Mail & Guardian

Poultry industry wants responsibl­e use of antibiotic­s

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Chicken is a much-loved source of protein for South Africans. Antibiotic­s are commonly used both for preventing and treating disease and to improve growth, according to Dr Charlotte Nkuna, senior executive at the South African Poultry Associatio­n.

Growth promoters are simply a class of antimicrob­ials, not used in human medicine, to help manage the gut health of poultry. Better

Vuuren, “but you can take it for granted that a sizeable proportion is used for growth promotion.”

Antibiotic­s should only be used to treat sick animals and, where appropriat­e, to prevent the spread of disease, he said. But the prophylact­ic use of antibiotic­s — giving healthy animals drugs to prevent them getting sick — must be avoided.

Globally, there is a move away from the use of drugs to promote growth, a trend South Africa is likely to follow.

The difficulty of monitoring the extent of antibiotic use in agricultur­al comes down to cost; surveillan­ce programmes are expensive and require a partnershi­p between the government and other role players, he said.

The laws that govern how antibiotic­s are dispensed to farmers also play a role in how they are used. Two Acts govern veterinary medicines — the Fertilizer­s, Farm Feeds, Agricultur­al Remedies and Stock Remedies Act of 1947 and the Medicines Control Act of 1965.

Under the stock remedies Act, farmers can buy some antibiotic­s over the counter to use as they see fit growth results because birds with healthier guts are able to use their food more effectivel­y.

The organisati­on discourage­s the routine use of antimicrob­ials for prophylact­ic purposes unless a diagnosed disease is being managed, she said.

Farmers should monitor the effectiven­ess of the drugs used and avoid using the last-resort antimicrob­ials, unless the use of other

and without the guidance of a veterinari­an. The intention of the Act was to enable farmers in rural areas, with little or no veterinary services, to get access to medicines.

Over time, the list of over-the-counter antibiotic­s has expanded and includes a major group of antibiotic­s that can be used to promote growth, Van Vuuren said.

There is much debate in the sector about changing this, but South Africa is a developing country and many farmers still don’t have veterinary services, he said.

There is a tension between access and excess, which is pertinent for a country that has roughly 35 000 commercial farmers, between two and three million small-scale farmers, and eight- to 10-million subsistenc­e farmers, Van Vuuren said.

The Medicines Control Act covers scheduled antibiotic­s, and only veterinari­ans can prescribe and dispense them.

Some more modern antibiotic­s are not registered for use in animals, Van Vuuren said.

Antibiotic use selects out resistant bacteria in animals, just as it does in humans, said Professor Marc Mendelson, co-chairperso­n of the South African Antibiotic Stewardshi­p Programme.

“The more antibiotic­s are used, the more resistant strains are selected out and therefore can be transferre­d to humans during the journey from production to plate,” he said. drugs will prolong the disease.

Although Colistin was not used in poultry for many years, its use has increased after it was found to be more effective in treating some conditions.

Resistance is not unique to Colistin, Nkuna added, but the drug is used for the treatment of human conditions, which makes it a more serious issue.

The emphasis should not be on

Antibiotic residues end up in meat, and antibiotic residues and antibiotic-resistant bacteria enter the environmen­t.

But the rise of AMR cannot be attributed to the use of antibiotic­s in agricultur­e alone.

The misuse of these drugs in human medicine is also a major contributo­r to resistance. It requires a global awareness campaign about antibiotic misuse and overuse in human and animal health, and in all other walks of life that introduce resistant bacteria into the environmen­t, Mendelson said.

One of the few surveillan­ce programmes of AMR in South Africa is provided by V-Tech, a veterinary pharmaceut­ical firm. The programme began in 2006 and covers poultry farms, cattle feedlots and piggeries countrywid­e, according to V-Tech’s chief executive and veterinari­an, Johan Oosthuyse.

Earlier this year, the programme identified i ncreasing cases of Colistin-resistant bacteria in poultry farms.

The early generation antibiotic, once not recommende­d for use in humans, has become a drug of “last resort”, because organisms have adapted to newer classes of antibiotic­s, leading to the rise of so-called superbugs.

Mendelson explained that a new mechanism to transfer a Colistinre­sistant gene known as MCR-1 has been identified in bacteria, first in the reduction of antibiotic use in agricultur­e but on “responsibl­e use”, she said.

Vaccines were alternativ­es for some diseases and there are alternativ­es for promoting gut health such as organic acids. Neutriciti­cals — herbal or natural products — are also being researched to assist in managing respirator­y and gut health, Nkuna said. — feed animals in China and later in other countries, including South Africa.

There is also a concern that this gene can now be transferre­d between different types of bacteria that cause more serious diseases in animals, and, according to Oostehuyse, potentiall­y humans.

The cost and implicatio­n of reducing reliance on antibiotic­s in agricultur­e needs further exploratio­n. The O’Neill review acknowledg­ed the significan­t gaps in data for both surveillan­ce of antibiotic use in agricultur­e and the economic costs.

It did note that a 2015 study by the US department of agricultur­e showed that producers that use antibiotic­s for production rather than treatment would suffer a decline of less than 1% in the value of what they produced.

The ability of the local agricultur­al sector to reduce its reliance on antibiotic­s can be done with better biosecurit­y or actions that safeguard the health of farm animals, Van Vuuren said. These include vaccinatio­ns, optimal nutrition for animals and access control on farms.

But the total eliminatio­n of antibiotic­s in agricultur­e is unrealisti­c, Oosthuyse said. South Africa has a “high animal disease challenge”, which is aggravated by informal farming.

The department of agricultur­e, forestry and fisheries did not respond to requests for comment.

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