Evaluating the Effect of Adaptation Length on Apparent Ileal and Total Tract Digestible Energy of Corn and Wheat Middlings in Growing Pigs

Abstract

This study invest\ufeffigates the effect of adaptat\ufeffion length of cornand wheat middlings (WM)-based diets on apparent ileal and total tract digest\ufeffible energy (DE) of corn and WM using the difference method. Twenty-one ileal cannulated pigs (BW=34.1 ± 1.5 kg) were allotted in a 3 × 3 factorial arrangement of treatments using the randomized complete block design with 3 diets (reference, reference+corn, or reference+WM) and 3 adaptat\ufeffion lengths (4, 8, and 12 days). Each pig was fed 4% of the BW of the lightest pig within each block. Reference+corn and reference+WM diets were produced by replacing 30% of the energy yielding components of the reference diet (corn-SBM-based) with corn or WM, respect\ufeffively. Ileal and fecal samples were collected on days 4, 8, and 12. Proc mixed model of SAS was used to analyze the data and a repeated statement was included to account for correlated observat\ufeffions made on the same animal. The main effect of diet type on ileal and total tract DE, dry matter (DM) and energy (EN) digest\ufeffibility was different with reference+WM diet having lower (P<0.05) values. Diets total tract DE (2.7%), DM (2.6%) and EN (2.8%) digest\ufeffibility increased (P<0.05; linear and quadrat\ufeffic effect) with increasing adaptat\ufeffion length. Ileal (3,325 vs 1,778 kcal/kg) and total tract (3,668 vs 2,864 kcal/kg) DE of corn was higher (P<0.05) than that of WM. Hindgut EN disappearance showed a tendency to increase (P=0.051) linearly with adaptat\ufeffion length (index method). Energy loss in the hindgut from the reference+WM diet was higher (P<0.05) compared to that of the reference diet (subtract\ufeffion method). Data from this study showed that the DE of corn and WM increased by 10 and 61%, respect\ufeffively, between the ileal and total tract values. Finally, four days of adaptat\ufeffion is sufficient for corn and WM ileal and total tract DE determinat\ufeffion.