Evaluation of the repeatability of male calves' birth weights in different grades of Jersey x Red Sindhi crosses

Abstract

To assess the consistency of birth weight among male calves born to half-J x half-RS, quarter-J x ¾ RS, three-eighths Jersey x five-eighths RS, and one-eighth J x seven-eight RS cows. The SHUATS in Prayagraj, Uttar Pradesh, India obtained the data from a pedigree cum history sheet. Male calves born to 77 cows during the first (L1), second (L2), and third (L3) lactations, as well as 127 observations of Jersey x Red Sindhi cows of varying quality, were all measured and recorded in kilos. Increased reproducibility across many cross-breed dairy cow performance tiers indicates superiority. This research shows that choosing cows with higher estimations based on the birth weight. of their male calves can increase the output of herds. The mean of birth weight of male calves L1, L2, and L3 were 18.11, 20.15, 22.07 kg. of ½ J × ½ RS, 20.50, 19.88, 20.77 Kg f ¼ J × ¾ RS crosses, 20.06, 20.88, 22.24 kg. of 3/8 J × 5/8 RS, 19.08, 18.76, 22.83 kg of 1/8 J ×7/8 R.S proportionately. The ranges of birth weight of male calves from the Ist (L1), IInd (L2) and third (L3) lactations were 15.80 - 20.10, 15.80 - 26.6, 19.6 - 25.8 kg. of ½ J × ½ RS, 15.42 - 24.94, 14.51 - 25.70, 13.6 - 28.12 Kg. of ¼ J × ¾ R.S, 14.96 - 26.40, 16.32 - 24.30, 15.42 - 27.50 kg. of 3/8 J × 5/8 RS crosses, 15.87 - 24.23, 12.70 - 24.51, 18.14 - 25.80 kg. of 1/8 J ×7/8 RS respectively. The mean of birth weight of male calves was 20.13 kg. of ½ J × ½ RS, 17.68 Kg. of ¼ J × ¾ RS, 21.07 kg. of 3/8 J × 5/8 RS, 19.92 kg. of 1/8 J ×7/8 RS respectively. The highest birth weight of male calves were 25.8 Kg. and the lowest 15.80 Kg of ½ J × ½ R.S, 28.12 kg. highest and lowest 13.60 kg. of ¼ J × ¾ RS, 27.50 kg at highest and lowest 14.96 kg of 3/8 J × 5/8 RS, 25.8 kg at highest and lowest 12.70 kg. of 1/8 J ×7/8 RS, respectively. The repeatability of birth weight of male calves for 0.60 ± 0.20 of ½ J × ½ RS, 0.46 ± 0.19 of ¼ J × ¾ RS, 0.78 ± 0.15 of 3/8 J × 5/8 RS, 0.57 ± 0.15 of 1/8 J ×7/8 RS. The more repeatability for various grades of crossbred dairy cattle shows better performance.