SEASONAL VARIATIONS OF FOOD PARTICLE SIZE IN MOOSE

Abstract

We investigated digesta of 15 adult and 5 juvenile moose (Alces alces) from eastern and southern Finland over 12 months. We determined the proportion of food particle size is at 2 ruminoreticular and 5 postruminal sites. Moose passed coarser food particles from the ruminoreticulum than grazing domestic ruminants. Presence of food particles >2 mm was lowest in winter and early spring when digestibility was low, and highest during vegetation growth (Jun-Sep), which coincides with greater forage selectivity. More than 50% of all samples from July to September consisted of coarse particles >4 mm. Sites of concentration of coarse particles changed, which suggested intermittent widening of the reticulo-omasal orifice. Moose are concentrate selectors and respond to the cyclic seasonality of their environment with foraging and digestive strategies that differ from grazing domestic ruminants.