>I've never found Se at more than 2mg per
dose. And even that's not nearly enough here (my gelding gets 4mg daily,
in addition to the tiny amount in his grain). When I did my original
search (several years ago), I was amazed at all so-called the "selenium
supplements" that had almost no Se in them. Many had only a
half milligram per dose.
You're right that NO product out there is more than
2 mg per dose. By law, that's all they can put in.
The NRC requirements still list the selenium requirement as 2 mg per day, which
is really puny--but I don't know what sort of Act of God it takes to get them
updated. Oregon State has the research to indicate that the daily
requirement is much higher, and Schering has also done research to that
effect. The products that are more concentrated have
to indicate smaller doses on their labels. The problem remains
that those with less concentration and larger doses are more difficult to
increase on your own, due to the very bulk of the supplement. Which is why
it is much easier to use a product that has a small dose size and also does not
have other ingredients that could put the diet out of kilter by doubling or
tripling the dose.
You're also right on target with your comment about
many "selenium supplements" having very little selenium in them at all.
That's why it is so important to do the math. Likewise, many people think
they are supplementing selenium simply because a given feed has selenium on the
label. I have a good friend who recently moved to central Oregon, where we
could pretty safely figure our hay at zero for selenium content. He
thought he was doing enough by feeding a senior product with selenium on the
label. Considering that the entire diet needs to average somewhere in the
realm of 0.9 to 1.0 ppm to be adequate, the fact that senior products contain a
maximum of 0.3 ppm isn't very helpful, particularly being fed with hay that
contains even less.
