As more information came out about the system, the McKenzies attended the first DairyNZ once-a-day seminar in Gore last year, and from there looked into it more, Mr McKenzie said.
''The main reason is the sustainability side of things. It's a really resilient way of farming.''
This year, as Southland was hit with drought, the McKenzies' cows carried on as normal, and did not drop off any weight, which he put down to the once-a-day system.
The lifestyle was also another draw card, he said.
Researching prior to changing to once-a-day involved calling farmers in the region who had already made the switch to full season and picking their brains.
When making the switch, the McKenzies increased cow numbers, going from 480 cows twice-a-day to 680 cows once-a-day.
Coming to the seminar had sealed the deal for Mr McKenzie, who left excited about the option of once-a-day.
Both he and his father like trying new things, so giving it a go was a new challenge for the pair, he said.
''I think we were probably a little bit naive.''
One thing he had learnt was culling was necessary and that he should have done more research before making the change, he said.
While twice-a-day, the McKenzies employed one additional full time employee, but when they went to once-a-day, dropped this to a calf rearer only.
Increasing the cow numbers had not been a good idea, Mr McKenzie said as he had ended up doing a lot more himself.
Some farmers lowered their feed costs changing to once-a-day, but Mr McKenzie believed the cows could eat just as much as the twice-a-day lot.
''If you back it off, you do see a drop in production''
Animal health had improved, but mastitis had become a big issue following the Christmas period, he said.
Some of the bigger producing twice-a-day cows had dropped production, while some of the smaller twice-a-day producing cows had increased production going to once-a-day.
Mr McKenzie had already changed to 16 hour milkings and would be going back to twice-a-day next year.
The biggest driver was seeing the drop in production and some of the bigger cows being lazy and just ''not being a cow'', he said.
Going forward, the McKenzies planned to keep breeding a once-a-day cow and would reconsider once-a -day a few years down the track.
A lot of it had been to do with Mr McKenzie being a contract milker and how valuable those extra milk solids were, he said.
- Southern Rural Life