Effects of the natural sweetener rebaudioside A on intake, nutrient digestion, rumen fermentation, and blood biochemical parameters in adult goats during summer.

Abstract

The effects of dietary rebaudioside A inclusion on feed intake, digestion of nutrients, rumen fermentation, and blood biochemical parameters of goats were evaluated in a replicated 3×3 Latin square study. Nine adult goats during summer were fed a basal forage/concentrate-based diet and the forage was chopped rice straw. The three dietary treatments were 0, 350, and 700mg rebaudioside A per kg chopped rice straw on a DM basis. No significant improvement was observed in dry matter intake (DMI) of forage and diet among treatments. Nutrient digestibility of DM and organic matter (OM) showed a significant trend (p<.10) across groups. Rebaudioside A inclusion significantly (p<.01) increased the concentration of total volatile fatty acids in the rumen, however, there were no differences in concentration of ruminal ammonia, and molar proportions of acetate, propionate, and butyrate. About blood metabolites, increasing rebaudioside A in the diet caused a quadratic response in glucose and total protein, and albumin concentrations. Under the conditions of this study, supplementation with rebaudioside A at 350 and 700mg/kg forage did not improve consumption of rice straw-based diet in adult goats in summer. However, the responses in digestibility, rumen fermentation, and blood metabolites appear to indicate the potential of rebaudioside A as a bio-active substance in goats.