Genetic analysis of performance traits of Red Sindhi and Jersey crossbreds.

摘要

A total of 801 Lactation records of 189 Red Sindhi and Jersey crossbred cows, from 1 to 11th parity, daughters of 29 sires, spread over a period of 28 years from 1977 to 2004 maintained at Uttaranchal State Government Cattle breeding farm, Kalsi, Dehradun were used to estimate the performance of breed and genetic parameters. The least square means of age at first fertile service, age at first calving, lactation milk yield, lactation length, dry period, service period and inter calving period were 1184+or-187 days, 1439+or-165 days, 1964+or-323 kg, 287+or-11 days, 140+or-51, 144+or-49 and 427+or-47 days, respectively. Effects of generation, sex of calf, birth season and period were non significant on age at first fertile service and age at first calving. Generation effects were significant on lactation milk yield and lactation length. Parity effects were significant on lactation length, dry period, service period and inter calving period. Sex of calf did not influence any of the traits significantly. Effects of calving season were significant only on dry period. The calving period affects significantly to lactation length, dry period, service period and inter calving period. The h2 estimates of age at first fertile service (AFFS), age at first calving (AFC), lactation milk yield (LMY), lactation length (LL), dry period (DP), service period (SP) and inter calving period (ICP) were 0.09+or-0.08, 0.11+or-0.06, 0.65+or-0.17, 0.07+or-0.07, 0.29+or-0.12, 0.28+or-0.12 and 0.25+or-0.11, respectively. Lactation milk yield had moderate genetic correlation with all traits under study. High phenotypic and genetic correlations among DP, SP and ICP were observed.