I completed this study in the fields of the Department of Animal Production - College of Agriculture and Forestry - University of Mosul to find out the effect of adding slow-release urea to the concentrated diet gradually instead of rapidly release urea in an attempt to improve the efficiency of feed utilization and improve rumen conditions and the reflection of that Digestion of compounds and nutrients in rams using 4 Awassi lambs aged between 9-12 months distributed into four treatments fed on a concentrated diet close in energy and protein content and different in its content of urea that It was gradually replaced by slow-release urea (menogen) where the first treatment (1.5% urea only), the second treatment (1% urea and 0.6% slow decomposition urea), the third treatment (0.5% urea and 1.2% slow decomposition urea) and the fourth (1.8% slow decomposition urea only) took the study took four e×perimental periods, each period lasting 19 days (14 days introductory period and 5 days sample collection period) with a cross over design. The digestibility coefficient of dry matter ingested was (74.74, 75.91, 76.14 and 75.87%), and the digestibility coefficient of protein reached (85.67, 86.70, 87.89 and 88.29) % and the coefficient of fiber digestion (29.64, 28.96, 49.53 and 41.43) % respectively for the four coefficients. The results did not indicate significant differences in the pH value of rumen fluid before feeding and two hours after feeding. While the results indicated significant differences (p<0.05) in the concentration of ammonia in the rumen liquid before feeding, where it amounted to 4.95, 6.07, 5.0 and 5.52 mmol / 100 mol, and significant differences were noted (p<0.05) in the number of bacteria before feeding, as it amounted to (45.25, 25.75, 13.25 and 26.50103× / ml), and two hours after feeding amounted to (22.50, 19.75 and 48). 75 and 52,00103× (/ ml and the numbers of protozoa before feeding, as it amounted to (12.00, 4.50, 6.00 and 7.00) 103× / ml and two hours after feeding, as it amounted to (5.25, 7.75, 12.75 and 6.50) 103× / ml rumen fluid respectively and the fourth. Through the results, it was noted that there is a positive effect of adding menogen to the diets of Awassi lambs in digestion and some characteristics of the rumen.
