Nutritional value of high and low tannin high-moisture sorghum grain silage in horses

The objective in this work was to determine the nutritive value of high and low tannin high-moisture sorghum grain silage in horse feeding by means of digestibility. A total of eight crossbred geldings at the age of six years and an average body weight of 330 kg were used in a complete randomized design with samples replicated on the same animals. The test-diets consisted of the ensiled high and low tannin sorghum grains replacing 30% of the dry matter of the reference diet, constituted exclusively by hay. The daily dry matter intake was equivalent to 2.0% of the body weight, so, the test diets were constituted by 30% of ensiled sorghum grains and 70% of hay. The digestibility coefficients of the nutrients of the low and high tannin sorghum grain silages were obtained by the difference between the coefficient of digestibility of the nutrients of the reference diet and the test-diets. The values of digestibility of dry matter, energy and protein of the high tannin sorghum grain silage were lower (73.65, 73.65 and 71.33%) than low tanin sorghum grain silage (87.70, 87.70 and 82.36%). The contents of digestible dry matter, digestible protein, digestible starch, digestible neutral detergent fiber and digestible energy were 59.08%, 10.63%, 71.48%, 2.32% and 3,954 Mcal/kg of dry matter of the low tannin sorghum grain silage and 50.58%, 8.16%, 67.80%, 3.72% and 3,192 Mcal/kg of the dry matter of high tannin sorghum grain silage, respectively, therefore, only contents of digestible neutral detergent fiber and starch were similar among silages. The use of low tannin sorghum grain silage, an alternative food in formulation of promising diets for horses feeding