Effect on Calf Sex of Milk Yield in Holstein Friesian Cattle Breed

Abstract

This study compared the effects of the sex of Holstein Friesian (HF) calves registered in the herdbook system on milk yield. The study material comprised 802042 milk and calving records between 2000 and 2014. When analyzing the data, the GLM ANO-VA method was used to investigate the effects of the sex of the calf and other environmental factors on milk yield. Of the calves born, 54.3% were female and 45.7% were male calves. The results show that the average lactation milk yield (LMY) of (HF) cows is 8604 +/- 3.6 kg, 305-day milk yield (305 MY) is 7028 +/- 2.4 kg and lactation length (LL) is 372 +/- 0.1 days. When cows give birth to female and male calves, LMY, 305 MY and LL are 8720 +/- 15.3 kg, 7148 +/- 10.0 kg and 370 +/- 0.5 days, respectively; 8482 +/- 15.3 kg, 6901 +/- 10.0 kg and 373 +/- 0.5 days were determined. Based on these results, it was found that cows that gave birth to female calves had a higher milk yield, and the effect of sex on milk yield was significant. The results obtained demonstrate distinct differences between cows giving birth to female versus male calves. Specifically, it was found that (HF) cows that give birth to female calves have a higher milk yield during lactation, and these differences were statistically significant. When evaluated by lactation number, the milk yield superiority of cows giving birth to female calves over those giving birth to male calves ranged from 3.89% to 1.13% for total lactation milk yield and from 4.98% to 1.80% for 305-day milk yield. Additionally, it was observed that the lactation length of cows giving birth to male calves was 1.06% to 0.55% longer than that of cows giving birth to female calves. Overall, across all lactations, HF cows that gave birth to female calves had a higher milk yield, indicating that the sex of the calf significantly influenced the milk yield of the mother.