Funded by the Swine Health Information Center, a study establishing oral fluid sampling guidelines for group-housed sows was recently finalized. Led by Dr. Jeff Zimmerman at Iowa State University, the project goals were to characterize group-housed sow behaviors associated with oral fluid sampling and establish best practices for sample collection as a function of gestation stage, parity and pen size. The results determined that oral fluids sampling can be easily conducted in group-housed sows with two important recommendations to maximize participation: 1) providing two ropes per pen and 2) allowing a sample time of 60 – 90 minutes.
Find the industry summary for Swine Health Information Center project #24-008 here.
In recent years, there has been a shift in some breeding herds to housing sows in groups, prompting the need for validating practical and cost-effective disease surveillance protocols in this population. The goal of this study was to develop sampling guidelines to optimize the collection of oral fluids for group-housed sows.
The project was conducted on a commercial breed-to-wean sow farm (6,500 head) across 12 pens with each pen holding 56 mid-gestation females sorted by parity. Oral fluids (using two ropes per pen) were collected for four consecutive days across the 12 pens: three pens of gilts, three pens of parity one sows, and six pens of multiparous sows. Sow behavior towards the ropes was characterized by individually marking a sub-set of animals and a 90-minute video observation was recorded. A food coloring dye was used to ensure detection of the environmental target in the oral fluids samples.
Results confirmed that 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 for diagnostic testing. However, sampling time in group-housed sows should be extended to 60 to 90 minutes to maximize participation, a longer duration than what is recommended for use when sampling 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 use of two ropes per pen is recommended to provide adequate access and reduce competition across sows. In addition, to reduce diagnostic costs, the two sample ropes from the same pen can be pooled prior to testing.
This study showed that diagnostic targets in the pen environment are transferred into pen-based oral fluid samples, confirming previous report findings in a study conducted with finishing pigs (Tarasiuk et al. 2024). This explains why pathogens not shed via the oral cavity (for example, PEDV) are consistently detected in oral fluids. As pigs explore their surroundings, diagnostic targets in the pen environment are picked up; as a result, these targets are deposited in the oral fluid sample and detected by diagnostic testing. These results highlight the ease of oral fluid collection and provide guidance for producers on best practices to routinely monitor herd health and detect emerging diseases in group-housed sows through oral fluids.
Reference: Tarasiuk et al. 2024. Pen-based swine oral fluid samples contain both environmental and pig-derived targets. Animals 14(5):766. https://doi.org/10.3390/ani14050766.
The Swine Health Information Center, launched in 2015 with Pork Checkoff funding, protects and enhances the health of the US swine herd by minimizing the impact of emerging disease threats through preparedness, coordinated communications, global disease monitoring, analysis of swine health data, and targeted research investments. As a conduit of information and research, SHIC encourages sharing of its publications and research. Forward, reprint, and quote SHIC material freely. For more information, visit http://www.swinehealth.org or contact Dr. Megan Niederwerder at [email protected] or Dr. Lisa Becton at [email protected].