Effects of flax supplementation and a Revalor-S implant on circulating insulin-like growth factor 1 (IGF-1) and muscle IGF-1 mRNA levels in finishing cattle

Date

2010-08-04T17:41:26Z

Journal Title

Journal ISSN

Volume Title

Publisher

Kansas State University. Agricultural Experiment Station and Cooperative Extension Service

Abstract

Sixteen crossbred steers weighing 875 lb were used to evaluate the effects of a 5% ground flaxseed supplement and a combined trenbolone acetate/estradiol (TBA/E2) growth promoting implant, Revalor-S®, on both circulating insulin-like growth factor-1 (IGF-1) and local muscle IGF-1 mRNA concentrations. Steers were randomly assigned to one of four treatments: . 1) Flax/Implant, 2) No Flax/ Implant, 3) Flax/No Implant, 4) No Flax/No Implant. Serum was harvested from blood collected via jugular venipuncture on day 0 (before implantation or flax addition), 14, and 28. Muscle biopsy samples were obtained from the longissimus muscle on days 0, 14, and 28. Implanted steers had 52 and 84% higher (P<0.05) circulating IGF-1 levels than non-implanted steers on days 14 and 28, respectively. Cattle fed diets without flax had higher levels of muscle IGF-1 mRNA than cattle fed diets with flax on day 28 (4.4-fold, P<0.01). Our data support that the administration of a combined TBA/E2 growth promotant increases circulating IGF-1 and local muscle IGF-1 mRNA concentrations in finishing cattle. However, this increase in muscle IGF-1 mRNA appears to be attenuated by the addition of a dietary flax supplement.

Description

Keywords

Beef, Flax, Revalor-S implant, Growth factor 1 (IGF-1), Muscle IGF-1 mRNA, Finishing cattle

Citation