Kinetic parameters of ruminal degradation of Marandu grass silage supplemented with brewer’s grain

Abstract

This study measured the kinetic parameters of the ruminal degradation of the silage of Brachiaria brizantha cv. Marandu. The experiment had a completely randomized design with five treatments and five repetitions; the treatments featured the inclusion of natural brewer’s grain to Marandu grass silage at levels of 0, 10, 20, 30 and 40%. The regression equation for the degradability of the soluble Fraction A of dry matter showed a linearly increasing pattern (P≤0.05) with an addition of 0.19% for each 1% of brewer’s grain included. The percentage of insoluble potentially degradable fraction (B) of dry matter was reduced linearly (P≤0.05). The ruminal degradation rate in the dry matter (c), expressed as % h-1, increased linearly (P≤0.05). The crude protein percentage in the Fraction B demonstrated a linear regression pattern as brewer’s grains were added (P<0.05), and there was a 0.06% reduction per unit of additive to Marandu grass silage. There was a linear increase in degradation rate c in the crude protein (P≤0.05) as the additive was included in the silage. A linear increase (P≤0.05) was observed for the regression of the potentially degradable fraction of NDF, represented by Fraction D. The inclusion of 20% of brewer’s grain to Marandu grass silage resulted in an improvement in the kinetic parameters of ruminal degradation.