26th July 2011

Crypto control path aim of research project

An investigation into the effects of the Cryptosporidium parasite which aims to deliver a path to a more evidence-based control strategy for on farm management, has been highlighted by Quality Meat Scotland.

The project, co-funded by QMS, Harbro and Alpharma/Pfizers, dubbed CRYPTOBEEF, was discussed at a QMS Research and Development briefing in Perthshire today (26 July). It is being undertaken by the University of Glasgow and Moredun Research Institute, Edinburgh.

Cryptosporidium, commonly known in farming circles as Crypto, is a single-celled parasite a bit smaller than a red blood cell that attaches to the cells lining the intestine of a wide variety of mammals. Farmers are most often concerned about Crypto because it causes diarrhoea and death in calves. It is similar to coccidia, but much more resistant to drugs and very resistant to both environmental stress and disinfection.

Professor Nick Jonsson, Director of the Scottish Centre of Animal Health and Food Safety, who is leading the project, said the list of questions without answers is long and some of the recommendations made to farmers for the control of Crypto are based on theory rather than evidence.

“For example, it is not known why some farms have heavy mortalities as a result of infection with the organism while neighbouring properties using similar management strategies do not,” said Prof Jonsson.

“Likewise, the effects of bedding management, hygiene and calving management on the disease are not well understood, although the fact that the parasite is transmitted from faeces to mouth of calves has led to suggestions that hygiene might be an important control strategy.

“It is thought that simultaneous infection with rotavirus increases the risk of disease, but not known whether vaccination with commonly used enteric vaccines has any impact on disease due to Crypto. It is probably no surprise that farmers and veterinarians have been increasingly indicating that the disease is a bigger problem than previously thought.”

In recent years several vaccines have been introduced to the market to control E coli, rotavirus and coronavirus, which are some of the main causes of calf diarrhoea, but there is no equivalent vaccine for Crypto.

The project has so far seen 41 farmers in the north east of Scotland questioned about their management relating to Crypto and its impact on their operations. Local vets identified farmers who wanted to be involved in the project some of whom thought that they had a problem with the disease and an equal number of farmers who did not think that they had a problem with the disease.

The objective was to identify differences between the two groups to try to get some leads on where to go with future studies to find useful control methods.

Prof Jonsson said: “So far, all data are preliminary and should not be over-interpreted. Those farmers who thought that they had a problem with Crypto had much higher numbers of scouring calves in the previous season than farmers who didn’t think there was a problem, and had a higher number of calves dying with scour.

“Once the set of faecal samples is complete, careful examination of the proportions of animals in each herd and proportion of herds with animals testing positive for Crypto will be undertaken and all of the parasites from the faecal and post-mortem samples will be examined genetically. Further discussions will take place with all participating farmers in July to get a more accurate indication of losses for this season.”

For more information about the CRYPTOBEEF project see the latest QMS R&D Report. Copies can be downloaded from the QMS website or for a print copy call 0131 472 4040 or email info@qmscotland.co.uk

For further press information please contact Carol McLaren, Head of Communications, QMS on 0131 4724112 or mobile: 07739 900653 email: cmclaren@qmscotland.co.uk


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