Vits and mins

[RubysGold]

I have an overweight mare, Kind of looking forward to the winter to give us a helping hand with weight loss. I have always just fed hay through winter, but she eats everything SO fast, she could eat a lot of hay, (which last year lead to her piling weight on, which I managed to get off her and now its back on)
So this year I will be mixing straw with some hay so that she can eat all night but not go through so much hay.
Now my question is, I read somewhere that when feeding straw, you need to make sure you feed them vits and mins. So what do I give her to ensure this?

She currently has a couple of handfuls of healthy hoof to put her devils claw on, but does that have the right vits/mins she'll need, or does she need a balancer or what?

 

[Miss L Toe]

You can use Fast Fibre [Allen and Page] and non molassed Dengie lo alfa chaff to carry more mins and vits, FF is a hay substitute and non fattening.
To keep her feeding over a longer timescale you can also soak the hay so that she is eating a lot of fibre, and also source a stalky type of hay not a ryegrass type.
There are special nets and so on, can she get a late night net?
It is important that she gets a full ration of her mins and vits, particularly if she is in work, there will not be enough in her chaff.
I am a bit of a worrier about feeding long straw as it can cause colic in TB types, but a small amount should be OK.