Effects of Dietary Stevioside Supplementation on Feed Intake, Digestion, Ruminal Fermentation, and Blood Metabolites of Goats

SIMPLE SUMMARY: This study evaluated the effects of stevioside, a natural sweetener that is an extract of Stevia, on feed intake and feeding behavior of goats. The results demonstrated that the consumption of forage was improved after supplementation with stevioside. Supplementation of stevioside resulted in improved total diet consumption of goats. These results are useful for ruminant producers to use natural sweeteners to regulate the intakes of animals. ABSTRACT: The objective of this study was to evaluate the effects of dietary inclusion of stevioside on feed intake, feeding behavior, nutrient digestion, rumen fermentation, and serum biochemical parameters in goats. Nine male Xiangdong black goats (21.8 ± 1.5 kg of body weight) were used in a replicated 3 × 3 Latin square. All goats were fed a basal diet including concentrate and forage (chopped rice straw). The three treatments were 0, 400, or 800 mg stevioside per kg chopped rice straw on a dry matter (DM) basis. Dry matter intake of forage and total diet linearly increased (p = 0.03 and p = 0.04) with increasing stevioside in the diet. There was no effect (p > 0.05) of stevioside inclusion in the diets on eating time, rumination time, or total mastication time for the goats. Total volatile fatty acid (VFA) concentration in the rumen responded quadratically (p < 0.01), decreasing from 0 to 400 mg/kg stevioside inclusion and increasing thereafter. The inclusion of steviosid in the diets promoted a quadratic increase in the apparent total tract digestibilities of neutral detergent fiber (NDF) (p = 0.02) and acid detergent fiber (ADF) (p = 0.01). Based on the results of this experiment, it could be concluded that supplementing goat diets with stevioside at 400 mg/kg to 800 mg/kg forage (about 270 to 541 mg/kg diet) resulted in increased dry intake of forage and total diet, suggesting that stevioside has positive potential as a feed additive to improve feed intake.