Effects of lowering dietary NDF levels prior to marketing on finishing pig growth performance, carcass characteristics, carcass fat quality, and intestinal weights (2011)

Abstract

A total of 264 pigs (PIC 327 × 1050, initially 90.1 lb) were used in a 90-d study to determine the effects of withdrawal of high dietary NDF (provided by wheat middlings [midds] and dried distillers grains with solubles [DDGS]) on growth performance, carcass characteristics, carcass fat quality, and intestinal weights of growing-finishing pigs. Pens of pigs were randomly allotted by initial weight and gender to 1 of 6 dietary treatments with 6 replications per treatment. There were 24 pens with 7 pigs per pen (3 barrows and 4 gilts) and 12 pens with 8 pigs per pen (4 barrows and 4 gilts). A positive control diet containing no DDGS or midds and a negative control diet containing 30% DDGS and 19% midds was fed the entire study duration (no withdrawal). The other 4 treatments were arranged in a 2 × 2 factorial with the main effects of withdrawal time (23 or 47 d) and NDF level fed during the withdrawal (low or medium). Pigs on these treatments were fed the negative control diet containing 30% DDGS and 19% wheat midds (19% NDF) prior to their withdrawal treatment. The medium fiber withdrawal diet contained 15% DDGS and 9.5% midds (14.2% NDF). The low-fiber withdrawal diet was the positive control diet without DDGS or midds (9.3% NDF). Increasing the duration of the withdrawal lowered overall ADFI (linear, P 0.61) growth performance. Withdrawing the high-fiber diet improved carcass yield (P < 0.004) with a greater response (P < 0.001) when the low-NDF diet was fed during the withdrawal instead of the medium NDF diet; however, increasing the withdrawal time from 23 to 47 d did not further improve yield (P = 0.11).