Effects of mannanoligosaccharides on composition of the cecal microflora and performance of broiler chickens.

A study was conducted to evaluate the effect of mannanoligosaccharides (MOS) on the composition of the cecal microflora and growth performance of broiler chickens. In this study, 300 one-d-old (male + female) broiler chickens (Cobb) were divided into three groups of 100 chickens each. During the starter (0-21d) and grower-finisher (22 to 42d) stages all groups were fed a standard basal starter and finisher diets. The treatments were: 1) Negative control (NC) (no additive); 2) MOS (Bio-Mos, Alltech Inc), 2.0 kg/ t (0-21d) and 1.0 kg/t (22-42d) and 3) Positive control (PC) (Avilamycin, 10 ppm/kg). At the end of the trial (42 d) five birds from each group were sacrificed and intestinal sections frozen in glycerin-salt solution. The following bacterial populations were enumerated – Total anaerobes, coliforms, lactobacilli, bifidobacteria, enterococci, salmonella and Cl. perfringens. Feeding MOS in the diet resulted in the enhanced growth of beneficial microorganisms, regulated the microbial environment in the cecum, and significantly increased the count of lactobacilli and bifidobacteria. Feeding MOS in the diet depressed Cl. perfringens and coliforms in cecal content, in comparison to the NC and PC. MOS significantly affected the live body weight of broiler chickens at 21d and 42d compared to the NC and the PC fed groups (P<0.001). MOS improved FCR (0-42d) compared to NC and PC, 1.768 vs. 1.915, and 1.799 respectively. Supplementing MOS or Avilamycin in the diets improved feed efficiency by 7.68% and 6.06% compared to NC. MOS also decreased broiler mortality by 2% and 4% compared to PC and NC, respectively. These results suggest that MOS can provide an alternative to the growth promoting antibiotic Avilamycin in broiler nutrition. In addition, the results suggest that MOS may be useful in controlling Cl. perfringens, an agent implicated in necrotic enteritis in broilers. Introduction The ban of antibiotic growth promoters in many countries worldwide has forced the broiler industry to search of natural alternative growth promoters to maintain of broiler performance and to control of diseases without antibiotics. The objective of the present study was to examine the effect of mannanoligosaccharides (MOS) on the cecal microflora and growth performance of broiler chickens. Materials and Methods Chickens, diet, and housing. Three hundred one-d-old (male + female) broiler chickens (Cobb) supplied by a commercial broiler hatchery were used in the current experiment. The chickens were divided into three groups of 100 chickens each. During the starter (0-21d) and growth-finisher (22-42d) periods all groups were fed the standard basal starter and finisher diets. The treatments considered of: 1) Negative control (NC) (no additive); 2) MOS (BioMos, Alltech Inc., USA), 2.0 kg per ton of feed for the first three weeks (0-21d) and 1.0 kg/t of feed thereafter (22-42d); 3) Positive control (PC) (Avilamycin (10 ppm/kg of feed). Throughout the growth period, feed and water were provided without restriction (ad libitum). The chickens were reared in heated premises on floors covered with fresh pine shavings. The environmental temperature, ventilation and photoperiod (light cycle) were regulated according to standard management practices for bird age and external weather. Sampling procedures. At the end of the trial (42d) five birds from each group were randomly selected and killed by neck dislocation for collection of cecal contents. By using