Annual variation in reproductive parameters and sexual behaviour of Saint Croix rams in a semi-desert region in Mexico

Abstract

The aim of this study was to determine the semen quality, sexual behaviour and testosterone (T) levels in Saint Croix rams under semi-desert climate conditions. Sixteen rams (70.6 ± 12.5 kg; 24.1 ± 0.3 months old) were randomly divided into a grazing group (GG, n = 8) and a supplemented group (supplemented individually with 1 kg.d −1 of concentrate (156 g CP.kg −1 DM and 2.5 Mcal EM.kg −1 DM). SG, n = 8). Each group grazed on buffel, grass. Every two weeks, semen was collected, and sexual behaviour traits were evaluated. SG rams had greater body weight (P < 0.0001) and greater semen quality than the GG rams. SG rams had greater values for reaction time and lateral approaches than GG rams (P < 0.0001). No interaction was found between treatment and month for T concentration (P < 0.05); the SG rams had greater values during most of the months, but GG rams had greater values during September. Month had a significant effect on T concentration (P < 0.05) with the highest values in autumn. It can be concluded that Saint Croix rams are able to adapt to adverse environmental conditions and that supplementary feed prior to the mating season improves ram sexual behaviour.

Multifaceted Interplay among Social Dominance, Body Condition, Appetitive and Consummatory Sexual Behaviors, and Semen Quality in Dorper Rams during Out-Of-Season and Transition Periods

“…This suggests that the social interactions come to pass throughout the year irrespective of seasonal variations [ 20 ]. A positive relationship between body condition score and sexual appetitive and consummatory behaviors was also reported in adult male Saint Croix sheep [ 21 ], which were able to adapt to the disadvantageous environmental conditions of a semi-arid ecotype, while maintaining sexual activity throughout the year. Yet, scrotal circumference was not affected by body condition [ 21 ], and neither was it in our study.…”

“…A positive relationship between body condition score and sexual appetitive and consummatory behaviors was also reported in adult male Saint Croix sheep [ 21 ], which were able to adapt to the disadvantageous environmental conditions of a semi-arid ecotype, while maintaining sexual activity throughout the year. Yet, scrotal circumference was not affected by body condition [ 21 ], and neither was it in our study. Moreover, in Malpura adult males, a triple-purpose Indian sheep breed, high-BCS rams (i.e., 3 to 4 units), displayed a greater number of appetitive and consummatory sexual behaviors compared to the low-BCS rams (i.e., 2.5 units) [ 22 ].…”

Hair sheep in the Americas: economic traits and sustainable production

“…Croix ram lambs reach puberty at around three months of age (SCHSIA, 2023), and are very active breeders (Foote, 2018). In a study conducted in Mexico to evaluate the reproductive parameters of St. Croix ram lambs, the scrotal circumference (SC) of the ram lambs ranged from 30 to 32 cm (Sanchez-Davila et al, 2020). According to Katahdin Hair Sheep International, Katahdin rams display early puberty, are aggressive breeders, display year-round fertility, and can successfully sire many ewes in their first exposure.…”

Reproductive Management in Goat Breeding

“…To improve its efficiency and better synchronize heat, the buck effect may be combined with a photoperiodic treatment. Also, supplementary feed prior to the mating season can improve ram sexual behaviour traits [8]. Flock synchronization by non-hormonal methods is usually consisted of a combination of two methods (light treatment and male effect).…”