Study on effects of different levels of yeast on growth performance and gut morphology of commercial broilers in Chittagong, Bangladesh

Abstract

The study was conducted to investigate the effect of diets formulated with different levels of Saccharomyces yeast on growth and gut morphology of broilers. Day-old broiler chicks of either sex (Cobb 500; n= 240) were distributed randomly into 4 (four) dietary treatments, each replicated three times, twenty birds per replicate in a completely randomized block design. Birds were reared in an open-sided housing condition with similar feeding, lighting and environmental management condition up to 35 days. Data were collected for feed intake and body weight and body weight gain and feed conversion ratio were calculated. Dressing percentage, organ weight and gut morphology of birds were measured at the end of the experiment. At 35 days of age, two birds from each replicate were sacrificed after 12 hours of fasting and samples of ileum and jejunum were taken. Result indicated that use of yeast had no significant effect (P < 0.05) on feed intake and body weight of broiler. Effect of different treatments on feed conversion ratio (FCR) of broilers differed significantly at 3rd week of age (P<0.05). Highest dressing percentage (72.44%) was found in the broilers that received 2 % yeast treated diet but it did not differ significantly. No adverse effect was observed with respect weights of different organs of birds fed yeast. However, significantly highest liver weight (3.92 gm.) was obtained in the birds fed 2.5% yeast. In present study, no significant differences were found in the villus height, crypt depth and muscularis height with increasing level of yeast supplementation where birds fed 2% yeast had the highest mean value. Finally, it was concluded that using of 2% yeast in poultry diet would be advantageous for better growth performance of broilers without any detrimental effects. Key words: Broiler, Yeast, Gut morphology, Growth performanc