Do Different Concentrations of Copaiba Oil (Copaifera spp.) in the Diet of Steers Affect Ruminal Fermentation?

The use of copaiba oil (COP) in ruminant nutrition is relatively recent, and results reported in the literature are still controversial. This study evaluated the effects of different concentrations of copaiba oil in the diet of steers on ruminal fermentation. Five rumen-cannulated steers were assigned to a 5 x 5 Latin square design and subjected to the following treatments: Control – (0 g of COP), 1.25 g COP, 2.50 COP, and 3.75 g COP kg-1 dry matter (DM), and monensin (positive control - concentrate containing 40 mg kg-1 DM). Animals were fed a diet with a forage-to-concentrate ratio of 50:50. Inclusion of copaiba oil from 1.25 to 3.75 g kg-1 did not alter ruminal pH, and the concentrations of NH3-N and propionate (mmol L-1) were similar among treatments (P > 0.05). Copaiba oil did not affect intake, digestibility, or propionate concentration (P > 0.05). Monensin increases (P ≤ 0.05) the concentrations of NH3-N and propionate (mmol L-1). Different concentrations of copaiba oil (Copaifera spp.) in the diet of steers did not affect ruminal fermentation. However, additional studies are needed to evaluate the inclusion of COP in diets with a higher forage proportion, better representing grazing conditions with predominant forage intake.