| An experiment was conducted to compare the effect of different levels of yeast (Saccharomyces cerevisiae SC47) commercial broilers performance. A total of 400 male one-day old chicks (Ross 308) in completely randomized design were used. The experiment consisted of 5 treatments (0, 0.5, 1, 1.5 and 2 Kg Yeast per ton diet) and 4 replicates each with chicks. The experiment of diets fed according to nutrient requirements of poultry in three different periods. During the experiment feed intake, average body weight gain, feed conversion ratio, mortality and feed cost measured. At the age of 49 day, of one bird each of replicates was select were of and slaughtered and carcass (carcass percentage, leg, breast, liver, heart and blood metabolites (W.B.C and R.B.C) was measured. The results showed that feed intake (g/h/d), body weight and weight gain in yeast groups diets at starter, grower and finisher were higher than controls and these differences was significant (p<0.05).Feed conversion ratio in group 3 (1 Kg yeast per ton of diet) was better than control and other treatments, but these differences wasn’t significant (p>0.05).Using yeast (Saccharomyces cerevisiae Sc47) in broilers diet decreased the percentage of mortality (p<0.05).The percentage Carcass, leg and breast didn’t affected by using yeast (p<0.05) but percentage liver, heart, gizzard, fat abdominal, blood metabolites (W.B.C. and R.B.C.) and mortality affected by using yeast and these differences was significant (p<0.05).Too price feed for each Kg weight gain in period starter, grower and finisher affected by using yeast and these differences was significant but in period finisher and In all period but these differences wasn’t significant (p>0.05). |
