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

Abstract

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 < 0.05) subcutaneous proportions of C20:3n-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 < 0 .05) subcutaneous proportions of t 11c 15-18:2, total and individual branched-chain FA. Subcutaneous fat from steers implanted with growth promotants had higher (P < 0.05) proportions of total polyunsaturated FA (PUFA), total 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.