J.E. Rossi and S.C. Loerch1
The Ohio State University Department of Animal Sciences
Abstract
Steer calves (n = 107; initial body weight (BW) = 602 ± 6.2 lb) were allotted to 12 pens with eight or nine steers per pen and four pens per treatment to determine effects on performance of restricting feed intake of a high concentrate diet vs various dietary proportions of corn silage. Periods of growth were as follows: 602 to 806 lb BW (Period 1), 807 to 1105 lb BW (Period 2), and 1105 to 1244 lb BW (Period 3). In two of the dietary regimens, steers were offered feed ad libitum throughout the experiment and were fed either a grain-based diet containing 15% corn silage in each period (AL), or were fed an 85, 50, and 15% corn silage diet (CS) in Periods 1, 2, and 3; respectively. In the third feeding regimen, a prescription intake (PI) feeding system was used. Steers were fed a 15% corn silage diet in each period. However, feed intake was restricted to achieve a predicted gain of 2.5 lb/day in Period 1, 3.0 lb/day in Period 2, and feed was offered ad libitum in Period 3. In Period 1, average daily gain (ADG) was greatest (3.70 lb/day) for steers offered the 15% corn silage diet ad libitum, intermediate (3.35 lb/day) for steers in the CS regimen, and lowest (2.87 lb/day) for steers in the PI regimen (P < 0.01). Feed efficiency was similar (P = 0.26) among treatments. For the entire experiment, ADG was similar (P = 0.41) among treatments and feed efficiency was lower (P < 0.10) for steers in the CS regimen compared with steers in the PI and AL regimens.