Feeder unit environmental factors associated with partial carcass condemnations in market swine

Abstract

The impact of feeder pig finishing unit environment on partial carcass condemnations was evaluated in two studies. In a case-control study, monitoring data from 40 farms were used in the analysis. The average partial carcass condemnation percentage of 23 case farms in 1987 was 6.7%, and that of 17 control farms was 1.3%. The following factors differed ( P<0.10) between case and control farms in univariate analysis: herd size, population density, ammonia concentration, amount of bedding, joint trough between pens, water delivery system, light intensity and education of the manager. Large differences between different geographical areas were also found but, owing to a relatively small sample size, could not be used in the analysis without problems. The final multiple logistic regression model ( R=0.63) included herd size, ammonia concentration and number of pigs per pen. In a follow-up study, a multiple regression model was developed to explain the impact of environmental factors on partial carcass condemnations in swine. Farms were selected by simple random sampling. The analysis included environmental data from 103 farms. Nine variables were significant ( P<0.10) in univariate screening. The final multiple linear regression model ( R 2=0.51) included the following variables: geographic area, amount of bedding, maximum airflow in pens, water delivery from nipple, feeder, and feeding type.