Sexual Performance of Rams Reared with or without Females after Weaning

Abstract

The objective of this study was to determine the effect of postweaning exposure to females on the subsequent sexual performance of young rams. Twenty-five crossbred rams were reared in a group with ovariectomized females from 4.5 to 9 mo of age. Ewes were brought into estrus every 2 wk during this period. A companion group of 23 crossbred rams was not exposed to females following weaning. Four 30-min sexual performance tests were administered at 10 mo of age. Rams reared with males and females (RMF) exhibited more mounts (P less than .001) and more ejaculations (P less than .002) than rams reared only with males (RM). The frequency of successful matings by the latter group did not increase with experience. Nine rams were sexually inactive in the sexual performance tests. Follow-up tests revealed that two of the RMF rams and one RM ram developed and maintained a sexual preference for males. The six remaining rams eventually mated with females when tested in familiar pens and subsequently exhibited normal levels of sexual performance even when tested in an unfamiliar enclosure. Exposure to ewes during the postweaning prepubertal period enhanced sexual performance. However, early exposure to females did not ensure that all males developed sexual preferences for females. The environmental context in which sexual performance tests are administered may inhibit the expression of heterosexual behavior in a small percentage of animals. After heterosexual behavior was expressed, the rams continued to show normal levels of sexual performance.(ABSTRACT TRUNCATED AT 250 WORDS)

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

“…There are several factors that could affect the libido and serving capacity of males. These factors result in a great variation of sexual performance of rams: season of year, breed differences, individual rams, previous breeding experience, method of restraint of ewes and age (Katz et al 1988, Mandiki et al 1998, Advi et al 2004, Dickson and Sanford 2005, Aguirre et al 2007, Marai et al 2008.…”

Biostimulation: Innovative Tool to Improve Reproductive Efficiency in Farm Animals

“…Couttie and Hunter (1956) suggested that when young bulls were reared in isolation, many failed to respond or showed less interest in mounting when first exposed to estrual females compared to bulls raised with females. Exposure of ram lambs to ewes during the postweaning prepubertal period enhanced their sexual performance (Katz et al, 1988). Yearling rams kept close to ewes in oestrus for 6 months found to have larger testes, higher plasma testosterone levels and greater sexual activity than control rams isolated from ewes (Illius et al, 1976).…”

La conducta sexual del carnero. Revisión

“…Rams, unlike cattle, and goats, are not sexually stimulated by witnessing the mounting of other sheep (4) . Exposure to females during an early age promotes sexual performance, but does not prevent that some males show homosexual preferences (5) . Based on these and other characteristics, there is enough information in the scientific literature on the subject, same that is provided in the following Sections.…”

“…Another common practice among producers is that during weaning, generally lambs are separated by sex. However, males must have heterosexual experiences during the period from weaning to year of age, making it easier to develop the sexual preference of rams to females (instead of to males), in addition to accelerating the emergence of sexual behavior (5) . Rams without experience, who are exposed to adult females, can delay the manifestation of his normal sexual behavior for several weeks.…”

“…Los carneros, a diferencia de bovinos y caprinos, no se estimulan sexualmente al presenciar la cópula de otros ovinos (4) . La exposición ante hembras durante una edad temprana favorece el desempeño sexual, pero no evita que algunos machos muestren preferencias homosexuales (5) . Con base en éstas y otras características, existe una basta información en la literatura científica sobre el tema, misma que se proporciona en las secciones siguientes.…”