Agree with Corporal, except the 'poor & delicate digestive system' bit I'm not so sure of. Fed naturally, they don't seem to be poor & delicate to me, but there are so many common feeds, practices, etc that are just unsuitable & cause them to be 'poor'.
have always assumed that all horse feeds on the market were good quality, but now I'm beginning to question that.
Yeah, like all human food is high quality & nutritious...
Good for you(& your horse) to question!
Right now he's being fed sweet feed, which doesn't really work for him, but he has to be fed what the BO buys. I am starting to think that every horse should be assessed individually to determin what type of feed would benefit them instead of feeding everyone the same thing.[/quote]
Most definitely. The basic diet - namely low energy, high fibre such as grass/hay is generally suitable for all, but it depends on age, conditions, weight, activity level, etc as to what else may or may not be suitable for any given horse. Sweet feed is a bit like McDonalds for horses - tasty, high sugar & energy, but little goodness. I'd do some homework on horse's digestion & what is natural for them and also find a good nutritionist/service(pref independent of feed co's) to help advise you.
Safergrass.org is one good site on feeding horses healthily.
He's got rain rot now, which I was told may be due to some vitamin or mineral difficiency and his coat is raggy and dull.
Yes, these are possible signs of nutritional deficiency/imbalance.