Comparison of in vivo and in vitro Dry Matter Digestibility of Mule Deer Forages

pIn vivo digestibility percentages from mule deer (Odocoileus hemionus) digestion-balance trials were usually higher than in vitro determinations obtained from the same experimental forage species. Linear regression analysis suggested a correction factor could be applied to in vitro estimates to make them more nearly correspond to in vivo dry matter digestibility values. Forages with in vitro digestibility values below 35% often varied markedly from in vivo estimates. It raises the question whether deer consume species lower than this in digestibility given reasonable choice.