Effects of feeding combinations of steam-flaked grain sorghum and steam-flaked, high-moisture, or dry-rolled corn on growth performance and carcass characteristics in feedlot cattle

The objective of these two feeding trials was to determine the associative effects of feeding steam-flaked grain sorghum (SFGS) in combination with st eam-flaked (SFC), dry-rolled (DRC), or high-moisture (HMC) corn on growth p erformance and carcass characteristics in feedlot cattle. In Trial 1, 200 y earling heifers were blocked by weight, allotted to 25 pens, and fed one of five finishing diets (77% grain, 15% corn silage, and 8% supplement on a D M basis) for an average of 137 d. The grain combinations were 100:0, 75:25, 50:50, 25:75, and 0:100 SFC:SFGS, respectively. Treatment had no effect on DMI (P > .05), but ADG, gain efficiency, and final live and hot carcass we ights decreased linearly (P < .05) as the proportion of SFGS increased in t he diet. Carcass backfat, quality grade, and liver abscess score were not a ffected (P > .05) by treatment. In Trial 2, 306 yearling steers were blocke d by weight, allotted to 30 pens, and fed diets that contained 74.5% grain, 10% corn silage, 7.5% soybean meal, 4% tallow, and 4% supplement (DM basis ) for an average of 139 d. The grain and grain combinations were 100% DRC, HMC, SFC, or SFGS and a 67%:33% combination of SFGS: DRC or SFGS:HMC. For s teers fed diets containing a single source of grain, those fed SFC gained 7 % more live weight and had a 7% higher gain efficiency(P < .05) than those fed DRC or HMC. Growth performance of steers fed SFGS was intermediate. Fee ding grain combinations (67% SFGS:33% HMC or DRC) resulted in a 5 to 6% pos itive associative effect (P < .05) for ADG and gain efficiency. Carcass cha racteristics were not affected (P > .05) by treatment. We concluded that th ere were significant benefits (positive associative effects) when SFGS was fed in combination with DRC or HMC, but the effects were smaller when SFGS was fed in combination with SFC.