Mating behavior of bucks and does in goat operations under range conditions

Abstract

The objectives of this study were to characterize the mating capacity of bucks under range condition and assess the effect of mating frequency on flock fertility. Two adjacent flocks of crossbred goats (Criollo×dairy breeds; n=70 does, 5 bucks and 141 does, 4 bucks) were used in this study. The mating period was 16 and 20 days for each flock, respectively, in January and February, 1996. Mating activity of bucks and does was recorded day and night during the first 11 days of the breeding period. The combined data of both flocks showed a strong relationship between number of goats in estrus and the average services of bucks ( r=0.95; P<0.01). With an excess of estrous does, bucks on average copulated 9.1 times daily during the first 11 days of the mating period. Considering both flocks combined, does copulated on average 4±1.8 times through the estrus period, and they did so with an average of 2.2±1.3 different bucks. Sexual activity of bucks was greatest from sunset to midday. Number of services from different bucks did not affect pregnancy rate (81.4% for goats serviced by 1–2 bucks and 77.8% for goats serviced by 3–4 different bucks; χ 2=0.25; P>0.05). Also pregnancy rate was not influenced by total number of services (81.3%, 75.0% and 81.4% for 1–3, 4–6 and >7 services, respectively; χ 2=0.67; P>0.05). Mean±S.D. daily liveweight loss of bucks during the entire mating period was 547±197 g. It was concluded that, with buck percentages higher than 3%, the number of ejaculations of bucks is linearly and positively related to number of females in estrus. Also, these findings indicate that neither number of copulations nor number of services from different bucks affected kidding rates.