Thermoregulation and Reproductive Performance of Grazing Desert Ewes (Ovis aries) as Influenced by Concentrate Supplementation

Abstract

Twenty sexually mature Desert ewes were used to study the effects of concentrate supplementation on thermoregulation and reproductive traits. The ewes were divided into two equal groups, control and supplemented; the supplemented group received daily 500 g of concentrate mixture (crushed sorghum grain and cotton seed cake). In both groups, oestrus was synchronized with hormonal method and the ewes were naturally inseminated. Pregnancy was diagnosed by the ultra-sonography technique. Dietary supplementation resulted in a shorter time of oestrus onset, higher rates of conception, lambing and a significant decrease in gestation length. The fertility and fecundity of ewes were also improved. Supplementations also increased significantly the pre-and post lambing weight of ewes and the birth and weaning weights of the lambs. The body weight, rectal temperature and respiratory rate increased significantly with the advance of pregnancy in both groups of ewes. These indices decreased significantly with the progress of lactation. The supplemented ewes maintained higher values of these indices during pregnancy and lactation.