Nutritional profiles of three genotypes of sugarcane silage associated with calcium oxide

Abstract

The objective of this study was to evaluate, based on chemical composition and in vitro dry matter (DM) digestibility, silages of different sugarcane genotypes after exposure to different doses of calcium oxide (CaO) and to identify that most appropriate dose for use in ruminant feed. The experiment was conducted using a completely randomized 3 9 4 factorial arrangement with three sugarcane genotypes ('IAC-862480', 'SP-791011' and 'CTC-3') and four levels of the additive CaO (0, 15, 30 and 45 g kg À1 ). A quadratic effect was observed (P < 0.05) for DM content in the silages of genotypes 'SP-791011' and 'CTC-3'. The organic matter content of genotypes 'SP-791011' and 'CTC-3' showed a negative linear effect that was associated with the addition of CaO, which promoted an increase in the mineral matter (MM) content in the silages. There was no effect (P > 0.05) of genotype or an interaction effect between genotype and CaO level on crude protein content in the silages. There was an interaction effect (P < 0.05) between genotype and CaO level on the level of neutral detergent fiber in the studied silages and the development of this interaction revealed a linear decrease in neutral detergent fiber in genotype IAC-86280 and a quadratic effect (P < 0.05) for genotypes 'SP-791011' and 'CTC-3'. Potentially degradable DM (pdDM) values showed a positive quadratic function with maxima at 34.8 g kg À1 CaO. The results obtained for potentially degradable neutral detergent fiber (pdNDF) showed that there was a negative linear effect for genotype 'SP-791011' and a quadratic effect with the maximum critical point for genotypes 'IAC-862480' and 'CTC-3'. Total DM losses decreased with levels of CaO. All genotypes evaluated showed potential for silage production. The addition of CaO in the ensiling of sugarcane at up to 45 g kg À1 reduces gas and effluent losses and increases the DM recovery of the silages.