The aim of this study was to evaluate the effect of body condition (BC) on the reproductive efficiency and follicular dynamics of mares during the breeding season. We evaluated 134 mares (92 broodmares and 42 lactating) that were submitted to artificial insemination in November and December, and then put under natural controlled breeding, in alternating days, from January to March. They were kept under daily heat detection in group at field, so that at the moment it was detected, daily follicular control was initiated by rectal palpation until the detection of ovulation. The BC was evaluated in the months of August, November, January and March. Anestro rate was 26.11% and pregnancy rate was 56.7%; however, when considering only the cyclic mares, it was 77%. The number of cycles/conception was 2.3 and of mounts/cycle 2.1. The BC evolution affected (P< 0.05) the number of cyclic mares and the pregnancy rate. The month of breeding season and the BC influenced all follicular characteristics and pregnancy rate (P<0.05). We could conclude that the body condition affects the mare's cyclical activity, follicular dynamics and fertility.
Body score; equine; pregnancy rate