Irish institute to offer ostertagia bulk milk tests

Dairy farmers wishing to monitor their herds for an internal parasite can now call on the services of a government department diagnostics laboratory.

The Northern Irish-based Agri-Food and Biosciences Institute (AFBI) has added bulk milk testing for the brown stomach worm Ostertagia ostertagi to its suite of health tests.

Priced at £14, the test will be available to farmers across the UK and Ireland and is another option alongside similar tests on the market, an AFBI spokesperson confirmed.

See also: Simple changes that help beat parasite resistance in cattle

Bulk milk sampling will be used to assess infestation levels and express this in terms of milk yield reduction. Individual animal testing can follow if required.


A disease caused by maturation of Ostertagia ostertagi larvae in the abomasum. There are two types of the disease. Adult cattle are typically not affected.

Type 1

Typically seen later in the grazing season after ingestion and rapid maturation of large quantities of infective larvae by susceptible calves or yearlings.

Disease can be more severe after a dry early summer followed by a wet August/September, leading to a mass emergence and ingestion.

Signs Loss of appetite, sudden and profuse green diarrhoea, loss of 10% of bodyweight (can be 20-40kg in growing cattle) and up to 90 more days to slaughter. Sudden death is rare.

Type 2

Infective larvae are ingested later in autumn and undergo a period of delayed development within the stomach wall rather than maturing immediately.

Larvae emerge later in winter to cause disease.

This form of the disease is prevented by routine anthelmintic treatment at housing during late autumn/early winter.

Signs Profuse diarrhoea.

Source: National Animal Disease Information Service

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