Effect of Dietary Yeast (Saccharomyces cerevisiae) Supplementation on Performance, Carcass Characteristics and Some Metabolic Responses of Broilers

Abstract

Abstract: This study was conducted to evaluate the effect of feeding graded levels of yeast on broiler performance, carcass

characteristics and some hematological indices. One day old Hubbard broiler chicks (n=160) were randomly allocated to five

dietary treatments. Each treatment consisted of 4 replicates of 8 broilers each. The dietary treatments contained 0% yeast

(Saccharomyces cerevisiae) as a negative control diet, 0% yeast + 30 ppm Oxytetracyline as a positive control, 1%, 2% and 3%

yeast in the starter and finisher diets. During the experimental periods of 6 weeks, feed intake, body weight gain and feed

conversion ratio values were calculated. At the end of the experimental period (6 weeks of age), some biochemical and

hematological indices, carcass characteristics traits and internal organs weights were recorded. Growth performance parameters

were significantly (P≤0.05) affected by experimental diets. Chicks fed either 0 or 3% yeast recorded the highest (P≤0.05) feed

intake, however, the best (P≤0.05) body weight gain was obtained by birds fed 0 or 1% dietary yeast compared to the positive

control diet. The highest (P≤0.05) feed conversion ratio was reported for birds fed the positive control diet and 3% dietary yeast

compared to the negative control diet. The inclusion of different dietary treatments had no significant (P≥0.05) effects on

dressing percentage, hot base and relative weights of heart, gizzard and abdominal fat. Nevertheless, birds fed 3% dietary yeast

showed significant (P≤0.05) decrease in the relative weight of the liver compared to the negative control diet. Relative weights of

breast and thigh were significantly (P≤0.05) higher in birds fed 1% yeast than those fed 3% yeast. There were linear decreases in

serum cholesterol and albumin of broilers fed graded levels of dietary yeast. It is concluded that yeast can be included in broiler

diet at 1% without detrimental effects on performance, and could therefore serve as a natural substitute for antibiotics.