Project Number: 6209-31630-002-19
Project Type: Specific Cooperative Agreement

Start Date: Aug 01, 2006
End Date: Aug 30, 2010

Objective:
The objectives of these cooperative research projects are to 1) evaluate the effects of dietary roughage concentration on the feeding value of distiller's grain in steam-flaked corn based beef cattle finishing diets; 2) evaluate the effects of corn processing method and feeding of distiller's grains on eating quality of beef; and 3) determine interactions of grain processing method (DRC and SFC) and wet distiller's grains cereal grain source (sorghum and corn) on site and extent of nutrient digestion. The purpose of this study is to replace samples lost due to a freezer break down.

Approach:
Three beef cattle feeding trials will be conducted. In Experiment 1, yearling steers will be utilized in a randomized complete block design with four experimental treatments. Experimental diets will include three levels of roughage (7.5%, 10.0%, and 12.5%) included in diets containing 25% wet distiller's grains (DM basis). The fourth treatment will be a control with no distiller's grains, 10.0% dietary roughage, and 13.5% CP. The roughage source will be alfalfa hay. All diets will be formulated to be equal in fat and calcium and be adequate in degraded intake protein concentration. There will be 6 pens per treatment. Samples of feed ingredients will be collected weekly and analyzed for dry matter, protein, fat, fiber, and sulfur. Statistical analysis will be conducted using the general linear procedures of SAS: contrasts of interest will be control with 10% roughage vs. wet distiller's grains (DG) with 10% roughage as well as linear and quadratic effects of roughage level in diets containing 25% wet distiller's grains. In Experiment 2, crossbred steers weighing approximately 650 pounds will be individually fed in a Calan gate system to determine effects of distiller's grain inclusion and corn processing method on marbling, shelf life, and consumer acceptance of beef loins, animal performance, and to determine if blood glucose concentrations are related to marbling attributes. Treatments will be arranged in a 2 x 2 factorial. Factors will be inclusion or absence of wet distiller's grains and corn processed by steam flaking or dry rolling. Distiller's grain inclusion will be 35%. Serum glucose concentrations will be monitored for each animal prior to feeding and at five time points post-feeding during four periods of the finishing study. Animal performance (dry matter intake, average daily gain, feed efficiency) will be monitored and carcass data collected. One loin from each animal will be purchased for analysis of taste panel acceptance, shelf life, fatty acid concentration, fatty acid profile, and activity of enzymes associated with marbling. In Experiment 3, six steers with ruminal and duodenal cannula will be used to determine the effects of corn processing methods (steam flaked or dry rolled) and DG sources (none, corn, or sorghum) on the site and extent of nutrient digestion.