They are in their sixth season of milking once a day (OAD) in a twin herringbone shed, and they have a 90ha run-off.
They winter graze and crop on 30ha.
"Our goal is to focus on cost control rather than milk production on the OAD system and to maintain a profitable and sustainable business long term through fluctuating payouts."
Although production has dropped 15 per cent, they make savings with labour, electricity and shed expenses, and there is a huge reduction in lameness.
"One of the biggest hidden savings is the cost of wintering has reduced as the cows are in Body Condition Score 5 at dry off without even trying.
"Therefore we only have to feed maintenance over winter.
"On twice-a-day we had to really pump feed into them over autumn and winter to get them to BCS 5.
"Now we don't have to worry as much anymore as the cows look after themselves."
The farm is also prone to flooding and up to 90 per cent of the farm can be under water in a big event.
"This was also a factor in milking OAD."
OAD also allows them to be fully involved in the day-to-day running of the farm and it is easier to get away to school events and sports days.
Mr McCall said they had a 90-day effluent storage pond, which was emptied when conditions permit.
"If there is a breakdown, or if staff are on leave, there is no urgency and we don't have to run the Cobra irrigator."
They follow best practice and irrigate effluent over 100ha, making sure they have more than 50m buffers from creeks and ditches.
In addition to back fencing in the winter, they feed stock in blocks rather than strips and use portable troughs to minimise soil disturbance.
They make baleage as well as growing a multi-species crop, direct drilling a mix of sunflowers, kale, faba beans, ryecorn, Italian ryegrass, hairy vetch, turnips, grazing radish, and buckwheat (which absorbs phosphorous).
In addition to nitrogen, sulphur and lime, they use hydrolysed fish fertiliser.
"We have been using multi-species for a couple of years.
"We got 14 tonne DM yield per hectare last year and we are happy with that.
"There is no transitioning for stock and no acidosis."
The crop, which is practical and cheaper, attracts birds, including fantails, which eat the bugs, and no spraying is required.
The water in the Pomahaka River is good enough for their three children Ollie , Matilda and Jonty, to swim in.
"We feel privileged to have the Pomahaka River right here, although it is quite good at flooding and we don't see that as quite so much a privilege," he said.
The couple have been riparian native planting by their two creeks for about 10 years, using seedlings from the Pomakaha Water Care Group's nursery, and plan to do more.