PSI-32 Effect of Cereal Grain Source and Cereal Silage Source on Nutrient Utilization and Performance of Finishing Beef.

摘要

The objective of the current study was to evaluate the effects of silage and cereal grain source and their interaction for finishing beef cattle. Steers (initial BW 464 ± 1.0 kg) were randomly assigned to 1 of 24 pens (12 steers/pen) in an 89-d finishing study. Diets were arranged in a 2 × 3 factorial with corn silage ( ) or barley silage ( ) included at 8% (DM basis). Within each silage source, steers were fed dry-rolled barley ( ; 86% of DM), corn ( ; 85% of DM), or an equal blend of barley and corn ( ; 85% of DM). Total tract digestibility was estimated from fecal samples using near infrared spectroscopy. Data were analyzed using the Mixed Model of SAS with the fixed effects of silage, grain, and the 2-way interaction. Carcass data were analyzed using GLIMMIX. There were no interactions detected. Final BW was not affected by treatment ( 0.05; 649 ± 3.2 kg). Feeding CG increased ( < 0.01) DMI by 0.8 and 0.6 kg/d relative to BG and BCG, respectively. The G:F was greater for BG than CG ( = 0.040), but was not different from BCG (0.17, 0.16 and 0.17 kg/kg, respectively). However, ADG (2.07 kg/d) was not different among treatments ( 0.05). Hot carcass weight was 6.2 kg greater and dressing percent was 0.57 percentage units greater ( 0.002 and 0.039, respectively) for steers fed CS than BS. Digestibility of DM, OM, NDF, CP and starch was greatest for BG ( = < 0.01) relative to CG or BCG. Current results indicate that when dry rolled, BG improved performance and digestibility compared to CG and BCG. Even at low inclusion levels (8% of DM), CS inclusion resulted in improved carcass characteristics relative to BS.