Dietary supplementation with fish oil and safflower oil, during the finishing period, alters brisket muscle fatty acid profile and n-6/n-3 ratio but not carcass traits of dairy beef bulls

Abstract

Objective: With increases in the global population, there is a need to identify strategies that increase beef output while maintaining or improving health benefits of beef products. Studies have demonstrated that there are many benefits to human health in response to reducing the dietary n-6 to n-3 ratio. The aim of this study was to characterize the carcass characteristics and brisket muscle fatty acid profile of young dairy bred bulls following dietary supplementation with n-6 or n-3 polyunsaturated fatty acids (PUFA). Material and Methods: Holstein-Friesian (n = 43) and Jersey (n = 7) bulls with a mean ± s.e.m. age and bodyweight of 420.1 ± 5.86 days and 382.0 ± 8.94 kg, respectively, were offered a cereal based concentrate diet on an ad libitum basis, fortified with one of three lipid supplements: control (CTL; no supplementary lipid), n-6 PUFA safflower (SO), or n-3 PUFA enriched fish oil (FO). Bulls were individually offered their respective diet for 12 weeks prior to slaughter. Carcass weight, conformation and fat score were recorded at slaughter for all animals, while brisket muscle was collected from 26 randomly selected bulls and lipid profile analysed using GC. Results and Discussion: Total n-3 PUFA concentration was greater for FO than either SO or CTL diets (P < 0.05). Although there was no difference in the muscle total n-6 concentration between diets (P = 0.52), n-6 to n-3 ratio was 3.2 and 3.9 times lower for FO (P < 0.001) than either CTL or SO diets, respectively. Total intake of n-3 PUFA accounted for 72% of the variation in the n-6 to n-3 ratio. Despite the differences in fatty acid profiles, there was no effect of dietary lipid supplementation on carcass weight (P = 0.63), conformation (P = 0.79), or fat score (P = 0.84. Implications and Applications: Beef producers can feed n-6 and/or n-3 PUFA enriched diets that would result in beef having potential health benefits and greater branding potential.