Supplementation of [alpha]-1,6-galactosidase and [beta]-1,4-mannanase to improve soybean meal utilization by growing-finishing pigs. (Nonruminant Nutrition)

Two experiments were conducted to test a hypothesis that dietary supplementation of a carbohydrase mixture (mainly composed of [alpha]-1,6-galactosidase and [beta]-1,4-mannanase) improves nutrient utilization of soybean meal by growing-finishing pigs. In the first experiment, eight,surgically cannulated, finishing pigs were fed soybean meal based diets containing the carbohydrase to evaluate supplemental effects (0.05 and 0.10%) on apparent and true ileal digestibility of soybean meal. A low-protein (4.4% CP) casein diet was fed to measure endogenous protein loss. Both apparent and true ileal digestibilities of major limiting amino acids, i.e., lysine, threonine, and tryptophan, were improved (P < 0.05) when the carbohydrase was added to the diet at 0.05% and 0.10% levels. Energy was utilized more efficiently (P < 0.05) by pigs fed the diet containing 0.05% carbohydrase than the control diet. In the second experiment, one hundred growing pigs (24.1 [+ or -] 0.6 kg) were fed either a control diet (3,278 Mcal ME/kg diet) or a low energy diet containing carbohydrase (3,109 Meal ME/kg diet, 5% lower ME than the control diet) for four weeks. Supplemental level of the carbohydrase was 0.05%. Pigs fed the low energy diet with carbohydrase had similar average daily gain to that of pigs fed the control diet either by each week or during the entire experimental period. Average daily feed intake of pigs did not differ between treatments during the first, second, and third weeks. During the fourth week, pigs fed the low energy diet with carbohydrase had higher feed intakes (P < 0.05) than pigs fed the control diet. However, there was no difference in average daily feed intake during the entire experimental period. Gain:feed ratio did not differ between the treatments either by each week or during the entire experimental period. According to the results, supplementing a carbohydrase mixture (mainly composed of [alpha]- 1,6-galactosidase and [beta]-1,4-mannanase) improves nutrient digestibility of soybean meal. Pigs fed the low energy diet had similar growth performance to that of pigs fed the control diet. Key Words: Pigs , Carbohydrase, Soybean meal