Like antibiotics with that?
Chicken has become a cut-price protein. We consume more of it than any other meat, and while the price of chicken has dropped, production has boomed and critics say it has a cost to animal welfare.
That chicken you ate for dinner last night was most likely given antibiotics every day of its life. The antibiotic zinc bacitracin is mixed into the daily feed of most meat (broiler) chickens as a preventive measure against necrotic enteritis.
It can also increase body mass gains in chickens, and is promoted by some manufacturers as a growth enhancement. It is not given to free-range chickens. The mass medication practice is approved by veterinarians, who are required to sign off on any antibiotics given to chickens, but the medicine is doled out by farmers. Antibiotic use rose 13 per cent during 2013/14, when compared with the previous reporting period, 2010/11, MPI reported.
‘‘Antibiotics other than zinc bacitracin are only given in cases of outbreaks of other diseases,’’ the Poultry Industry Association of New Zealand boss Michael Brooks says. Like a spike in macrolide antibiotic use that was attributed to an outbreak of femoral head necrosis in poultry in 2011/12, a degenerative skeletal problem in fast-growing poultry also known as ‘‘brittle bone disease’’.
The use of macrolides and lincosamides (which include medicines used in humans) rocketed; in the 2012/13 season in-feed sales of the bacteriakilling medicines rose 53 per cent on the previous season. And sales between 2010 and 2014 overall were up 25 per cent.
The World Health Organisation (WHO) classifies macrolides as among the ‘‘highest priority critically important antimicrobials’’ to make sure ‘‘practising physicians and veterinarians, and other interested stakeholders involved in managing antimicrobial resistance ensure that all antimicrobials, especially critically important antimicrobials, are used prudently both in human and veterinary medicine’’.
Globally, concerns have been raised that using antibiotics in poultry and other livestock could lead to the development of drugresistant bacteria which might cause disease in humans. WHO said in some countries up to 80 per cent of antibiotics were used to stop animals from getting sick, and to speed up growth. Macrolides are one of few available therapies for serious campylobacter infections, particularly in children. And up to 90 per cent of fresh chicken bought in New Zealand may be contaminated. An antibioticresistant strain of campylobacter was first found in 2014, with human cases in Manawatu, Auckland and Wellington. The superbug was traced to three major poultry suppliers in the North Island. In 2017 MPI and the Ministry of Health jointly created an Antimicrobial Resistance Action Planning Group and published the National AMR Action Plan. It aims to ensure antibiotic use is prudent and safe.
Consumer NZ has highlighted the rising use of macrolide tylosin by industrial farming in a 2016 report.
‘‘Tylosin has accounted for 83 per cent or more of macrolide and lincosamide sales over all three reporting years. Of the tylosin-based products, between 64 per cent and 75 per cent were sold for administration in feed and registered for use in pigs to treat ileitis, poultry to treat respiratory disease as well as necrotic enteritis, and in beef cattle to treat liver abscess,’’ the report said.
MPI found the overall increase in the use of antimicrobials (synthetic and naturally occurring antibiotics) is partly a result of an increased number of chickens and dairy cows. Along with pork, these industries are the biggest users of antibiotics. Brooks said antibiotic levels in chicken are monitored by MPI. Brooks said birds treated with antibiotics must go through a withholding period to ensure the medicine has done its job, and left the animal’s system before it can enter the food chain. Remaining antibiotics must be less than the maximum residue level allowed under the Food Act 2014.
The most recent data from MPI shows zinc bacitracin sales have averaged 22,176 kilograms a year since 2004, and the drug accounted for 37 per cent of total veterinary antibiotic sales in 2011/12, and 35 per cent in 2012/13 and 2013/14. About twothirds of antibiotics sold for use in feed or water from 2011-2014 were zinc bacitracin. It’s also the most commonly used antibiotic in the poultry industry.
Zinc bacitracin is ‘‘important’’ to human health, meaning it is not the only available option to treat any particular human diseases. Antibiotics in this category are not used to treat diseases caused by organisms that can be transmitted from animals to humans, or develop resistant genes from animals. Brooks insists studies have shown the risk of resistance due to use in animals is minimal, and the antibiotics most commonly used on New Zealand poultry farms were not used for humans, or had extremely limited use in human medicine.
‘‘There’s an industry policy of never using, on a routine basis, antibiotics of critical or high importance to humans,’’ he said. ‘‘Now McDonald’s has announced the same policy internationally.’’
The fast food giant said it would reduce the use of human antibiotics. McDonald’s New Zealand spokesman Simon Kenny said the chain’s New Zealand chicken suppliers were expected to stop using the antibiotics by the end of 2019.
And the WHO has urged farmers to stop using antibiotics to prevent disease in healthy animals, as with the administration of zinc bacitracin. New Zealand Veterinary Association (NZVA) has a goal for New Zealand agriculture to be antibiotic-free except in emergency cases by 2030. ‘‘It’s an aspirational goal,’’ NZVA chief executive Mark Ward said.
NZVA chief veterinary officer Helen Beattie said it was about making sure people made good choices when they used antibiotics critically important for human health.