Comparing the Fattening of Awassi lambs on Atriplex Pastures, Barley Residues after Harvesting and Different Levels of Supplementary Feeding with the Traditional Lamb Fattening on Concentrates.

This study aims to compare the fattening of Awassi lambs on Atriplex pastures, barley residues after harvesting and adding different levels of supplementary feeding (grain barley and wheat bran) with the traditional lamb feeding on concentrates. The study was conducted at the Agricultural Research Center of Al-Salamiah, and the experiment lasted107 days.One hundred Awassi lambs were used in this experiment, and distributed into five groups according to Randomize Statistical Design (control group and four treatment groups). The control group was provided (traditional fattening) with 1200 g of concentrated diet per head (16% cotton seed cake, 57% barley grain, 25% wheat bran, 0.5% NaCl, and 1.5% calcium carbonate), and 500g of barley straw. The treated groups were grazing (at rate of at least eight hours daily) in an area of 80 acres planted with both Atriplex since more than 5 years and barley in this year, and were supplied with complementary feed as the following: first group (T1): 250g of barley grain per head, the second group (T2) 250g of barley grain and 100g of wheat bran, the third group (T3) 250g barley grain and 200g of wheat bran, the fourth group (T4), 250g of barley grain and 300g of wheat bran. The cost of feed components was calculated according to the prices in the local markets and the rental value of planted land with Atriplex and barley were estimated at 1000 SP. The average body weights at the beginning and the end of the experiment were as follow: The control group, and the treated groups (T1, T2, T3 and T4):(35.45 and 55.50), (35.20 and 48.8), (35.00 and 48.76), (34.80 and 52.26), (35.40 and 52.48) kg, respectively. The difference of the beginning weights were not significant between all the groups, but the final weights were significantly different (p <0.05) between the control group and the treated groups. There were significant differences in the digestibility of the dry matter, organic protein, hemicelluloses and energy between the control and the treatment groups at the level of (P <0.01).Regarding the economic cost of the body weight increments, it has the cost of 159, 120, 132 115 and 129 pounds per kilo for the control group and T1, T2, T3 and T4 groups respectively, and were significantly different (p <0.01).This study recommends lamb 250g of barley grain and 200g of wheat bran per day, when fattening on pasture Atriplex and barley residues after harvesting, because it achieved the best economic value.