Acrylamide-occurrence in mixed concentrate feed for dairy cows and carry-over into milk.

During the preparation of cooked foods acrylamide is formed from asparagine and reducing sugars at high temperatures. By-products of oil, starch and sugar production, which may be found in animal feed, partially result from processing steps using heat treatment that are similarly likely to form acrylamide. Possibly, pelletizing during the processing of mixed concentrates may also be involved in acrylamide formation. Thus the occurrence of acrylamide in animal feed and the potential for carry-over into animal products should be tested. Independently of the feed matrix, 1.5 g per day of acrylamide was fed to a cow for ten days resulting in a mean concentration of 175 microg/kg of acrylamide in the milk. From the data obtained the mean carry-over was found to be 0.24%, and a mean half-life time of 2.8 h was estimated. This means acrylamide was rapidly transformed in the cow. The acrylamide concentrations in three commercial mixed concentrates were respectively 180, 145 and 140 microg/kg feed. To test the possible effect of pelletizing, the peripheral zones were separately analysed. No difference in concentration was observed. Based on the carry-over rate estimated in this study, a maximum concentration of approx. 0.2 microg/kg of acrylamide would be expected in milk from cows fed with such feeds.

Mycotoxins in soybean feedstuffs used in Germany.

Fifty samples of soybean meal-25 of them samples of high-protein soybean meal-and one sample of soybean hulls obtained from the feed industry in Germany were analysed for the mycotoxins aflatoxins, deoxynivalenol (DON), zearalenone (ZON) and ochratoxin A (OTA). Additionally, 4 samples of high protein soybean meal which were suspected of containing high mycotoxin levels were analysed. Aflatoxin B1 (AFB1) was detected in 32 of the 51 non-suspicious samples but the maximal concentration was only 0.41 µg/kg. DON could not be detected in any of the non-suspicious samples. ZON was detected in 23 of the 51 samples with a maximal concentration of 18 µg/kg. It was present in 18 of 25 samples of soybean meal and in the sample of soybean hulls but only in 4 of 25 samples of highprotein soybean meal. This finding suggests that ZON is mainly located in the hulls of soybeans, because high-protein meal does not contain hulls. OTA was found in 4 samples, with the greatest concentration detected being 1 µg/kg.All of the four suspicious samples of high protein soybean meal contained high ZON concentrations of up to 363 µg/kg. The contamination with other mycotoxins was on the same order of magnitude as in the case of the non-suspicious samples.

Heavy metals, chlorinated pesticides and polychlorinated biphenyls in sudden infant death syndrome (SIDS).

The concentrations of lead in blood and of cadmium and mercury in kidney tissue were determined by atomic absorption spectrometry in cases in SIDS and a control group containing cases of known causes of death. SIDS cases were split into groups from urban and rural areas and areas highly polluted with lead and zinc (sites of lead and zinc works). Neither the concentration of lead in blood (median 26.5 to 50.0 micrograms/l), nor the concentration of cadmium (median 24.0 to 44.0 micrograms/kg ww) or mercury (43.0 to 69.0 micrograms/kg ww) showed significant differences between the groups. In addition the concentrations of persistent chlorohydrocarbons (hexachlorbenzene; alpha, beta and gamma hexachlorcyclohexane; heptachlorepoxide; dieldrine; total DDT; polychlorinated biphenyls) were measured in subcutaneous fatty tissue in SIDS cases from rural and urban areas and in a control group. These substances also showed no significant concentration differences in cases of SIDS.

[The significance of mycotoxin assimilation for the contamination of milk and milk products]. / Bedeutung einer Mykotoxin-Aufnahme für die Kontamination von Milch und Milchprodukten.

The two possible pathways contaminating milk and milk products with mycotoxins are either the secretory or post-secretory route. The latter is of only little importance due to cooling conditions in production and storage. A secretory contamination can only occur with such mycotoxins, which undergo no complete degradation through their passage into the milk. From the mycotoxins, present in cow's feed; virtually only aflatoxin B1 yields a milkborne metabolite, the aflatoxin M1. The carry over rate is low (2 +/- 1%), but can be enhanced by polyhalogenated biphenyls, also present in the forage. Under normal conditions, however, this enhancement will not be measurable due to low equimolar concentrations of both reactants. The aflatoxin M1 content in herd's bulk milk depends exclusively on the content of the precursor aflatoxin B1 in the ration of the cow and is with less than 10 ng/kg fairly low at present in the Federal Republic of Germany. A careful supervision of the imported feed ingredients for mixed feed, however, will ensure to keep those batches out of dairy cow feeding which exceed a certain level of aflatoxin. The legal threshold is 10 micrograms/kg, being even too high to ensure a milk containing less than 10 ng/kg under high energy feeding conditions. The discussed thresholds for aflatoxin M1 in milk are 50 and 10 ng/kg resp., the latter value is scheduled for milk used in infant nutrition. To keep this low concentration the intake of aflatoxin B1 must be less than 2 micrograms/kg of the daily ration.

[Residues of chlorinated hydrocarbons in milk and milk products - situation and evaluation (author's transl)]. / Rückstände chlorierter Kohlenwasserstoffe in Milch und Milchprodukten - Situation und Bewertung

Residues of the most varied chemical substances can be found in milk and in milk products. For the transfer into milk such factors as fat solubility, persistance with respect to metabolic processes and accumulation capacity in certain organic systems are of particular importance. For the description of the situation with respect to residues of chlorinated insectides the results of analyses obtained in 20 supply areas of the German Federal Republic are presented and interpreted. In 1974 the following mean values were found (fat basis): alpha-HCH 0.04, gamma-HCH 0.072, heptachloro-epoxide 0.024, dieldrin 0.021 and DDT 0.20 ppm. These mean values are far below the max. quantities legally permissible and in no way constitute a toxicological risk (referred to ADI). In the German Federal Republic the concentrations of hexachlorobenzene in some cases reach the permissible max. quantity of 0.5 ppm on a fat basis. There is reason to assume that this substance finds its way into the milk not only via its application as a fungicide but probably also via a number of other, in part unknown, sources of contamination in or on vegetable products. With PCB (polychlorinated biphenyls) average concentrations from 0.2 to 0.3 ppm must be expected to be present in milk and milk products (fat basis). At present a toxicological interpretation of the values found is hardly possible.