Influence of non-genetic factors on fortnightly test day milk yields and first lactation 305-day milk yield in Sahiwal cattle

The data on 643 Sahiwal cows, maintained at NDRI Karnal were analyzed to study the effect of non-genetic factors period, season, days open and first lactation length on first lactation 305-days milk yield and fortnightly test day milk yields. The least squares means for first lactation 305-day milk yield was found to be 2005.28±36.17 kg. The least squares means of overall fortnightly test days milk yields ranged from 5.07±0.17 kg (Test day-1) to 8.58 ±0.19 kg (Test day-3). Effect of period of calving and first lactation length was found to be highly significant (P<0.01) on first lactation 305 days milk yield. However, the effect of period of calving on Test day-11, Test day-12, Test day-14, Test day-18 and Test day-19 was found to be significant (P<0.05). The effect of first service period was highly significant (P<0.01) on Test Day 2 and significant (P<0.05) on Test day-3 and Test day-4, respectively.