Action limits’ have been set for substances for which no residue limits have been set in the law, to be able to decide whether the result of a residue analysis should be regarded as positive or negative. The action limits for natural hormones depend on the age and gender of the animal.
Urine samples
Two urine samples taken on the farm, originating from a veal calf and a young bovine, and one urine sample from a cow in the abattoir, contained a -nortestosterone in concentrations exceeding the action limit. This hormone can occur naturally in bearing cows and young calves. Natural causes may also explain the elevated levels of ß-nortestosterone found in ten urine samples from pigs. The traces of other natural hormones in the urine were lower than the action limit.
Blood samples
In addition to the urine samples that were studied, blood samples were also checked for the presence of hormones. The action limits were not exceeded in blood samples taken on the farm. Higher than normal levels were found twice in blood samples from the slaughterhouse.
Synthetic hormones
No synthetic hormones were found in the 923 urine samples collected on the farm or in the 2,302 urine samples taken in the abattoir. Synthetic hormones with a gestagenic effect and the synthetic hormone chlorotestosteronacetate can only be detected reliably in kidney fat. In 1997 none of these substances were found in kidney fat. Thyreostatic (thyroid hormones) were also not found.
ß-oestradiol
In 1997 the Foundation for Quality Guarantee of the Veal Sector found ß-oestradiol in only two of the 5,777 batches of calves that were slaughtered. All other samples, which were taken at random by the Foundation, were negative. A ‘batch’ here is a group of animals originating from one farm that have been reared at the same time.