Oral Fluid Sampling in Group-Housed Sows: Field Observations

Oral fluid sampling is a well-established, non-invasive method for disease surveillance in growing pigs; however, its application in group-housed gestating sows is under-researched. This study (1) characterized sow behaviors associated with oral fluid sampling and (2) documented the transfer of an environmental target into pen-based oral fluid samples. Field observations were conducted on a commercial sow farm in 12 pens of gestating sows sorted by parity (gilts, parity one, and multiparous sows). Sow oral fluid sampling behaviors were quantified by recording interactions with rope samplers using video cameras and then analyzing the recorded footage. All oral fluid sampling attempts were successful. Unlike growing pigs, experience with rope samplers ("training") did not increase sow participation, but participation in oral fluid collection did increase as sampling time increased. The transfer of environmental components into oral fluid samples was demonstrated by introducing a fluorescent tracer into the pen and then detecting specific fluorescence in the samples (8 of 12 pens). These findings support the implementation of oral fluid sampling in group-housed sows and provide practical recommendations for optimizing surveillance protocols, including extended sampling times and use of at least two ropes per pen.