Effect of non-genetic factors on various economic traits in Karan Fries crossbred cattle

摘要

Data of 681 cows were collected for a period of 15 years, and analysed to see the effect of non-genetic factors on different economic traits in Karan Fries crossbred cattle. The overall least squares means of age at first calving (AFC), service period(SP), 305 days or less milk yield (305DMY), total milk yield (TMY), lactation length (LL), preceding dry period (PDP), calving interval (CI), average milk yield per day of lactation length (MY/LL) and average milk yield per day of calving interval (MY/CI) were 1043.40±6.64 days, 133.66 ± 3.89 days, 4113.61±55.90 kg, 4677.84±50.35 kg, 365.10± 3.34 days, 67.93 ± 2.12 days, 439.03±5.39 days, 12.93±0.99 kg and 11.08±0.13 kg respectively. It was observed that the period of birth was significant (P<0.01) on age at first calving. Similarly season of calving and period of calving was also significant (P<0.05) on service period, 305 days or less milk yield and milk yield per day of calving interval, while season of calving was significant (PO.01) on total milk yield and milk yield per day of lactation length. Effect of period of calving was also significant (P<0.01) on age at first calving, 305 or less milk yield, total milk yield, lactation length, milk yield per day of lactation length and milk yield per day of calving interval. Parity was significant (P<0.05) on service period, 305 days or less milk yield, total milk yield, lactation length, calving interval, milk yield per day of lactation length and milk yield per day of calving interval.