COLONIZATION AND DEGRADATION OF CATTLE DUNG - ASPECTS OF SAMPLING, FECAL COMPOSITION, AND ARTIFICIALLY FORMED PATS

Many biotic and abiotic factors influence colonization and degradation of cattle dung pats. Thus, studies using the pat as an experimental unit require precise methodology to prevent misinterpretation of results. This paper reports trials in which impact of methodological procedures on dung fauna and dung degradation was investigated. Factors investigated were pat position on pasture, sampling techniques, influence of various diets, and a comparison between naturally voided versus artificially formed pats. Parameters used to measure these factors included quantitative and qualitative monitoring of dung fauna, including Coleoptera, Diptera, bacteria, nematodes, and Lumbricidae, and assays of pH, moisture content, and organic matter content of dung. An influence of pat position on colonization was seen, with Staphylinidae occurring more frequently in pats located toward the center of a pasture compared with pats located close to a road. Coleoptera larvae preferred the northern parts of the pats. Pat composition influenced colonization of coleoptera. Staphylinidae and Scarabaeidae preferred pats from cattle fed with grass, but Hydrophilidae preferred pats from cattle fed com silage. More Coleoptera larvae were collected from pats produced by grazing cattle compared with pats from cattle fed hay or corn silage. There were no significant differences between artificial and natural pats as to the total number of coleoptera, Diptera, or bacteria collected. However, development of Diptera larvae was accelerated in the artificial pats. Degradation of pats measured by content of organic substance and pat area was similar in artificial and natural pats.