Extrato do caroço do açaí como potencial modulador da fermentação ruminal.

Abstract

Some plant extracts have been considered promising as additives for ruminal modular fermentation. Research into the action of its bioactive compounds was driven by the decision of the European Union that banned the routine use of antibiotics in animal feed, among which the ionophore antibiotics that are the most widespread on the market are included. The açaí seed is a residue generated after processing the fruit for pulp inheritance, its waste corresponds to about 60 to 85% of the fruit and its commercial use is still limited, resulting in an exorbitant excess of this residue. In order to reduce the waste generated by the processing of açaí pulp, new applications for its seed are sought. To this end, studies have shown that the seed contains a considerable amount of bioactive compounds, such as polyphenols, which have antioxidant, antimicrobial and anti-inflammatory properties, with potential for applicability in animal production. The açaí seed extract (ASE) has a higher concentration of polyphenols than the fruit and the bark (28,3%), with a greater antioxidant capacity than the pulp itself. These results show that the part with the highest content of bioactive compounds is being neglected and discarded by the industry. Given this, the objective was to evaluate the effects of açaí seed extract on in vitro digestibility and in vitro rumen fermentation parameters under different dietary conditions. Three experiments were carried out using different roughage:concentrate (r:c) ratios (90:10; 50:50 and 20:80). For each experiment, four doses of ASE were evaluated, namely: 0, 0.3, 3 and 30 mg of ASE/g of substrate. In each experiment, 144 flasks were incubated for 6, 12 and 24 hours in an oven at 39°C. Analyzes were performed to determine in vitro dry matter degradability (IVDM), volatile fatty acid (VFA) and ruminal ammoniacal nitrogen (N-NH3) concentrations. For substrate r:c - 90:10, at 12 and 24 hours of incubation, the inclusion of ASE at a dosage of 0.3 mg/g showed lower IVDMD (p<0.05) when compared to the control treatment. For the r:c - 50:50 substrate, at a 12-hour incubation time, the highest dosages (3 and 30 mg/g) showed higher IVDMD, compared to the treatment without ASE and to the 0.3 mg/g dose of ASE. For the substrate r:c - 20:80, in the incubation times of 12 and 24 hours, dosages 3 and 30 mg/g showed higher IVDMD. Regarding the concentration of N-NH3, for the substrate r:c – 90:10; 50:50 and 20:80 in 24 hours of incubation, the inclusion of the extract did not show significant differences for the concentration of N-NH3. For the 90:10 substrate, the dose of 3 mg ASE/g substrate was lower for the acetate:propionate ratio. The inclusion of ASE has negative effects on IVDMD when the simulated diet has a high fiber content as evidenced in the 90:10 r:c ratio. On the contrary, with high concentrate content (r:c 20:80) the inclusion of 3 and 30 mg of ASE/g of substrate improves IVDMD, indicating that its effects can be positive in diets with high concentrate content.