Etude des activités d'un troupeau de poulinières de trait et de leurs poulains au pâturage

Abstract

The grazing behavior of a herd of 8 draft brood mares and their foals and 12 non-lactating mares was studied. Recordings were made during 15 days between April-Nov. at intervals of 5 min from sunrise to sunset. Only diurnal activities were measured. The herd was grazing during 3-5 cycles. Brood mares grazed for 592 .+-. 91 min. The distribution of the activities of the mares, grazing, standing, lying and gadding + grooming (other activities), was 67, 22, 3 and 8%, respectively. The inter-day variations were much higher than the intra-day variation. The differences between days were essentially related to season and climatic conditions. The differences between animals can be partially explained by the physiological state and, in the brood mares, by the variation in their requirements during lactation. The number of diurnal sucks in the foal was very high 48 h after birth, but decreased rapidly with age; grazing time increased. These observations are related to the fact that in the foal the growth rate decreases with age. The minimum number of animals necessary for estimating the grazing time of a given day and with a given accuracy was determined. The present results were compared with those obtained in cattle and emphasize some particularities in horses: a long grazing time in the mare, high frequency of sucks and a high growth rate in the foal.