The present experiment was carried out to evaluate the effects of using palm kernel meal (PKM) with or without live yeast (LY) in diets on the growth performance, digestibility of diet nutrients, rumen fermentation parameter and selected blood biochemical indices of beef calves. Fifteen uncastrated male crossbred beef cattle calves were used with an average body
weight of 303.5 kg and ages ranged from 10 to 12 months. Calves were divided into 5 equal groups (Three calves in each group). The experimental trial extended for 4 months. Fattening calves were assigned to 5 diets (treatments) as following: G1 (basal diet), G2 (basal diet with 10% PKM), G3 (basal diet with 10 % PKM + LY), G4 (basal diet with 20 % PKM) and G5
(basal diet with 20 % PKM + LY). Growth performance parameters were recorded biweekly throughout the experiment .Fecal, rumen content and blood samples were collected from each calve 3 times (day zero, after 2 month, after 4month). The results of growth performance showed significant (p≤ 0.05) increase in body weight gain, feed intake and better feed
conversion in G3 in comparison with other groups. Rumen fermentation results revealed that calves in G3 showed significant increase in total volatile fatty acids (TVFAs) concentration and decrease in ammonia concentration, Calves in G4 had significant decrease in concentrations of TVFAS and ammonia nitrogen levels. Serum biochemical analysis indicated that calves in G3 and G5 had increase in total protein and BUN values in middle of the experiment with increase in creatinine level at the end of the experiment. The levels of albumin in G3 and G5 were decreased throughout the experiment period.The results concerning nutrient digestibility showed some little degree of variation between different groups .However, all the nutrient digestibility values were within normal ranges. The conclusion is that supplementation of beef calves diet with 10% PKM + LY has a great effect on calves performance,total bodyweight, gain rumen fermentationparametersandblood biochemical indices.