18 September 1998

Antibiotics curb on cards

By Simon Wragg

REGARDLESS of scientific belief that antibiotic growth promoters can safeguard animal health and optimise production where used correctly, industry chiefs believe a UK ban is imminent.

Paul Toplis, a specialist in formulating piglet diets, told delegates at a growth promoter conference held last week at Sutton Bonnington, Notts, and organised by feed additive supplier Britphos, that a ban would be founded on precaution and not necessarily scientific fact. "Science isnt getting a look in," he said. "Weve lost the battle politically."

Since 1962, 12 government committees have been set up to discuss use of growth promoters. The Committee of Microbiological Safety of Food, still sitting, has suggested it may recommend ban on antibiotic growth promoters by the end of this year.

Despite positive effects in the digestive tract, such as stabilising acidity and aiding digestion of nutrients, these products have a bad name. But they have positive environmental impact, reducing ammonia and urea, said Mr Toplis.

Joseph Kamphues, head of animal nutrition at Institute of Animal Nutrition, Hannover, said environmental benefits are often ignored: "For example, CO2 emissions are cut by over 14% with their use."

Production benefits of antibiotic growth promoters include improved growth rate of about 16% and feed conversion of almost 10% in piglets; reduced risk of rumen acidosis, particularly of use for intensive beef cattle; reduced rumen viscosity leading to lower risk of bloat in dairy cattle; and as an anti-coccidial treatment for lambs, added Dr Kamphues.

Despite this, public concern focuses on prophylactic use of antibiotic growth promoters in young animals, but less so for treating illness in later life. According to Peter Silley, research director at DW Scientific, Yorks, later treatment using these products could still induce antibiotic resistance although development depends on many factors.

Chris Challinor, Tescos red meat agricultural manager, said consumers were more concerned about antibiotic growth promoter use than genetic modification. While Tesco had no intention of banning such substances, he said producers may need to improve recording and possibly accept auditing to reassure consumers.

With evidence suggesting a ban, Berks-based pig consultant, William Close, urged producers to look at alternatives without delay.

"We could expect to see large-scale herd infections where a ban is introduced and no alternative strategy is in place."

Alternatives include organic acids, which in some tests have increased growth by 23%; oligo-sacharides, which cuts digestive problems and improves growth rates by up to 8%; enzymes that protect protein degradation; and herbs – particularly garlic; minerals and fibre, said Dr Close.

As an example, he explained that increasing fibre using sugar beet pulp in piglet diets led the number of days with diahorrea to fall from 36 to 21. Feeding a small amount of chopped straw also reduced diahorrea, albeit to a lesser degree.

However, Julian Wiseman, of Nottinham University, said research suggested some alternatives, particularly vegetable protein, used widely since the ban on meat and bone meal, could react to organic acids – the health consequences of which have not been quantified.

Niels Kjeldsen, head of Denmarks national pig committees nutrition and reproduction department, assured delegates that alternatives do work. However, a voluntary ban on AGP use in pigs over 35kg liveweight cost producers an extra £1/finished pig.

While several alternatives are being used by the Danes, including wet fermented feed, Dr Kjeldsen said reducing feed protein levels was essential to avoid illness, including diarrhoea, following removal of antibiotic growth promoters. "However, cutting protein reduced growth rate and increased fat levels," he warned.

However, better disease control on-farm from all-in/all-out systems and reduction in cross-suckling of piglets could help reduce illness and the effect of antibiotic growth promoter removal, added Dr Kjeldsen.

Many speakers agreed taking piglets to higher weaning weights may help reduce illness where these products are banned. "Where a sow could still be mated three weeks after farrowing, slightly later weaning could be a possibility," added Dr Close. &#42

CONFERENCE MESSAGES

&#8226 Ban likely soon.

&#8226 Huge losses likely.

&#8226 Alternatives exist.