Factors affecting weight and age at first calving, first lactation milk yield in Gir cows

Abstract

The present study was undertaken on data of 113 Gir cows maintained at Kasturba Gram Dairy Farm, Indore, Madhya Pradesh, India over a period of 18 years from 1995 to 2012, based on age at first calving. The overall means for weight at first calving (WFC), age at first calving (AFC), and first lactation milk yield (FLMY) were 402.22± 1.28 kg, 1709.04± 51.92 days and 1664.95± 280.72 litres respectively. The heritability estimates for WFC, AFC and FLMY were 0.248± 0.234, 0.307± 0.206 and 0.112± 0.252 respectively. The genetic correlation between WFC and AFC was positive and significant, while it was negative in between WFC and FLMY. The genetic correlation between AFC and FLMY was low and negative. The phenotypic correlations between all traits were positive.