It was aimed toevaluate intake, apparent digestibility and in situ degradability ofdry matter (DM), crude protein (CP) and neutral detergent fiber (NDF) of coastcrossand Tifton 85' bermudagrass hays, and of diets with four concentrate levelsfor growing animals. The fecal production was estimated by means of internalmarkers, indigestible neutral detergent fiber (NDFi) and acid detergent fiber(ADFi), obtained after 144 hours of ruminal incubation. It were used eight monthsold bovines and 32 non castrated animals in the growing phase, all Nellore,to evaluate intake and digestibility. Three-fistulated rumen bovines were usedto study the disappearance of the dry matter (DM), crude protein (CP) and neutraldetergent fiber (NDF) of the hays. The incubation times were 6, 12, 24, 48,72, 96, 120 and 144 hours. The nutrient intakes of coastcross hay weresmaller than Tifton 85 values. The DM, NDF and ADF apparent digestibility ofthe hays did not differ between markers, although the markers did not presentstatistical difference to estimate the coefficient of digestibility of coastcrosshay, though for Tifton 85 nutrient apparent digestibility there was differencepresenting larger value for ADFi. In the growing phase, all coefficients ofdigestibility were smaller when NDFi was used as marker. The degradation ratedid not differ among the hays, inside of each studied entity (DM, CP, and NDF).
