• Clearcutting Brazilian Semiarid Tropics: Observations on Its Effects on Small Ruminant Nutrition during the Dry Season

      Kirmse, R. D.; Provenza, F. D.; Malechek, J. C. (Society for Range Management, 1987-09-01)
      Small ruminant production in northeast Brazil is limited by prolonged nutritional stress during the dry season. Our study assessed the effects of clearcutting woody vegetation on the nutrition of goats and sheep during the initial dry season following clearing. Dry matter intake g day-1 was higher for animals on cleared than on uncleared areas (818 vs. 627; P<0.05). Extrusa from esophageally fistulated animals grazing cleared, as opposed to uncleared, areas was more digestible (52 vs. 47%; P<0.05), was similar in crude protein (7.1 vs. 7.1%; P<0.05), and was lower in neutral detergent fiber (49 vs. 51%; P<0.05) and lignin (14 vs. 16%; P<0.05). Intake and diet quality declined on both cleared and uncleared areas as forage availability declined. Animals on cleared areas benefitted from increased availability of herbs and of biomass from palatable trees that coppiced and retained green leaves throughout much of the dry season. Animals on uncleared areas relied heavily on leaf litter from trees, which provided a poorer quality, but persistent, source of forage throughout the dry season.
    • Habitat Selection, Foraging Behavior, and Dietary Nutrition of Elk in Burned Aspen Forest

      Canon, S. K.; Urness, P. J.; DeByle, N. V. (Society for Range Management, 1987-09-01)
      Prescribed burning is frequently used to enhance regeneration of aspen. The effects of burning aspen on wild ungulates are poorly understood. We used free-ranging tame elk to assess diet composition and quality on a site containing a 40-ha aspen burn, pure unburned aspen, mixtures of aspen and conifers, and other habitats. Foraging preferences of elk among the habitats were also investigated. Overall, no dietary nutritional differences were found between burned and unburned aspen habitats. Diet composition by forage class varied somewhat, due primarily to an abundance of very palatable post-fire forbs on the burn. Time spent feeding was significantly different among habitats. The burn was substantially more attractive for foraging probably because preferred forages were consistently available and greater foraging efficiency was possible than in other habitats.