The aim of this study was to evaluate the efficacy of orally administered leucomycin at 90 and 180ppm for the prevention of porcine proliferative enteropathy (PPE) in experimentally infected pigs. A total of 90 commercial five-week-old pigs were randomly assigned to receive leucomycin in feeding at 90 (T2), 180ppm (T3), or untreated (T1). All animals in the treated groups received medicated feed for 14 days starting one day before inoculation. Each pig was inoculated intragastrically with approximately 4.5x10(9) Lawsonia intracellularis in the form of porcine intestinal mucosal homogenate. Body weight, feed consumption and clinic signs were evaluated throughout the study. Necropsies and gross evaluation of intestines were performed in all animals on day 23 post-inoculation (pi) or at death, and ileum samples were collected for immunohistochemistry (IHC) for L. intracellularis. Clinical presentation of the disease was more evident in the non-medicated group (T1) than in the medicated ones (T2, T3) between days 16 and 21pi. Average daily gain, average daily feed consumption and feed conversion efficiency were better in groups treated with either dose of leucomycin. The total intestine lesion length per group (T1, T2 and T3) was 869, 473 and 331cm, respectively. The majority of the animals (84.4%) were positive for L. intracellularis antigen in ileum sections stained by IHC. Under the conditions of this study, leucomycin administered in feed at 90 and 180ppm for 14 days was effective in improving performance of pigs inoculated with intestinal homogenate containing L. intracellularis.
swine; proliferative enteropathy; Lawsonia intracellularis; control; leucomycin
