The effect of feeding a low- or a high-starch diet on the in vitro fermentative capacity of equine faecal inocula

Seven mature Welsh-cross pony geldings provided the faecal inocula in a cross-over design experiment, consisting of two 14-day periods. In period 1, four ponies (group 1) were offered a low-starch fibre mix (LS), and three (group 2) were offered a conventional high-starch coarse mix (HS). Both groups were offered these mixes in a 50:50 ratio with mature grass hay, to give a total daily dry-matter intake of 17·5 g/kg live weight per day. Diets were then switched in period 2. At the end of each experimental period freshly voided faeces were collected from each animal and assessed for their ability to ferment grass hay (H), fibre mix (FMix) or starch-based coarse mix (SMix) using the gas production (GP) technique of Theodorou et al. (1994). Donor animal diet and donor animal had no effect on any end-point measurements. Lag times recorded for the SMix were significantly (P