Effect of Non-Genetic Factors on First Lactation Production and Reproduction Performance in Sahiwal Cattle

Abstract

Data on 880 first lactation records of Sahiwal cattle maintained at NDRI Karnal, spread over a period of 47 years (1961-2007) were used to study the effect of certain non-genetic factors viz. season and period on first lactation production and reproduction traits. The first lactation traits considered were age at first calving (AFC), first lactation 305-day or less milk yield (FL305DMY), first lactation length (FLL), first service period (FSP) and first calving interval (FCI). Among the non-genetic factors, the period had highly significant (P<0.01) effect on all the traits except FCI. The season had no significant effect on all the first lactation production and reproduction traits. The regression of AFC was highly significant on FL305DMY. The overall least squares means for AFC, FL305DMY, FLL, FSP and FCI were 1111.26 days, 1894.11 kg, 290.41 days, 134.02 days and 420.02 days, respectively. It was concluded that the first lactation traits were highly influenced by the period of birth/calving. However, variation in the seasons had no significant effect on these traits indicating the endurance of Sahiwal cattle to the hot tropical climatic conditions with respect to the above traits.