STUDY THE EFFECT OF AWASSI EWE LAMBS BODY WEIGHT ON SOME REPRODUCTION EFFICACY PARAMETERS

Abstract

The study was crried out at the animal farm – Animal Resources Department – College of Agriculture and Forestry-University of Mosul, in order to evaluate the effect of body weight on carcass weight and some body fat measurements, and its relation with the reproductive capacity . 75 female lambs were divided at the puberty age into three weight groups (25animal. Each) the 1st . group High weight (38-44 kg) , 2nd group Intermediate weight (33.5-37.5 kg) , and 3rd group : Low weight (28-32.5 kg) . Five lambs were slaughtered in order to study the body fat parameters and the reproductive system development , The remaining lambs (20 femal lambs/group) were subjected to estrous synchronization by progesterone vaginal sponges for 12 days , then when the sponges removed , the lambs were injected with 500 U of eCG. Result revealed a significant increase in carcass weight , tail weight , abdominal fat , kidney's fat and tail weight : carcass weight % and body fat : carcass weight % in the high weight group as compared with low weight group , and a significant or arithmetic increase in high weight group in reproductive system parameters including : reproductive system weight , ovaries weight , oviducts weight and uterine horns length as compared with the other two groups . Results also revealed that the best fertilization rate , fertility and lambing% at weaning in the ewes of high and intermediate groups as compared with low weight group . In conclusions , it is possible to mate the Awassi female lamb with high ( > 38 kg) and intermediate body weight (> 33.5 -37.5 kg) at early ages .