To speed up the progress of marker-assisted selection (MAS) in cattle breeding, kinesin family member 1A (KIF1A) genes were chosen based on our previous genome-wide association study (GWAS) analysis results. We detected insertion/deletion (InDel) variation in these three candidate genes in 438 individual cattle (Xinjiang Brown cattle and Wagyu × Luxi crossbreed cattle). These findings may aid future analyses of InDel genotypes in cattle breeds and speed up the progress of MAS in cattle breeding.

The aim of this study was to evaluate the influence of body weight on the efficiency of dairy cows. Data were derived from 161 commercial Austrian dairy farms. An optimum body weight range for efficiency does exist as the relationship of milk yield and body weight is nonlinear. Specialized dairy breeds seem to respond more intensively to body weight range than dual-purpose breeds. Cows with medium weights are the most efficient. A further increase in dairy cows’ body weights should be avoided.

The lactation curve and lactation survival are important in dairy cattle breeding. Their simultaneous improvement results in economic benefits. The genetic relationship between the lactation survival and the lactation curve shape traits of milk yield and fat and protein percentages using information from of 25 981 primiparous Tunisian Holsteins was investigated. Cows that had higher persistencies for fat and protein percentages were more likely not to survive.

The aims of the study were to estimate allele and genotype frequencies at g.-274C > G locus in the promoter region of the SIRT1 gene and to investigate, for the first time, the relationship among different genotypes and milk and reproduction traits in the Agerolese cattle breed. The investigated population was found to be polymorphic at the investigated locus. Concerning milk production performance, significant differences between genotypes were found.