Authors: J.O Daramola, A.A Adeloye and A.O Soladoye
Int. Livestock Research for Rural Development 18 (9) 2006
Abstract
Two trials were conducted to investigate the effect of exogenous melatonin on sexual behaviours of West African Dwarf (WAD) goats. Thirty two WAD goats (20 does and 12 bucks) were used.
Does were administered doses of melatonin at 0,3,6 and 9mg. In the second trial, bucks were administered doses of melatonin at 0,3,6 and 9mg. Melatonin was administered orally for ten consecutive days.
Oestrus response (P<0.05) was 40, 60, 100 and 80% for the 0, 3, 6, and 9mg melatonin respectively. Does induced with 6mg melatonin had shorter interval (22.0 ± 0.22 days) between treatment termination and onset of oestrus compared to 0 (24.5± 0.5 days), 3 (25.0±0.98 days), and 9mg melatonin (23.5 ± 0.74 days). Similarly, does induced with 6mg melatonin had longer duration of oestrus (58.6±1.49 hrs) compared to 0 (54.0 ± 1.19 hrs), 3 (55.0 ± 0.99 hrs) and 9mg melatonin (58.0 ±1.16hrs). In addition, does induced with 6mg melatonin had higher (P<0.05) serum oestrogen concentration (25.36± 11.46 pg/ml) compared to 6.98± 4.93 pg/ml, 23.77± 6.77 pg/ml and 16.94± 0.89 pg/ml for 0, 3 and 9mg melatonin respectively. Sexual behaviours of bucks showed increased (P<0.05) full erection with 6mg melatonin (2.0+0.4) compared to 0 (0.66+0.2), 3 (1.66+0.28) and 9mg melatonin (1.33+0.2).
The findings of this study indicate that treatment of WAD does with 6mg melatonin resulted in a two and half-fold increase in the does that came on heat. Similarly, treatment of bucks with 6mg melatonin improved sexual behaviour in WAD bucks.