Читать книгу Bovine Reproduction - Группа авторов - Страница 363

Two of the major factors that influence reproductive efficiency and hence profitability due to greater lifetime production in cattle are age at puberty and postpartum anestrous interval. Heifers that have an earlier age at puberty generally have greater lifetime productivity. Age at puberty is moderately heritable, so selection over multiple generations should reduce the number of days to puberty. We now have the technology to evaluate genetic markers for age at puberty in cattle. For example, quantitative trait loci have been identified that predict male reproductive traits including age at puberty in cattle [47]. Similarly, random amplified polymorphic DNA markers have been used for identifying Nelore bulls with early (precocious) or late (non‐precocious) puberty [48]. In heifers, an association weight matrix (AWM) has been constructed based on 22 related traits with single nucleotide polymorphisms [49]. The AWM results recapitulated the known biology of puberty, captured experimentally using validated binding sites, and identified candidate genes and gene–gene interactions for further investigation. Takada et al. [50] evaluated Nelore heifers to detect known polymorphisms in candidate genes related to sexual precocity and identified five genes that influence sexual precocity. Advances in genomic technologies will likely provide a powerful tool for selecting heifers at birth that will have a greater probability of being reproductively successful if managed correctly [51].