Effects of substitution and concentration of common feedstuffs on performance and carcass characteristics of finishing beef cattle

Abstract

Beef cattle diets are typically composed of a mixture of roughages, grains, byproducts and a supplement. This dissertation investigates how the substitution and concentration of common feedstuffs in beef cattle diets affects their feedlot performance and carcass characteristics. A finishing trial was designed to determine the effects of substituting alfalfa haylage for corn silage at two different neutral detergent fiber (NDF) concentrations on beef cattle performance and carcass characteristics. From the results of this study, it was concluded that alfalfa haylage can be substituted for corn silage when advantageous for feedlot producers without compromising performance or carcass quality. Surprisingly, steers fed greater NDF concentration did not have increased feed intake. Further research is needed to elucidate how dietary NDF concentration affects feed intake, and performance. A meta-analysis investigated how dietary distillers grains plus solubles (DGS) concentration, moisture content, oil content, and grain processing affect beef cattle carcass characteristics. Concentration of DGS in the diet significantly affected hot carcass weight, marbling score, backfat thickness and yield grade through its known effect on growth. Oil content of DGS tended to affect ribeye area while DGS moisture significantly affected yield grade, although neither would lead to results of commercial significance. Oil content of DGS tended to affect incidence of carcasses with liver abscesses, possibly resulting from an effect on diet integrity.