Whether putting food in the refrigerator, the freezer, or the cupboard, you have plenty of opportunities to prevent foodborne illnesses. One of the basics of food safety is cooking food to its proper temperature.
Re: Average hay consumption. A cow needs about 3 per cert of its body weight in roughage a day, a 1000 lb cow needs 30 lbs of hay if it has no other source of roughage.
You can figure that you are going to need to feed hay around 150 days per year. If your cow weighs 1,200 pounds, she will need 24 pounds of good quality hay for 150 days. So a good starting point would be to have 3,600 pounds of hay per cow per year.