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

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.