The effect of male proximity on vaginal patency, estrous cycle length and feed intake of female grasscutters.

Abstract

This study was conducted to investigate the influence of male proximity on vaginal patency, estrous cycle length and feed intake of nulliparous and pluriparous grasscutter (Thryonomys swinderianus) does. Twelve non-pregnant and non-lactating adult female (six nulliparous and six pluriparous) grasscutters and six proven male grasscutters were used for the study in a 2 × 2 factorial design. The factors were the type of contact between the sexes (no visual contact v. visual contact) and parity (nulliparous v. pluriparous). The condition of the vaginal membrane, which was monitored daily, was used as an indicator of the reproductive status of the experimental females. The findings of the study showed significant effect (P < 0.001) of male presence on feed intake. Visual contact between breeding pairs significantly (P < 0.05) increased the rate of vaginal opening (11 ± 3.3% v. 22 ± 3.3%) and significantly (P < 0.001) reduced the length of estrous cycling in the grasscutters (58 ± 5days v. 20 ± 5days). However, the duration of vaginal patency was not (P > 0.05) affected by the contact type. Parity had a significant (P < 0.05) effect on the duration of vaginal patency with pluriparous does recording longer duration compared to nulliparous does (76 ± 12h v. 38 ± 12h), but not on feed intake (P > 0.05). The study has revealed that housing breeding grasscutters such that females have visual contact with males could increase rate of vaginal patency and reduce the length of the estrous cycle in both pluriparous and nulliparous grasscutter does. This practice however compromises feed intake of the females.