This manual describes the use of the transfer model to estimate the concentration of dioxins (total TEQ) in body fat of the pig based on oral exposure to feed contaminated with dioxins. The model has several input fields (left side) and output fields (right side). The input and results can be saved using the button “Report (*.docx)”. Source information and a citation suggestion are provided (top).

Step1: Contamination level of feed
The user can provide the contamination level (expressed in ng total TEQ/kg feed) in the contamination field. For the background level of dioxins in feed a default value is provided. The user can adjust this default value.

Step 2: Feed intake
The user first has to select the type of feed that is contaminated with dioxins.
a)    This can either be:

  • Total compound feed (blend of various raw materials and/or additives)
  • Wet mixes (mixture of compound feed, solid and liquid by-products and water)
  • Compound feed ingredients
  • Other

When compound feed ingredients are selected, a drop down menu will appear to select the contaminated compound feed ingredient.

b)    After selecting the contaminated feed (ingredient), default feed intake values are provided (in kg dry matter per day) for four age categories of the pig (day 0-67, day 68-95, day 96-137, day >138) 1. The user can adjust these default values to the values corresponding to the actual feeding regime.

Step 3: Exposure period of pig to contaminated feed
To estimate the concentration of dioxins in body fat of the pig, the user has to enter the age of the pig at the beginning of the exposure period, the duration of the exposure of the animals to the contaminated feed (ingredient) and the time period after the exposure stopped (all expressed in days).

Step 4: Regulatory limit (optional)
A regulatory limit (for instance maximum level) for body fat (expressed in pg total TEQ/g body fat) can be inserted. This limit will be displayed in the output graph on the screen, but not yet in the report.

Step 5: Results
A graph with the total TEQ concentration versus time will be generated for either the central compartment or the fat compartment (expressed in pg/g central compartment or pg/g body fat). The user can switch between the different graphs using the button below the graph.
The growth of the pig has been taken into consideration in the model, based on the data depicted in figure A and B. These figures show the body weight and percentage body fat versus the time. The total TEQ concentrations, body weights and fat percentages are valid for the average pig.

Figure A: Pig growth - body weight vs. age

 

Figure B: Pig growth - Fat percentage vs. age

Step 6: Saving input and output
By using the “Report (*.docx)” button, present in the left corner, input data and the results of the model run can be stored locally as a report file in word. The optional regulatory limit is not yet visible in the report. Input data and results are not stored at the website.

Step 7: Citation suggestion
At the top of the model page the references that describe the model are listed, as well as a citation suggestion. Please use the suggested citation, when referring to the model.


 1 Van Raamsdonk LWD, Kan CA, Meijer GAL, Kemme PA (2007) Key figures for some farm animals and their consumption patterns [in Dutch]; https://research.wur.nl/en/publications/kengetallen-van-enkele-landbouwhuisdieren-en-hun-consumptiepatron.