The effect of fructose supplementation on feed intake, nutrient digestibility and digesta retention time in Reeves’s muntjac (Muntiacus reevesi)

Abstract

The aim of the study was to determine the effect of fructose supplementation in the diet on feed intake, nutrient digestibility and digesta retention time in Reeves's muntjac (Muntiacus reevesi), a browsing cervid. In Experiment 1, six adult males of Reeves's muntjac were used in a replicated 3×3 Latin square design and fed a diet consisting of dehydrated chopped lucerne (ad libitum), high-fibre pellet (120g/day) and wheat bran (30g/day) without (F0) or with addition of 12 and 24g fructose/day (F12 and F24, respectively). In Experiment 2, the same six adult muntjacs were used in crossover design and fed F0 or F12. Doses of supplemental fructose were set to increase intake of water-soluble carbohydrates (WSC; ≈40g/day; ≈8% of WSC in consumed dry matter [DM]) by 25 and 50% relative to F0. Feed intake was controlled daily (Experiment 1 and 2) and total tract digestibility and digesta retention time were determined (Experiment 2). In Experiment 1, DM intake of chopped dehydrated lucerne decreased with fructose supplementation (F0 vs. F12 and F24; p=.01) but was not different between F12 and F24 (p=.76). Total DM intake was also not different between treatments (p≥.13). In Experiment 2, DM intake of lucerne, total DM intake and nutrient digestibility was not affected by fructosesupplementation (p≥.17), but mean retention time of long particles in the whole GIT tended to be longer for F12 compared to F0 (p=.09). Under conditions of the current study, additional fructose intake (resulting in a range of WSC content in consumed DM from 8.6% to 13%) had only minor impact on feed intake and investigated functions of the gastrointestinal tract of Reeves's muntjac.