tailieunhanh - Effect of genetic and non-genetic factors on first lactation production and reproduction traits in HF × Gir Cattle

HF × Gir cattle, Genetic parameter, First lactation traits The present investigation was carried out with the objective of performance appraisal of HF × Gir cattle with respect to production and reproduction traits. The performance records of 421 HF × Gir half breed cattle sired by 48 bulls were collected for production and reproduction traits spread over a period of 39 years (1977 to 2015) from ResearchCum Development Project on Cattle, Mahatma Phule Krishi Vidyapeeth, Rahuri District Ahmednagar (Maharashtra). The overall least squares means for first lactation total milk yield (FLTMY), first lactation 300 days milk yield, first lactation length (FLL), First dry period (FDP), First service period (FSP), First calving interval (FCI) and Age at first calving were ±, ±, ± , ±, ±, ± and ± days, respectively. Further, the least squares analysis revealed non significant effect of season of calving and age at first calving groups on all first lactation reproduction and milk production traits. Whereas, the effect of period of calving was found to be highly significant on FLTMY, FL300DMY and AFC and nonsignificant on FLL, FDP, FSP and FCI. However, the effect of sire was found to be significant on FLTMY, FL300DMY and AFC. The heritability of all traits except FCI and FSP were moderate in magnitude which indicated these traits are more influenced by additive genetic variability and hence there is more scope for improvement by selection. The highly significant genetic and phenotypic correlation was found between production and reproduction traits. | Effect of genetic and non-genetic factors on first lactation production and reproduction traits in HF × Gir Cattle