This publication is the Proceedings of a workshop held at the Royal Veterinary and Agricultural University in Copenhagen, Denmark on 4th - 6th February, 1980, sponsored by the Commission of the EUropean Communities (CEO) as a part of the programme of coordination of agricultural research in the field of animal pathology. The CEO wishes to thank those who took responsibility for the organisation of the workshop, those who presented the papers, and all participants. VII CONTENTS SESSION I METHODOLOGY I MONITORING PASTURE INFECTIVITY AND PASTURE CONTAMINATION WITH INFECTIVE STAGES OF Dictyocaulus viviparus 3 R. J. Jcentsrgensen THE CORRECT HANDLING OF FAECAL SAMPLES USED FOR EXAMINATION OF Dictyocaulus viviparus LARVAE 11 H. J. W. M. Cremers SOME EFFECTS OF STORAGE ON THE RECOVERY OF Dictyocaulus viviparus LARVAE FROM FAECES 17 M. T. Fox EXPERIENCES WITH OUR TECHNIQUES FOR THE RECOVERY OF NEMATODE LARVAE FROM HERBAGE H. -J. Burger 25 A TECHNIQUE FOR THE RECOVERY OF INFECTIVE TRICHOSTRONGYLE LARVAE FROM SOIL 31 K. Bairden, J. L. Duncan and J. Armour SESSION I METHODOLOGY II A MODIFIED AND SIMPLE MCMASTER TECHNIQUE 45 Sv. Aa. Henriksen COMPARISON OF TECHNIQUES FOR ASSESSMENT OF THE CONTAMINATION OF PASTURE HERBAGE WITH INFECTIVE NEMATODE LARVAE 51 J. -P. Raynaud and L. Gruner RECOVERY OF Ostertagia FROM THE BOVINE ABOMASAL MUCOSA BY IMMERSION IN WARM NORMAL SALINE 69 N. E. Downey CONTROLLED/CRITICAL TESTS IN THE EVALUATION OF ANTHELMINTIC ACTIVITY 75 D. D{