|Silva, Julio - WEST TEXAS A&M UNIV|
|Brown, Michael - WEST TEXAS A&M UNIV|
|Ponce, Christian - WEST TEXAS A&M UNIV|
|Smith, Douglas - WEST TEXAS A&M UNIV|
Submitted to: Beef Cattle Research in Texas
Publication Type: Experiment Station
Publication Acceptance Date: July 10, 2007
Publication Date: August 30, 2007
Citation: Silva, J.C., Cole, N.A., Brown, M.S., Ponce, C.H., Smith, D.R. 2007. Effects of dietary fat and wet sorghum distiller's grains plus solubles on feedlot performance and carcass characteristics of finishing heifers. 2007 Beef Cattle Research in Texas. The Texas A&M University System. The Agriculture Program. p.83-88. Interpretive Summary: The bioethanol industry has grown rapidly in the past 10 years, thus generating a large quantity of by-products, namely distiller’s grain, that are available to be used as livestock feed. During the ethanol production phase, the fat in the grain (normally 3 to 4%) is increased to 10% or more in the distiller’s grains. In the Southern Great Plains, beef cattle finishing diets are frequently supplemented with 2 to 4% fat to increase the diets' energy density. However, it is not clear if some or all of the supplemental fat should or can be removed when distiller’s grains are fed. The purpose of this study was to determine the optimal level of supplemental fat to use in finishing diets containing 15% wet sorghum distiller’s grains plus solubles (WSDGS). In this study, 400 yearling heifers were fed one of five diets: (1) 0% WSDGS and 0% yellow grease (fat); (2) 0% WSDGS and 3% fat; (3) 15% WSDGS and 0% fat; (4) 15% WSDGS and 1.5% fat; or (5) 15% WSDGS and 3.0% fat. The WSDGS replaced steam-flaked corn and cottonseed meal. Overall, dry matter intake (DMI) and average daily gain (ADG) were approximately 5% greater for heifers fed 15% WSDGS than for those fed 0% WSDGS; but feed efficiency was not affected by feeding WSDGS. Among heifers fed WSDGS, DMI and ADG tended to be greatest for heifers fed 1.5% fat and feed efficiency was improved as more fat was added to the diet. The results suggest that when WSDGS are fed at 15% of the diet dry matter in steam-flaked corn based diets, approximately 1.5% or less of supplemental fat is required in the diet for optimal performance. However, the optimal fat concentration will be determined by ingredient costs and cattle prices.
Technical Abstract: Four hundred yearling heifers in two experiments were fed for an average of 106 days. Treatments included 0% wet sorghum distiller’s grains plus solubles (WSDGS) and 0% yellow grease (fat), 0% WSDGS and 3% fat, or 15% WSDGS and either 0, 1.5, or 3.0% fat. The WSDGS replaced steam-flaked corn and cottonseed meal. Overall dry matter intake (DMI) was 5% greater (P<0.01) for heifers fed 15% WSDGS than for those fed 0% WSDGS. Among heifers fed WSDGS, DMI was greatest for heifers fed 1.5% fat (P=0.04; quadratic effect). Overall average daily gain (ADG) was 5% greater (P=0.04) for 15% WSDGS compared to 0% WSDGS. Among WSDGS, ADG tended to be greater for 1.5% fat (P=0.12; quadratic effect). Feed efficiency did not differ between 0 or 3% fat when 0% WSDGS was fed, nor was feed efficiency altered by replacing a portion of flaked corn with WSDGS (P>0.36). However, feed efficiency was improved as more fat was added to WSDGS diets (P=0.06). Heifers fed WSDGS had a higher DMI and greater ADG than heifers fed flaked corn, but feed efficiency did not differ. Adding more than 1.5% fat to diets containing WSDGS tended to reduce growth performance.