ANALYSIS - At the British Pig & Poultry Fair 2012 earlier this month, Daniel Parker, a Slatehall Vet Practice, and Oliver Hoddinot, a poultry producer, conducted a workshop on antibiotic stewardship, writes Nuria Martínez Herráez, ThePoultrySite editor.
Daniel Parker offered to the attendees to the workshop some theory about antibiotic
stewardship and antibiotic resistance in animals and humans.
He pointed out the high interest in the press about the use of antibiotics in animal production and the growing call from consumers and other groups to reduce their use in poultry and other farm livestock.
There have been several reports published on this issue. For instance, the EFSA and ECDC joint report on antimicrobial resistance in zoonotic bacteria affecting humans, animals and food.
Mr Parker explained what exactly ‘antibiotic resistance’ means: if someone is using antibiotics too often, their body will develop resistance to the chemicals contained on these antibiotics.
There are three main ways for bacteria to become resistant to antibiotics:
- break down the antibiotic
- mutate (the antibiotic target is modified or removed), and
- pump the antibiotic out of the cells.
There are several ways for antibiotics to provoke resistance in the bacterial cells: acquisition of
new genes, mutation of genes, etc.
The ESBL enzymes, which confer resistance to penicillin and 2nd, 3rd and 4th generations of cephalosporins, are spread by sharing a bacterial RNA carried on plasmids, which are promiscuous and spread between bacteria.
Some variants of ESBL and Amp–C enzymes are identified and seen in both human and animal bacteria resistance.
Mr Parker explained there is growing concern about the loss of antibiotic efficacy due to antimicrobial resistance because, through the food chain, resistance can be transferred from food production animals to humans.
He mentioned some examples of antibiotics resistance.
For example, the EFSA/ECDC report found that a high proportion of Campylobacter in humans is resistant to the antimicrobial, ciprofloxacin. In addition, many strains of this pathogen were found to be resistant to the antimicrobial, particularly in chickens.
Regarding Salmonella, the same report showed a high proportion of Salmonella resistant to antibiotics but no resistance to ciprofloxacin in humans. However, in animals and food, high levels of resistance in Salmonella were reported for commonly used antimicrobials as well as for ciprofloxacin in poultry.
Therefore, it may be concluded that some genes and plasmids are common to humans and poultry.
Mr Parker also mentioned that in 2011, 94 per cent of retail poultry samples tested positive in ESBL in the Netherlands.
He added that the use of all antibiotics will potentially develop resistance in bacteria.
He went on to explain that the use of antibiotics in food production animals remained steady from 2005 and 2009 and tetracyclines were the most commonly used group.
From his point of view, the RUMA (Responsible Use of Medicines in Agriculture) approach is the one that should be taken in the industry: “All animal medication should be used as little as possible but as much as necessary,” said Mr Parker.
Moreover, he emphasised that science is still not clear about the link between resistance developed in humans and their use in poultry.
Mr Parker then moved on to the use of antibiotics in the UK’s industry. According to the British Poultry Council, the use of 3rd and 4th generations of cephalosporins are not used in the poultry meat chain due to their importance for humans in order to avoid the risk of bacteria developing resistance to them.
The use of fluoroquinolones has been stopped as well in day-old chicks for the same reason.
The British Poultry Council strives to reduce the overall use of antibiotics. However, Mr Parker pointed out this is a difficult task because the changes from the use of one antibiotic to another can be complicated (e.g. the dose can vary from one to another).
Taking the stage then was Oliver Hoddinott, a poultry producer who has been growing broilers since 1997, talked about his own experience of reducing the use of antibiotics in poultry.
He explained that the lack of time and attention paid to details can lead to decreases in bird performance and health. As a result, the birds may be exposed to wet litter, higher pododermatitis, poor FCR and coccidiosis.
These problems have a financial impact: the poor performance brings lower returns and, at the same time, veterinary costs are increased due to the use of antibiotics in an attempt to recover the bird health and their performance.
The financial impacts may extend to farm restructuring, a need for more labour, a change in the veterinary advice and a return back to focus the attention to details.
The changes introduced after the improvements made were:
- Gumboro vaccination was strengthened and the timing was improved
- VPD’s, each shed was treated individually
- IB vaccine timing was improved
- Treatment was only used for diagnosed diseases
- Use of mains water, and
- Use of a probiotic
The improvements in biosecurity and hygiene measures included:
- Wash out for all sheds, foamed with detergent and high-quality disinfectant (twice)
- The bedding was changed to shavings
- A barrier system was introduced to avoid cross-contamination between buildings
- A catchers’ canteen outside the facilities was provided, and
- Pressure washers were placed in the entrances of the buildings (with water a disinfectant).
The results of reducing antibiotics and introducing these new measures were:
- An increase of weight per age in the birds
- Improved FCR
- Drier litters and reduced pododermatitis, and
- Fewer health issues generally, and especially in leg problems.
Mr Hoddinott concluded that poultry producers should not be afraid to make hard decisions. They also
need to connect with consumers and to stop believing that antibiotics are the wonder cure: they are
essential in treating specific diagnosed diseases.
He added: “We can use them [antibiotics] when we need them.”