Subcutaneous fatty acid composition of steers finished as weanlings or yearlings with and without growth promotants

Abstract Background The current study evaluated the subcutaneous fatty acid (FA) composition of calf- and yearling-fed steers with or without growth promoting implants. Crossbred steers (n = 112; 267 ± 5.0 kg) of the same contemporary group were allocated to one of four production system and implant strategy based treatments in a completely randomized design with a 2 × 2 factorial arrangement of treatments. Results There were no interactions (P > 0.05) between production systems and growth promoting implants for the total and individual subcutaneous FA. Yearling as opposed to calf finishing reduced (P n-6, trans (t) 12-18:1, C14:0, several minor cis-monounsaturated FA (c-MUFA; c 9-14:1, c 11-16:1, c 11-18:1, c 12-18:1, c 13-18:1, c 9-20:1 and c 11-20:1), and increased (P t 11c 15-18:2, total and individual branched-chain FA. Subcutaneous fat from steers implanted with growth promotants had higher (P n-6 PUFA, C18:2n-6 and individual t- 18:1 isomers (t 6 to t 10) compared to non-implanted steers. Conclusions Overall, current findings show that production systems and growth promotants led to only minor differences in subcutaneous FA composition of beef steers.