Abstract

In this experiment, 24 awassi lambs were used, aged between 3-4 months and with an average weight of 19.32±605 kg.They were distributed into four groups and fed four diets with similar basic components.The first treatment contained 1% urea, the second treatment 2% slow release urea(SRU)(Minogen), the third treatment 0.5% urea and 1% SRU and the fourth treatment 1% urea and 2% SRU.Data were statistically analyzed using a completely randmized design (CRD), the results indicated that there were no significant differences in the weights of the slaughtered animals, the percentages of dressing, the area of the ocular muscle, the phisical inventory of the three ribs, subcutaneous fat, internal and external slaughter offal weights and the weights of the carcass parts, except the weight of the shoulder and neck, which showed significant differeces(p≤0.05) in their weights in favour of the second treatment compared to the other treatments, the shoulder weight and the neck weight. There were also significant differences (p≤0.05) in total fat weight and the fat-tail weight in favor of the second treatment compared to the other treatments, the total fat weight and the fat-tail weight. There were also significant differences (p≤0.05) in the concentration of urea in the blood serum in favor of the fourth treatment compared to the other treatments, the results, also significant differences appeared (p≤0.05) in the concentration of cholestrol in the blood serum in favor of third treatment compared to the other treatments, and the results, while there were no significant differences in the concentration of total protien, albumin and triglycerides in the blood serum.It was notted that there is positive effect of adding urea and menogen to the diets of awassi lambs in some carcass properties and some blood serum characteristics.