|Cole, Noel - Andy|
Submitted to: American Society of Animal Science
Publication Type: Abstract only
Publication Acceptance Date: 3/15/2007
Publication Date: 7/8/2007
Citation: Silva, J.C., Cole, N.A., Brown, M.S., Mitchell, D.L., Ponce, C.H., Smith, D.R. 2007. Effect of dietary fat concentration and wet sorghum distiller's grains plus solubles on feedlot performance and carcass characteristics of finishing heifers [abstract]. In: Journal of Animal Science, Volume 85, Supplement 1, Annual Meeting of American Society of Animal Science, July 8-12, 2007, San Antonio, Texas. T335. Interpretive Summary:
Technical Abstract: Three hundred ninety-eight crossbred yearling heifers (initial BW = 373.5 kg) were used in two experiments to examine the effect of dietary fat concentration on the feeding value of wet sorghum distiller's grains plus solubles (WSDGS). Treatments included two 92% concentrate diets based on steam-flaked corn (SFC) with 0% or 3% added fat from yellow grease and three diets with 15% WSDGS and either 0, 1.5, or 3% added fat from yellow grease (4 pens/treatment within study). Heifers were fed an average of 106 d before slaughter. Overall DMI was 6.1% greater (P < 0.01) for heifers fed WSDGS than for those fed SFC. Among heifers fed WSDGS, DMI was greatest for heifers fed 1.5% fat (P = 0.04; quadratic). Overall ADG was 5% greater (P = 0.04) for WSDGS compared to SFC. Among WSDGS, ADG tended to be greater for 1.5% fat (P = 0.12; quadratic). The ADG:DMI did not differ between SFC with 0 or 3% fat, nor was ADG:DMI altered by replacing a portion of SFC with WSDGS (P > 0.36). However, ADG:DMI increased linearly as more fat was added to WSDGS diets (P = 0.06). Hot carcass weight was increased an average of 5 kg (P = 0.05) when WSDGS replaced a portion of SFC, but carcass weight was greatest for heifers fed WSDGS with 1.5% fat (P = 0.09, quadratic). Heifers fed SFC without fat had a larger LM area, lower marbling score, less rib fat, and a lower yield grade (P < 0.08) than heifers fed SFC with 3% fat. Heifers fed WSDGS had more rib fat and a higher yield grade (P < 0.03) than heifers fed SFC. Inclusion of fat in SFC diets did not alter the distribution of carcass quality grades, but SFC with 3% fat produced fewer (P = 0.01) yield grade 1 carcasses than when fat was not fed. Feeding WSDGS did not alter carcass quality grade distribution compared to feeding SFC, but WSDGS produced fewer yield grade 3 carcasses (P = 0.03) than SFC. Heifers fed WSDGS had a higher DMI and greater ADG than heifers fed SFC, but gain efficiency did not differ. Adding more than 1.5% fat to diets containing WSDGS tended to reduce growth performance.