National Dairy Research Institute, Kamal, Haryana-132001.
354 records of Sahiwal animals spread over a period of 24 years (1980–2003) wen: analyzed to estimate the effect of certain non-genetic factors on birth weight (BW), age at first calving (AFC), and weight at first calving (WFC). The least squares means for birth weight, age at first calving and weight at first calving were 20.41 + 0.23 Kg, 1078.09 ±21.12 days and 367.69 ±4.48 Kg respectively.