greenapplesodaex wrote:so... it would be wise to sell them before they die, right?
Yes, and the day they'll die is not a set one. If you save every night before you sleep then if you wake up the next morning and your animal dies you can reload from the night before, go to sleep again, and your animal will most likely live at least one more day.
or, for chickens, you can carry one chicken to sleep each night and it'll live one more day. Very handy if the farm is closed and your chicken is ill. I used to do that a lot.. haha.