225 Identifying optimal levels of silage used as a roughage source in finishing beef cattle performance and liver abscess rate

Abstract

Abstract Including a roughage source in high grain finishing diets can minimize the potential for acidosis and decreased animal performance. An individual feeding study was conducted comparing different levels of corn silage used as a roughage source on finishing performance and liver abscess rate. Sixty crossbred steers (432 kg ± 0.45 kg) were stratified by BW and assigned randomly to 4 treatments with 15 head per treatment. Treatments consisted of 3 inclusions of corn silage at 0 (CS0), 7.5 (CS7.5) and 15% (CS15) of the diet DM and a control treatment with 7.5% alfalfa (Alf). Steers were fed for 117 d in a Calan gate controlled individual feeding system. Refusals were taken weekly and corrected for DM. There were no differences for final BW (P < 0.88), DMI (P < 0.51), ADG (P < 0.88), or G:F (P < 0.20). There were no differences for carcass characteristics such as HCW (P < 0.83), marbling (P < 0.59), LM area (P < 0.84), or fat thickness due to treatment (P < 0.45). There were also no differences in dressing percentage (P < 0.26) or calculated yield grade (P < 0.63). Only 3 out of the 60 animals had liver abscesses, with 2 animals fed CS0 and 1 animal fed Alf. These data suggest that cattle, typically at high risk for reduced performance, are less likely to experience negative effects of high grain diets, like acidosis, when fed individually. When managed accordingly, no roughage is needed in the diet.