Comparison of genetic parameters of first lactation 305 day milk yield using single versus multi-trait animal models in Murrah buffaloes

摘要

First lactation records of439 Murrah buffaloes, sired by 50 bulls on production traits viz. first lactation 305-day or less milk yield (FL305MY), first lactation length (FLL) and reproduction traits like age at first calving (AFC), first calving interval (FCI) and first service period (FSP) were used to compare the heritability estimates of FL305MY under single-trait animal model (ST-AM) versus multi-trait animal models (MT-AM) in Murrah buffaloes. The heritability estimate of FL305MY was 0.245±0.012 under single-trait animal model. Under two-trait models, the heritability estimate was found to be highest in FL305MY with AFC as covariate combination as 0.329±0.079. Under three-trait models, the heritability estimate was highest (0.235±0.089) in FL305MY, FLL and FSP combination. Comparison of heritability estimates of FL305MY from different models revealed that the estimates were varying from single to multiple traits in different combinations. The lower residual variances (211060 and 240410) andhigher heritability (0.329±0.08 and 0.245±0.089) of two-trait (FL305MY with AFC as covariate) and three-trait (FL305MY, FLL and FSP) combinations indicated that these combinations should be used for selection of Murrah buffaloes.