The experiment was conducted to evaluate the effect of tannin on in situ degradability parameters of the dry matter and crude protein of six sorghum silage genotypes, harvested in the dough stage of maturation. Four steers canulated in the rumen were fed twice a day, ad libitum, with Cynodon dactylon hay. The sorghum silage genotypes were: BR 303, BR 304, BR 601 e AG 2006 (without tannin in grain) and BR 700 e BR 701 (with tannin in grain). Five grams of each sample were introduced into nylon bags, and incubated for 6, 12, 24, 48, 72, and 96 hours. The time zero (t0) was used to calculate soluble fraction. No effects of tannin in grain on mean disappearance of dry matter and on crude protein at 96 hours of incubation were observed. The tannin in grain was capable to decrease the potential degradability of dry matter on sorghum silages BR 700 and BR 701, harvested at dough stage. There was not negative effect of tannin in silages of BR 700 and BR 701 on the parameters of potential degradability and degradation rate of the crude protein.
sorghum silage; crude protein; dry matter; in situ degradability; tannin
