[Biology of gastrointestinal nematodes of ruminants]

(Biologia dei nematodi gastrointestinali dei ruminanti.)

Full Abstract

The development and survival of free-living stages of gastro-intestinal nematodes of small ruminants are influenced by several abiotic and biotic factors. Within the abiotic factors, most important are the environmental temperature and humidity. They regulate the development of larvae from eggs dispersed on the pasture by the animals faeces. Each parasite species that infect ruminants requires a different time to development, depending on temperature and humidity. Among trichostrongylids, Ostertagia, Teladorsagia and Nematodirus show a strong adaptation to low temperatures. Nematodirus larvae are able to survive to winter inside the egg shell. Temperature and humidity influence the distribution and survival of larvae on pasture. The larval third stage can migrate from faeces to pasture vegetation and they accumulate at the basis of vegetation where stay during the day or in the soil to avoid the desiccation. The forage species affects the migration of larvae on herbage too. Many biological factors contribute to disperse the larvae on the pasture. Dung burying beetles, coprophagous beetles and earthworms can greatly reduce the larvae of some trichostrongylids on pasture. They contribute to the spread of the faecal material on the pasture and allow the larval death as a consequence of drying.

Author information

Author/s: Manfredi, M T (MT);

Affiliation: Department of Animal Pathology, Hygiene and Veterinary Public Health (DIPAV), Section of General Pathology and Parasitology, University of Milan, Italy. mariateresa.manfredi(-atsign-)unimi.it

Journal and publication information

Publication Type: English Abstract; Journal Article; Review

Journal: Parassitologia (Parassitologia), published in Italy. (Language: ita)

Reference: 2006-Sep; vol 48 (issue 3) : pp 397-401

Dates: Created 2006/12/20; Completed 2007/02/20; Revised 2007/11/15;

PMID: 17176950, status: MEDLINE (last retrieved date: 2/18/2009)

Sourced from the National Library of Medicine. Abstract text and other information may be subject to copyright.

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