Reducing foregut digesta viscosity is the primary mode of action of feed enzymes in improving performance in broilers fed wheat and barley based diets (Bedford & Classen, 1991, Graham et al, 1992). In pigs, inclusion of appropriate fibre-degrading enzymes can improve the apparent digestion of nutrients in the small intestine (Graham et al, 1988). This has been attributed to both reduced digesta viscosity and an opening up of the feed cell walls enclosing the nutrients. However, the exact mechanism of this effect is unknown. This trial was designed to investigate the influence of enzyme supplementation on gut parameters in the pig.
A total of 40 crossbred pigs were weaned at about 9.5 kg and placed into 5 blocks of 8 individual metabolism cages based on litter origin, sex and liveweight. There were 2 treatment replicates per block. The mash diets were based on barley (751 kg/t), soyabean meal (150 kg/t), fish meal (40 kg/t) and soya oil (20 kg/t), with 1 kg/t chromic oxide as a marker. A hulled, low β-glucan (2.9 % of DM; Arra, Finland) and a naked, high β-glucan (5.3 % of DM; Condor, Canada) barley were used, and diets were fed without or with added /3-glucanase. Pigs were fed for 21 days, then sacrificed. Digesta was collected from the stomach, 4 equal lengths of the small intestine, the caecum and 2 equal sections of the colon plus rectum.