Effect of different levels of mannan-oligosaccharide supplementation on the apparent ileal digestibility of nutrients, N-balance and growth performance of weaned piglets.

Several studies report that dietary mannan-oligosaccharides (MOSs) improve the growth performance of piglets, however, only a few studies focus on nutrient digestibility. The aim of the study was to investigate the effect of dietary MOS on ileal digestibility of nutrients and on N-balance and growth performance of piglets weaned at 28 days of age. Three experiments were conducted: a digestibility trial with a total of 30, simple T-cannulated piglets (Exp. 1), a N-balance trial with a total of 48 intact piglets (Exp. 2) and a performance trial with a total of 324 piglets (Exp. 3). In Exp. 1 and 2, the same five dietary treatments were carried out by supplementing the basal diet with 0, 1, 2, 4 g MOS or with 0.2 g antibiotic growth promoter (AGP, Avilamycin) per kg of diet. In Exp. 3, three dietary treatments were used as follows: the basal diet was supplemented no additive, 2 g MOS or 0.2 g AGP (Avilamycin) per kg of diet. Dietary MOS (2 or 4 g/kg) enhanced the ileal digestibility of crude protein similar to antibiotics. Addition of 1 g/kg MOS significantly increased the digestibility of Ca and P by 8.4% and 7.7% units, respectively; however, further increment did not enhance the absorption. Addition of 1 or 2 g/kg MOS significantly increased the ileal digestibility of lysine, methionine, cystine and threonine with the same magnitude or even more than the AGP. In our study, MOS supplementation had no influence on N-balance and growth parameters. Because of the better apparent ileal digestibility of certain nutrients, however, the protein, lysine, methionine, cystine, threonine, Ca and P contents of the diet can probably be reduced without weakening the rearing performance of piglets, when the diet is supplemented with 2 g/kg MOS.