The effects of group size and subtherapeutic antibiotic alternatives on growth performance and morbidity of nursery pigs: a model for feed additive evaluation

Olsen, Kristin M; Gabler, Nicholas K; Rademacher, Chris J; Schwartz, Kent J; Schweer, Wesley P; Gourley, Gene G; Patience, John F

Oral fluid samples were collected via rope sampling from two pens per dietary treatment (eight pens total) on days 0, 21, and 40. Pens were chosen for oral fluid collection based on fixed special sampling, so that each area of the barn was equally represented (Rotolo et al., 2017) . A cotton rope was hung in the pen for approximately 1 h, and fluid was extracted from the rope by placing the saturated end into a plastic bag and squeezing out the fluid (Prickett et al., 2008) . The resulting fluid samples 3 Samples were collected at necropsy from pigs that died as determined necessary by the diagnostic veterinarian. On day 26, oral fluid samples from four symptomatic pens were collected and tested. On day 40, oral fluid and serum samples from eight pens, equidistantly spaced throughout the barn, were collected and tested. If a sample was positive for a specific pathogen, the whole barn was considered to have exposure to that pathogen. 4 PCR = polymerase chain reaction.