Survey of disease pressures in twenty-six niche herds in the midwestern United States

Objective: To provide diagnostic and veterinary support to niche producers in order to generate information on disease pressures in niche herds. Materials and methods: Twenty-six producers under contract with three niche-marketing companies were accepted into the program. A standardized diagnostic protocol, including serology and tissue diagnostics, was undertaken on suckling, nursery, finishing, and breeding animals. The diagnostic frequencies of diseases in niche-pork systems were compared to those in age-matched, diseased pigs submitted to the Iowa State University Veterinary Diagnostic Laboratory (ISU VDL) or in published reports. Results: Overall seroprevalence was lower (P < .001) for porcine reproductive and respiratory syndrome virus and higher (P < .001) for swine influenza virus in niche herds than in published data. Porcine circovirus associated disease was the most common disease diagnosed in niche nursery and finishing pigs. Compared to general ISU VDL submissions, Mycoplasma hyopneumoniae and porcine circovirus type 2 were detected in a higher percentage of niche pigs with respiratory disease (P < .001), a higher percentage of niche nursery pigs developed Lawsonia intracellularis enteritis (P < .001), and there was a greater degree of clinical internal parasitism in niche herds. Implications: Niche producers typically raise pigs in continuous-flow systems, without antibiotics, and in different environments than larger commercial swine operations. Results of this study indicate that these production changes can contribute to differences in the diagnostic frequency of several diseases and the ages at which diseases are clinically manifest in niche herds.