The Determination of Incubation Time and Amount of Faecal Content of Horse Faeces as an Inoculum Source for Digestibility Determination of Forages with in vitro Procedure

摘要

This study was carried out to determine incubation time and amount of horse fecal content for measuring in vitro dry matter digestibility of roughages (barley straw, wheat straw, lentil straw, wheat silage, corn silage and alfalfa hay) and their comparison with in vivo digestibility values. In in vitro study, inoculums were prepared using 100, 150, 200, 250, 300, 330, 500, 660 ve 1000 g faeces for per liter of buffer. Roughages were incubated with these inoculums at two incubation times (48 vs 72 h) before 48 h pepsin-HCl digestion. Six fat tailed Awassi rams (42.7±2.5 kg) at the age of two years were used as experimental animals (3 per treatments) in an apparent digestibility experiment. According to result of this study, the best equation for estimating in vivo DM digestibilities was obtained with usage of inoculum containing 250 g faeces for per liter buffer solution at length of 48 h incubation (r = 0.93, Y = 24.11 (±2.57) + 0.62 (±0.05) X, R2 = 0.87 ve RSD = 3.19) and 660 g faeces for per liter buffer solution at length of 72 h incubation (r = 0.94, Y = 16.08 (±2.88) + 0.72 (±0.05) X, R2 = 0.89 ve RSD = 2.88). Even though, result from this study showed that horse faecal fluid had high potential to be used for predicting in vivo DM digestibility, further researches dealing with larger number of feeds with known in vivo DM digestibility are required to improve usage horse faecal fluid for in vitro inoculums source.