Introduction
Feeding cattle to achieve stepwise increases in rate of gain has been shown to result in similar performance and carcass characteristics as steers offered feed ad libitum throughout the feeding period (Knoblich et al., 1997; Rossi et al., 2000). Offering feed ad libitum and decreasing the proportion of dietary roughage as the feeding period progresses may result in stepwise increases in rate of gain similar to that observed with restricting DMI of high-concentrate diets.
Cattle consuming roughage-based diets have greater gastrointestinal tract weights than cattle consuming concentrate-based diets (Rompala et al., 1988), which may increase maintenance requirements and negatively affect rate of gain during compensatory growth. Diets consisting of high proportions of corn silage (Loerch, 1990) or hay (Gunter et al., 1998) have been used to limit rate of gain in the first half of the feeding period; subsequent effects on rate of gain during the finishing phase are unknown.
Objectives were to determine the effects of varying the proportion of corn silage when fed ad libitum throughout the feeding period versus a prescription intake feeding regimen on performance and carcass characteristics of steers.