Abstract
The breeding data of 145 Sahiwal cattle spread over a period of 30 years (1987-2016) maintained at IDF, Nagla of GBPUA&T, Pantnagar (Uttarakhand). The study was conducted on least squares means, genetic and phenotypic parameters and genetic and phenotypic trends of first lactation production and reproduction traits. In Sahiwal, the estimates of genetic trends for FL305DMY, FLMY, FLL, AFC, FCI, FDP, FSP, FLMY/FLL and FLMY/FCI were 6.26±8.56 kg, 2.02±9.29 kg, -1.53±0.76 days, -3.24±3.36 days, 1.08±2.00 days, 2.57±1.90 days, 0.16±1.99 days, 0.02±0.02 kg and -0.009±0.02 kg, respectively. The estimates of phenotypic trends for these traits were 7.92±8.46 kg, 4.64±9.05 kg, -1.35±0.71 days, -2.20±2.00 days, -0.22±3.54 days, 1.14±2.03 days, -1.17±2.03 days, 0.04±0.02 kg and 0.01±0.002 kg, respectively. The genetic trends of first lactation 305 days milk yield were estimated to be 6.26 ± 8.56 kg/year. The genetic trends were found positive and statistically non-significant. The phenotypic trends were found as 7.92 ± 8.46 kg/year in Sahiwal. The phenotypic trend was found positive but statistically non significant. The environmental trends were found as 1.67 ± 1.40 kg/year. The environmental trend was found positive but statistically non-significant. For overall improvement in production, emphasis should be given to some reproductive traits like AFC and SP along with lactation milk yield while planning selection strategies.