Effects of dietary xylanase and liquid feeding on growth performance and nutrient digestibility of weaner pigs fed diets high in millrun (wheat by-product)

Abstract

The viability of including millrun (a byproduct of wheat milling) in diets for weaned pigs was assessed in two 26-day feeding experiments, the first using 48 and the second 128 individually housed, entire male pigs (Large White × Landrace) weaned at 28 days (average weight 7.4 kg). In Experiment 1, millrun included in iso-energy, iso-lysine diets at 0, 12.5, 25, 37.5, and 50% had no effect on performance or digestibility. Therefore, in Experiment 2, pigs received diets containing 50% millrun in a 2 × 4 factorial design. The two factors were: (1) feed form (dry or liquid) and (2) enzyme supplementation (0 or 300 μg/g of a xylanase primarily targeting soluble non-starch polysaccharide (sNSP), 400 μg/g of a xylanase targeting only insoluble NSP, or both xylanases. The inclusion of NSP-degrading enzymes had no significant effect on pig performance or diet digestibility. Feed conversion ratio (FCR) was improved by 0.10 ± 0.02 in liquid-fed pigs (P < 0.05). Apparent digestible energy and faecal gross energy (GE) digestibility were not affected by treatment, but ileal GE and crude protein (CP) digestibility were, respectively, 9.0 ± 3.4 and 2.5 ± 0.65 percentage units higher in pigs fed liquid diets (P < 0.05). Dietary treatment significantly affected the concentrations of sugar, starch, total NSP, and sNSP in digesta from different segments of the gut, without affecting pig performance. In conclusion, weaner pigs can be fed appropriately formulated diets containing 50% millrun without loss of performance. The FCR and CP digestibility were improved by liquid feeding, but not by the addition of NSP-degrading enzymes.