Effect of amount of high-fibre pellet in the diet and bedding type on feed intake, nutrient digestibility, eating behaviour and rumination in bongo (Tragelaphus eurycerus)

Two studies were conducted to determine the impact of the amount of high-fibre pellet (HFP) in the diet and bedding material on feed intake, eating behaviour, rumination, activity and resting behaviour, and also nutrient digestibility in bongo (Tragelaphus eurycerus). In Study 1, bongo were fed meadow hay (ad libitum), lucerne hay (0.5 kg/day), browse (0.7 kg/day) and a 'basal diet' containing 0.75 kg/day (low; LP), 1.50 kg/day (medium; MP) or 2.25 kg/day (high; HP) of HFP consisting mostly of insoluble fibre sources (dehydrated grass, dehydrated lucerne, wheat bran). In Study 2, experimental diets resembled those used in Study 1 with the main difference being that bongo were fed 1 or 2 kg of HFP/day and pens were bedded with straw (SB) or wood shavings (WB) (2 × 2 factorial design). In Study 1, dry matter (DM) intake of meadow hay decreased linearly (p < 0.01) with an increasing amount of HFP in the diet but total DM intake increased (p < 0.01). Eating time of basal diet (min/day) increased linearly (p = 0.01), whereas eating time of meadow hay tended to (p = 0.06) decrease linearly with an increasing amount of HFP in the diet. In Study 2, total DM intake was greater for HP treatments compared to LP treatments (p < 0.01) but meadow hay DM intake did not differ between treatments. Straw was consumed by animals and its usage as a bedding material increased meadow hay DM intake and browse DM intake (p ≤ 0.02), and consequently total DM intake (p = 0.03), compared with wood shavings bedding. Feeding more HFP to bongo tended to (p = 0.07) decrease rumination time per day and increased rumination rate (g DM/min). In conclusion, an increased amount of HFP (>1.5-2 kg/day/animal) rich in insoluble fibre in the diet consisting mostly of meadow hay may decrease the intake of roughages by bongo and reduce rumination time. On the other hand, the usage of straw (instead of wood shavings) as bedding unexpectedly increased the intake of roughages by bongo.