Effect of natural shade on the grazing behavior of breeding ewes from Pelibuey breed

Resumen

A total of twenty-four breeding ewes from Pelibuey breed were used, divided into two treatments of 12 animals each, to determine the effect of natural shade on the behavior of these animals during grazing. In treatment one, they grazed in the system with natural shade and in treatment two, without shade. Each treatment included the three physiological states: non-pregnant cow, pregnant and lactating. Both groups grazed in two paddocks of natural grasses, of 1.3 ha: one without natural shade, and another with shade from the trees Casuarina equisetifolia (casuarina) and Samanea saman (carob tree).The grazing performance was recorded. Every 10 min., observations during six hours of grazing per day were recorded. Contingency table analysis was used to test the interaction between activities and system type, with and without shade, between activities and day session, and between activities and season for each system, with trees and without them. With the analysis of comparison of proportions (chi square), the time percentages were compared. There was interaction between the activities and the characteristics of the farms, with and without trees, and between the activities and the day session. The animals that had access to
the shade of the trees spent more time grazing-walking. When they grazed with trees, they selected activities in the shade, such as rest and rumination. A higher proportion of grazing time was recorded during the morning session. In the system with trees, the highest proportions of grazing time were obtained in both seasons.
Key words: grazing, trees, animal behavior, silvopastoral system