As 2008 draws to a close we must now review what has happened with Salmonella monitoring and control on farm, how it has affected industry and what important factors should be consider for 2009.
It has now been almost a year since the National Control Programme for Salmonella in layers was implemented by government. Producers should have been testing for Salmonella in accordance with this programme. DEFRA have publicised this widely and industry veterinarians have also advertised the need to comply with this programme.
Although testing has been in place, this period has in effect been a "grace period" from the point of view of the consequences of a positive Salmonella enteritidis or Salmonella typhimurium. ie a period to establish the status of your flocks (which is hopefully negative) but if positive to work closely with your veterinary surgeon and Animal Health to address the problem.
That time is now over! As of 2009 all eggs from positively confirmed Salmonella enteritidis and Salmonella typhimurium flocks will have to be heat treated. In the current economic climate with feed and production costs, heat treatment of eggs is unlikely to be a viable economic option. In addition, Official testing will also now take place as of early 2009 whereby samples will be taken by DEFRA and tested for salmonella. This means that anyone that had not been testing and should have done so, must speak to their veterinary advisor immediately to test the status of their flocks in accordance with the National Control Programme.
Where do we stand right now?
There is some good news. Over the past year producers’ compliance with the National Programme has been excellent. Most producers have now complied with the testing specified in the National Control Programme and now know the status of their flocks. In summary the incidence of Salmonella enteritidis and Salmonella typhimurium is low from our personal experience processing large number of Salmonella samples for producers. A small number of cases have been identified but where these have occurred producers have worked closely to resolve the issue in time for 2009.
Indeed, the UK poultry industry has a much better record than other countries on Salmonella control, and arguably commercial layers lead the way.
Unfortunately, Salmonella is the silent enemy – you can’t see it or smell it and your birds will not tell you when they are infected.
Control
The secret to success in the approach to salmonella control covers three main areas. You need to think about:
• Meaningful monitoring
• Effective vaccination
• Enhanced biosecurity
Meaningful monitoring
At this point in time, the important fact is to know the Salmonella status of your flock. It is important that samples are taken on time and correctly in accordance with the programme. Samples should be taken using the correct methodology, using the correct sampling materials and received by the laboratory within 48 hours of sampling. Samples should be submitted to a laboratory with ISO17025 accreditation. If you are still unsure which samples should be taken, when they should be taken and how to take them then please contact your veterinary surgeon to discuss immediately.
Effective vaccination
Vaccines for Salmonella enteritidis and typhimurium have been available for some time, either for injection or via the drinking water. Whichever vaccine you use the important aspect is to ensure that each bird gets its full dose – either by making sure each bird gets injected or drinks its fair share of vaccinated drinking water. There is no substitute for taking expert advice here- consult your veterinary surgeon to discuss the best vaccination programme to protect your birds. This is the area where there is perhaps the greatest complacency. The vaccines work, otherwise they would never get a licence, but they are only one ingredient in the recipe for effective salmonella control.
Enhanced biosecurity
Biosecurity is a set of management practices which when followed help to reduce the risk of infections in your flocks.
Biosecurity is a very broad term and must be considered at a practical level on free range farms.
The areas you need to consider in particular with Salmonella control are:
• Cleaning and disinfection at depopulation;
Poor attention to cleaning your house, egg store and even the range can allow salmonella to persist on your site and infect clean pullets arriving on site, undoing a lot of hard work. Review all your procedures, from general blow down (dust can harbour salmonella) and cleaning (especially those hard to reach ledges and nooks and crannies), through to good quality disinfectants properly applied at the correct dilution rate. It is important to have the terminal disinfection procedures outlined within your flock health and welfare plan that is taiolered to your farm and the risks present. Don’t forget about the area around the house and equipment that might be taken out of the house during cleaning and then returned which might easily re-contaminate a cleaned house. These procedures must also include the drinker system, header tanks and feed bins; areas frequently forgotten about on the "out of sight, out of mind" principle.
• Feed:
Compound feed is seldom a potent source of salmonella contamination for poultry these days, due to the procedures in place in all the major feed mills. However, if you are supplying any scratch feed or added wheat then this needs to be of the highest quality, having been stored in vermin proof storage areas prior to use. Vehicles delivering feed are a potential source of infection and ALL vehicles that must come onto your site need to be visibly clean. Don’t be afraid to challenge drivers but in return make sure that vehicles can leave your site in a similarly clean condition. Don’t expect them to park up in filthy, poorly drained areas. Supply wheel sprays for use on arrival and departure. Think about other producers sites which may be visited after you.
• Equipment:
Vehicles, egg graders, live bird transport, egg lorries and keyes trays are all capable of becoming contaminated with faeces and dust and therefore have the ability to carry Salmonella.
Examine all equipment when it arrives on site and before it gets a chance to contaminate the environment of your farm.
Be bold and turn away vehicles or equipment which are not adequately cleaned.
• People:
Although it might be considered a rare event for people to carry bugs from farm to farm, they can certainly be efficient at moving bugs within a site, from house to house.
As indicated above, if you have a house effectively cleansed and disinfected, do all you can to keep it isolated and clean and not contaminate it by walking from the range or another house into the clean shed without a good change of protective clothing and boots.
Provide all visitors with protective clothing and make sure they follow all your biosecurity procedures.
Use foot dips, hand washing or hand sanitisers between houses and when leaving the premises.
• Wild birds:
Wild birds will carry Salmonella. Whereas it may be impossible to prevent them entering your site or contaminating the range, do all you can to discourage them from staying, especially by cleaning up all feed spillages.
• Other birds:
It goes without saying that you should purchase your birds from high quality sources and that you communicate with your supplier to make sure you are both on the same wavelength about what you require and expect. Although all suppliers of day old chicks or point of lay pullets should be working to the highest possible standards, make sure that you do not undo all that good work by contaminating them when they arrive on site.
It is following transport that birds are most stressed and vulnerable and likely to be good detectors of any small contamination which may be present on your farm.
