In the Uk a lot of haylage is fed. Here, it is cut exactly the same as for hay and baled a day before it would be ready for hay. There are several layers of wrap, five or six, so that punctures are less likely.
If using big bales then a squeeze is needed to lift them Forks on a tractor will puncture the skin and although patches can be put on for tears the rupture into the bale will make it go bad.
As said it needs using within four or five days. Weather plays a part in this cold weather and it will be safe to use for longer.
I do not know if there is a great deal of difference with soil from the US and UK but I have never heard of botulism from haylage here though did read a report about it in the US.
It is richer than hay, hard feed can be dropped to lower rations, horses do like it.
It does need time to finish fermenting before it is used. I had a sample bale a month or so ago and it was not 'cooked' I am now using it and it is fine. It takes about 3 months from baling.