Factor analysis of swine farm management practices on Prince Edward Island

This study used multivariable analysis to describe the role of the environment in respiratory disease of pigs. Environmental effects acting on pigs were assessed by visiting 76 pig farms. Management areas examined were farm size, growth rate, feeding styles and feedstuffs, manure handling and bedding, ventilation, pen space and flooring, moving and mixing pigs, sources of pigs, contact with people in the barn, labour source and experience. Data were gathered by physically measuring dimensional parameters, and by visual determination of other characteristics. One person performed the farm visits in a consistent manner. From the examination of the 76 farms, 43 management variables were calculated. The 43 variables were condensed using factor analysis into 6 factors. The factors are 6 uncorrelated variables that describe the 43 correlated management variables in a more statistically efficient manner. The 6 factors describe farm types based on which management variables score highly with each factor. The farm types that emerged were as follows: (1) smaller farms using extensive farming techniques - high volume and space per pig and straw as bedding; (2) a farm type using group pig flow, a system that used solid pen partitions, did not move pigs between pens, and a higher ratio of pigs to water spaces; (3) a farm type with room pig flow that was larger (pigs sold) than others in this study population, was farrow-to-finish and had modern facilities; (4) farms that bought pigs from different sources, did not seek veterinary advice, and had slow-growing pigs; (5) a family farm type that primarily floor-fed the pigs; (6) an integrated farm type that was larger than average, made its own feed, was closer in proximity to other farms and had other farmers as primary visitors. The 6 farm types were biologically plausible descriptions of farm management on Prince Edward Island. The results of the factor analysis were then used in a regression analysis of enzootic pneumonia and pleuritis prevalence at slaughter. (The results and conclusions of these analyses are presented in a subsequent paper.)..