| worm burdens of dairy heifers in england and wales. | 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 ... | 1981 | 7197843 |