Resumen
This study aimed to measure carbohydrate and protein fractioning of silage of Brachiaria brizantha cv. Marandu. The experiment was designed in a completely randomized design with five treatments and five repetitions, with the treatments the inclusion of natural dehydrated brewery residue to Marandu grass silage at levels of 0, 10, 20, 30 and 40%. The dehydrated barley inclusion resulted in a linear reduction (P<0.05) of total carbohydrate content, which decreased 0.35% per unit of residue added. The content of fraction B2 decreased linearly as dehydrated barley was added (P<0.05). Nitrogen content increased linearly when residue was added to silage of Marandu grass (P<005). Fraction A, obtained from Marandu grass, presented linear increasing behavior according to the inclusion of dehydrated barley. This inclusion promoted a linear decrease (P<0.05) of fraction B1+B2, which resulted in a 0.37% reduction for each 1% of byproduct added. The inclusion of 20% of dehydrated barley to Marandu grass silage resulted in an improvement of protein and carbohydrate fractions.