Aerobic stability of sugar cane in natura hydrolysed with calcium oxide to be used in equine diets

Abstract

Sugar cane (Saccharum officinarum) is a grassy plant used in Brazil during the dry season as forage in the diet of equines. This research intended to assess the aerobic stability of sugar cane in natura, hydrolysed with calcium oxide, aiming at its preservation during storage to be used in equine diets. The research was carried out at the Federal Institute of Southeast Minas Gerais – Campus Barbacena, Brazil. The local temperature varied from 10 to 33 °C and relative air humidity from 25% to 87%. It was a fully randomized split-plot design with five repetitions. The plots were sugar cane in natura with the addition of zero, 0.5, 0.75, and 1% of calcium oxide and the sub-plots were hydrolysis times of 0, 6, 12, 24, 36, 48, 72, and 96 hours. The sugar cane was manually harvested from the first cut with a nine-month growth period, chopped into 2 cm pieces, and mixed with calcium oxide with no dilution. The sugar cane stability was evaluated from the measurement of the brix degree, pH, and temperature of each treatment. Only after 36 hours of storage was a reaction noticed on the sugar cane brix degree level, pH, and temperature (P<0.05) due to the addition of the calcium oxide. From 36 to 96 hours of storage, the pH of the treatment without added calcium oxide was lower than the pH of the other treatments (P<0.05), showing the calcium oxide acting, at the used concentrations, at controlling the microbiologic fermentation of the stored sugar cane. The concentrations of 0.5, 0.75, and 1% of calcium oxide were efficient for the conservation of the sugar cane stored for 96 hours and its addition is necessary only when the sugar cane is intended for storage over 36 hours.