Responsible antimicrobial use reinforces public trust

By Kurt Preugschas

Editor’s note: Kurt Preugschas is a swine veterinarian and owner of Precision Veterinary Services. He can be contacted at The work featured in this article was initiated by Javier Bahamon, Quality Assurance and Production Manager, Alberta Pork. He can be contacted at

Antimicrobials are sometimes necessary in hog production, but their use has come under the microscope in recent years, on account of limiting antimicrobial resistance.

Antimicrobials are natural or synthetic substances that can kill or block the growth of micro-organisms, including bacteria that can make livestock sick. Antimicrobials are a valuable tool for veterinarians and hog producers to support animal health, control diseases and ensure animal welfare is maintained.

While the positive effects of responsible antimicrobial use are known, the potentially harmful impacts to human health and the environment are being more closely considered these days by global authorities and stakeholders within the Canadian livestock industry. The ultimate concern with using antimicrobials in hog production is the development of antimicrobial resistance.

Starting in late 2017, Alberta Pork recruited Precision Veterinary Services to work with 20 Alberta hog producers – mostly farrow-to-finish operations – from all regions of the province on benchmarking their antimicrobial use. This project did not directly measure antimicrobial resistance, but it may be possible to extrapolate the notion that, the more antimicrobials are used, the more risk there is of developing antimicrobial resistance. While this relationship is not entirely straightforward in nature, measuring antimicrobial use can be a fairly simple way of monitoring and understanding the relative risks while making improvements.

Antimicrobial use trending downward

Use of Class 1 and 2 drugs decreased over the five-year study, while use of Class 3 and 4 drugs increased slightly.
In-feed antimicrobials are most-common.

Prior to conducting the study, we suspected that antimicrobial use varied greatly from one farm to the next. Following the completion of the study, that was confirmed. However, the underlying positive reality is that antimicrobial use has been trending mostly downward. Over the five years assessed, there was a 43 per cent decrease of antimicrobials administered via injection, an 18 per cent decrease of antimicrobials administered through water, but an 11 per cent increase in antimicrobials administered in-feed. Overall, that represents a 13 per cent total decrease, moving lower as time goes on.

Heath Canada considers Class 1 antimicrobials as having ‘very high importance’ for human health. The 78 per cent drop in their use over only a handful of years is encouraging. The results suggest that Class 1 drugs are primarily being replaced by Class 3 alternatives, which are much less important for human medicine.

In 2018, Heath Canada mandated that all Class 1, 2 and 3 drugs for any use would have prescription status, available only from veterinarians and pharmacies. An example of a Class 1 drug used in the swine industry is ceftiofur – a pharmaceutical that treats infections in pigs, including bacterial pneumonia caused by Streptococcus suis. Examples like these have raised the level of concern over causing antimicrobial resistance and antimicrobial pollution in the environment.

This downward trend of antimicrobial use in Alberta hog production aligns with the goals of the Global Leaders Group on Antimicrobial Resistance, which was formed two years ago to tackle the problem. The group includes politicians, researchers and private sector representation from across the world, meeting quarterly to advise on prioritized actions to address the matter. Alberta hog producers, it seems, are on the right track in this regard.

Antimicrobials add potentially avoidable costs

In many cases, the antimicrobial cost per sow was three times greater for high-use farms compared to low-use farms.
The average difference in antimicrobial cost per pig was more than $6 greater for high-use farms compared to low-use farms.

In today’s costly farming environment, anywhere money can be saved is a good thing for producers’ bottom lines. While proactive, up-front investments into herd management – such as the use of vaccines – cost more in the beginning, they can certainly pay off in the end. Antimicrobial use, on the other hand, is usually a reactive response to a problem that could ultimately be avoided or lessened.

Costing data collected as part of the study showed a considerable amount of savings for farms with low antimicrobial use. Given the assumption that 27 pigs are weaned per sow per year, a high-use farm with a 500-sow farrow-to-finish operation, as an example, could end up paying $80,000 more than a low-use farm of comparable size.

While hog prices are reaching their predictable summer peak, cost of production, likewise, is at an all-time high. Any advantage a producer can get is worth taking.

Biosecurity reduces the need for drugs

Automatic ventilation systems with ventilation curves can optimize the barn environment and reduce the need for antimicrobials.

Improving animal and human health, cleaning up the planet and saving money are all great, but how can antimicrobial use decline even more, from a practical perspective?

Biosecurity is fundamental to preventing livestock illness and disease in the first place. Internal biosecurity assessments were performed as part of this study to evaluate any correlation between the internal biosecurity practices of individual farms versus those farms’ levels of antimicrobial use.

In general, having a higher health status – less disease on-farm – is positive and reduces the need for antimicrobials to prevent negative animal welfare outcomes, but even lower health status farms – more disease on-farm – can still have low use rates. Interestingly, this study established no correlation between health status and the amount of antimicrobial use, meaning that management – not disease status – is a much larger factor in the equation.

When it comes to barn hygiene, most farms are doing a good job in the nursery and farrowing areas, but improved hygiene in the grower section was identified as the area with the most opportunity for reducing antimicrobial use. Ensuring ventilation curves are in place for all areas of the barn can help. Automated ventilation on its own is not enough, and, in fact, ventilation curves were observed as the difference between farms with high and low antimicrobial use.

Stabilizing a farm’s overall health is most critical for reducing the need for antimicrobials. Limiting the number of live animal entries into the barn and making simple changes such as not giving iron or antibiotics to piglets less than 24-hours-old can help further. This reinforces the value of producers working closely with their veterinarians to optimize disease prevention, control and treatment protocols.

Alberta hog producers continue to improve

Thanks to the cooperation of Alberta’s hog producers, the entire industry is benefitting from paying more attention to the judicious use of antimicrobials. Going forward, Alberta Pork is looking to secure additional funding to advance this research, with the hope of including even more producers and veterinarians. Similar studies from other parts of Canada are contributing to an even wider understanding of the issue, providing additional opportunities to collaborate and share knowledge.

From understanding how and how much antimicrobials are used on-farm, and by auditing internal biosecurity, farmers can not only operate their businesses cost-consciously but also work toward the noble goal of improving public trust in the industry, which supports everyone across the value chain, all the way down to domestic and international pork consumers.

An even better future for livestock health is within reach, as the industry commits to continual improvement in management practices for all aspects of production, including antimicrobial use.