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ARS Home » Plains Area » Bushland, Texas » Conservation and Production Research Laboratory » Livestock Nutrient Management Research » Research » Publications at this Location » Publication #360503
Research Project: Improved Practices to Conserve Air Quality, Maintain Animal Productivity, and Enhance Use of Manure and Soil Nutrients of Cattle Production Systems for the Southern Great Plains

Location: Livestock Nutrient Management Research

Title: Effects of supplemental fat concentration on feeding logistics, animal performance, and nutrient losses of heifers fed finishing diets based on steam-flaked corn and sorghum-based distillers grains

Author
item SILVA, JULIO - West Texas A & M University
item COLE, N. ANDY - Retired ARS Employee
item PONCE, CHRISTIAN - West Texas A & M University
item SMITH, DOUG - West Texas A & M University
item GREENE, L. WAYNE - Texas A&M Agrilife
item SCHUSTER, GRETA - West Texas A & M University
item BROWN, MIKE - West Texas A & M University

Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/11/2019
Publication Date: 4/15/2019
Citation: Silva, J., Cole, N.A., Ponce, C.H., Smith, D.R., Greene, L., Schuster, G., Brown, M.S. 2019. Effects of supplemental fat concentration on feeding logistics, animal performance, and nutrient losses of heifers fed finishing diets based on steam-flaked corn and sorghum-based distillers grains. Journal of Animal Science. 97(6):2583-2597. https://doi.org/10.1093/jas/skz130.
DOI: https://doi.org/10.1093/jas/skz130

Interpretive Summary: Feedlot operators need to use cost effective feed ingredients to maintain profitability, and therefore energy rich by products are commonly used. One of these commonly used by-products is distiller's grains (DG). However, the effects of supplemental fat on animal performance and nutrient losses of cattle fed diets containing DG has not been extensively studied. Therefore, scientists from ARS (Bushland, TX) and Texas A&M AgriLife Research conducted a 106 day feeding study using 398 crossbred yearling heifers (initial body weight = 373.5 kg) to evaluate the effects of yellow grease (a common fat source used in Southern Great Plains feedyards) and wet DG with solubles made from grain sorghum on animal performance, carcass characteristics, and nutrient losses and feeding management practices. Animal performance and dry matter intake were affected by DG and fat; however, there were few effects on carcass composition. Feeding DG required from approximately 20% more trips with the feed tuck to feed the same number of animals, resulting in increase expense for the feedlot operators

Technical Abstract: The use of distiller's grains (DG) in high concentrate beef cattle finishing diets has become a common practice. However, the effects of supplemental fat on animal performance and nutrient losses of cattle fed diets containing DG has not been extensively studied. Therefore, we fed 398 crossbred yearling heifers (initial BW = 373.5 kg) in two experiments to evaluate the effects of yellow grease concentration and sorghum-based wet distiller's grains with solubles (SWDGS) on performance, carcass characteristics, and nutrient losses of finishing beef cattle. Treatments included two 92% concentrate diets based on steam-flaked corn (SFC) with 0% or 3% of DM as added fat from yellow grease and three diets with 15% SWDGS (DM basis) and either 0, 1.5, or 3% added fat from yellow grease (8 pens/treatment). Heifers were fed an average of 106 d before slaughter. Overall DMI was 6.1% greater (P less than 0.01) for heifers fed 15% SWDGS than for those fed 0% SWDGS. Among heifers fed 15% SWDGS, DMI was greatest for heifers fed 1.5% fat (P = 0.04; quadratic effect). Overall ADG was 5% greater (P = 0.04) by heifers fed 15% SWDGS than those fed 0% SWDGS. Among heifers fed 15% SWDGS, ADG tended to be greater for 1.5% fat (P = 0.12; quadratic effect). The ADG:DMI did not differ between 0% SWDGS with 0 or 3% fat, and ADG:DMI was not altered by replacing a portion of SFC with SWDGS (P greater than 0.36). However, ADG:DMI increased linearly as more fat was added to diets with 15% SWDGS (P = 0.06). Hot carcass weight was an average of 5 kg greater (P = 0.05) when SWDGS replaced a portion of SFC, but HCW was greatest for heifers fed 15% SWDGS with 1.5% fat (P = 0.09, quadratic effect). Heifers fed 0% SWDGS without fat had a larger LM area, lower marbling score, less rib fat, and a lower yield grade (P less than 0.08) than heifers fed 0% SWDGS with 3% fat. Averaged across all fat levels, heifers fed 15% SWDGS had more rib fat and a higher yield grade (P less than 0.03) than heifers fed 0% SWDGS. Inclusion of fat in the 0% SWDGS diet did not affect carcass quality, but heifers fed 0% SWDGS with 3% fat had fewer (P = 0.01) yield grade 1 carcasses than when fat was not fed. Feeding 15% SWDGS did not alter carcass quality grade distribution compared to feeding 0% SWDGS, but 15% SWDGS produced fewer yield grade 3 carcasses (P = 0.03) than 0% SWDGS. When SWDGS replaced a combination of cottonseed meal (1/3) and SFC (2/3) and was fed at 15% of diet DM, the calculated NEg of SWDGS (1.36 Mcal/kg) was 91% of tabular value for dry rolled corn grain (1.50 Mcal/kg).