I'm wondering how long a Jersey cow generally lives and produces? This is a family cow. She's milking 3 gallon a day right now, freshened in June. Said she peaks at 4 gallons a day. She has one quarter that doesn't make much as it had mastitis before. She's a full blood jersey and will be bred to a Guernsey before sold, but it won't be confirmed. I do have an angus bull I can breed her to if that one doesn't take. She is 6 yrs old. They are asking $700 for her.