Estimating the repeatability of birth weight for female calves of various classes of crossbred cows

This study aims to estimate the repeatability of birth weight of male calves in various grades of ½ Jersey × ½ Red Sindhi, ¼ Jersey × ¾ Red Sindhi, 3/8 Jersey × 5/8 Red Sindhi, 1/8 Jersey ×7/8 Red Sindhi crossbred of cows. Data was collected from pedigree cum historysheet maintained at the Department of Animal Husbandry and Dairying, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj, Uttar Pradesh, India. Birth weight of female calves from the first (L1), second (L2) and third (L3) lactations of 74 cows and 122 observations of various grades of Jersey x Red Sindhi crossbred were recorded in kilograms. The mean of birth weight of female calves L1, L2 and L3 were 17.68, 18.18, 17.17 kg of ½ Jersey × ½ Red Sindhi crosses, 18.48, 18.16, 16.64 Kg of ¼ Jersey × ¾ Red Sindhi crosses, 18.29, 18.69, 20.85 kg of 3/8 Jersey × 5/8 Red Sindhi crosses, 18.71, 17.63, 18.83 kg of 1/8 Jersey ×7/8 Red Sindhi crosses respectively. The ranges of birth weight of female calves from the first (L1), second (L2) and third (L3) lactations were 14.9-21.3, 14.6-24.6, 14.9-20.70 kg of ½ Jersey × ½ Red Sindhi crosses, 14.51-23.58, 14.6-23.13,13.5-21.31 Kg of ¼ Jersey × ¾ Red Sindhi crosses, 16.32-19.51, 15.0-25.4, 15.42-26.5 kg of 3/8 Jersey × 5/8 Red Sindhi crosses, 14.1-23.6, 14.51-21.7, 15.87-21.3 kg of 1/8 Jersey ×7/8 Red Sindhi crosses respectively. The overall mean of birth weight of male calves was 17.18 kg of ½ Jersey × ½ Red Sindhi crosses, 17.84 Kg of ¼Jersey × ¾ Red Sindhi crosses, 19.23 kg of 3/8 Jersey × 5/8 Red Sindhi crosses and 18.24 kg of 1/8 Jersey ×7/8 Red Sindhi crosses respectively. The highest birth weight of female calve were 24.60 Kg and lowest 14.60 Kg of ½ Jersey × ½ Red Sindhi crosses, 23.58 Kg and lowest 13.50 kg of ¼ Jersey × ¾ Red Sindhi crosses, 26.5 kg and 15.0 kg of 3/8 Jersey × 5/8 Red Sindhi crosses, 23.6 kg and 14.1 kg of 1/8 Jersey ×7/8 Red Sindhi crosses, respectively. The repeatability of birth weight of female calves for 0.19 ± 0.36 of ½ Jersey × ½ RedSindhi crosses, 0.22 ± 0.02 of ¼ Jersey × ¾ Red Sindhi crosses, 0.80 ± 0.14 of 3/8 Jersey × 5/8 Red Sindhi crosses, 0.14 ± 0.29 of 1/8 Jersey ×7/8 Red Sindhi crosses. Better performance is demonstrated by crossbred dairy cattle with greater repeatability across grades. In order to increase herd output, the current study found that the birth weight of female cow calves may be helpful in choosing those with higher estimations.