Bohai Black cattle are one of the well-known cattle breeds with black coat color in China, which are cultivated for beef. However, no study has conducted a comprehensive analysis of genomic diversity and selective pressures in Bohai Black cattle. Here, we performed a comprehensive analysis of genomic variation in 10 Bohai Black cattle (five newly sequenced and five published) and the published whole-genome sequencing (WGS) data of 50 cattle representing five “core” cattle populations. The population structure analysis revealed that Bohai Black cattle harbored the ancestry with European taurine, Northeast Asian taurine, and Chinese indicine. The Bohai Black cattle demonstrated relatively high genomic diversity from the other cattle breeds, as indicated by the nucleotide diversity (pi), the expected heterozygosity (H_E) and the observed heterozygosity (H_O), the linkage disequilibrium (LD) decay, and runs of homozygosity (ROH). We identified 65 genes containing more than five non-synonymous SNPs (nsSNPs), and an enrichment analysis revealed the “ECM-receptor interaction” pathways associated with meat quality in Bohai Black cattle. Five methods (CLR, θπ, F_ST, θπ ratio, and XP-EHH) were used to find several pathways and genes carried selection signatures in Bohai Black cattle, including black coat color (MC1R), muscle development (ITGA9, ENAH, CAPG, ABI2, and ISLR), fat deposition (TBC1D1, CYB5R4, TUSC3, and EPS8), reproduction traits (SPIRE2, KHDRBS2, and FANCA), and immune system response (CD84, SLAMF1, SLAMF6, and CDK10). Taken together, our results provide a valuable resource for characterizing the uniqueness of Bohai Black cattle.

Oxidative stress can damage intestinal epithelial cell integrity and function, causing gastrointestinal disorders. Astragaloside IV (ASIV) exhibits a variety of biological and pharmacological properties, including anti-inflammatory and antioxidant effects. The purpose of this research was to investigate the cytoprotective action of ASIV and its mechanisms in calf small intestine epithelial cells with hydrogen peroxide (H₂O₂)-induced oxidative stress. ASIV pretreatment not only increased cell survival, but it also decreased reactive oxygen species generation and apoptosis, enhanced superoxide dismutase, catalase, and glutathione peroxidase levels, and it reduced malondialdehyde formation. Furthermore, pretreatment with ASIV elevated the mRNA and protein levels of nuclear factor erythroid 2-related factor 2 (NFE2L2), heme oxygenase-1 (HMOX1), and NAD(P)H quinone dehydrogenase 1 (NQO1). The NFE2L2 inhibitor ML385 inhibited NFE2L2 expression and then blocked HMOX1 and NQO1 expression. These results demonstrate that ASIV treatment effectively protects against H₂O₂-induced oxidative damage in calf small intestine epithelial cells through the activation of the NFE2L2-antioxidant response element signaling pathway.

In this study, we utilised palm kernel cake as a substrate and fermented it with a composite of bacteria (Pediococcus pentosaceus CGMCC No. 27203 and Lactobacillus plantarum CGMCC No. 27202) and enzymes. We conducted a trial with twenty-four cattle, randomly divided into two groups of twelve cattle each. The control group (CON) was fed the standard farm diet, whereas the treatment group (PKC) received a diet with 3% of soyabean replaced by fermented palm kernel cake. The trial lasted for six weeks. The results showed no significant differences in growth performance between the PKC and CON groups. The abundance of Firmicutes, Bacteroidetes, Proteobacteria, and Spirochaetes was significantly higher in the PKC group than in the CON group. At the genus level, the abundances of Anaeroplasma, norank_f__Bacteroidales_UCG-001, norank_f__Absconditabacteriales_SR1, norank_f__p-251-o5, Prevotellaceae_NK3B31_group, Prevotellaceae_UCG-001, Prevotellaceae_UCG-004, and Treponema significantly increased in the PKC group. Lipid digestion and absorption pathways were significantly enriched in the PKC group. The results indicate that adding fermented palm kernel cake to the diet can increase the abundance of Bacteroidetes and Fibrobacteres in the rumen of beef cattle, enhancing the ability of the PKC group to degrade protein, carbohydrates, and fibrous materials in the feed, thereby improving the feed utilisation efficiency in beef cattle. Adding fermented palm kernel cake to the diet improved carbohydrate metabolism, metabolism of cofactors and vitamins, and nucleotide metabolism. Correlation analysis between the rumen microbiota and metabolic pathways showed that Prevotellaceae_UCG-001 and Prevotellaceae_UCG-003 were positively correlated with amino acid metabolism, Rikenellaceae_RC9_gut_group and Succiniclasticum were positively correlated with metabolism of cofactors and vitamins, and Prevotella and Ruminococcus were positively correlated with nucleotide metabolism. These findings elucidate the differences in rumen microbiota when fermented palm kernel cake is added to the diet, providing a theoretical basis for the application of fermented palm kernel cake in the diet of beef cattle.

Platelet-derived growth factor D (PDGFD) is a member of the PDGF gene family, and it plays an important role in the regulation of adipocyte development in mammals. Furthermore, genome-wide association studies (GWAS) have previously identified it as a candidate gene associated with fleece fiber variation, body size, and the fat-tail phenotype in domestic Chinese sheep. In this study, a total of 1919 indigenous Chinese sheep were genotyped to examine the association between nucleotide sequence variations in PDGFD and body morphology. Our results detected both a 14 bp insertion in intron 2 and a 13 bp deletion in intron 4 of PDGFD. Moreover, these two InDel loci had low to moderate polymorphism. Notably, the 13 bp deletion mutation of PDGFD was found to significantly affect sheep body size. Yearling rams in the Luxi black-headed sheep (LXBH) containing a heterozygous genotype (insertion/deletion, ID) were found to have larger body length, chest depth, and body weight than those with wild genotypes. Furthermore, adult ewes in the Guiqian semi-fine wool sheep (GSFW) containing a homozygous mutation (deletion/deletion, DD) were found to have smaller chest width than their peers. Moreover, yearling ewes in this group with the same homozygous mutation were found to have lower body weight, chest width, and cannon circumference compared to those of other individuals. This study demonstrates that PDGFD InDel polymorphisms have the potential to be effective molecular markers to improve morphological traits in domestic Chinese sheep.