Transfer from Plants to Livestock and Animal Food

4 Transfer from Plants to Livestock and Animal Food 

Having addressed the accumulation of PCDD/Fs in plants, this section will discuss the transfer from plants to animals, focusing in particular on cattle. First, 

As was mentioned in the introduction, it has been shown that feed is the primary source of PCDD/Fs to cattle. Water and air make negligible contributions to exposure.52 The same can be expected for other livestock, given the very low vapour pressure and hydrophobic nature of this class of compounds. 

Hiester,P. Bruckmann,R. Bohm, P.Eynck, A. Gerlach, etal., Organohalogen Compd., 1995,24,147. 

A steady state exists when the uptake, storage and excretion of a substance does not change with time. Given that the concentrations of PCDD/Fs in feed are relatively constant, milk cows and egg laying hens are in an approximate PCDD/F steady state. The one exception is the cow that has calved for the first time. In this case the PCDD/Fs that it has accumulated as a heifer are initially 

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