In the wild, would animals continue to nurse if the mother didn't stop them?!
Answers: Well, all animals eventually stop producing lactase, the hormones that digests lactose, the milk sugar. This includes domestic animals. Humans ideally produce less lactase after age five; it's why there are many populations (most of them non-white) that have large incidences of lactose intolerance. So the mother animal will show her offspring how to find food, and once she is confident they can do so, she turns off the tap, so to speak.
do you mean would calves still have their mothers milk, if they lived in the wild versus being in confined in the meat industries? If so yes of course, many typesof animals have life long bonds and their love for their child is as much as we would experince for our children. - it maybe shown differently, but it is still there.