TiHo Bibliothek elib - Tierärztliche Hochschule Hannover

Summary
the group F III were fed with uncontaminated feed for 2.75 / 4.5 / 5 resp. 5.75 months
before the slaughter. The dioxin burden in their carcasses varied between 1.04 and
3.29 pg WHO-PCDD/F-TEQ/g fat (1 sample > maximum level). The pooled liver
samples of these primiparous beef cows (group F I – F III) contained dioxin contents
of 6.22 - 20.11 pg WHO-PCDD/F-TEQ/g fat so that all exceeded the maximum
level (4.50 pg WHO-PCDD/F-TEQ/g fat).
Conclusions
The production of “safe“ beef (PCDD/F content < maximum level) from animals
grazing on dioxin loaded grassland and by feeding roughage containing notable
amounts of PCDD/F is possible, but only if the contaminated feedstuffs were
substituted by uncontaminated ones for a sufficient period of time before the
slaughter of the animals. The results of this study show that if the animals were fed
uncontaminated feed at least 3 months before slaughter and – in this time – their
body weight increased about 10 % and additionally, some dioxins were excreted via
milk (no absolute necessity), the dioxin burden in the carcasses of these animals
decreased below the maximum permitted level for beef. In accordance with these
results, it may be possible to use dioxin exposed grassland for the production of
“safe” beef – regarding the consumer protection – which is of a high quality.
Nevertheless, it should be noted that the livers of all these animals have to be
excluded from the food chain by all means. However, the implementation of this
feeding-concept would require a change in the current legislation: The restrictions
associated with the universal feed ban for feeds exceeding the maximum permitted
level of contamination would necessarily have to be eased in order to allow the use
of feed exceeding the maximum permitted level for “undesirable substances” for a
certain time.
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