Genetic and phenotypic parameters of first lactation traits in Sahiwal cows

The data was collected on first lactation traits of 1367 Sahiwal cows born to 112 sires spread over a period of 71 years from 1944 – 2014 maintained at Government Livestock Farm, Chakganjaria, Lucknow. The overall least squares mean of first lactation traits viz. age at first calving (AFC), first lactation period (FLP), first dry period (FDP), first calving interval (FCI) and first service period (FSP) were estimated to be 1287.12±6.81 days, 321.60±2.80 days, 195.57±4.07 days, 514.86±4.82 days and 231.34±4.88 days, respectively. The effect of season was found to have non-significant influence on all the first lactation traits except first lactation period. The Sire and periods of calving were found to have significant influence on all first lactation traits. The heritability estimates of age at first calving, first lactation length, first dry period, first calving interval and first service period were: 0.39 ± 0.16, 0.27 ± 0.08, 0.06 ± 0.10, 0.10 ± 0.10 and 0.15 ± 0.10, respectively.