On average, the untreated HIV infected patient will progress to AIDS in about 5-10 years. Since 1996, the introduction of powerful anti-retroviral therapies has dramatically changed the natural progression of HIV infection to the development of AIDS.
You CAN feed your horse just hay, but you have to up the portions and it also depends upon the type of hay you are feeding. Alfalfa mix is normally the best but there again, you're goinng to have to feed more hay to make up for the not feeding grain when you are riding.
Oat hay is an excellent feed for horses. The choice between alfalfa and oat hay depends on price per unit of energy or protein and the type of horse being fed. Depending on the area of the country in which it is grown, oat hay can be low in protein and contain only marginal calcium, phosphorus, and carotene.