The Relationship Between Friesian Calves Performance and Growth Hormone and Leptin Levels
The Relationship Between Friesian Calves Performance and Growth Hormone and Leptin Levels
Al-Moataz Bellah Mahfouz Shaarawy1, Mahmoud Yassin Mohamed1*, Mahmoud Sayed Sayah2,1, Ashraf Ali Mehany1, Ezzat Arafa Ahmed El-Beltagi1, Shimaa M. Ali1
ABSTRACT
Studying the possible association between the growth rate reflecting leptin (LP) and growth hormone (GH) levels, is a route for forecasting the performance of later growth and reproductive traits in Friesian calves. thirty calves (15 males, and 15 females), were categorized into three equal groups. The 1st group (n=5 males and 5 females), which recorded the lowest values from GH, and LP at weaning (105 d) considering then the average daily gain (ADG) from birth to weaning in each animal; 2nd group that had moderate values, and 3rd group that had the highest values. The results indicated that the 3rd group exhibited the 33.47% and 19.60% highest ADG, with decreased levels of GH by 14.05% and 17.96%, and elevated LP by 22.41% and 32.72% in males and females at 540 d, respectively, compared to then the 1st group, which delayed in all ages. In addition, skeletal growth (body length, height at withers, and heart girth) adhered to the same pattern. Calves in the 3rd group reached maturity earlier (about 50d and 63d) and recorded heavier body weights (about 35 kg and 55 kg) of both males and females, respectively. Also, sexual activity, semen characteristics and testosterone levels for bulls developed earlier than the 1st group. Heifers in the same group were superior in reproductive performance such as reaching puberty, and fertility compared to other groups. The 3rd group showed the highest concentrations of serum proteins, glucose, and lipid profiles. The 2nd group came next, and 1st group registered the lowest concentrations. In conclusion, data on GH and LP levels from birth to weaning could be a useful early-life selection tool for selecting high-performing individuals and predicting improved animal performance in the distant future throughout different ages (from 105 d to 540 d of age).
Keywords | Friesian, Leptin, Growth hormone, Growth performance, Reproduction
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