The interaction between enzyme supplementation and lactose level on the performance of weanling pigs fed barley based diets

A 2 × 2 factorial arrangement was used to investigate the interaction between lactose level (170 vs. 275 g/kg) and enzyme supplementation (with or without Endo-1,3 (4)-β-glucanase) in barley based diets (250 g/kg) on piglet performance post weaning. Ninety six weaned piglets (24 days old, 6.5 kg live weight) were blocked on the basis of live weight and were assigned to one of 4 dietary treatments (n = 6) for 21 days. There was an interaction (P < 0.05) between lactose level and β-glucanase supplementation on average daily gain (ADG), food conversion ratio (FCR) and apparent digestibilities of dry matter (DMD), organic matter (OMD) and nitrogen (N). Pigs offered 170 g/kg lactose and β-glucanase supplementation had an improved FCR and ADG compared to the 170 g/kg lactose and unsupplemented barley. However, β-glucanase supplementation at 275 g/kg lactose had no effect on FCR and ADG compared to the 275 g/kg lactose and untreated barley. Pigs offered the diet containing the low level of lactose and β-glucanase supplementation increased (P < 0.05) DMD, OMD and N digestibility compared to the β-glucanase supplemented high lactose diet. However, there was no effect of lactose level in the unsupplemented diets. In conclusion, the inclusion of β-glucanase at the 170 g/kg lactose level improved ADG, FCR and diet digestibility. β-glucanase had a negative effect on FCR and ADG at the 275 g/kg lactose level.