Ketosis is a common metabolic disorder in the early lactation of dairy cows. It is typically diagnosed by measuring the concentration of β-hydroxybutyrate (BHB) in the blood. This study aimed to estimate the genetic parameters of blood BHB and conducted a genome-wide association study (GWAS) based on the estimated breeding value. Phenotypic data were collected from December 2019 to August 2023, comprising blood BHB concentrations in 45,617 Holstein cows during the three weeks post-calving across seven dairy farms. Genotypic data were obtained using the Neogen Geneseek Genomic Profiler (GGP) Bovine 100 K SNP Chip and GGP Bovine SNP50 v3 (Illumina Inc., San Diego, CA, USA) for genotyping. The estimated heritability and repeatability values for blood BHB levels were 0.167 and 0.175, respectively. The GWAS result detected a total of ten genome-wide significant associations with blood BHB. Significant SNPs were distributed in Bos taurus autosomes (BTA) 2, 6, 9, 11, 13, and 23, with 48 annotated candidate genes. These potential genes included those associated with insulin regulation, such as INSIG2, and those linked to fatty acid metabolism, such as HADHB, HADHA, and PANK2. Enrichment analysis of the candidate genes for blood BHB revealed the molecular functions and biological processes involved in fatty acid and lipid metabolism in dairy cattle. The identification of novel genomic regions in this study contributes to the characterization of key genes and pathways that elucidate susceptibility to ketosis in dairy cattle.

This study aimed to investigate the flavor formation and meat quality differences among different beef cuts in Chinese Wagyu cattle. The metabolites and gene expression profiles of chuck, neck, rump, tenderloin, and longissimus lumborum cuts were analyzed. The results revealed that a total of 240 volatile organic compounds and 779 lipid molecules were detected among the beef cuts, with hydrocarbons (accounting for 29.71%) and triglycerides (representing 41.21%) emerging as the most prominent compounds, respectively. The sensory-directed analysis highlighted the significance of sweet and fruity aroma compounds, which contributed to the distinct aroma profiles among different beef cuts. Additionally, a total of 60 key lipid molecular markers, including FA(18:1), PC(40:5), TG(18:0_16:1_18:1), and TG(36:0_18:1), etc., were identified as playing crucial roles in the generation of essential lipid compounds across five different beef cuts. Integrative analysis of multi-omics data pinpointed a cluster of differentially expressed genes (e.g., DLD, ACADM, PCCA, SCD), which were involved in the regulation of valine, leucine, and isoleucine degradation pathways and lipid metabolism. Taken together, this study has identified key metabolites and candidate genes influencing meat quality across different beef cuts, providing a valuable resource for the molecular breeding of high-quality traits in beef cattle.

Various bovine species have been domesticated and bred for thousands of years, and they provide adequate animal-derived products, including meat, milk, and leather, to meet human requirements. Despite the review studies on economic traits in cattle, the genetic basis of traits has only been partially explained by phenotype and pedigree breeding methods, due to the complexity of genomic regulation during animal development and growth. With the advent of next-generation sequencing technology, genomics projects, such as the 1000 Bull Genomes Project, Functional Annotation of Animal Genomes project, and Bovine Pangenome Consortium, have advanced bovine genomic research. These large-scale genomics projects gave us a comprehensive concept, technology, and public resources. In this review, we summarize the genomics research progress of the main bovine species during the past decade, including cattle (Bos taurus), yak (Bos grunniens), water buffalo (Bubalus bubalis), zebu (Bos indicus), and gayal (Bos frontalis). We mainly discuss the development of genome sequencing and functional annotation, focusing on how genomic analysis reveals genetic variation and its impact on phenotypes in several bovine species.

To fill the gap in systematic data on mineral contents and their dietary contributions in four mainstream dairy products (sterilized, pasteurized, fermented, modified milk) from Henan Province, China, this study aimed to characterize the mineral profiles [magnesium (Mg), iron (Fe), zinc (Zn), selenium (Se), copper (Cu)] and clarify the mineral nutritional disparities between domestic and imported sterilized milk. A total of 150 samples were analysed via inductively coupled plasma mass spectrometry (ICP-MS). Results revealed significant mineral content differences across dairy types: fermented milk had significantly lower Mg and Zn than sterilized and pasteurized milk (p < 0.05). Imported sterilized milk exhibited higher Mg (160.10 ± 31.88 mg/kg) than domestic counterparts (147.41 ± 32.47 mg/kg, p < 0.05). In terms of mineral intake contribution rates (defined as the percentage of mineral intake from dairy products relative to the Recommended Nutrient Intake (RNI), unit: %), the rates are ranked in descending order as follows: Se (11.68–25.32%) > Mg (11.11–20.76%) > Zn (5.88–16.33%) > Cu (0.62–1.81%) > Fe (0.25–1.00%). This study elucidates the mineral profiles of Henan’s dairy products, supporting residents’ dairy choices and optimisation of dairy processing technologies.

Fatty acid composition is a complex trait governed by a polygenic architecture. Although numerous genetic variants associated with fatty acids have been id