Tips to achieve responsible antibiotics use

There has been much debate about the primary drivers for the development of antibiotics resistance in human pathogens – and the overuse of antibiotics in agriculture has been blamed by some parties and NGOs for this problem.

However, the epidemiology of antimicrobial resistance is complex and simply laying the blame on one sector is unrealistic. Nevertheless, all sectors need to consciously review their prescribing and usage practices of antimicrobials to prolong the useful life of these valuable chemicals.

The Responsible Use of Medicines in Agriculture Alliance (RUMA) has adopted a simple mantra: “As little as possible, as much as necessary”, and we should all have this in mind every time we think a group of birds need treating.

But there are also some basic actions that should be considered to ensure responsible and minimal use of antibiotics, and these can be incorporated in the farm health plan.

Antibiotics are most commonly used because something has gone wrong and the birds have succumbed to a bacterial infection. Working on the premise that “prevention is better than cure”, the following would be key areas on which to focus.

Biosecurity

Most infections are brought to the farm through a breakdown in biosecurity. Ensuring robust biosecurity that operates 24/7 is a number one priority. In this context, it will be interesting to see the effect of boot barriers for campylobacter control on antibiotics use going forward.

Hygiene

Disease carry-over from one cycle to the next is an important route of infection into a flock. While terminal hygiene needs to be rigorous, with appropriate chemicals, it is important to ensure a focus on initial washing, as this dilutes the microbiological load and improves efficacy of disinfectants.

Drying between washing and final disinfection is also important, as dessication again reduces microbiological load. Advice should be sought from hygiene chemical suppliers and cleaning processes should be assessed both visually and bacteriologically.

Drinking water quality

Drinking water quality is well recognised as important to bird health. The introduction of nipple drinkers had a profound effect on the health of broilers, particularly on bone and respiratory health. The liveability in commercial ducks is lower in sheds with open water systems (required by some assurance systems), than in sheds with nipple drinker systems.

On most farms with mains water supplies, the quality of the water arriving at the farm will be potable. However, biofilm will build up in water lines over time, so it is important to ensure they are well cleaned and sanitised between crops to remove it. Biofilm bloom can be exacerbated when supplements and treatments – for example vitamins – are used, so intercrop water hygiene is critical following these treatments.

Vaccination

Most disease challenges in birds will result in secondary bacterial infection, for which antimicrobials will be prescribed. Prevention of those primary disease challenges through appropriate vaccination programs will affect antimicrobials use.

However, some live viral vaccines can affect the functionality of the local mucus membrane and the immune response, so overuse or inappropriate use can itself create problems for the flock. Vaccine programmes should be developed with the supervisory veterinary surgeon with a comprehensive knowledge of the farm, regional and national disease status.

Management

Modern meat and egg poultry stock have been selected for improved productivity, be it egg numbers or growth rate and feed conversion ratio. Environmental conditions can have a profound effect on bird behaviour and health, so micro-management of that environment is essential to achieve the genetic potential delivered by the breed companies

In recent years the introduction of indirect heating systems in broiler housing has enabled managers to more easily manage humidity and that improvement in shed environment has benefited overall bird health.

Disease investigation

Health problems will occur in all livestock. However, when a problem arises it should be investigated to understand the cause and whether the use of antimicrobials is appropriate for the condition. Furthermore, should the disease be caused by bacteria, it is important to undertake antimicrobials sensitivity testing to ensure the correct type and dose of antibiotics is selected.

For more detailed advice, see RUMA’s guidelines for the Responsible Use of Antimicrobials in Poultry Production