Hygiene performance rating at farm level - an auditing scheme for evaluation of biosecurity measures' effect on prevalence of Campylobacter from selected broiler producers.

Background: Preventing pathogens from entering the broiler premises is the main biosecurity measure at farm level. In conventional broiler production, chickens are kept indoors during the entire production period. Pathogens can enter the broiler-producing unit from sources such as water, equipment, personnel, insects, and rodents. The possible routes must be controlled, and corrective measures applied when necessary. The objective of this study was to (1) develop a hygiene protocol and test the scheme on 30 farms, and (2) compare the results to their Campylobacter-colonised status. A Hygiene Performance Rating protocol at farm level (HPR-F) was developed to systematically review the production to identify risk areas to biosecurity. The HPR-F consists of 13 categories with related questions. For each question, a score was given from 1 to 3, where 1 meant "acceptable", 2 was "potential for improvements", and 3 was "not acceptable". Scores for each question were multiplied with weight factors for hygienic impact and economic consequences describing whether the necessary improvement depends on a significant investment or is a cheap quick-fix and calculated into a percentage where 100% is perfect hygiene. The 30 farms in the study were selected from one county in Norway. The Campylobacter-results for each of the 30 farms in 2019-2021 were given according to rules in the Norwegian Action Plan against Campylobacter faecal sampling on-farm 3-6 days prior to slaughter.

Results: The overall results from the HPR-F showed that the general hygiene level was high in all farms. The mean total hygiene score was 82% and varied from 70 to 92%. The category Handling dead chicken had the highest hygiene score (93%), and Ventilation had the lowest score (55%). The HPR-F results were compared to the Campylobacter-status for the 30 farms: Campylobacter-negative flocks had slightly higher total scores than Campylobacter-positive flocks (P = 0.19). Among others, the category Outdoor area (vegetation close to the premises' walls) was identified as the most stable factor in relation to be colonised with Campylobacter.

Conclusions: The HPR-F tested in this research trial provides a tool for veterinarians, advisors, and poultry farmers to improve biosecurity at farm level and enhance the preventive animal health initiatives.