One hundred sixty-four crossbred beef
steers were used to determine optimal Rumensin
® concentrations in limit-fed, high-energy,
growing diets. Diets contained 30, 40, or 50
grams of Rumensin per ton of dry matter (R30,
R40, and R50). Average daily gain and feed
efficiency during the growing phase were not
different (P>.80) among treatments. Steers that
received R50 in the growing phase had the
highest average daily gains during the finishing
phase (P<.05). This resulted in heavier carcass
weights for R50 than R30 (P<.05) and R40
(P<.12). Feed efficiencies during the finishing
phase were not different among treatments
(P>.40).