Effects of Distillers Dried Grains with Solubles as a Protein Source in Creep Feed. 2. Subsequent Feedlot Performance, Carcass Measurements, and Plasma Parameters

A 2-yr study was conducted to evaluate the effects of protein source in a creep ration as well as creep vs. no creep treatments on subsequent feedlot performance and carcass characteristics of steers. During each year, 36 steer calves were assigned to treatments: corn distillers dried grains with solubles (DDGS) or soybeanmeal (SBM) as the protein sources compared with a noncreep dietary treatment. After the creep feeding phase, they were placed in the feedlot. During the receiving period in both years, creep-fed steers tended to have greater DMI (P < 0.10) than noncreep-fed steers, resulting in different (P < 0.01) ADG between creep-fed and noncreep-fed steers in yr 1, but not yr 2. During both years, cost of gain tended to be lower (P ≤ 0.11) for creep vs. noncreep-fed steers. During the grow-ing period in yr 1, noncreep-fed steers were more efficient (P < 0.01) than creep-fed steers, and SBM steers tended to be more efficient (P < 0.10) than DDGS steers. During the growing period in both years, noncreep-fed steers tended to have greater (P < 0.10) ADG than creep-fed steers. In yr 1, creep-fed steers had greater (P < 0.05) final live weights and hot carcass weights, and tended to have greater (P ≤ 0.10) dressing percent, fat thickness, yield grade, and carcass value as compared with noncreep-fed steers. In yr 2, there were no differences in subsequent feedlot performance and carcass characteristics attributed to previous creep feeding treatment. In yr 2, DDGS had lower (P < 0.05) longissimus muscle area than SBM steers. In conclusion, protein source had no effect on ADG or final weight; however, DDGS tended to reduce the cost of gain.