The size and composition of abomasal worm burdens from 143 casualty and cull dairy heifers were estimated. Over 60 per cent had totals of less than 10,000, only four exceeded 100,000 and the overall mean was 16,285. Ostertagia ostertagi was almost always present and usually formed the major proportion of the total. Trichostrongylus axei was recorded in 83 heifers and was the most common species on 17 occasions. The numbers of arrested early fourth stage worms were highest in winter and declined rapidly during spring. O lyrata was only found when O ostertagi was present and always as a small percentage of the total. Similarly in the case of two of the minor species, Skrjabinagia kolchida (= Grosspiculagia podjapolskyi) was never found independently of O leptospicularis (= O crimensis). These relationships are regarded as suggestive of polymorphism.
Statistics from Altmetric.com
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.