3 August 2001

Less stress and trace elements fight disease

By Jeremy Hunt

LIVESTOCK are more resilient to bacterial and viral infections, such as foot-and-mouth and bovine tuberculosis, when receiving an optimum intake of trace elements and experiencing minimum stress.

Thats the view of retired agricultural chemist and Llanelli, south Wales, dairy producer Helen Fullerton whose lengthy paper on the subject has been sent to DEFRA and prominent UK animal disease scientists.

She believes that insufficient consideration has been given to extensive research data, compiled over 40 years. This data proves the weakened condition of the host animal plays a part in increasing susceptibility to disease.

"Protection against the F&M virus depends primarily on a cell-mediated immunity (CMI) response, in which lymphocytes activate cytotoxic cells before virus replicates within cells of the pharynx and soft palate.

"Lymphocyte cells are suppressed when zinc or selenium intakes are inadequate, if the animal is subjected to stress, secondary infection or a parasitic load indicating cobalt inefficiency and also during pregnancy."

She highlights vitamin E, copper, zinc, iodide and plants rich in bioflavoids as being critical to providing antioxidant protection against infection. She also believes there is much to commend the addition of borax to drinking water or feed to induce resistance to F&M.

"We must defend our livestock by providing the correct nutritional status in terms of trace elements and combine that with higher standards of management."

However, Mrs Fullerton is against the introduction of a vaccination policy to control F&M.

"It can be expected that vaccination will be introduced into the EU following pressure from member states – but it is not the long term solution. There are problems of multi-strains, short-term immunity and hazards of escape or theft of vaccine. Global mobility means that in the event of a vaccination failure the UK would again be vulnerable to an F&M epidemic."

Mrs Fullerton believes the short term antibody-induced immunity afforded by vaccination against F&M- must be replaced by long term resistance.

"We must not underestimate F&M research undertaken more than 75 years ago by organic farming pioneer Sir Albert Howard.

"His trials, with fit and healthy organically reared cattle receiving the correct intake of trace elements, showed 100% resistance to F&M despite contact with neighbouring infected stock.

"The key area that now demands urgent research concerns CMI. This is known to be involved in an animals defence against F&M, but the mechanism has not been fully explained."

Mrs Fullerton hopes her research findings into CMI will be accepted by scientists working in the field of animal disease.

"My research demonstrates how animals with an optimum trace element intake, and reared on a system where management stress is avoided, can benefit." &#42

DISEASE PREVENTION

&#8226 Trace element balance vital.

&#8226 Avoid management stress.