Propolis or cashew and castor oils effects on composition of Longissimus muscle of crossbred bulls finished in feedlot

The natural additive products (propolis or essential oils), in replacing antibiotics, could be used as an alternative for feed strategies to improve animal production. This work was performed to evaluate the effect of natural additives as propolis or essential oils on meat quality of crossbred (Aberdeen Angus vs. Nellore) bulls. Thirty bulls were kept in feedlot (individual pen) for 55 d and randomly assigned to one of three diets (n = 10): control (CON), propolis (PRO), or essential oils (OIL). CON diet consists of corn silage (45% DM) and concentrate (cracked corn, soybean meal, glycerin, limestone, and mineral salt, 55% DM). The PRO group received same CON diet plus 3 g animal-1 d-1 of propolis premix added to the concentrate. The OIL group received same CON diet and 3 g animal-1 d-1 of a premix (cashew Anacardium occidentale L. and castor Ricinus communis L. oils) added to the concentrate. Fat thickness (5.0 mm), pH (5.9), Longissimus muscle area 58.0 cm2, marbling, texture, color (L* = 36.6, a* = 17.3, and b* = 5.9), lipid oxidation (0.08 malonaldehyde kg-1 meat), and WarnerBratzler shear force (3.3 kg) were unaffected by the diet. PRO and OIL diets had no effect neither on moisture (73.7%), ashes (1.1%), protein (23.8%), and lipids (1.7%), fatty acid composition or polyunsaturated/saturated fatty acid (PUFA/ SFA, 0.13), and n-6/n-3 ratio (6.9) on Longissimus muscle. Addition of natural additives as propolis extract or cashew and castor oils in the diet of bulls when they are finished in a feedlot did not change meat qualities.