|Neel, James - Jim|
Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: 3/6/2008
Publication Date: 7/11/2008
Citation: Duckett, S.K., Neel, J.P., Fontenot, J.P., Clapham, W.M. 2008. Effect of finishing steers on different forages or high concentrate diet on rib composition, color, and palatability. Journal of Animal Science Supplement. 86(E-Suppl.2):382.
Technical Abstract: Angus-crossbred steers (n = 128) were used to determine the effects of forage species grazed in the last 41 d or high concentrate finishing on rib composition, color, and palatability of beef. Steers grazed mixed pastures (bluegrass/white clover) for 93 d and then grazed alfalfa (AL; n = 36), pearl millet (PM; n = 24), or mixed (MP; n = 36) pastures for the final 41 d of finishing. Due to drought conditions in year 3, steers did not graze PM pastures. Steers were also finished on traditional high concentrate diets (C; n = 32) for 134 d. Total lipid content of LM was 60% lower (P < 0.01) for forage-finished than C with no differences among forage species. Saturated fatty acid percentage was higher (P < 0.05) for AL, PM, and MP than C due to greater (P < 0.05) concentrations of stearic acid. Monounsaturated fatty acid (MUFA) percentage was higher (P < 0.05) for C than all forage-finished treatments. MUFA was also higher (P < 0.05) in PM than AL. Omega-6 fatty acid concentration was higher (P < 0.05) for AL than PM and C with MP intermediate. Linolenic acid and total omega-3 fatty acid concentrations were higher (P < 0.05) for AL than MP and PM, which were also greater (P < 0.05) than C. The ratio of omega-6 to omega-3 fatty acids was lower (P < 0.05), hence more desirable from a human health standpoint, for forage-finished (1.27) than C (6.07). Trans-11 vaccenic acid (TVA) concentration was greater (P < 0.05) for forage-finished than C; whereas, trans-10 octadecenoic acid concentration was greater (P < 0.05) for C than forage-finished. The cis-9 trans-11 isomer of conjugated linoleic acid (CLA) concentration was greater (P < 0.05) for PM than AL and MP. CLA percentages were higher (P < 0.05) for all forage species compared to C. Forage species grazed during the final 41 d of finishing altered the concentrations of CLA, MUFA, omega-6 and omega-3 fatty acids. Forage finished beef was leaner and contained greater concentrations of CLA, TVA, and omega-3 fatty acids than concentrate finished.