Cell Wall Digestibility Affects Forage Value of Woody Twigs

Food and fecal samples collected from digestion trials with mule deer (Odocoileus hemionus) were analyzed according to Van Soest's comprehensive system of feed analyses. The true digestibility coefficient of the cell contents of formulated rations and woody twigs was as great for deer as it is for herbages eaten by domestic ruminants. The true digestibility coefficient of the cell wall constituents of woody twigs, however, was lower than that for herbages.