Efeito da idade de corte sobre a composição bromatológica e as características da silagem de cana-de-açúcar plantada em dois espaçamentos e três idades de corte

Abstract

The objective of this experiment was to identify the effect of row spacing (0.90 m and 1.30 m) and harvesting ages on the chemical composition and characteristics of sugarcane silage and productivity of the RB72-454 variety sugarcane. The experiment was carried out from November 2004 to January 2006. Treatments consisted of a combination of 0.90 m and 1.30 m row spacing and harvesting ages were 240 days (plant-cane), 180 days (regrowth) and 420 days (plant-cane). A randomized block experimental design was used, with five replications per treatment. The experimental silos were PVC pipes with individual covers, stored in a ventilated place for 90 days. The data analysis demonstrated there was no significant effect of the row spacing on the sugarcane chemical composition. The harvest age had significant effect on contents of dry matter, crude protein, mineral, neutral fiber detergent, acid fiber detergent, lignin and obrix. Reduction in the cell wall constituents was observed with the maturation of the plant, because of the increase in soluble carbohydrates. The silage showed increased protein content and cellular wall constituent because of the use of the soluble carbohydrates in the fermentation process. The nutritive composition not was affected by row spacing. Sugar cane harvesting at 240 and 180 days resulted in greater nutritive losses during ensiling. © 2009 Sociedade Brasileira de Zootecnia.