Report of the Scientific Committee of the Spanish Agency for Food Safety and Nutrition (AESAN) on the representative sample size for post-mortem inspection of poultry and farmed lagomorphs

*This record is given in both English and Spanish

The Implementing Regulation (EU) 2019/627 provides generally that all slaughtered birds must undergo post-mortem inspection by the authority, which applies by extension to lagomorphs. However, it also provides for the possibility for the competent authority to decide to submit a representative sample of birds or lagomorphs to inspection, provided that a number of additional requirements are met. A study has thus been carried out to provide a method for establishing what would be a representative sample for post-mortem inspection by sampling of these types of animals. The prevalence of seizure in birds and/or lagomorphs, as well as the sizes of the flocks or lots under inspection have been identified as some of the parameters of interest for proposing a sampling method. It has thus been shown from the literature that the prevalence or percentage of seizures in both birds and lagomorphs would never reach 2 %. It has also been shown that most of the flocks or lots inspected will normally consist of more than 8000 animals. However, there are a significant number of cases of flocks or batches of lagomorphs consisting of significantly fewer than 8000 animals, which could be considered as finite populations. On the one hand, it has been seen that from a statistical point of view the population
under study would fit into a binomial distribution. Approximating this distribution from a normal distribution, it has been possible to calculate for a percentage of seizures of 2 % that in the case of lots larger than 8480 animals the sample size to be submitted to post-mortem inspection would be 424 animals. For smaller lots or herds the calculation of the minimum sample size would be given by a hypergeometric distribution. It has been possible to calculate the range of sample sizes for small population sizes, as well as how to perform all calculations. It is recommended that the time of sampling at slaughter should be chosen randomly throughout the period of slaughter of the flock or lot.