Effect of Genetic and Non-Genetic Factors on the Performance of Cross-Bred Dairy Cattle Under Organized Farm Condition

The present investigation was carried out to study the production and reproduction performance of crossbred dairy cattle under an organized farm.The data were classified according to genetic groups, seasons and periods.The mean lactation milk yield was 2316.36 ± 57.52 and 2908.31 ± 80.78 liters in Jersey crossbred and Holstein-Frisian crossbred cows, respectively.The mean age at first calving, lactation length, dry period, calving interval and service period was found to be 1017.50 ± 24.88, 294.95 ± 3.00, 99.80 ± 2.34, 394.75 ± 3.05, and 115.48 ± 3.12 days, respectively in Jersey crossbred cow.The corresponding figure for Holstein-Frisian crossbred cow was 1127.24 ± 35.63, 305.88 ± 2.95, 98.38 ± 2.56, and 404.26 ± 3.20 and 127.03 ± 3.63 days, respectively.The effect of genetic group was found to be highly significant (P < 0.01) on lactation length, lactation milk yield, calving interval, service period and age at first calving and non-significant for dry period (P > 0.05).The Holstein-Friesian crossbred cows had significantly (P < 0.01) longer lactation length and higher lactation milk yield.However, Jersey crossbred cows had significantly (P < 0.01) shorter calving interval, service period and age at first calving.The effect of season of calving was highly significant (P < 0.01) on lactation length, lactation milk yield, calving interval and service period and non-significant on dry period.The effect of season of birth was highly significant (P < 0.01) on age at first calving.During pre monsoon season lactation milk yield was significantly higher with significantly shorter calving interval, service period and age at first calving.The effect of period was observed to be significant (P < 0.05) for lactation length and calving interval while it was non-significant (P > 0.05) for lactation milk yield, dry period, service period and age at first calving.In the second period there was apparently higher lactation milk yield with significantly shorter calving interval.Reproductive performance of Jersey crossbred cows was found to be significantly better in comparison to the Holstein-Friesian crossbred cows while productive performance was better in later one.Cows calved during pre monsoon season were found to be better compared to other seasons.It can be concluded that Jersey crossbred cows showed superior performance in respect of reproduction.Therefore, it will be better to maintain this cross breed for dairy farming under the humid sub-tropical climate of Assam.