It was carriedout two assays with the purpose of evaluating the mobile nylon bag techniqueand the method of total feces collection method in the estimative of the apparentdigestibility of starch and other nutrients in high moisture sorghum grain silagesin horses. Four adult horses of mixed origin at the age of 7 years and averagebody weight of 330 kg were used. In the first assay, the digestibility of thenutrients in the silage of high moisture sorghum grain with low level of tanninwas evaluated by utilizing the total feces collection and the mobile nylon bagtechnique with silage samples ground in three particle sizes. In the secondassay, the two methods were used for estimating the digestibility of the nutrientsof the silage of high moisture sorghum grain with high level of tannin. A randomizedblock experimental design was used, considering each animal as a block. Thedisappearance of the nutrients, in the naylon bag, of the samples of the highmoisture sorghum grain silages ground in three particle sizes of 1, 8 and 13mm was also evaluated in laboratory. Daily dry matter intake was 2.0% of thebody weight and test diets were made up of 30% of high moisture sorghum grainsilages and 70% of coast-cross hay. The coefficients of dry matter digestibility,energy and protein of both silages were similar among the total feces collectionmethod and the mobile nylon bag technique when 8-mm feed samples were used.The coefficient of starch digestibility was similar among the methods when sorghumsamples were ground at 1 mm in the mobile nylon bag technique. Reduced particlesize increased the nutrient losses of the nylon bags after washing in water.The mobile nylon bag technique allows to estimate the digestibility coefficientof nutrients, however, further studies for evaluation of particle size of thesamples should be conducted.
