Seasonal variations in the reproductive function of Baoule cattle in Burkina Faso

Abstract

Seasonal variations in the reproductive function of the trypanotolerant Baoule breed of cattle were studied in a controlled environment by evaluation of hormonal and behavioral components. In expanding the notion of the season to encompass available food sources as well as nutritional status, we can conclude that even in an experimental station, seasonal variations exist in the reproductive cycle. The percentage of animals cycling varies from 91 % during the fresh dry season to 50 % during the warm humid pre-rainy season (p < 0.01). The cycling animals are heavier than the non cycling animals (210 kg ± 40 kg vs 176 kg ± 39 kg, p < 0.01). In the cycling cows, no seasonal variations were observed in the duration of the cycle (21 ± 2.1 days), the duration of oestrus (9 h 57 min) or the plasma progesterone levels. However, the nycthemeral distribution of oestral behavior varies with the season.