Technical assistance to the Commission (Article 31 of Regulation (EC) No 178/2002) for the preparation of a data collection system of welfare indicators in EU broilers’ slaughterhouses
Council Directive 2007/43/EC on the protection of chickens kept for meat production requires Member States to submit to the Commission the results of a data collection of welfare indicators in broiler slaughterhouses. The Commission prepared a draft document for a harmonised data collection system of welfare indicators in broiler slaughterhouses for a one-year period and requested EFSA to assess whether the sample size chosen in the document would be sufficient to achieve the objectives of the data collection. The structure of the population as well as possible stratification factors influence the sampling protocol of a data collection. In this case, the sampling should occur in each Member State at three levels: i) at slaughterhouses; ii) at flocks within each sampled slaughterhouse and iii) at broilers and feet within each sampled flock. Based on the methodological approach developed for this mandate, the assessment shows that for 15 MS, 1% of the total number of flocks slaughtered in one year is not a sufficient sample to assess 1% prevalence of the given conditions. For 3 MS, 1% sample is sufficient depending on the combination number of flocks and broilers/feet chosen. For 1 MS, when any combination is used, 1% of flocks slaughtered is a sufficient sample to assess prevalence of 1%. A general approach for designing and ensuring representativeness of sampling plans in MS was proposed. The recommended sampling scheme better fitting for this data collection is a three stage sampling scheme, where the selection of the unit at each level could be based on established criteria. Finally, in the case an EU harmonised data collection is implemented in the future, it is recommended to submit the collected data in a harmonised way through the EFSA Data Collection Framework. This report proposes a possible data model for the submission of the data.