The consequences of an excessive Salmonella status is increasing. Where once only a warning was given by the slaughterhouse, many institutions in the Netherlands are now also looking into the Salmonella status. But how is this categorization established?
Blood results show the level of antibodies against Salmonella. This level of contamination is expressed in the OD (Optical Density) value (%). The higher the OD-value is, the more antibodies against Salmonella are present in the blood serum. Therefore the contamination will even be higher. These OD-values are used to categorise your business in one of the three possible categories.
Per trimester your business will be scored:
1 point: 20% or less of the blood tests have an OD value higher then OD 40;
2 points: more than 20% and less than 40% of the blood results have an OD value greater than OD 40;
3 points: 40% or more of the blood tests have an OD value greater than OD40.
Then, the scores of the last three trimesters are added up in order to determine the category:
Category I: Low risk. The sum of the last three trimesters is 3 or 4.
Category II: Moderate risk. The sum of the last three trimesters is 5, 6 or 7.
Category III: High risk. The sum of the last three trimesters is 8 or 9.
Source: PVE | Productschap Vee, Vlees en Eieren
Please note that; as shown above, the status is based on the overall score of the 3 trimester per one whole year. When you tackle the Salmonella status with for example a Plan of Approach then the titers (OD values) will drop down. Which can be seen in the blood tests. As the category is based on 3 trimesters it could be the case that you will not directly see this drop down in the calculated category. It is therefore advisable to regularly take blood samples with your vet in order to check the Salmonella status.