Resumo

GOMES, S.P.; LEAO, M.I.; VALADARES FILHO, S.C.  e  PAULINO, M.F.. Intake, digestibility and microbial production in steers fed with different forages, supplemented or not. Arq. Bras. Med. Vet. Zootec. [online]. 2006, vol.58, n.5, pp. 884-892. ISSN 0102-0935.  http://dx.doi.org/10.1590/S0102-09352006000500026.

The intake and total apparent digestibility of dry matter (DM), organic matter (OM), crude protein (CP), ether extract (EE), total carbohydrates (CHO), neutral detergent fiber (NDF) and non-fiber carbohydrates (NFC); the total digestible nutrients (TDN) intake and the microbial protein production (MicP) in diets of steers were determined. The in situ degradability of feeds was also evaluated. Five steers averaging 185.4kg live weight (LW) and fistulated in the rumen and esophagus were randomly, assigned in a completely randomized experimental design. They were fed on: 1- chopped elephantgrass (CE); 2- tifton-85 bermudagrass haylage (PS); 3- brachiaria decumbens hay (FB); 4- brachiaria decumbens hay plus concentrate at 0.5% LW (FB:C1); and 5- brachiaria decumbens hay plus concentrate at 1.0% LW (FB:C2). Tifton-85 bermudagrass haylage provided higher intake of DM (6.0kg/steer/day) and TDN (4.2kg/steer/day) related to other forages, showing that its use is a good alternative for bovine feeding. The addition of concentrate to the brachiaria decumbens hay increased the forage intake, from 2.7kg/steer/day to 3.9kg/steer/day, constituting a strategy for the poor quality forages use. The highest concentrate C2 intake (1.0% LW) increased DM (0.9kg/steer/day) and TDN (1.0kg/steer/day) intake of FB:C2 dietary, relative to FB:C1 dietary.

Palavras-chave : steer; intake; forage; concentrate; microbial protein.