The influence of age and number of heats in the fertility value of Arabian and Andalusian mares have been studied. The Arabian mares have a whole fertility value 11 % higher than the Andalusian ones. The fertility is low ...

The plasmatic progesterone levels in Arabian and Andalusian mares during the reproductive cycle have been studied. In the partum there is a significant décrease in plasmatic progesterone levels. During the heat these levels ...

Following the traditional method of exploitation, for a period of four years 165 Spanish-bred mares were observed. The heats. per month from January to June and the gestation rates in each month were determined. The number ...

The length of heat in Andalusian and Arabian mares, and the optimum day of breeding in the first postpartum heat, have been studied. In our results the average of all the heat was 5.78 + 1.54 days. No significant diferences ...