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.
For a large part of the year cows on pasture will not eat any hay. The cows will be eating fresh grass and will need no supplemented hay. If the cow in question does not have access to fresh grasses or it is winter in your region and fresh grasses are not available the cow will generally consume twenty five to thirty pounds of hay a day.