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.
I personaly always figured around 25lbs of hay per day for a average size cow when i was putting up hay. Alot of that of course they can get if pasture is available/accessable. Multiply that by your number of cows x average days you actually have to feed.
When feeding the same forage, cows that weigh 1,300 pounds will consume more on a daily basis compared to lighter weight cows that weigh 1,100 pounds. In addition, cows that are lactating will consume more feed than cows that are not lactating.