The interaction between cereal type and lactose level on piglet performance and diet digestibility post weaning

Abstract

AbstractBoth barley and wheat contain anti-nutritive factors such as glucans and xylans respectively. However, β-glucans have been shown to promote lactic acid bacteria in the large intestine and this would be very beneficial in the absence of in-diet antimicrobial growth promoter. A 2 × 2 factorial was used to investigate the interaction between cereal type (wheatv. barley) and lactose inclusion (170v. 275 g/kg) on piglet performance post weaning. Two hundred and sixteen weaned piglets (24 days of age, 6·0 kg weight) were blocked on the basis of weight and were assigned to one of four dietary treatments. The treatments were as follows (T1) 170 g/kg lactose and wheat, (T2) 275 g/kg lactose and wheat, (T3) 170 g/kg lactose, wheat and 200 g/kg barley and (T4) 275 g/kg lactose, wheat and 200 g/kg barley. The diets were formulated to have identical concentrations of digestible energy (16 MJ/kg) and total lysine (16 g/kg). The pigs were offered the diets ad libitum for 33 days post weaning. There was a significant interaction (P< 0·05) between cereal source and lactose level in average daily gain (ADG). In wheat-based diets the inclusion of 275 gkg lactose resulted in a significant improvement in ADG, compared with the 170 g/kg lactose inclusion. However, in barley-based diets the inclusion of 275 g/kg lactose significantly (P< 0·05) reduced ADG. There was no significant effect of cereal type or lactose level on food intake or food conversion ratio (FCR). The inclusion of 275 g/kg lactose significantly reduced nitrogen digestibility (P< 0·01). In barley-based diets, the high level of lactose inclusion depressed digestibilities of dry matter (P< 0·01), organic matter (P< 0·05) and gross energy (P< 0·05) compared with low lactose inclusion. However, in wheat-based diets, lactose level had no significant effect. In conclusion, improvements in performance were achieved up to 275 g/kg lactose in wheat-based diets. However, in barley-based diets a dietary lactose level of 170 g/kg was adequate.