# Commission Decision of 29 September 2006 concerning a financial contribution from the Community towards a baseline survey on the prevalence of Salmonella in slaughter pigs to be carried out in the Member States (notified under document number C(2006) 4306) (2006/668/EC), Division 1: Sampling frame

Extent: E+W+S+N.I.

A minimum number of pigs, kept during at least the preceding three months in the Member State, shall be ad random sampled in accordance with Table 1.
Table 1
Minimum sample size
Based on an infinite population (> 100 000 per year), an estimated prevalence of 50 %, a confidence level of 95 % and a accuracy of 2, 3, 4 and 5 % respectively.
Number of pigs present in the population
Minimum sample size
> 20 000 000
2 400
10 to 20 000 000
1 067
2 to 10 000 000
600
< 2 000 000
384
Member States shall take a 10 % extra number of samples, to be analyzed in case some samples would be excluded from the study for various reasons.
Samplings shall be stratified by month to ensure to cover the different seasons.
Sampling shall be stratified by slaughterhouses that participate and proportional to slaughterhouse capacity. Each Member State shall rank all slaughterhouses according to their fattening pigs throughput in the previous year. Thus, each Member State shall identify those plants that accounted for at least 80 % of all slaughtered fattening pigs.
The total number of pigs and carcases to be sampled in each of the slaughterhouses included in the study shall be estimated by multiplying the sample size (e.g. 2 400) by the proportion of fattening pigs processed in the previous year. For example, if one slaughterhouse accounted for 25 % of fattening pigs slaughtered in the selected slaughterhouses (those representing at least 80 % of all fattening pigs slaughtered in the Member State), then (2 400 × 0,25) 600 pigs shall be sampled. These shall be evenly divided so that 50 pigs were sampled in every month, for 12 months. A further example is shown in Table 2.
Naturally, if a slaughterhouse is no longer in production, if a new facility has been opened or there is predicted to be a significant change in plant throughput during the survey, then the estimated throughput shall be adjusted accordingly.
Table 2
Weighing of slaughterhouses for the purpose of allocating the number of fattening pigs to be sampled from each slaughterhouse; calculation of sampled animals per slaughterhouse
This number should represent at least 80 % of slaughtered fattening pigs in a Member State.
Slaughterhouse ID
Number of fattening pigs processed previous year
Percent of total slaughter included in the study
Number of samples per slaughterhouse
Samples per month(/12)
AXD
88 000
17,6
0,176 × 2 400 = 422,4
422,4:12 = 36
SVH
25 000
5,0
TPB
75 000
15,0
MLG
100 000
20,0
GHT
212 000
42,4
Total
500 000
100,0
For each slaughterhouse each month, a number between 1 and 31 shall be selected at random. If the randomly selected number is a slaughtering day, for that month, then that day is selected for sampling. If not, then a new number is selected randomly. This process is performed once a month and repeated so many times as there are samples to be collected at the slaughterhouse. For example, in the slaughterhouse AXD the process shall be repeated at least 36 times to select at least 36 working days randomly. Naturally, it might be more than one carcase to be sampled on the same day.
As the number of animals slaughtered on a specific day may vary enormously, the random selection of the individual animal shall take place at the slaughterhouse at the day randomly selected for sampling. The given day, the total number of animals is known, and the personnel of the slaughterhouse shall then randomly select a carcase or carcases using the randomisation sheet which has been provided to them and which has been generated using a maximum that exceeds the highest possible number of fattening pigs slaughtered on any given day in any slaughterhouse in the Member State.
A randomisation table may then look as shown in Table 3.
Table 3
Randomisation table
i.e. the fifth carcase to be processed on the 19th day of that month should be sampled for the survey.
Slaughterhouse
Day of the month
Identity of carcase
AXD
19
5
4
2
12
124
12
2
8
59
The following animals shall be excluded from the baseline study:
animals with a live weight of less than 50 kg or more than 170 kg,
animals that have undergone emergency slaughter,
any carcase that is totally condemned.

---
Source: https://www.legislation.gov.uk/eudn/2006/668/annex/I/division/1 (the official version)
Page: https://openlegislation.uk/eu-decision-2006-668/annex-I/division-1
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.

