Homestead Hay Needs
Oh hay!

Hay is a big part of farm life. Most livestock either rely on hay as their primary feed, use it is bedding, or enjoy it as a feed supplement in winter. This means that if you have animals, you're going to go through a lot of hay in the wintertime.
We have fifteen goats (and kids in spring), two sheep, two pigs, and seventeen geese who use hay in one way or another. For the goats and sheep it is their primary food source all winter long. In the summer, they forage all day but still get some hay at night. For the sheep and pigs, it's their bedding during the winter months (occasionally switched out for straw). And for pigs and geese it's a wintertime feed treat, not their regular diet but a tasty supplement.

With these animals, we go through 500-600 bales of hay in a year. Calculating how much hay you may go through considers a number of variables: your climate and how much forage you can offer, what types of animals you have, and within those types what breeds and sizes and whether or not not you'll be breeding. Chat with local farmers about their hay consumption, ask the people you may be getting animals from, and be ready to tweak your numbers the first few years.
There are also a number of ways to get hay. Hay can come in square or round bales, as well as chopped forage called chaffhaye and silage. There are a lot of options for feeding, we prefer square bales and a mix of 1st and 2nd cut hay. Why? First cut hay is less expensive than 2nd (at least in our area) and combined with the right feed provides pretty good protein/nutrition for goats and sheep. Second cut hay, which has more protein and is usually a finer hay with more clover and grasses rather than weeds, is a bit more expensive but that higher protein is good for our animals, especially those that are being bred. In Maine we get only two cuts, and sometimes only one, so we only have these options available. Other areas of the US may get a 3rd or even 4th cut of hay in a season.

We also prefer square bales. When our goat Mary Jane had listeria recently, my research indicated that a common way goats get listeria is through mold in the center of round bales. For a small farm such as ours, square bales are ready to move around by hand, break out into handy feeding "flakes", and can store in barn lofts without getting moldy. For a larger farm round bales may make more sense.
There are also various ways to obtain hay. You can cut your own fields with investments in equipment and a good understanding of what you are doing. Haying equipment is expensive and often needs repairs, which can be costly and can set you back during the critical window of time that you can hay. Haying also requires a lot of attention to the weather, as hay can never be put away wet. Nevertheless, with experience cutting your own hay may end up a good option.
Sometimes, depending on what area you live in, you can hire a local farmer to cut your fields for you. But if you don't have that option or don't have fields, the best option is often to build a relationship with a farmer where you can pick up your hay every year, as we do. Picking up your hay helps keep it a bit less expensive, and if you trust your farmer you know it will be dry, good hay for your animals. You do have to make sure you have a good storage space for the hay -- barn lofts are always the best option, but inside on pallets can also work.

You can consider buying hay from a feed store year round as well, which sometimes is the only option. However, feed store hay is often 2 or 3 times the price of local hay, and you cannot guarantee your feed store will have hay in stock every time you need it.
Finally -- there's 90 bales in this picture. So be sure to set aside some time and energy for putting up hay! It's a great farm workout, and an annual tradition. Also be sure to budget for it every year, as hay is the biggest annual farm expense for most homesteaders with livestock.