Consumo, digestibilidade dos nutrientes e características ruminais de cordeiros alimentados com níveis crescentes de concentrado em ambiente tropical no Vale do Alto Guaporé - MT

The objective was to evaluate the use of concentrate in the diet of lambs on intake and total digestibility coefficient (DC) of nutrients, ruminal characteristics, rectal and body temperature. It was used four lambs without breed defined (SRD), entire, with average body weight (BW) of 19.3 +/- 2.07 kg using a Latin square design, 4 x 4. The animals were housed in metabolism cages and were fed twice a day with diet consisting of corn silage and concentrate at a ratio of 20, 40, 60 and 80% dry matter in the diet, composite of corn grains and soybean meal. Leftovers were measured daily and the feces were collected through bags. Data from variables studied were submitted to ANOVA and regression analysis at 5% probability. The increasing levels of concentrate in lamb diets affected (P<0.05) of linear form decreasing the intake of NDF, ADF and quadratic of DM, OM, CP, EE, NFC and TCH intake. There was no effect (P>0.05) of concentrate levels on digestibility coefficient of DM, OM, EE, NDF, ADF, NFC and TCH. However, the digestibility coefficient of CP showed a quadratic effect (P<0.05). The pH and ammonia nitrogen showed a quadratic effect (P<0.05) for the time after feeding. The rectal and body temperature of lambs was not affected (P>0.05) by dietary concentrate. It can be concluded that 38% of concentrate in diets of lambs favors the maximum dry matter intake, organic matter and crude protein. The digestibility coefficient of the nutrients, except for protein, are not altered with the addition up to 80% concentrate in diet for lambs, as well as, this does not affect the pH and ammonia nitrogen concentration of ruminal fluid, rectal and body temperature.