Effect of body condition and season of the year on estrous cycle, estrous, follicular development and ovulation rate in Pelibuey ewes under tropical conditions
The effect of season and body condition on the follicular development and the ovulation rate in Pelibuey ewes were assessed. During the periods August-November and February-May, 38 ewes were distributed in two groups according to their body condition score high body condition (HBC) and low body condition (LBC). Estrus was detected twice a day and the ovaries were daily examined by ultrasonography through an interestral period. Ovulation rate (OR) was determined by ultrasonography and then confirmed by laparoscopy. An effect of body condition on the estrous length was found (29.6 ± 2.3 and 20.2 ± 2.5 h HBC and LBC, respectively), whereas there were no differences in the estrous cycle length and the maximum follicular diameter. The number of follicles ≥ 4 mm and the ovulation rate were higher in ewes of high body condition and during the main reproductive season (1.8 vs 1.3 and 2.0 vs 1.4 OR and follicles, respectively).