PHENOTYPIC, GENETIC AND ENVIRONMENTAL TRENDS IN MILK YIELD AND MILK PRODUCTION EFFICIENCY TRAITS IN KARAN FRIES CATTLE

The first lactation records of 643 Karan Fries cattle sired by 77 bulls maintained at NDRI, Karnal herd during 1992-2009 were used to estimate the phenotypic, genetic and environmental trends of economic traits viz. first lactation total milk yield (FLTMY), first lactation total milk yield per day of first calving interval (FLTMY/FCI), first lactation total milk yield per day of first lactation length (FLTMY/FLL). The phenotypic trends were estimated as 34.04 ± 8.62 kg (0.90 percent of herd average), 0.05 ± 0.04 (0.57 percent of herd average) and 0.06 ± 0.02 kg (0.48 percent of herd average) for FLTMY, FLTMY/FCI and FLTMY/FLL respectively. The genetic trends were compared by six methods as Smith method1 (SM1), Smith method 2(SM2), Powell and Freeman method1 (PM1), Powell and Freeman method2 (PM2), Least Squares method of Burnside and Legate (LSMBL) and BLUP methods. The annual genetic trends for FLTMY were found to be positive by SM1 (1.08 kg), PM1 (0.83 kg) and BLUP (3.44 kg). The annual genetic trends for FLMY/FCI were positive and significant by SM2 (0.56 ± 0.10 kg) and PM2 (0.43 ± 0.09 kg). The annual genetic trends for FLMY/FLL were found to be positive by SM1 (0.08 ± 0.11 kg), LSMBL (0.01 ± 0.06 kg) and BLUP (0.01 ± 0.02 kg) methods. However, the estimates obtained by BLUP method had the lowest standard errors and were more reliable compared to other methods.