EFFECT OF TANNINS ON GALLIFORM CECAL PARTITIONING

Winter diets of ruffed grouse (Bonasa umbellus) and other galliformes are high in tannins. We fed quebracho, a condensed tannin, to ruffed g rouse and found no effect on dry matter intake or body mass at levels up to 6% of the diet. However, a high-fiber diet with 8% quebracho res ulted in reduced dry matter intake and body mass loss. Grouse could no t tolerate a diet with 8% tannic acid, a hydrolyzable tannin, which ca used a large reduction in dry matter intake and body mass. Northern bo bwhite (Colinus virginianus) and ruffed grouse responded to dietary qu ebracho tannin by increasing the proportion of digesta that was excret ed from the ceca. In the northern bobwhite, 59%-76% of the tannin reco vered from the feces was in cecal feces. There was no difference in av erage passage rates of liquid and fiber digesta, although variation wa s high in tannin-fed birds. The role of the ceca in handling tannin re quires further investigation.