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Estimation of the numbers of trichostrongylid larvae on pastures

Veterinary Parasitology 46(1-4): 197-203

Estimation of the numbers of trichostrongylid larvae on pastures

Estimates of the density of larvae on herbage are used in epidemiologic studies to determine seasonal or monthly variations in contamination of pastures with third-stage larvae of the trichostrongyles, and to provide an index of the risk of exposure of grazing animals. Estimates of density are affected by many variables, including laboratory techniques, climate, forage types, and farm and animal management methods. Thus, a comparison of results given by different workers is not desirable. In obtaining and interpreting larval density estimates, it is important to standardize the technique over the period of observation. Because techniques for estimation of larvae are cumbersome and time-consuming, statistical design is often compromised. Herbage samples should be taken randomly and with sufficient replication to overcome the variability of the herbage sampling technique. Studies to determine an appropriate sampling design to obtain the best estimate for pastures of all sizes have not as yet been carried out.

Accession: 002373474

PMID: 8484210

DOI: 10.1016/0304-4017(93)90058-u

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Related references

Oripov, A.O., 1980: The prevalence of trichostrongylid larvae on pastures of the Uzbek SSR. On the pastures where Karakul sheep are grazed, in the foothill-mountain and desert-pasture zone of the Uzbek SSR, infective trichostrongylid larvae were found from March to January; however in the summer months, June to August, numbers were very...

Vladimirova, A., 1980: Study of the infectivity of trichostrongylid larvae overwintered on pastures. Experiments showed that Haemonchus contortus, Ostertagia circumincta, Nematodirus spathiger and Trichostrongylus colubriformis larvae remained infective to lambs after overwintering on pastures in various landscapes of Bulgaria. The survival of tr...

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