Effects of melatonin implants on reproductive performance of dairy sheep and dairy goats

Abstract

Contents This study investigated the effects of melatonin implants in the female and male animals before the breeding season on the reproductive performance of Tahirova sheep and Turkish Saanen goats. Seventy‐five sheep and 53 goats (including 6 rams and 4 bucks) were used in the research. Melatonin implants (18 mg) were applied to half of the female and male animals, one to female animals and three to male animals. The rate of oestrus was determined as 100% in the melatonin (M) and control (C) groups. The non‐return rate, conception rate and lambing rate were close in both groups of ewes and rams groups (p > .05). The rate of oestrus was 100% in the melatonin and control groups of does and bucks groups in Turkish Saanen goats. The non‐return rate in does was 75.0 ± 9.02% in M group and 92.0 ± 5.53% in C group (p = .0101), the non‐return rate was 83.3 ± 6.92% in group M and 84.2 ± 8.59% in group C for bucks (p = .5570). For ewes, the duration from ram introduction to first oestrus, conception and lambing was significantly lower in group M than in group C (p ≤ .05). Litter size of M in ewe and ram groups were 1.70 ± 0.08 and 1.59 ± 0.09, respectively, whereas it was 1.62 ± 0.10 and 1.74 ± 0.10 in C group, respectively. Birth weight significantly differed between ewe groups (p = .0017). For goats, the duration from buck introduction to first oestrus, conception and lambing was similar in the groups of does and bucks (p > .05). Litter size of M in doe and buck groups were 1.57 ± 0.11 and 1.53 ± 0.12, respectively, and 1.46 ± 0.11and 1.50 ± 0.09 in C group, respectively (p > .05). While the live weight and body condition score (BCS) of ewes were significantly affected by melatonin implants (p ≤ .05), the live weight and BCS of does were not affected. In conclusion, it might be said that melatonin implants obtained better results for reproduction in Tahirova sheep than Turkish Saanen goats.

Systematic review of hormonal strategies to improve fertility in rams

“…However, in a recent study using the same type of melatonin implant in both females and males, the group that had received the implant had significantly lower values for first oestrus, conception rate and lambing compared to the control animals ( Tölü et al, 2022 ).…”