Phenotypic and Genotypic Factors Affect on Milk Yield per Day Calving Interval and Dry Period of Dairy Cattle in an Around of Madhepura District of Bihar

摘要

A study was carried out to evaluate genetic and non-genetic factors affecting milk yield per day calving interval and dry period in cattle. A total of 229 Desi, 85 Holstein Friesian Crossbred (HFX) and 103Jersey Crossbred (JX) cows maintained in private dairy units. Calving interval, the month of calving, parity and quadratic effects of age at calving fitted as covariates significantly affected the milk, fat and protein yields. Milk, fat and protein yields obtained increased with an increase in calving interval. A dry period, typically 40 to 60 day, between?lactations is believed to be required to maximise milk yield in the subsequent lactation. The factor for causing the variation in milk yield (MY) and calving interval (CI) is DP thus, influencing the efficiency of MY in the dairy cow. A reasonable length of DP is necessary because this period provides time to regain the energy lost during the previous lactation and to regenerate the secretory cells of animal for next lactation. The overall least-squares means (±standard error) of milk yield per day calving interval (Kg.) of Desi 2.525±0.032, HFX 5.725±0.054, JX 4.866±0.051 and dry period of 143.289±0.682, 115.084±1.155 and 117.868±1.093 days respectively. The effect of various non-genetic factors on milk yield per day calving interval and dry period studied among Desi, HFX and JX cows under farmer managemental condition. HFX had more than double and JX had nearly equal MY/day CI than Desi cows.