Effect of birth type and sex on growth performance, wither height, humerus-radius bone dimensions, humerus-ulna growth plate width and selected hormone profile in growing Gurcu goat kids

Objectives: In this study, the effects of sex and birth type on growth performance, withers height (WH), radiographic measurements and selected hormone profiles in Gurcu goat kids were investigated.

Methods: Twenty kids (single female = 5, single male = 5, twin female = 5, twin male = 5) were included in the study. Body weight (BW), WH, radiographic measurements (humerus length [HL], radius length [RL], proximal humerus epiphyseal plate width [HEP] and distal ulna epiphyseal plate width [UEP]) and biochemical analysis (for serum calcitonin, free triiodothyronine [FT3], free thyroxine [FT4], growth hormone [GH] and insulin-like growth factor-I [IGF-I]) were performed at 1, 3, 5, 7, 9 and 12 months of age.

Results: BW was significantly higher in males starting from the seventh month compared to females (p < 0.05). HL was higher in males at seventh (p = 0.009) and ninth (p = 0.033) months, whereas RL was lower in twins at the third month (p = 0.021). UEP was wider in males at seventh (p = 0.008) and ninth (p = 0.036) months. Closure of HEP was observed in 65% of kids by the 12th month. Calcitonin was lower in twins at third (p = 0.045) and fifth (p = 0.006) months, with changes observed due to group and time effects (p < 0.05), whereas other hormones only changed with time (p < 0.05). Positive correlations were observed between BW, WH, HL, RL and IGF-I. There was a negative correlation between BW, WH, HL, RL, IGF-I and HEP, UEP, calcitonin, FT3, FT4, GH.

Conclusion: Sex and birth type in Gurcu goat kids may have an impact on growth performance, radiographic measurements and certain hormonal profiles.