The coefficients of apparent digestibility of dry matter (CADDM), organic matter (CADOM), crude protein (CADCP), ether extract (CADEE), total carbohydrates (CADTCHO), nonfiber carbohydrates (CADNFC), neutral detergent fiber (CADNDF) and acid detergent fiber (CADADF) were determined to evaluate the effect of the increasing dietary energy levels. The estimate of the apparent digestibility of the nutrients, using the method of fecal total collection, and the estimate of fecal dry matter production (FDMP), by the indigestible acid detergent fiber (IADF), as internal marker, were also compared. Eighteen Santa Inês sheep (averaging live weight of 20 kg and six months old) were full fed diets with 2.42; 2.66 and 2.83 Mcal metabolizable energy/kg of dry matter and allotted to a randomized block design, with six replicates. FDMP estimate, using IADF, was performed to be compared with the FDMP, determined by the total feces collection. It was observed increasing linear effect for CADDM, CADOM, CADEE, CADTCHO and CADNFC, as the the dietary energy levels increased. However, CADNDF and CADADF decreased linearly and, for CADCP, there was no effect, as the the dietary energy levels increased. IADF can be used as internal marker to estimate the coefficient of apparent digestibility in sheep.
concentrate; feed; indicator; nutrients
