Effect of feeding wheat millrun on diet nutrient digestibility and growth performance in starter pigs

Abstract Text: Wheat by-products from flour milling could be an alternative feedstuff to reduce feed cost of pigs. Thus, the objective was to evaluate how graded substitution of soybean meal (SBM) and wheat with wheat millrun influenced nutrient digestibility and growth performance in starter pigs. The wheat millrun contained (as-fed) 12.1% ADF, 37.0% NDF, 16.8% CP, and 0.74% lysine. Diets were balanced for NE using canola oil and for AA using crystalline AA to contain 2.41 Mcal NE/kg and 4.39 g standardized ileal digestible (SID) Lys/Mcal NE. Five pelleted wheat-based diets containing 0, 5, 10, 15, or 20% wheat millrun in substitution for up to 15% SBM and 5% wheat were fed to 160 weaned pigs (housed in pens of 4 pigs) for 3 wk (d 1–21) starting 2 wk after weaning at 21 d of age. Freshly-voided feces were collected by grab sampling on d 19–20. Increasing inclusion of wheat millrun to 20% linearly reduced (P<0.001) diet apparent total tract digestibility (ATTD) of DM by 4 percentage units and diet ATTD of GE by 2.9 percentage units, but did not affect ATTD of CP. Diet NE values predicted using measured diet DE values and analyzed macronutrients linearly increased (P<0.05) by 0.02 Mcal/kg with increasing inclusion of wheat millrun, indicating that the NE value of wheat millrun was underestimated for weaned pigs. Increasing dietary inclusion of wheat millrun tended to linearly reduce (P=0.07) ADFI by 65 g/d for d 1–7, linearly increased (P<0.05) G:F by 0.10 for d 8–14, and did not affect growth performance variables in other weeks. Overall (d 1–21), increasing dietary inclusion of wheat millrun did not affect ADFI, ADG, or G:F. In conclusion, up to 20% wheat millrun can replace 15% SBM and 5% wheat in diets formulated to equal NE and SID Lys and fed to nursery pigs starting 2 wk after weaning without detrimental effects on growth performance.

Keywords: growth performance, pig, wheat millrun