Estimation of Genetic, Phenotypic and Environmental Trends in Various Production and Reproduction Traits of Tharparkar Cattle at Organized Farm at Bikaner

A total of 284 performance records belonging to 63 Tharparkar cows in at least three lactations or more spread over a period of fifteen years (2002 to 2016) were utilized to estimate the trends in various traits. The estimates of phenotypic trends for AFC, SP, CI, DP, LL, LMY, MYPD and MYCI were-11.054±9.41 days/year (0.70% of HA), 0.841±0.42 days/year (0.61% of HA), 2.061±1.04 days/year (0.496% of HA), 1.682±1.04 days/year (1.21% of HA), 2.70±2.31 days/year (0.95% of HA), 19.42±7.21 kg/year (0.96% of HA), 0.033±0.07kg (0.60% of HA) and 0.023±0.03kg (0.55% of HA), respectively. Phenotypic trend was observed positive and significant (P≤0·05) for calving interval, service period and lactation milk yield. Age at first calving and service period shown increase genetic trend in present study. Comparison of methods of estimation of genetic trend showed that the BLUP method should be used for estimation of genetic trends of economic traits as this method has lower magnitude of standard error in comparison to other methods. 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.