Toward Practical Biological Control of Parasitic Nematodes in Domestic Animals

In a series of laboratory and field experiments where the nematophagous fungus Arthrobotrys oligospora was mixed directly with feces it has been demonstrated that it is possible to use nematophagous fungi for biological control of animal parasitic nematodes. A procedure used for selection of nematophagous fungi that can pass the digestive tract of ruminants, horses, and pigs is described. The selected fungus, Duddingtonia flagrans, has been used in further field experiments, and the results have confirmed that by the addition of D. flagrans to feed supplement it is possible to reduce the parasitic burden significantly.     

A Field Experiment on Rain Splash Dispersal of Infective Larvae of Ostertagia Ostertagi (Trichostrongylidae) from Cow Pats to Surrounding Grass

Ostertagia ostertagi is an important tricho-strongyle nematode parasite of cattle in several countries, including Denmark. It leaves its host as eggs with faeces. After hatching it develops in the cow pat up to the third and infective stage, which is then transmitted to the surrounding grass.     

Effects of Treatment of Cattle with some Anthelmintics on the Subsequent Degradation of their Dung

Recent reports seem to indicate that the use of certain anthelmintics in cattle may cause adverse effects on non-target faunal inhabi-tants of cow pats, thus interferring with the normal degradation and recycling of dung deposited on pasture (Anderson et al. 1984, Lumaret 1986, Wall & Strong 1987). The present communication presents some data from a microcosm experiment on the pos-sible effects of some commonly used anthel-mintics on the rate of cow dung decomposition.