Table I.

Proportion (in %) of different nematode genus recovered after necropsy of tracer lambs

Nematode species	Prevalence (%)	Rate of population (%)	Range of infection intensity
Trichuris spp.	100.00	1.32	1 – 44
Teladorsagia spp.	86.10	25.22	10 – 1680
Trichostrongylus axei	77.80	18.43	20 – 1270
Trichostrongylus spp.	77.80	16.42	40 – 4440
Strongyloides papillosus	58.35	31.18	10 – 2200
Nematodirus spp.	52.78	5.20	10 – 610
Chabertia ovina	41.70	0.22	1 – 19
Oesophagostomum venulosum	38.90	0.16	1 – 37
Haemonchus contortus	36.15	1.83	1 – 210
Cooperia oncophora	8.30	0.06	10