It’s interesting how a headline can lead someone astray. A headline in Saturday’s “Japan News Review” announced, “Dutch milk suspected behind Japanese mad cow outbreaks.”
Not waiting to read the article, I immediately dove into the scientific literature to see what I had missed. Was it really possible for mad cow to be transmitted through milk? I couldn’t find a single research article to support this theory.
When I went back and read the original article, I discovered that the cattle hadn’t been fed milk, but rather a milk substitute that contained powdered animal fat. That didn’t make a lot more sense. Tallow (a rendered animal fat) has long been considered a low risk animal by-product by the World Health Organization.
The theory that Japanese cattle were infected with mad cow prions by being fed milk substitute containing Dutch animal fat is an old one. A very similar story appeared on CNN in 2001.
There are other possible explanations for the Japanese mad cow outbreak. The milk substitute was actually processed in Japan, using animal fat from the Netherlands as one ingredient. The powder might have been contaminated by meat and bone meal - a high-risk material for mad cow transmission - during mixing. Another source might have been dried cattle blood, which is sometimes used as an ingredient in mild substitute for feeding cattle.
There’s only one thing I’m sure of. Dutch milk did NOT transmit mad cow disease, in Japan or anywhere else.
3 months ago