title: Effect of forage type with or without corn supplementation on animal performance, beef fatty acid composition, and palatability.
abstract: Thirty-two steers were used to examine forage type (legumes [ and ] vs. grasses [ and ]) with or without individual corn grain supplementation (0 vs. 0.75% of live weight [LW]/d) on beef fatty acid composition and palatability. In each year, steers ( = 16/yr) were randomly assigned to forage type ( = 8/forage type per yr) and to supplementation treatments within forage type ( = 4/supplementation treatment/forage type per yr). Forage types (grasses vs. legumes) were replicated in 2 paddocks of perennial and annual forage type pastures. A mixed model was developed with forage type, corn grain supplementation, and the 2-way interaction as fixed effects and 2 different error terms, one for testing forage and another for testing grain supplement and grain supplement × forage interaction. Corn grain supplementation increased ( = 0.01) ADG by 0.29 kg/d and final LW by 13 kg. Hot carcass weight, dressing percentage (DP), and KPH were greater ( < 0.05) for steers supplemented with corn grain. Carcasses from steers grazing legumes had greater ( = 0.04) DP compared with carcasses from steers grazing grasses. Alpha-linolenic acid concentration was higher ( < 0.05) in LM of steers grazing legumes than in LM of steers grazing grasses, both without supplementation. Supplementation decreased ( < 0.05) linolenic acid levels for both forage types; however, the magnitude of this reduction was greater for legumes than for grasses. The ratio of -6 to -3 PUFA was greater ( = 0.03) in the LM of corn grain-supplemented steers than in the LM of nonsupplemented steers. Supplementation of corn grain decreased ( < 0.05) the percentage of odd-chain fatty acids and increased ( < 0.05) the percentage of MUFA in the LM. Warner-Bratzler shear force values were not altered ( > 0.05) by forage type, supplementation, or the 2-way interaction. Beef finished on legumes had greater concentrations of -3 PUFA, whereas beef supplemented with corn grain had a greater ratio of -6 to -3 fatty acids. On a gravimetric basis (mg/100 g LM), -3 PUFA and CLA contents were not altered with supplementation, indicating that corn grain can be supplemented at this level in a forage-finishing beef system without negative consequences on perceived beneficial fatty acids.
authors.forename: A M
authors.initials: AM
authors.lastname: Wright
authors.forename: J G
authors.initials: JG
authors.lastname: Andrae
authors.forename: C Fernandez
authors.initials: CF
authors.lastname: Rosso
authors.forename: M C
authors.initials: MC
authors.lastname: Miller
authors.forename: E
authors.initials: E
authors.lastname: Pavan
authors.forename: W
authors.initials: W
authors.lastname: Bridges
authors.forename: S K
authors.initials: SK
authors.lastname: Duckett
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001823:Body Composition / Q000187:drug effects; D001835:Body Weight; D002417:Cattle / Q000502:physiology; D004032:Diet / Q000662:veterinary*; D019587:Dietary Supplements; D007887:Fabaceae; D005227:Fatty Acids / Q000737:chemistry; D008460:Meat / Q000032:analysis*; D013649:Taste; D003313:Zea mays / Q000737:chemistry*; D017962:alpha-Linolenic Acid / Q000494:pharmacology
chemical_list: D005227:Fatty Acids; D017962:alpha-Linolenic Acid