"This announcement recognised the immediate need for additional expertise to come through our borders."
Dairy managers and vets had specialist skills developed over many years, "which we can't replicate overnight," O'Connor said.
"With the new dairy season kicking off last week, migrant dairy farm workers will supplement the domestic workforce and provide critical support.
Despite the previous border class exception for vets, a domestic vet skill shortage remained acute, including in hard to recruit roles in isolated rural practices, O'Connor said.
The new class exception would allow vets to enter New Zealand if they had between 3-5 years' experience and met the remuneration threshold of $85,000 per year.
O'Connor said dairy farm workers and vets played a key role in animal welfare, food safety, and safeguarding New Zealand's international reputation as a producer of safe and sustainable food.
"In making this decision, we've balanced the need to keep New Zealanders safe and ensure appropriate MIQ capacity, with seasonal and strategic skills shortages, and seasonal variations for overseas New Zealanders travelling home.
The Government had previously approved exceptions for vets, along with shearers and rural mobile plant machinery operators to relieve workforce pressures, O'Connor said.
"These new border exceptions will help drive New Zealand's economic recovery from Covid-19," Damien O'Connor said.