Does buck stimulation affect the reproductive performance of goats synchronized with Medroxyprogesterone Acetate (MAP) sponges?

Abstract

This investigation was executed to determine effect of buck exposure on estrus response, onset of standing estrus, ovulation rate, conception rate and pregnancy rate in goats synchronized with medroxyprogesterone acetate (MAP) sponges. Sponges were placed inside the vagina for fifteen days in buck exposed and isolated groups. Post sponge withdrawal, estrus activities were continuously observed. The interval between sponge withdrawal and the onset of standing estrus were 32.3±10 h (18-51 h) and 45.2±10.9 h (27-51h) in buck isolated and exposed group respectively (p<0.05). Ovulation and conception rates were confirmed by serum progesterone level using radioimmunoassay. Ovulation rates were 100% in both groups and conception rates were 93% and 100% in buck exposed and in isolated group respectively (p>0.05). Pregnancies were confirmed by ultrasound on day 35 post mating which were 93%, was and 69% in buck exposed and isolated group respectively (p>0.05). Based upon the evidence, it was inference that post sponge removal sudden buck exposure cause markedly earlier estrus onset while the continuous buck exposure was unable to show significantly impact on conception and pregnancy rates compare to isolated group.