Question I should have asked is how much are you talking about? Answer would be totally difference for one milk cow or 100 feeder steers.
At one time I had a Hay Wrap machine. Fit on the back of my Ford 4000. Neighbors put up the large round bales at the time and I had to put on 250 pounds of weight on the front of the tractor to keep it on the ground. Regular cut hay was wrapped with plastic on the sides and a bit over the ends. Cost was about $3.00 per bale for wrap and depreciation. What I noticed with it was, when set out, the cattle would eat anywhere they could get to. Very little wastage. With regular unwrapped bales, they go from the ends inside.
Wrap was not biodegradable. After being cut off with the bale in the air I would pack them into a garbage bag in a metal can. When full it went to the trash collection center.
You can use a Hay Wrap to make haylage. One bale is sealed at the end and set down to start a row. Next is wrapped as normal and jammed up against the first one, sealing it in the row. This is continued with the last bale sealed on the outside end. Basically you could put up haylage in a day. Cut as soon as the dew if off. By the time you finish cutting a field, went back to the barn to put on the windrower, fooled around a bit, windrowed, went back to the barn to put on the baler, fooled around a bit, material may have dried down enough to start rolling. Once rolled, you put on the wrap. Technically, one person with one suitable-sized tractor, should be able to put up ten or more acres of haylage a day. I didn't try this.
I sold the equipment after my neighbor when to the smaller, tighter bales. The spear on the Hay Wrap was too large to penetrate these bales. It kept knocking them over. I had to put them down by a tree, then ram the spear into them. Became too cumbersome of a process with only one tractor without a front end loader-spear option. I spoke with Hay Wrap about the problem and they said they could custom build a machine for me, but couldn't retrofit the one I had. I advised them it was for sale if they knew someone. Afterwards I talked to the local welding shop about cutting off the large spear and replacing it with a smaller one. Rained the morning I was to take it there and before noon I got a call asking if it was still for sale.
I don't have Hay Wrap's number handy, but you frequently see their ad in farming magazines.
Grass silage goes back to at least the 40s. Louis Bromfield was a fan of it. Read his Malabar Farm series of books.
Ken S. in WC TN