INFLUENCE OF BUCK EXPOSURE, PROGESTAGEN TREATMENT AND SEASON ON REPRODUCTIVE RESPONSES IN GOATS, A RESEARCH PROJECT TOPIC ON MICROBIOLOGY
ABSTRACT
Intravaginal progestagens in combination with gonadotrophins have been used to synchronise oestrus in goats. Recently, the use of “biostimulation” in combination with progestagens is advocated because of ethical concerns regarding hormone residues in food products, environmental contamination and decreased fertility of gonadotrophin-treated does. The aim of the study was to evaluate the influence of buck exposure and progestagen treatments on reproductive responses in goats. Six experiments using Red Sokoto (RS) and Sahel (SH) goats were carried out in the dry (November to April) and rainy (May to October) seasons. In experiment one, the influence of continuous exposure to bucks during progestagen treatment and season on oestrus behaviour and fertility of goats was evaluated. The RS does were treated with Controlled Internal Drug Release (CIDR) device with or without continuous exposure to aproned bucks for 14 days in the dry and rainy seasons. Does were bred on standing oestrus. The result showed that the male effect was comparably effective in inducing oestrus in goats during the dry and rainy seasons. Mean oestrus response rare was higher in buck-exposed than non-exposed Red Sokoto does in both the dry (87.5 % vs 52.5 %) and rainy seasons (88.6 % vs 50.0 %). Exposure to buck during CIDR treatment also improved oestrus response and conception rates in RS does. In experiment two, the effect of buck stimulus at the end of progestagen treatment and season on oestrus pattern and fertility of goats was evaluated. The SH does were treated with exogenous progesterone via a CIDR device with or without aproned buck exposure seven days to the end of progestin treatment in the dry and rainy seasons. The SH does were bred on standing oestrus. The results indicated that the male effect was more pronounced in inducing oestrus in SH goats in the rainy season than dry season. Mean oestrus response rate was higher in buck-exposed than non-exposed Sahel does in the dry (57.4 % vs 40.4 %) and rainy (60 % vs 45 %) season. In experiment three, the influence of buck exposure, season and dose of fluorogestone acetate on oestrus behaviour and fertility of goats was evaluated. The RS does received either 30 mg or 45 mg fluorogestone acetate intravaginal pessaries with or without continuous exposure to aproned bucks for 14 days in the dry and rainy seasons. Does were bred on standing oestrus. Oestrus response was higher in the buck exposed than non-exposed RS does in the dry (67.9 % vs 52.5 %) and rainy (80.0 % vs 71.1 %) seasons. It was concluded that dose of progestagens did not significantly affect oestrus response, time to onset of oestrus, duration of oestrus and mounts per oestrus period. Exposure of does to buck during progestagen treatment enhanced oestrus response and pregnancy rates in Red Sokoto goats.
