Efeitos do teor de carboidratos solúveis sobre as características da silagem de cana-de-açúcar

Abstract

The objectives of this trial were to quantify the water soluble carbohydrates (WSC) concentration present in sugarcane that nullifies ethanol production, and to evaluate the effects of WSC content on nutritive value and other fermentative characteristics of sugarcane silage. A completely randomized design was used with three treatments and four repetitions per treatment. Sugarcane was squeezed in order to remove juice. In the first treatment, juice was totally added back to sugarcane (100%). In the second treatment, only 50% of the juice was added back to sugarcane, along with 50% of water. In the third, 100% of water was added, with no addition of juice. Treatments resulted in WSC concentrations of 41.6, 34.0, and 23.0% on dry matter basis. The material was ensiled in 12 laboratory silos (plastic buckets). Silos were opened 85 days after ensiling, when organic acids concentration and chemical composition of silages were determined. Withdrawal of sugarcane WSC resulted in negative linear effects on dry matter, WSC concentration, and in vitro digestibility of dry matter, but with linear increase for acid detergent fiber, neutral detergent fiber, and lignin concentration. Considering the fermentation data, there was linear decrease for dry matter losses, lactic and butyric acids, and ethanol concentration. No treatment effect on aerobic stability data was observed. Ethanol production would be null if sugarcane had only 12.4% of water-soluble carbohydrates on dry matter basis. © 2008 Sociedade Brasileira de Zootecnia.