Development of a method for semi-quantitative visual monitoring of cleaning operations in farm barns

The scoring of visual cleanliness is both subjective and relatively inaccurate, and may vary significantly depending on the observer. The monitoring method that identifies total flora using an agar plate is simple, fast, reliable and discriminatory. However, itis little used due to cost and logistics constraints. The aim of this study is to propose an alternative method that is more accurate than standard visual scoring and more practical to employ than agar plates. Three methods for monitoring the effectiveness of cleaning operations have been compared: • scoring of visual cleanliness; • measurement of contamination using an agar plate to make a total bacterial count; • semi-quantitative scoring of visual cleanliness using a paper towel. The results for semi-quantitative scoring of visual cleanliness using a paper towel are similar to those obtained using agar plates. While the use of paper towels in scoring cleanliness is suitable in terms of identifying defects in the cleaning phase, it is not appropriate in cases where the disinfection operation has been performed incorrectly.