Libido and serving capacity of mature hair rams under tropical environmental conditions

Abstract

The objectives of the present study were to evaluate the libido and serving capacity of Pelibuey (PB), Blackbelly (BB), Dorper (DR) and Katahdin (KA) hair sheep rams in three seasons under tropical environmental conditions. Twenty-eight mature rams were individually exposed for 10 minutes to an immobilized, oestrous-induced ewe twice per season. The total number of sexual behaviours, reaction time to first mating and latencies between mating were recorded. Reaction time and latencies were affected by breed effect (P < 0.05) and except for the latency time for the second ejaculation, the season was also significant (P < 0.05) while no interaction effects were observed (P > 0.05). All rams attained at least one ejaculation during testing. The overall mean (± S.E.M.) of reaction time and latencies to second and third mating were 37.62 ± 4.97s, 136.43 ± 9.75 and 180.95 ± 11.87 seconds, respectively. PB, BB and KA rams were faster than DR in reaction time and latency to second mating (P < 0.05). For latency to third mating, PB and KA rams were faster than BB and DR (P < 0.05). The libido activities that rams performed most frequently were anogenital sniffing and foreleg kicks. It was concluded that under tropical environmental conditions PB, KA and BB rams showed better serving capacity than DR, with shorter reaction time and latency to second mating. Hair rams exhibited more frequencies of anogenital sniffing and foreleg kicks.