Parâmetros cinéticos de degradação de alimentos proteicos, em novilhos alimentados com doses crescentes de tanino condensado de Acácia negra

Abstract

The efficiency of ruminal protein degradation is essential to maximize the utilization of feed in ruminants. This study evaluated the kinetic parameters of dry matter (DM) and crude protein (CP) degradation for five feeds: peanut meal, wheat bran, whole rice bran, DDG (distillers' dried grains), and brewery residue, supplemented with increasing doses of condensed tannins from Acacia mearnsii. The kinetic parameters revealed significant differences among the feeds. Wheat bran and brewery residue showed high CP degradability rates (0.13 and 0.08 h⁻¹, respectively), making them ideal for rapid nutrient availability. In contrast, whole rice bran and DDG exhibited lower degradation rates (0.04 and 0.05 h⁻¹), indicating sustained nutrient release, which is beneficial for long-term nutrient supply strategies. Peanut meal, despite its lower DM degradation rate (0.04 h⁻¹), demonstrated a high potentially degradable fraction of CP (73.58%), highlighting its potential as a balanced energy and protein source. The effects of tannins on the kinetic parameters were insignificant, suggesting that the tested doses did not affect DM or CP degradation. This finding supports the feasibility of using these feeds in diets supplemented with moderate tannin levels. The feeds studied have specific characteristics that can be utilized in the formulation of customized diets. Wheat bran and brewery residue are recommended for rapid digestion, while whole rice bran and DDG are suitable for sustained nutrient release. Peanut meal is a viable alternative as a moderate energy and protein source. The use of tannins did not compromise feed degradability, indicating their potential in sustainable management strategies.