Effect of Copaiba Oil (Copaifera spp.) on Intake Digestibility, Degradability, and Ruminal Variables in Beef Steers

This study evaluated the effect of copaiba oil (COP) or sodium monensin, used as nutritional additives for beef cattle. Five steers cannulated in the rumen were assigned to a 5 x 5 Latin square design to the COP treatments: Control - (0 g of COP), 1.25 g COP, 2.50 COP, and 3.75 g COP per kg-1 dry matter (DM) or monensin (concentrate with the addition of 40 mg kg-1 of sodium monensin (DM basis) of total diet. The COP did not affect intake and digestibility. Monensin decreased (P ≤ 0.05) DM and nutrients intake; however, it did not affect digestibility compared to control treatment. Conversely, the monensin supply provided lower (P ≤ 0.05) mean pH values and, increases in the concentrations of N-NH3 and propionate (mmol L-1). The increased propionic acid production resulted in higher (P ≤ 0.05) proportions (mmol 100 mmol-1) of propionate, and reduction in the molar proportions of acetate and butyrate, with a consequent reduction in the acetate:propionate ratio. Copaiba oil in 1.25 to 3.75 g kg-1 does not alter the ruminal metabolism of cattle. However, sodium monensin reduces DM intake and decreases the acetate:propionate ratio in the rumen fluid.