The fatty acid (FA) composition of longisimus dorsi (LD) and subcutaneous fat (SCF) from Rubia Gallega (RG) calves was compared for three dietary oil sources (linseed, LO; sunflower, SFO or soybean, SYO). Oils were added (4.5%) to a commercial concentrate and no differences on animal performance, carcass characteristics or meat quality among diets were noted. Total n-3 polyunsaturated FA (PUFA) increased in LD and SCF when feeding LO diet (P<0.001). The trans(t) FA profiles were dominated by t11-18:1, except when feeding SFO diet, where ∑t6- to t10-18:1 exceeded t11-18:1 leading the highest (∑t6-to t10-18:1)/t11-18:11 ratio in LD (P<0.05). The overall changes in n-3 PUFA and t18:1 when feeding LO and SYO could be viewed as positive for human health, but quantitatively it was apparent that most dietary PUFA were completely biohydrogenated. Inhibiting PUFA biohydrogenation will be an important next step to improve the FA composition of RG cattle.
Keywords: CLA; Oil supplementation; Trans-fatty acids; Vaccenic acid; n-3 fatty acids.
© 2013.