Evaluation of sugarcane rind on the nutritional value of ruminant feeding

Abstract

Several studies on the kinetics of sugarcane's fiber digestion have been published, but, to date, no study has evaluated the influence of sugarcane rind on the digestion of fresh sugarcane by ruminants. This study aimed to evaluate the effects of sugarcane components (rind and pith) on chemical composition, in vitro digestibility, metabolizable energy, and sugarcane quality. A randomized block design was used in a split-plot scheme with five sugarcane genotypes [plot] (RB068027, RB058046, RB987917, RB867515, and RB855536) and three sugarcane components [sub-plot] (rind, pith, and whole cane), Each treatment consisted of four replicates. The chemical composition, in vitro gas production, in vitro digestibility, metabolizable energy, and sugarcane quality were evaluated. No interaction between components and genotypes was observed for the variables analyzed herein. Although the rind had a higher crude protein content, it showed a large amount of insoluble crude protein. The rind had higher fibrous fractions, comprising 87.33 % of the indigestible fraction of the neutral detergent fiber (NDF). The sugarcane rind showed ~ 71.20 % more lignin than the pith tissue. Further, the rind decreased by 6.5 % in vitro dry matter digestibility compared to the whole sugarcane. The in vitro NDF digestibility of the rind was 18.38 % lower than the whole sugarcane. The RB068027 genotype showed the lowest sugarcane quality. Despite the higher content of potentially digestible neutral detergent fiber (pdNDF) in the rind, its high lignin content influences the quality of the final fibrous fractions of sugarcane and negatively impacts the nutritional value. The genotypes do not differ nutritionally, but RB855536 presented higher biomass and energy yields.