Antibiotics reduction strategies for turkey farmers

Many misconceptions about animal production and antibiotics resistance remain among consumers, retailers, legislators and politicians.

Simply put, antibiotics resistance is the ability of bacteria to survive or even flourish in the presence of that antibiotic – and it has become a serious issue internationally.

Sally Davies, the UK chief medical officer, said antibiotics resistance is one of the greatest threats to modern health. While the use of antibiotics in animals “is not a massive problem”, she stressed that every effort must be made to ensure that they did not become one.

See also: How to rear turkeys for the Christmas market

According to poultry vet Stephen Lister, of Crowshall Veterinary Services, there is nothing to be gained by playing a blame game; the issue is a shared responsibility of all those prescribing and using antibiotics in both animals and humans.

Already, very few products are available to treat minor species such as turkeys and the only option available to vets may be to prescribe “off-label” – in other words, a drug that is licensed for another animal species – under strictly controlled conditions.

Looking ahead, Mr Lister said the industry would need to explore all techniques to reduce dependence on all antibiotics by improving stockmanship, management and disease diagnosis and exploring alternative means of disease control such as vaccinations and the use of alternative products.

Mr Lister said a comprehensive “three Rs” approach to antibiotics use – reduction, refinement and replacement – should be in place. And he called for more transparency, so consumers would better understand the implications any further constraints on drug use could have on animal production. 

Alternative strategies

Alternative therapies could also be a useful option for the turkey sector, Maria Parigi of the zootechnical institute in Forli, Italy, told the meeting.

She and her colleagues have looked at the efficacy of an enhanced acidifier on E coli bacteria that cause systemic disease in turkeys and lead to poor growth and even death in affected birds.

Causing a range of symptoms, colibacillosis is regarded as a major problem in the turkey industry worldwide, not least because the bacteria are developing resistance to commonly used antibiotics.

Using turkeys kept under laboratory conditions, she and her colleagues found a significant reduction in the number of E coli bacteria in the intestine in those birds receiving the higher level of the acidifier (2kg/t of feed) and none of the lesions typical of the disease in day 20.

On day 30, liver damage was significantly lower in this group than in the control birds that did not receive the product.

While the product did not eliminate the bacteria completely, Dr Parigi said that it did appear to slow down its replication, reducing the risk of transmitting the disease to other flocks.

Blackhead: No approved controls

A total ban on antibiotics use would have devastating consequences for producers. Some of the possible consequences are already being felt by the turkey industry, where there is now no approved and effective drug to control blackhead in many countries, including the UK, according to US poultry vet Steven Clark, of Devenish Nutrition, LLC.

Also known as histomoniasis, blackhead is caused by a simple organism, a protozoan called Histomonas melegridis, which lives in the heterakis worm.

A turkey can pick up the infection if it eats one of the worms and can easily spread the infection to pen-mates, leading to significant mortality. Outbreaks tend to be sporadic, but cases have been confirmed in the UK and other European countries.

As Dr Clark explained, all in-feed blackhead treatments in the US are banned, and producers there must now rely on management and a range of alternative plant products known as phytogenics to prevent the disease.

Although researchers have had some success with vaccination, there is no prospect of a commercial product being available anytime soon. 

A multifactorial approach is required. Control of coccidiosis is important, as this infection appears to make turkeys more susceptible to blackhead.

Tight biosecurity can help to keep the heterakis worm out of turkey houses and may be key where broiler breeders are kept nearby as they can carry the worms without showing symptoms.

Litter treatments, such as acids, can be effective in reducing the risk of infection, while the installation of fences within the turkey house may stop the spread through the flock.

Otherwise, prevention of blackhead relies on extra-label drug options, under veterinary supervision, but these are not permitted for routine use.