle breeds. A total of 3,208,816 deletions and 2,082,604 insertions were identified, with the majority found in intergenic and intronic regions. Hotspot regions enriched in immune-related genes were identified, underscoring the role of these variants in disease resistance and environmental adaptation. Our analysis revealed a strong influence of transposable elements (TEs), particularly LINEs and SINEs, on genomic rearrangements. The variants were also found to overlap with economically important traits, such as meat quality, reproduction, and immune response. Population structure analysis revealed genetic differentiation among the breeds, with Wuling cattle showing the highest differentiation. Notably, the NOTCH2 gene was identified as a candidate for regional adaptation due to its significant differentiation across populations. These findings provide valuable genomic resources for enhancing breeding programs, aiming at improving the productivity and resilience of indigenous cattle breeds in China.

Lysophosphatidic acid (LPA) is a small bioactive phospholipid which plays an important role during embryonic development and promotes developmental potential of in-vitro-produced (IVP) embryos in several species, including sheep and pigs. In bovines, LPA accelerates IVP blastocyst formation through the Hippo/YAP pathway. However, other LPA effects and its potential receptors during bovine embryo development are less clear. In this study, we used enzyme-linked immunosorbent assay (ELISA) to assess the presence of LPA in bovine oviductal fluid and determine cell apoptosis in embryos after LPA stimulation by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay and quantitative reverse transcription polymerase chain reaction (qRT-PCR). We further evaluated potential receptors of LPA through molecular docking, RNA-seq data analysis and quantitative RT-PCR. LPA was found to be present in oviductal fluid. An increase in total cell number and a decrease in apoptosis levels were detected in day 7 blastocysts after LPA treatment. Among eight LPA receptors (LPARs), GPR87 and LPAR2 showed the highest affinity with LPA and their transcripts were expressed in embryos after the 16-cell stage in RNA-seq and qRT-PCR analysis. However, only the expression of LPAR2 was significantly increased in day 6 blastocysts after LPA stimulation, indicating its potential role in LPA-mediated signaling pathways. Our data highlight the positive effects of LPA on embryos and enrich information of related signaling mediators of LPA during embryonic development.