Xen- (prefix): Foreign or other. As in: 1  Xenoantigen -- An antigen that is found in more than one species.  Xenograft -- A surgical graft of tissue from one species to an unlike species, genus or family.
Diet. Snow Geese feed almost exclusively on plant material. During the breeding season, they eat many seeds, leaves, and roots of aquatic vegetation. The very young birds feed on invertebrates. Berries become more important in the fall. In winter, waste grain from agricultural fields has become a primary food source.
Geese will also eat windfall fruit under orchards and some unharvested crops and crop residues, which can harbor and over winter disease and insect pests. As geese are vegetarian, a small number of ducks can be kept with the geese to help control insects, slugs and snails.