Mr Payne has been a long-time advocate of once-a-day milking and Mrs Charmley said the benefits on their farm would far outweigh any negatives.
"Yes, it will be a challenge, but we'll have a better work/family balance and we'll be able to do more of the environmental work we're so passionate about," she said.
"The move will also reduce the pressures on our farm environment."
The opening of Dannevirke's Farm Source store came just one day before Fonterra announced a lift in its payout for the current 2016/17 season to $6.15 a kilogram of milk solids, up from its previous forecast of $6.
Fonterra also raised its initial forecast for the upcoming 2017/18 season to $6.50.
This increase will inject $594 million in GDP into the New Zealand economy over the next year and lift the average dairy farmer's income by $80,000.
Fonterra's North Island distribution manager, Jason Boyle, said the new-look store (formerly RD1) had vibrancy and was a "breath of fresh air".
As well as newly branded Farm Source stores to come in Featherston and Longburn, Fonterra has built a milk transfer station in Hastings.
"It's great to get a footprint north of Pahiatua on this side of the island," he said.
Mrs Collis said during last year's mayoral campaign she looked at her own values and what she stood for and realised they matched those of Fonterra.
"It's about a co-operative spirit, doing the right thing, challenging boundaries and keeping us one step ahead," she said.
"Fonterra makes me proud. They've attracted top staff here, have earthquake-strengthened this building and there is a culture of change in Fonterra, making the best return for farmers."
There are 13 female mayors in New Zealand, only two of whom are dairy farmers, and Mrs Collis says she has a lot to live up to.
