Effect of corn silage inclusion with different corn processing on finishing steer performance and carcass characteristics

Abstract

Objectives were to determine the effect of corn silage inclusion within dry-rolled corn or steam-flaked corn finishing diets on cattle growth performance and carcass characteristics. The experiment used British and continental crossbred steers (n=480; initial body weight = 389 ± 17 kg) in 4 × 2 factorial arrangement of treatments with 6 replications per treatment. Treatments consist of four inclusions of corn silage (0%, 15%, 30%, or 45%; DM basis) within either a dry-rolled corn (DRC) or steam-flaked corn (SFC) diet. A corn silage by corn processing interaction was observed for dry-matter intake (DMI; P = 0.05). As corn silage inclusion increased in the diet, DMI increased linearly (P < 0.01) for both corn processing methods. Dry matter intake was not different between SFC and DRC fed cattle at 0% (P = 0.33), 30% (P = 0.90), or 45% (P = 0.31) corn silage inclusion. The interaction was due to DMI of cattle fed 15% silage, as cattle fed DRC consumed 0.5 kg/d less (P < 0.01) than cattle on the SFC diet. Quadratic effects were observed for final body weight (BW), hot carcass weight (HCW), average daily gain (ADG), feed efficiency (G:F), marbling, and fat depth (P < 0.01), regardless of corn processing. Cattle fed 15% or 30% corn silage gained faster (P < 0.01) than those fed 0% or 45% corn silage. Feed efficiency decreased quadratically (P < 0.01) as silage inclusion increased in the diet with G:F similar for cattle fed 0% and 15% silage and decreased curvilinearly for cattle fed 30% and 45% silage. The incidence of liver abscesses was greater (P = 0.03) in cattle fed 0% corn silage than for steers fed 15, 30, or 45% corn silage. Corn processing method, independent of silage, had no effect (P = 0.42) on liver abscess incidence. Feeding SFC increased (P < 0.01) steer final BW and HCW when compared to cattle fed DRC, regardless of silage inclusion. Corn silage inclusion had similar effects on performance in both DRC diets and SFC diets except for DMI. As corn silage inclusion increased in the diet, feed efficiency decreased linearly (P < 0.01). Cattle fed SFC gained 7.9% more (P < 0.01) and were 6.7% more efficient (P < 0.01) than cattle fed DRC. In diets containing either DRC or SFC, corn silage can be included at up to 30% of the diet without negative impacts on ADG or HCW.