Verification of the determinants of production ability and the artificial control of the IGF-1 related to the future lactation and reproduction in female calf

本研究旨在探讨基因型和/或饲养管理对奶牛胰岛素样生长因子-1 （IGF-1）产生能力的影响，IGF-1与奶牛产奶量和生殖功能有关。对于基因型，我们证实了生长激素受体（GHR）的一个单核苷酸多态性（SNP）与激素注射后血液IGF-1水平的升高率之间的关系。此外，GHR-SNP类型与产奶量和初产犊后能量状态有关。另一方面，在饲养管理方面，犊牛饲粮中添加精耕细作代乳剂可导致犊牛血液中IGF-1水平升高；然而，注射激素后血液IGF-1水平的增加率在强化和常规母乳替代品之间没有差异。总之，我们的研究表明，奶牛的IGF-1生产能力受到GHR-SNP的影响。

The aim of the present study was to investigate the effect of genotype and/or feeding management on the ability of insulin-like growth factor-I (IGF-1) production related to milk production and reproductive function in dairy cows.For genotype, we confirmed the relationship between one of the single nucleotide polymorphisms (SNP) of growth hormone receptor (GHR) and the increasing rate of blood IGF-1 level after hormonal injection. In addition, GHR-SNP type was related to milk yield and energy status after first calving. On the other hand, for feeding management, the supply of the intensive milk replacer for calves induced higher blood IGF-1 level; however, the increasing rate of blood IGF-1 level after hormonal injection did not differ between intensive and conventional milk replacer. Overall, our study showed that the ability of IGF-1 production was influenced by GHR-SNP in dairy cows.