ChileanJAR

Intravaginal sponges of Medroxiprogesterone acetate were used in Suffolk sheeps. At the sixth day post-treatment, 100 and 40% of the treated and control ewes had heats (P < 0.01). Qestrus presentation average time was 53.25 and 263.55 hours, for the same groups (P < 0.01). The treated group presented a higher oestrus repetition (P < 0.05), and as result, the experimental group had a higher rate of service return (P < 0.05). Average time elapsed between initial and final lambing was 13.9 and 19.6 days, for each group, respectively. The lambing period lasted 45 and 65 days, for the treated and the control groups. Lambing concentration was expressed by the fact that at the ninth day of lambing, 66.7 and 22.2% of the experimental and control ewes had lambed (P < 0.01). The treatment did not influence reproductive efficiency.