INFLUENCE OF BUCK EXPOSURE, PROGESTAGEN TREATMENT AND SEASON ON REPRODUCTIVE RESPONSES IN GOATS
INFLUENCE OF BUCK EXPOSURE, PROGESTAGEN TREATMENT AND SEASON ON REPRODUCTIVE RESPONSES IN GOATS
No Thumbnail Available
Date
2015-09
Authors
OMONTESE, BOBWEALTH OAKINA
Journal Title
Journal ISSN
Volume Title
Publisher
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
ix
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. In experiment 4, the influence of male stimulus at the end of progestagen treatment, dose of fluorogestone acetate and season on oestrus and fertility of Sahel goats was evaluated. The SH does were treated with either 30 mg or 45 mg fluorogestone acetate intravaginal sponges with or without limited buck exposure in the dry and rainy seasons. Does were bred on standing oestrus. Oestrus response was higher in the buck-exposed does (70.8 %) than in the non-exposed does (50.0 %). Pregnancy rates were higher in the dry (60.9 %) than in the rainy season (45.8 %). It was concluded that dose of progestagens did not significantly affect oestrus response in Sahel goats. Teasing during progestagen treatment enhanced oestrus response and pregnancy in the goats. The dry season favoured pregnancy rates in Sahel goats than the rainy season. In experiment five, the serum progesterone profiles of RS does treated with different progestagens with or without continuous buck exposure was evaluated. Does received either CIDR devices, 30 mg fluorogestone acetate intravaginal pessaries, 45 mg fluorogestone acetate intravaginal pessaries, with or without continuous exposure to aproned Red Sokoto bucks for 14 days. Serum progesterone levels were similar in the buck-exposed and non-exposed Red Sokoto does across the days of treatment. In experiment six, the serum progesterone profiles of SH does treated with different progestagens with or without limited buck exposure was evaluated. Does received CIDR devices, 30 mg fluorogestone acetate intravaginal pessaries, 45 mg fluorogestone acetate intravaginal pessaries, with or without limited exposure to bucks. Serum progesterone levels were similar in the buck-exposed and non-exposed Sahel does across the days of treatment.
Description
A THESIS SUBMITTED TO THE SCHOOL OF POSTGRADUATE STUDIES AHMADU BELLO UNIVERSITY, ZARIA, NIGERIA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE AWARD OF THE DEGREE OF DOCTOR OF PHILOSOPHY IN THERIOGENOLOGY DEPARTMENT OF THERIOGENOLOGY AND PRODUCTION AHMADU BELLO UNIVERSITY, ZARIA NIGERIA
Keywords
INFLUENCE,, BUCK EXPOSURE,, PROGESTAGEN TREATMENT,, SEASON,, REPRODUCTIVE RESPONSES,, GOATS,