A new technique for the extraction of Nematodirus battus eggs from sheep faeces.

Details are given of a method for the separation of the eggs of the nematode Nematodirus battus from sheep faeces. Faecal pellets obtained from worm-free lambs experimentally infected with N. battus were homogenized and passed through a graded series of metal sieves. The material retained in a 53 mum aperture sieve was transferred to a cylindrical column and the eggs were cleaned and separated from other suspended material by controlled differential flotation using tap water. A model experiment indicated that, within limits, the principle held for any size of tower. The density distribution for eggs at the morula stage of development was determined. Suggested flow rates for a specified tower are given.