I've just been in Devon for 3 days at the UKNHCP Annual Conference.
On day 3 we had a speaker called Clare Macleod who was excellent and all the information she gave was completely useful and relevant.
She's written a book called The Truth About Feeding Your Horse which I can recommend and is easy to understand!!
Her website details are below if you are interested in buying the book.
http://www.equinenutritionist.co.uk