Collect oral fluid samples from group-housed sows by hanging two cotton ropes per pen and allowing 60 to 90 minutes of sampling time to yield best results, suggests a recent study funded by the Swine Health Information Center (SHIC) and led by Jeff Zimmerman at Iowa State University.
As more breeding herds shift to housing sows in groups, the need for validating practical and cost-effective disease surveillance protocols in this population is greater than ever.
Oral fluid sampling has become a popular way to monitor herd health because it’s non-invasive, cost-effective and efficient. It’s also simple and safe for caretakers to collect, according to a recent nationwide survey on oral fluid sampling in U.S. swine farms published in Pathogens.
Zimmerman’s oral fluids sampling study in group-housed sows set out to determine practicality and best practices for the swine industry.
What Did the Sows’ Behavior Reveal?
Researchers conducted the study on a 6,500-head commercial breed-to-wean sow farm. Oral fluids were collected using two ropes per pen for four consecutive days across the pens. Sow behavior towards the ropes was characterized by individually marking a sub-set of animals and a 90-minute video observation was recorded, the study shows.
Results revealed oral fluids can be routinely collected from group-housed gestating sows using cotton ropes, a process used successfully in growing pig populations. In all groups and on all sampling days, the volume of oral fluid collected during the study was more than adequate to conduct diagnostic tests.
Larger Animals Need Longer Sampling Time
However, experts caution that sampling time in group-housed sows should be extended to 60 to 90 minutes to maximize participation, a longer duration than what is suggested for growing pigs.
The longer sampling time is needed for sows due to their larger size and the fact that fewer sows can access the ropes at any given time when compared to growing pigs, the experts say. The use of two ropes per pen provides adequate access while reducing competition across sows. By combining the two ropes from a single pen before sending them to the lab, you can reduce costs and only pay for one test per pen.
The researchers note that this study showed diagnostic targets, such as a gene, protein or antibody whose presence or absence is used to detect disease, in the pen environment are transferred into pen-based oral fluid samples. This confirms previous report findings in a study conducted by Tarasiuk with finishing pigs.
This explains why pathogens not shed via the mouth (for example, porcine epidemic diarrhea virus, a highly contagious coronavirus that causes severe diarrhea, vomiting, and dehydration in pigs) are consistently detected in oral fluids.
Detecting emerging diseases and monitoring herd health in group-housed sows can be done with ease through oral fluid collection, the researchers say.
