Christopher Mark Bennett, 56, was working on a farm in Raglan when the abuse occurred in November 2014.
Bennett had been rounding up stock when he rammed a difficult cow that was in full milk, with his quad bike at least twice.
The Ministry for Primary Industries began an investigation after witnesses, who were horse-riding on the farm, reported the incident.
MPI investigations manager, Simon Anderson, says offending of this nature is unacceptable.
"The Animal Welfare Act exists to protect animals from this sort of abuse.
"There is never an excuse for ill-treatment of animals. MPI takes any reports of abuse very seriously. If we find evidence that warrants charges being laid, we will prosecute."
Bennett was convicted and sentenced to 125 hours community work and disqualified from working in the dairy industry for 12 months when he appeared in the Hamilton District Court on July 29.
