Side effects of excess magnesium

[Mrs Jingle]

Roughly £15 here for a 20kg sack of calmag, that even at relatively high doses seems to last forever, much, much cheaper alternative. I am seriously wondering now if I should go back to using it? Help!!!

 

[criso]

I know lots of people who use calmag and report it does the job just as well as magox. You have to feed a little bit more but it's still loads cheaper. Others reckon magox is better absorbed and contains less impurities. Definitely no calcium in it though.

Re the calcium levels, I have had a few analyses done at different yards as have friends and while there are variations, calcium is consistently high and magnesium low so I worry more about too much calcium than magnesium.

At my current yard it's so high that not only I am avoiding Alfalfa which is pretty high in calcium but sugarbeet which also contains reasonable levels of calcium.

Doesn't leave me alot to feed!

 

[amandaco2]

The only thing about persistantly high magnesium levels is it can affect calcium....but high levels isn't the same as high amounts in feed, depends how much is absorbed.
Likely to be the wormer....

 

[LucyPriory]

Ah right, well it is calcined magnesite that I was using (used for cattle in my part of the world and called calmag on the labelling), and I was led to believe that it also contained calcium? In fact I am sure that it said so on the label? But I could be wrong, I often am!

So would I be OK to still feed that then...I have gone back to buying very expensive magnesium from Progressive Earth as I thought I was getting it seriously wrong with the cattle Calmag?

Gosh it is all so confusing!

Some people believe calmag has calcium in it because of the 'cal' and will argue the case, but it doesn't - the 'cal' is for calcined. Much if not all mag ox will have its origins in calmag but will have had some or near all of the silica and carbon removed.

As I don't view these substances to be a problem I am happy to use calmag, as do many of my clients. It is cheap and more importantly it works for my horse. Some horses don't like the gritty texture, I've never had a problem provided it is properly mixed into a suitable carrier.

It's only the marketing puff that makes it confusing

There are areas of the UK where the forage is low in calcium but in the areas I worked on high calcium has been much more of an issue. Add that to the calcium in popular feeds such as alfalfa and beet and in terms of balance there is a greater likelihood of a relative shortage of magnesium.

The idea that all horses can get all they need from their grazing may well have been true at some point but not today. A lucky few may be fine, but IME far more are not.

 

[cptrayes]

Now I am totally confused, I had read (on here I think??) that the opposite is the case, that too much calcium inhibits the uptake of magnesium. Which is why I stopped using Calmag as I felt I might be depleting the uptake of magnesium (which is the thing I particularly wanted to feed at a reasonably high'ish level) by using the calmag as a cheaper alternative?

Calmag does not contain calcium. The Cal stands for calcined.

 

[cptrayes]

I kept three horses and two ponies fighting fit over thirty odd years and never fed a single supplement to any of them - I believe that they are totally unnecessary.

They may be unnecessary for you alan, you lucky ***. But my land is high in iron and sky high in manganese and if I do not supplement copper I have copper deficient horses which can be seen in the colour of dark coats and in the concavity of their feet.

Not all of us are lucky enough to have perfectly balanced grazing and forage as you are. I'm stuck with my geography, nothing can be done to balance my land, it is coming up in the water. Other people are stuck in livery with ryegrass haylage on ryegrass grazing.

You're just lucky, not clever

 

[cptrayes]

This is probably more reliable as he quotes Katy watts and dr kellon...

http://www.hoofrehab.com/diet.htm

Something in here about mg affecting ca...

http://equiforce.com/an-integral-part-of-equine-nutrition.aspx

The problem with all these studies is that they have been practically impossible to test. Both those reports are making assertions unsupported by any references to clinical trials.

Calcium/phophorous has been well documented for centuries, with the resulting disease known as "bran head".

Anecdotally, I can fully support the iron/manganese/copper problem.

But for the other balances, I asked how this research was done and the answer is that horses were fed huge, life threatening and even deadly overdoses/underdoses to see what the results were.

I still have not seen any clinical or even anecdotal evidence that there is any problem whatsoever dosing 25-50g a day of magnesium oxide. I have myself been dosing 25g a day for 3 horses for 7 years and never seen any issues. I know that I am far, far from alone in feeding this quantity, and that friends of mine have horses that go first stage laminitic if they don't get 25g a day.

 

[tallyho!]

It's very hard to find actual "evidence" you know.

I spent quite a bit of time trying to papers but nope, nada.

Like CPT says, it's all based anecdotally and if it works for your horses then carry on. I am mostly concerned about the calchos ratio to be honest. Even so, my 2yo filly gets mag, copper, zinc and selenium supplemented... I do this because I had the forage tested.

THAT is the key - if you don't know, forage test. It costs money, but so does buying minerals at least then you will know for sure exactly WHAT mineral to supplement according to your pasture (especially if your horse lives on a beef farm like mine).

The problem with beef pasture is that is is fertilised with NPK which can leach out other stuff from the soil and therefore the plant itself. The farmer himself has to supplement his cows to prevent disorders in cattle such as staggers and selenium deficiency which causes something I've forgotten the name of (calves can't stand up) etc.