Reinecke, R.K.Snyman, H. MariaSeaman, HelgaBigalke, R.D.Morren, A.J.Verster, Anna J.M.Verwoerd, Daniel WynandWalker, Jane B.Cameron, Colin McKenzieGilchrist, Frances M.C.Steyn, P.J.J.2016-07-062016-07-0620161979Reinecke, RK, Snyman, HM, & Seaman, H 1979, 'Studies on Haemonchus contortus. II. The effect of abomasal nematodes on subsequent challenge with H. Contortus’, Onderstepoort Journal of Veterinary Research, vol. 46, no. 4, pp. 199-205.0330-2465http://hdl.handle.net/2263/53876This article has been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-Format.Fifty-thousand infective larvae of Trichostrongylus axei dosed to 7-9-month-old Merinos protected them against a subsequent challenge with 50 000 infective larvae of Haemonchus contortus. Protection varied with the period between an initial dosages of T. axei and challenge with H. contortus as follows: After 90 days it was more than 80% effective in more than 80% of sheep; at 119 and 180 days there was still a significant reduction in the numbers of H. contortus recovered (P<0,05 and P<0,001, respectively). Prior infestation with either Ostertagia circumcincta or with Haemonchus placei was ineffective against challenge with H. contortus.en©1979 ARC - Onderstepoort and Faculty of Veterinary Science, University of Pretoria (original). ©2016 University of Pretoria Department of Library Services (digital).Veterinary medicineVeterinary medicine -- South AfricaArticle