A Fecal Collection Apparatus for Deer Nutrition Studies

Abstract

An apparatus was designed and field tested for total collection of feces from tame, free-grazing deer in range nutrition studies. Design details are presented. Better information is needed on food consumption rates of wild ungulates in their native habitats. Most data for the North American deer (Odocoileus spp.) have come from studies where animals are confined to pens or stalls and fed measured quantitites of either artificial diets (e.g. Holter et al. 1977) or hand-harvested native foods (e.g. Smith 1953). The validity of inferences from these data to the range situation is limited by numerous factors, including bias due to behavioral problems associated with confinement (Mautz 1971) and negation of the selective grazing process. All conventional techniques for determining forage dry-matter intake by the free-ranging animal require a quantitative estimate of fecal production rates. These data, along with independent estimates of diet digestibility, are then entered into the standard digestion equation to yield calculations of dry-matter intake (Smith and Reid 1955). Fecal out-put of the grazing animal can be determined through use of suitable indigestible markers such as chromic oxide (Smith and Reid 1955) or through more laborious total collection procedures (Cook et al. 1952). Even when the marker technique is used, a limited number of independent estimates determined by total collection procedures is usually necessary for correction of bias in the indicator technique. This paper describes the design and field application of a fecal collection apparatus that we used successfully on hand-reared male mule deer (0. hemionus) in 2.5-ha native range enclosures. Du Plessis (1972) described use of a fecal collection bag in a study of blesbok (Damaliscus albafrons) in South Africa, but details on construction or evaluation were not presented. The only reference we found to use of fecal collection devices on North American deer was that of Forbes et al. (1941) where small canvas bags were attached by leather straps to white-tailed deer (0. virginianus) fawns in digestion studies conducted in pens.