Use of corn gluten feed and dried distillers grains plus solubles as a replacement for soybean meal and corn for supplementation in a corn silage-based stocker system.

摘要

Corn gluten feed and dried distillers grains plus solubles (DDGS) were evaluated as replacements for soybean meal and ground ear corn when supplemented with corn silage during 2 yr of a beef cattle stockering program. Experiment 1: In YR 1, 104 steers (initial BW=305+or-30 kg), and in YR 2, 56 steers and 38 heifers (initial BW=301+or-32 kg) were stratified by weight and assigned to 1 of 9 groups. Each group was randomly assigned to 1 of 3 corn silage-based (75% of DM) diets supplemented with: (i) corn gluten feed (CGF), (ii) DDGS, or (iii) soybean meal and ground ear corn (CSBM) at 25% of DM. On d 0, 28, 56, and 84, BW and BCS were recorded. Additionally, ribeye area, 12th rib fat thickness, intramuscular fat, and rump fat thickness were assessed via ultrasound on 9 (YR1) and 4 (YR 2) steers per pen that were randomly assigned as observational units. Average daily gain was greater (P<0.05) for steers fed DDGS and CSBM compared with CGF (1.08, 1.08, and 0.94 kg/d, respectively). Average DMI (P<0.05) was less for DDGS compared with CSBM with CGF intermediate (18.1, 18.8, 20.2 g/kg BW, respectively), and the resulting G:F was greatest for DDGS (P=0.01). Cost per kilogram of BW gain was least for DDGS (P>0.05). Ultrasound data indicated no differences (P>=0.13) in predicted carcass traits among treatments. Experiment 2: Diets from Exp. 1 were subjected to in vitro digestion for incubation times of 0, 2, 4, 8, 16, 24, 48, and 72 h to estimate DM degradation, gas production kinetics, and CP fractions. The potentially degradable DM fraction was greater (P=0.01) for CSBM compared with CGF and DDG. Total gas production and rate of gas production was not different among treatments (P>0.42). Rumen degradable protein was greatest for CSBM and least for DDG (P=0.001). These data indicate that DDGS can be used to replace soybean meal and corn in silage-based stocker systems to decrease feed costs without compromising animal performance and CGF may decrease animal performance.