This experiment aimed to evaluate the dry matter intake (DMI) under grazing, obtained through the chromium, in continuous infusion of chromic oxide, dosed once (CR1x) or twice (CR2x) daily, and in mordant form (CRMord), together with the following internal digestibility markers: in vitro dry matter digestibility (IVDMD), indigestible DM (iDM) and indigestible neutral detergent fiber (iNDF) and acid detergent fiber (iADF). Five F1 Limousin x Nelore steers, fistulated in the esophagus and rumen and supplemented in pasture of Brachiaria decumbens, were used. A randomized blocks design, in split plit plot outline was used, in which the supplements were considered as main plot, the methodologies of chromium as split plots and internal markers as split split plots. Supplement effects were not observed on DMI. The use of CR1x methodology underestimated the fecal excretion and DMI (DMI of 2.11% of LW) compared to the methodologies CR2x and CRMord (3.11 and 2.93% LW) that presented better values for DMI, not differing to each other. Interactive effect was observed between supplement and markers, with no differences in the values supplied by the same marker in the different supplements. The IVDMD, the marker of larger precision, presented medium value for DMI of 3.16% LW, overestimating the intake of all supplements. The iDM and iNDF were constant among supplements (2.48 and 2.54% LW of DMI), not differing to each other, being recommended for studies with animals at pasture. The DMI estimated by iADF showed variable results among supplements; the intakes were, on average, by using iADF (2.72% LW) higher compared to iDM and iNDF and lower compared to IVDMD.
chromium; markers; mordant chromium; pasture intake; supplements
