Intake and total apparent digestibilities of the nutrients and average daily gains (ADG) by beef cattle fed diets based on concentrate and Brachiaria brizantha cv. Marandu silage in the following proportions: 20:80, 35:65, 50:50 and 65:35, in dry matter basis were evaluated. Twenty-four crossbred (Holstein x Zebu) steers, with initial live weight of 364 kg were allotted to a randomized blocks design. At the ensiling process, an enzyme-bacterial inoculant Nutroeste 50 t was applied to the forage. For the determination of fecal dry matter, indigestible acid detergent fiber was used as a marker. The animals were housed in individual pens and fed ad libitum. The experiment lasted 84 days, divided in three periods of 28 days after 15 days of adaptation. The dry matter (DM), organic matter (OM), crude protein (CP), ether extract (EE) and total carbohydrates (CHO) average intakes increased linearly with the increment of the concentrate in the diets. The total apparent digestibility of DM, OM, CHO and non fiber carbohydrates also increased linearly with the increment of the concentrate levels in the diets. Similar behavior was observed for ADG, with increments of 0.0184 kg/unit of concentrate added. However, apparent digestibilities of CP, EE and digestibility of neutral detergent fiber were not affected by the diets, showing values of 77, 88 and 60%, respectively. No wilted Brachiaria brizantha silage in the 50:50 concentrate to forage ratio for beef cattle Holstein x Zebu steers, promoted average weight gain close to 1.0 kg/day.
crude protein; dry matter; feedlot; grass silage; performance
