Abstract
This study was carried out by using 9 Awassi Lambs, 10-12 months of age with average body weight 48.25kg. The lambs were divided into three groups each of three lambs, and fed on one of the three rations which contained different levels of undegradable protein (UDP) (20, 40, 60%) of the total protein of the rations. Results indicated that there were no significant effect of the different levels of UDP on dry and organic matter and crud protein digestibility. While, the digestibility coefficient of ether extract was highly (P < 0.01) increased in group fed on the rations contained 40 or 60% UDP as compared with 20% UDP, it was ranged between 60.39 – 82.28%. The digestibility coefficient of neutral detergent fiber and acid detergent fiber were significantly (P < 0.01) in the ration contained 40% UDP as compared with 20 and 60% UDP. The average digestibility coefficient were ranged between 52.26 – 63.3 % and 36.68 – 49.52% respectively. Rumen liquor pH before feeding was not affected by UDP levels, but it was significantly (P < 0.01) decreased 4hrs after feeding in 20 and 40% UDP (5.82 and 5.83) as compared with 60% UDP (6.14). In contrast, ammonia concentration in rumen liquor was significantly (P < 0.01) decreased before feeding in ration (60% UDP) 4.29 mg/100ml. as compared with ration (20 and 40% UDP) 9.24 and 8.43mg/100ml. While ammonia concentration were similar in the samples taken 4hrs after feeding in all rations. The calculated microbial protein synthesis according to the digested organic matter was significantly (P < 0.01) higher in the lambs fed on 40% UDP (128.16g/d) as compared with 20 and 60% UDP (109.45 and 109.03 g/d) respectively, Statistical analysis of blood constituents showed no significant difference between the three levels of UDP on blood glucose, total protein, albumin globulin and triglyceride concentration.
