77 Performance of growing pigs fed wheat-based diets containing wheat millrun and a multi-carbohydrase enzyme

Abstract

Abstract The inclusion of wheat millrun, a low-cost milling co-product, into swine rations is limited by high non-starch polysaccharide content. The objective of these trials was to determine the response of growing pigs to wheat millrun inclusion, with or without, a multi-carbohydrase enzyme (xylanase, cellulase, amylase, glucanase, invertase). In Exp1, the effects of millrun inclusion and multi-carbohydrase on nutrient digestibility were investigated. The six treatments, arranged as a 3x2 factorial, included millrun (0, 15 or 30%) and enzymes (0 or 1 mg/kg) as main effects. Barrows (n = 48; 60.2±2.2 kg) were housed individually and fed 3×maintenance for 11d. Feces and urine were collected d8-11. In Exp2, 4 treatments (0 or 30% millrun and 0 or 1 mg/kg enzyme; 2x2 factorial) were fed to 180 pigs (60.2±2.2 kg) housed in groups of 5 until they reached 125 kg BW. The diets were isonitrogenous while energy was reduced in the millrun diets. In Exp1, apparent total-tract digestibility (ATTD) of energy and N, and digestible energy (DE) content, declined linearly (87.3 to 81.5%; 86.3 to 83.5%; 3.86 to 3.68 Mcal DE/kg DM, respectively; P < 0.01) with increasing millrun inclusion. ATTD of energy was reduced by the inclusion of the enzymes (85.0 to 84.2%; P = 0.05) but there was no effect on DE content, or N ATTD (P > 0.10). In Exp2, ADG and G:F were reduced in pigs fed millrun (P < 0.05) while pigs fed diets supplemented with enzymes had reduced G:F during the initial 14d. There was no effect of millrun or enzyme on ADFI or days to market (P > 0.10). No interactions were detected between millrun and enzyme in either Exp1 or Exp2 (P > 0.10). In conclusion, reduced ADG and energy and N digestibility, were observed with the inclusion of 30% wheat millrun in diets for growing pigs, regardless of multi-carbohydrase enzyme inclusion.