Evaluation of a two-stage in vitro technique for estimating digestibility of equine feeds using horse faeces as the source of microbial inoculum.

摘要

To develop a two-stage in vitro technique that simulates both precaecal and hind gut digestion processes, four enzymatic predigestion treatments by pepsin and alpha -amylase (ET0=control, ET1=2 h pepsin+2 h amylase, ET2=2 h pepsin+4 h amylase, ET3=8 h pepsin+16 h amylase) were tested on oat hay (OH), barley grain (BG) and soyabean meal (SBM). Investigated parameters were enzymatic organic matter digestibility (OMDe), and gas production (G48 h, G72 h) and OM digestibility (OMD) using horse faeces as a source of microbial inoculum. Enzymatic predigestion treatments affected (P<0.05) investigated parameters and their ranking differed among feeds. Only OMD of BG and SBM were higher after the predigestion treatment. OMD prior to (ET0) and after ET3 application were, successively, 0.357 versus 0.351 (OH), 0.71 versus 0.79 (BG) and 0.70 versus 0.78 (SBM). Net gas production overestimated fermentation potential of non-predigested feeds. G72 h (ml/g DM) prior to (ET0) and after ET3 application were, successively, 80.3 versus 58.0 (OH), 151.7 versus 30.4 (BG) and 110.6 versus 37.7 (SBM). It was concluded that the enzymatic predigestion treatments effects varied among tested feeds, and that the suggested procedure be extended and validated with a large array of feeds of known digestibility values..