Basic steps for oral fluid collection on swine farms
Oral fluid collection is a simple way to gather samples for diagnostic testing.
Producers are always looking for ways to be more efficient as they manage their swine herds. One method that can help producers complete disease surveillance quickly on their farms is to collect oral fluids for diagnostic testing. This method is an acceptable way to sample your herd for various common swine diseases and can be done by yourself or employees in your facility. Supplies needed for collection, the collection process and submission of oral fluid samples are discussed below. More information on submitting oral fluids samples and laboratories currently offering oral fluid testing is discussed in “Producers can utilize oral fluid collection for diagnostic work”.
If you plan to submit oral fluid samples for diagnostic testing you will need a minimal amount of supplies to get these process started. You will need approximately 3 feet of cotton rope, gallon size plastic bags to collect the saliva in, single use plastic boots will also work well, knife or scissors to cut the bag, sterile snap cap or screw top collection tubes, permanent marker and gloves. The rope should be 100 percent cotton because of is absorption ability, 3 strand and not dyed. If you are sampling in the nursery you can unwind the rope and use one stand per pen of sampling.
Once you have assembled your supplies you are ready to begin the collection process. Start by hanging the rope in a pen away from feed or water. Remember that organic matter can contaminate the sample and care should be taken to avoid dropping the rope on the barn floor or hanging the rope so that it reaches the floor. Hang the rope by looping it around the fence or tie it in a knot. Once the rope is secure, unravel the ends to give the pigs more chewing room. When you are sampling pens of 25 pigs or more two ropes may be used to samples from the same pen. The pigs should have time to interact and explore the rope, chewing on it allowing for saliva to collect in the cotton material. Once the rope is saturated, approximately 30 minutes of hang time, remove the rope while wearing rubber gloves to prevent contamination.
Next, you will need to remove the oral fluid from the cotton rope. Place the rope into your plastic bag or boot and proceed to squeeze the saliva out of the rope, removing the rope as you sufficiently strip the fluid. In order to get a good sample you will need to collect approximately 2.5 ml. of fluid. Once oral fluid has been collected from the rope, place it into a test tube by snipping or cutting the corner of your plastic bag and draining it into the tube. Insert the cap on the tube and identify the sample with the marker. Samples should be kept chilled once they are collected.
When shipping oral fluids they should be sent the same day as they were collected and kept cold using a Styrofoam cooler and ice packs. If you are asking for PCR tests at the lab, samples can be frozen and sent at a later time. When shipping the samples, you need to follow the federal guidelines for sending serum samples, which include; properly labeling your container, using an insulated, leak proof container that is lined with a plastic bag and packing the samples with ice packs and absorbent materials. Before sealing your package, the proper paperwork for the diagnostic lab should be included.
Once the diagnostic lab receives your samples, they will run the requested tests and the results will be sent back to you. The timeframe is similar to serum sampling and you should not experience a delay when submitting oral fluids. This collection method is easily done by a properly trained employee and can be an efficient method to complete disease surveillance on your herd. Michigan State University Extension recommends that all farms implement a disease surveillance protocol on their farm, using cotton ropes to complete collection of oral fluids for diagnostic testing is a great tool for disease surveillance for producers in the pork industry.