Poor Mast Research Articles

Forage Digestibility and Diet of Deer on Southern Upland Range

Four white-tailed deer ( Odocoileus virginisnus) were shot from a mixed pinhardwood habi- tat in east Texas at each of six consecutive 10-week intervals. Browse items made up at least 19 percent of the diet in all seasons. Forbs were important dietary constituents in May, mushrooms in July, and acorns in autumn. Acetic acid:propionic acid ratios in rumen liquor samples were wider in the spring after a poor mast year (4:1) than during other seasons (2:1). More gas (S ml gas per gram of solids per hour) was produced in controlled fennentations of rumino-reticular (R-R) contents of deer feeding on acorns than on othejr dietary items. In in vitro digestion trials, composited mixed browse, mixed forbs, mixed grasses, and loblolly pine (Pinus taedu) samples were generally highest in nutrient quality during spring. Grasses and forbs were significantly less digestible rhen mature than when imnlature. Forbs were digested better than were browse or pine tissues. Dead leaves were poorly digested. Green grasses selected during the winter were as digestible as those growing during spring and summer. For- ages most refractory to microbial fermentation had higher lignin:acid-detergent fiber (ADF) ratios than other foodstuffs.