Particle size (PS) may be reduced when feeds are ground through small screen sizes leading to increased losses from artificial fibre bags during in situ or mobile bag experiments in equines. Smaller PS may also alter the water holding capacity (WHC) of feeds which in turn may alter bag transit times during mobile bag experiments. This study examines PS and WHC in a range of starch based equine feedstuffs ground through two screen sizes.
Five feedstuffs (F) were used ie: barley (B), maize (M), peas (P), wheat (W) and naked oats (NO). Feedstuffs were subjected to three types of physical pre-processing (Pr) ie: unprocessed (Un), micronised (Mi) or extruded (Ex) and then ground through either a 1.0 or 0.5 mm screen size (SS). For PS analysis a 25g sample of each feedstuff was sieved through a stack of 11 sieves ranging in pore diameter between 45 μm and 2 mm using a mechanical shaker for 20 min.