Health and Lean Growth Performance of Barrows Reared in All-In, All-Out or Continuous Flow Facilities With or Without Antibiotic

Purdue University 1997 Swine Research Report. Health and well-being of pigs may be markedly affected by management and environment in modern pork production units. All-in, all-out animal flow during the growing-finishing phase of swine production is well established as a means for reducing certain diseases and improving growth performance (Clark et al., 1991; and Cline et al., 1992). Environment is a complex composite of many factors and stressors interacting with one another. Exposure to stress increases the animals chance of being challenged by respiratory diseases. Respiratory disease in pigs has its most serious effects in the finishing stages (Done, 1991). Mycoplasma hyopneumoniae and Pasteurella multocida type A are causative agents of chronic respiratory disease that result in decreased overall performance. Actinobacillus pleuropneumoniae and A. suis can be causes of chronic pneumonia, but usually are present as acute pneumonia. The importance of these diseases during the finishing stages is associated with intensive systems of housing which change the relationship between the microorganisms and the pig and its environment (Done, 1991). The purpose of this study was to compare the effect of all-in, all-out management to continuous flow management, during the growing-finishing phase, on growth rate and severity of disease. In addition, the effect of chlortetracycline on overall health and lean growth in both environments was tested.