14lbs = 35oz in 24 hours. 5 x 7oz -- but yours might want a bit less or a bit more, as long as its around that mark I would be happy.
A few weeks ago my daughter was having 6oz then 3 more oz's an hour later, so 9oz feeds basically and when I told the clinic I got told that was too much - but it's what she wmnated at the time and the next week she was back to 6 and 7oz bottles. They dictate what they need.