When you hear the word “summer,” do the words “heat” and “humidity” instantly come to mind? How about the words “Salmonella” and “outbreak”? The truth is that the heat and humidity of summer can create the ideal environment on a dairy for a Salmonella outbreak.
A recently released National Animal Health Monitoring System (NAHMS) survey of heifer-raising operations shed some light on areas where all dairymen can improve their biosecurity plans to help ward off Salmonella and other diseases. It’s important to think ahead to prepare your dairy and ensure you aren’t leaving any doors open for the disease to enter.
Whenever cattle from another source enter the dairy — whether purchased from another dairy or returning to the milking operation from a heifer grower — there is the possibility that other diseases are tagging along.
Not only could the bacteria be living in the cattle but also on the trailer or truck transporting the cattle to your dairy. Fewer than one-third of those surveyed noted cleaning out and washing transportation vehicles after every shipment of calves.1
Closing the door
Procedures for cattle entering your herd should be an important part of your biosecurity plan. Whether buying new cattle or bringing your heifers back, work with your veterinarian to establish testing and quarantine protocols before commingling the cattle with the rest of your herd. And try to get the health history of any new cattle being purchased for your records.
Clean trailers transporting cattle — remove manure and disinfect surfaces — after every shipment. Work with the company and people transporting your cattle to discuss their biosecurity measures.
Rodents and wildlife can drop by unexpectedly and may carry bacteria, such as Salmonella, that can be transmitted to dairy cattle. Other pests such as birds can potentially be carriers. Wildlife isn’t the only source of disease. Even your pets can carry diseases that can be passed to dairy cattle.
Closing the door
While it may be impossible to keep wildlife and pets off your property, it is important to take steps to keep other animals away from your cattle to reduce the risk of disease transmission. Additional fencing may be needed to keep wildlife out and to keep other livestock from contacting dairy cattle. Wildlife and rodents often are looking for food. Keep your feed storage clean and protected to keep animals out of those areas.
People can also bring Salmonella and other diseases to a dairy. Every day, lots of people — employees, veterinarians, nutritionists, visitors, consultants, etc. — can travel on and off your operation, including to and from cattle pens.
Closing the door
For anyone going in or near cattle pens, properly managed footbaths can disinfect footwear that carries bacteria between groups of cattle. Veterinarians and AI technicians also should wear clean coveralls and boots before entering cattle pens. Visitors should not be allowed to enter or go near the feeding areas or pens. If they need to, make sure they adhere to biosecurity measures, using footbaths and wearing protective clothing.
Develop a prevention plan
With many access points to the dairy, implementing a Salmonella prevention plan is important for your dairy to help close doors to the disease. Your veterinarian can help you review the areas where Salmonella could enter your dairy as well as other management practices that can limit your risk of Salmonella. A good first step is to take a risk assessment, such as the one found at SalmonellaRisk.com/Assessment.
1 National Animal Health Monitoring System. Dairy Heifer Raiser, 2011: An overview of operations that specialize in raising dairy heifers. #613.1012 October 2012.