He also said men joining the course tended to "find out about booze" in first year, leading to dropouts.
But he was later reported saying the information he gave "was not factual".
His comments inflamed opinions in the country and some people called for him to resign.
In an interview, Chris Kelly said the veterinary field, once a majority-male career, was now "dominated by women".
He continued: "That's fine, but the problem is one woman graduate is equivalent to two-fifths of a full-time equivalent vet throughout her life because she gets married and has a family, which is normal.
"So, although we're graduating a lot of vets, we're getting a high fall-out rate later on."
Critics have pointed out that men also have families and care-giving responsibilities.
The interview was in the context of changes being made to the university's veterinary science course, to make it more practical.
The university's website says it offers the only veterinary degree in New Zealand.
Mr Kelly said more men than women dropped out in the first year "because women mature earlier than men, work hard and pass. Whereas men find out about booze and all sorts of crazy things during their first year."
Tweets and a Facebook post sent out by the university, purportedly including an apology by Mr Kelly, appear to have been deleted since. The New Zealand Herald reported that he wrote: "I was trying to explain changes Massey University has made over a number of years in the veterinary science programme in response to industry needs, and I also concede that the information was not factual."
In response to the comments, a wildlife hospital attached to the university posted a picture of seven female vets and vet technicians, calling them "awesome 100% of the time".
As well as taking on ceremonial duties, chancellors in New Zealand have a role in the governance of universities. Vice-chancellors tend to take on a more active role.
From 2017, the vice-chancellor of Massey University will be Professor Jan Thomas, a woman who is a veterinarian and biochemist by training.
The chancellor of a New Zealand university appears to have apologised for saying a woman vet was "equivalent to two-fifths" of a man because she would take time out to have a family.