Effect of aα-galactosidase supplementation of cereal-soya-bean-pea diets on the productive performances, digestibility and lower gut fermentation in growing and finishing pigs

Abstract

AbstractAn experiment was carried out to study the effect of addingα-galactosidase to the diet on the performance and digestive parameters of growing-finishing pigs. Fifty-four gilts, average body weight (BW) of 43 (s.e. 0·4) kg, were allocated to 18 pens and used in a production experiment divided in two consecutive periods of 28 days each (growing and finishing). In each period gilts were given a diet based on cereals, soya-bean meal and peas, supplemented (Enzyme) or unsupplemented (Control) with 200 units per kg ofα-galactosidase. All diets included 2 g Cr2O3per kg as a digestibility marker. Food intake and body weight were recorded every 2 weeks and faecal samples by pen were collected at the end of each period. Average daily gain (ADG), food: gain ratio and faecal digestibility of dry matter (DM), crude protein (CP) and neutral-detergent fibre (NDF) were calculated. At the end of the production experiment nine gilts from each treatment were selected and given the finishing diet for a further 10 days before being slaughtered. Samples of digesta from the ileum and caecum were collected and ileal digestibility of monosaccharides determined. Short chain volatile fatty acids (SCVFA ) and purine bases (PB) in caecal digesta were analysed. The use ofα-galactosidase improved the ADG (P< 0·01) and the food: gain ratio (P< 0·01) simultaneous to increases in the faecal digestibility of DM (P< 0·05), CP (P< 0·05) and NDF (P= 0·07) in the finishing period. Alpha-galactosidase supplementation also improved the ileal digestibility of some monosaccharides (galactose, rhamnose, mannose and fucose) of the dietary fibre fraction (P< 0·05); and reduced total caecal concentration of SCVFA (P= 0·15), proportion of branched-chain VFA (P< 0·001), and concentration of total PB (P< 0·001). It is concluded that addingα-galactosidase to a cereal-soya-bean meal-pea diet improves ADG, food: gain ratio and digestibility in fattening pigs, and reduces the amount of fermentable substrate flowing to the large intestine.