SEXUAL-BEHAVIOR OF DONKEY JACKS - INFLUENCE OF EJACULATORY FREQUENCY AND SEASON

The courtship of 5 jacks was evaluated weekly for 12 mo. The character istics of sexual behavior were recorded before the collection of 2 eja culates, at 4-h intervals, into an artificial vagina in the presence o f a female in either natural or induced estrus. The maximum time given to the jack to perform the ejaculatory mount was Ih. If the jacks did not ejaculate, another attempt was made the following week. At the ti me of collection, the male and female remained free in a paddock (20 m (2)). The data presented in this study is based on results in which th e first and second ejaculates occurred successively. Statistical analy sis was done by a 2 x 2 factorial design in randomized blocks. The mea n+/-SEM of sexual behavior characteristics for the first and second ej aculate were, respectively: time until first mount=0.7+/-0.2 and 0.9+/ -0.2 min; time until first erection=11.9+/-1.1 and 11.6+/-1.1 min; tim e until ejaculation=15.0+/-1.2 and 13.6+/-1.2 min; frequency of partia l exposure of penis=3.4+/-0.4 and 3.2+/-0.4; frequency of total exposu re of penis=1.0+/-0.2 and 1.1+/-0.2; frequency of flehmen responses=6. 6+/-0.5 and 4.6+/-0.5; frequency of erections=1.3+/-0.1 and 1.2+/-0.1; frequency of retreats away from the female=1.8+/-0.2 and 1.0+/-0.2; f requency of mounts with erection but without ejaculation=0.3+/-0.1 and 0.1+/-0.1; frequency of mounts without erection=2.0+/-0.1 and 1.2+/-0 .1; and frequency of pelvic copulatory movements=4.8+/-0.4 and 4.4+/-0 .4. Individual differences were observed (P<0.05) for partial and tota l exposure, flehmen responses, mounts without erection and pelvic copu latory movements. The variables flehmen responses, retreats away from the female and mounts without erection showed significant differences (P<0.05) between ejaculates. Seasonal effect: on sexual behavior chara cteristics were not found. However, a monthly effect was noted for fle hmen responses, partial exposure of the penis, mounts without erection , retreats away from the female and pelvic copulatory movements when t he 2 ejaculates were combined.