Effect of feeding different levels of dietary protein and addition of baker’s yeast (Saccharomyces cerevisiae) on Awassi lambs. performance. 3-Blood parameters

24 Awassi lambs were used to study biochemical changes in blood parameters as affected by concentrate diets containing different levels of dietary crude protein (CP) (low, medium and high) offered with or without baker s yeast (Saccharomyces cerevisiae, SC, (0 or 0.5%). Concentrate diets were offered to lambs at rate of 3% of live Body weight (BW) in addition to free choice of barley straw. Blood samples were withdrawn from lambs before feeding (0 time), 3 and 6 hrs post feeding. Results showed that blood urea nitrogen (BUN) concentrations were inversely affected by the mentioned factors, where, it increased with each increase in CP level, higher (P 0.01) value (45.73 mg.100 ml-1) was detected with high level as compared to that detected with low level (40.97 mg.100 ml-1), while, it decreased (P 0.01) from 44.88 to 41.01 mg/100 ml due to addition of yeast. Higher blood glucose (BG) (P 0.01) and blood total protein (BTP) (P 0.05) concentrations were detected in blood samples withdrawn from yeast supplemented lambs. Increasing level of dietary protein had no effect on BG, BTP and blood triglyceride (BTG). The concentration of blood components associated lipid { blood cholesterol (BCH) and BTG} were not affected by addition of SC.