Four crossbred bovines (Zebu x Holstein) fed in nature, hydrolyzed, hydrolyzed sugar cane hay and silage as roughage sources constituting 70% of the diets were used to study the effect of alkali treatment of sugar cane (1.5% of NaOH at 50%) on dietary total digestibility and dry matter intake and rate of passage of sugar canes. The fiber was the most influenced fraction by the alkali treatment and increased at least by 45% of digestibility. The increases of 25.0 and 16.7% on intake of hydrolyzed- (1.5% BW) and hydrolyzed sugar cane hay-based diets (1.4% BW) were probably influenced by the higher fiber digestibility. The estimated values of ruminal and cecco-colon rate of passage and retention time in each treatment did not differ among in nature, hydrolyzed and hydrolyzed sugar cane hay-based diet, whereas the lowest rates (1.5 and 7.4%/h) and highest retention time (71.4 hours) were observed for the hydrolyzed silage. It was concluded that alkali treatment with sodium hydroxide, with or without sugar cane hay, increased fiber digestion of hydrolyzed sugar cane in total tract and increased intake, without effect on passage rate. However, post ensilage of hydrolyzed sugar cane could not show effects.
alkali treatment; bovines; fiber; hydrolyzis; roughage
