Yes, it could be profitable if you have identified something your customers want and are willing to pay for. Horse owners are very picky customers. Horse owners are also litigious and should you have something like blister beetles in your area, you'd better have some insurance.

In your area, you might well find that cold season forage grasses are not the optimum thing to grow. Their production goes into a "summer slump" because they prefer to grow in colder climates. The reason why we do so well with cold season grasses in the west is because our nights are cool and this keeps the cold season grasses growing well, even in the summer when our days are up to 90F+. The nights being around 40F keep the grass thinking it is cool enough to keep growing.

Horse owners don't buy hay based on a test. They buy based on appearance, feel and smell. They're not always rational. They're not always nice people to deal with. They're a very finicky customer, on the whole, especially if you're selling to high-dollar horses.

If you can identify a product to cater to them, you can certainly make some money at it.

BUT....

realize that unless you have the sort of climate we do in the west (where we have big, long periods of clear, dry weather with no rain) that you're going to have hay that is rained on, and for this, you're not going to get the premium price. In Diamond Valley, NV, our producers could put up some timothy hay that would be worth $270/ton (that was last season, before the fuel prices went up) FOB their farms. That was for perfect timothy hay in three-string bales that weighed perhaps 90lbs. When you push a pencil on $270/ton hay, 5+ tons/acre in two cuttings... well, that makes things pencil out very nicely indeed.

Once it was rained on with even a light shower, it was worth only $90 to $100/ton. If it got soaked, it might be worth only $50/ton, because there's not much food value for the cattleman in timothy hay. At $50/ton, you were upside-down on the input costs. The numbers on perfect hay look very attractive, but you won't always make perfect hay and you'd like to not take such a big hit. Rained-on alfalfa, for example, would still be worth $80/ton when timothy was worth only $50. Perfect alfalfa would be worth only $150/ton, a lot less than timothy.

BTW -- if you're going to make money at haying, have enough equipment that when the hay is ready to go, so are you. This means that you either have a single line of new equipment that is very reliable, or you have lots of duplicate, cheap older equipment. However you do it, when the weather report says it's time to go, you must be able to get it done - that day, no waiting around for parts or repairs. This is how you get the hay put up looking perfect; when you see you have a good stretch of weather, you get 'er done. This is especially true if you're doing this alone and have another job. After you're done with a cutting/baling cycle, then you can fix equipment before the next cutting.