The effect of feeding a low- or high-starch diet on equine faecal parameters

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 fed a low-starch fibre-mix (LS), and three (group 2) were fed a conventional high-starch coarse-mix (HS), both groups were fed these mixes in a 50:50 ratio with mature grass hay, to give a total daily dry matter (DM) 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 analysed for cellulolytic and amylolytic bacterial numbers, volatile fatty acid (VFA) and lactate concentration. There was no effect of diet on the number of cellulolytic and amylolytic bacteria, VFA or lactate present in the faeces of the experimental ponies. Consequently, it would appear that the effect of feeding LS or HS on faecal parameters is minimal; however, further work is required to determine the accuracy of faeces as a model for changes in the hindgut environment of the horse.