The Social Dominance of the Rams Did Not Influence Their Sexual Behavior but Did Affect the Number of Lambs Sired and the Lambing Rates

Abstract

The objective of this study was to evaluate the sexual behavior of rams based on their social dominance (SD) when paired into dyads consisting of dominant rams (DRams) and subordinate rams (SRams) across two breeding seasons (BS) and to assess its impact on the number of lambs sired and lambing rate. Twelve adult rams (six dyads per BS) were used and introduced to 17 and 18 ewes during the summer breeding (SumB) and winter breeding (WinB) seasons, respectively. There were no differences in SD, except for the flehmen response (p < 0.0001). Significant differences (p < 0.05) were found in body development and scrotal circumference, as well as in the sexual inspection traits between BS and ram group. The breeding week influenced each sexual behavior variable (p < 0.05). A higher percentage of single lambing was observed in WinB (46.2%) compared to SumB (27.4%) (p < 0.05). SD had an effect on the type of lambing (p < 0.05), with DRams exhibiting 35.6% twin lambing, while SRams showed only 10.6%. In conclusion, SD did not impact the sexual behavior of hair rams. SD influenced the lambing rate, with DRams producing a higher percentage of twin lambs compared to SRams in hair ewes during the breeding season.