It all depends on what you are doing with the horse. Your best bet would be to talk to your local vet or animal nutritionist in your area. They will be able to tell you more, especially about locally sourced feed. Another decent source for you may be the Merck Veterinary manual online, it gets pretty technical at times but will give you a rough idea. There are also all sorts of books available for balancing and formulating rations you could get, but don't forget to actually look at your horse, his coat,eyes,feet will all let you know if you are getting the ration wrong. Also as a suggestion stay away from the wierd and wonderful rations, it does your horse no good if he won't eat it, even if it is balanced.

Thank you so much for the suggestions.

I just bought a 9 year old Quarter Horse from a friend of mine. In the many questions I asked before taking delivery of my new friend I asked what he had been feeding the horse.
Simply put he said he had been feeding her coastal hay and sweet feed, specifically Sweet Bossy #9, a large coffee can of this feed twice a day.
Reading the bag of feed it seems this is principally a feed for cattle. Is this a good thing to continue feeding her?
Thanks

Well since my last posting, I have done some research and have learned that in general, no horse should be on alfalfa as more horses are ending up with insulin resistance and alfalfa is not good for that. Bermuda and Timothy seem to be the best best but Vit E, table salt (no iodine) and supplements with Biotin,selenium and other minerals will be good. The best website I came across is thoughtfulhorseman.com which gives references for the information posted. Those references I checked came clear and I decided to get my supplements from the same site.
BTW, something new I came across my research for the most suitable food was about garlic and how one should NOT feed garlic to horses. Apparently they are actually detrimental which does not mean death at the moment of ingestion- if you know what I mean.
Hope the 'reader's digest' version of what I have been researching for the past 3 months comes helpful to you.

The type of concentrate should depend on the horse, but in general one should strive to have the majority of the diet be forage, with as little grain as possible to keep the horse in good health. Especially for a stalled horse, more hay will not only keep the gut moving as designed, but will also prevent bordome and vices. If you find that your horse does well on only hay, a good vitamin/mineral supplement or grain will fill in the gaps. However, if hard work and/or a fast metabolism cause your horse to require grain, look for one formulated for your horse's lifestyle. I do not find sweet feeds to be a good choice, as the large amounts of sugar are not natural and can lead to insulin resistance and obesity problems. It can also cause some horses to be constantly "wired" and hyperactive.

Excellent question and one that I had when I first got my horse. I advise you to consult the website www.thoughtfulhorseman. Of course, you want to ease your horse to the new feed if it is different from what you end up giving. Mine is a now 5 year old mare who is on Bermuda hay and the supplements the complete what MY AREA's Bermuda Hay generally lacks. You will find more info on the provided website. Most horses are overfed so make sure you are not lovingly overfeeding your horse just to learn that you set him/her off on a bad start with insulin resistance to come. Hope this helps.