Mannanoligosaccharide as Alternative to Antibiotic Growth Promotants in Broiler Chicken Diets

Abstract

Five experiments were conducted to examine the growth-promoting effects induced by MOS(Bio-MOS, Alltech Inc.) and the mechanisms underlying these effects in broiler chickens. To elucidate the mechanisms of the growth-promoting effects of MOS, its roles in energy and nutrient utilization, and the development of gut microflora and gut morphology of birds were investigated. Young birds responded to MOS more than old birds did. Improved BWG (3 to 14% increase)and/or FCR (2 to 10% decrease) were observed in birds fed MOS-supplemented diets compared to the negative control, however, these effects were largely dependent on diet and rearing environment. W11en birds were reared under an optimal experimental condition, MOS did not show any significant effects on the growth rate of birds except a tendency for MOS to increase BWG was noticed. On the other hand, MOS significantly improved the growth rate of birds fed a wheat-based diet and the effects were much greater than those in birds fed a com-based diet. Similar results were found with nutrient digestibility and brushborder membrane enzyme activities. Although no significant differences in AME were noticed in birds fed a corn-based diet between MOS treatment and the negative control, the AME value of a sorghum wheat-based diet was significantly improved by MOS and the net energy value of the diet was numerically improved by MOS. Dietary MOS also appeared to positively affect the flock uniformity, especially when birds were reared on a wheat-based diet. The liveability of birds was not significantly affected by MOS.