Effect of collection time on the fermentative activity of microbes in equine faeces

The present study intended to evaluate the influence of the collection time of faeces on in vitro fermentation determined with the gas production technique and on the bacteriological counts of the fresh faeces, utilized as inoculum source. Three adult horses, fed hay and concentrates 3 times a day, were used as faeces donors. Fermentation of 5 feedstuffs (barley, oats, alfalfa, meadow hay, and wheat straw), was studied after four collection times: immediately before the morning meal (9:00 h, t0), 2 h after the morning meal (11:00 h, t2), 2 h after the 12:00 h meal (t5) and immediately before the 17:00 h meal (t8). Although there were no differences in pH and bacteriological counts, the proportion in volatile fatty acids, except for acetate, and the extent of fermentation were the highest for t2 (P<0.05). Moreover, there was an interaction (P=0.0244) for the asymptotic amount of the produced gas between the collection time and the type of feedstuff. These results show that the collection time based on the feeding schedule of the donor horses has an influence on the fermentative activity of faecal bacteria.