LAUSR

Inflammatory mediators, such as cytokines, can reduce feed intake and drastically modify the partitioning of nutrients. Thus, it may increase the animal’s maintenance requirements, reduce milk production and piglet growth, impact reproductive performance, and reduce sow lifetime productivity. The objective of this experiment was to evaluate a non-invasive method, not tested before in swine, to assess cytokine profiles from post-partum uterine lavage. The uteri of second and third parity sows (n=14) were flushed with sterile saline solution (0.9%) on days 2, 4, and 14 post-parturition. An artificial insemination (AI) catheter, in its plastic covering, to avoid vaginal contents, was inserted through the vagina into the cervix. A flexible inner catheter was passed through the outer AI catheter and into the uterine horn. Sterile saline (30-40 mL) was flushed through the inner catheter into one uterine horn. After inner catheter removal, a tube was attached to the end of the outer AI catheter to allow collection of the natural back-flow of uterine lavage fluid (avg 24.7% recovery). Uterine fluid collected was immediately centrifuged and the supernatant stored at -20°C. Samples were freeze-dried, re-suspended in sterile saline (2 mL), and stored at -80°C. Cytokine profiles of the uterine fluid were evaluated using a multiplex ELISA panel including interleukin (IL)-1β, IL-6, IL-8, IL-4, IL-10, tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ). Cytokine concentrations were calculated relative to protein content (pg/mg of protein). IFN-γ and TNF-α were lower than the limit of detection in most samples (5/38 and 1/38, respectively). IL-4 and IL-10 concentrations did not differ among days of collection (P >0.14). IL-8 was greater on day 4 than on days 2 or 14 (P< 0.05). IL-1β and IL-6 were greater on days 2 and 4 than on day 14 (P< 0.05). Uterine flushing is a novel non-invasive method to access uterine inflammatory cytokines in sows.