| seasonal variations in the gastro-intestinal nematode populations of scottish hil sheep. | in each of two consecutive years, groups of breeding ewes were removed from a hill farm in the west of scotland on four occasions, namely late pregnancy, early lactation, autumn and early winter. at slaughter the major nematode genus present in the alimentary tract was ostertagia, with o circumcincta the predominant species but three species previously found in scottish hill sheep, bunostomum trigonocephalum, strongyloides papillosis and chabertia ovina were absent. an absolute increase in total ... | 1975 | 1144923 |