The shift to Christmas calving was driven by the farm's soil type. The land, which has been in the Bassett family for 109 years, sits on a drained swamp.
"We have a completely different type of soil to our neighbours. The property is wet in the winter, but it grows grass in the summer," Bassett said.
"We had to think outside of the box to get the most out of the farm."
The farm was well-equipped to combat weather extremes, such as a drought. It has a 40-bale rotary milking shed with in-shed feeding and a 450-cow feed pad.
"Our annual milk production has only fluctuated by 2,500 kgMS over the last five years," Bassett said.
The herd was fed crushed barley, which was grown on a 129-hectare support block, five kilometres down the road. That block of land was not irrigated.
The Bassetts grow 70-80 hectares of barley a year, which they plant themselves using minimum tillage practices.
"The soil at the runoff is quite stony, but we have noticed a huge difference by not disturbing it as much," Bassett said.
"We're onto our fourth and fifth rotation of barley in those paddocks and we now plant into black soil, rich in organic matter."
Up to 140 Hereford calves were reared using whole milk and are weaned when they weigh 100-120 kilograms.
"We usually sell them at the second weaner cattle fair at the Feilding Saleyards and they get between $5.50-$6 per kilogram of liveweight," Bassett said.
The bottom 25 per cent of the herd is mated to Hereford. Hereford bulls are also used to tail the herd for five weeks at the end of mating.
Bassett was a trained artificial insemination technician and did his own AI for six weeks.
"We used to use LIC's Premier Sires bull team, but we switched to the company's economy pack when the payout dropped in 2014," he said.
"We have continued using that pack. It's good value for money and we only use semen from daughter-proven sires."
"The price of semen is important to me. If it is Holstein Friesian, the price is right and the bull has plenty of daughters, then I will use him," he said.
The spring herd's empty (not in-calf) rate sat at 14-15 per cent, but the figure was only two to three per cent across the entire herd.
Robert and Nicola have one staff member, Andrew Pike, who was an integral part of the business and has been with the Bassetts for 28 years.
Rob's father Don, who has lived on the farm for the past 75 years, also helped out.
The Bassetts joined Holstein Friesian NZ in 2005, when they started leasing a neighbouring farm and bought the pedigree herd on the property.
"We saw how favourably our grade cows stacked up against the pedigree animals, so we began registering them on the supplementary register," Bassett said.
"About 75-80 per cent of the herd are now registered pedigree Holstein Friesians."
"It's very little extra work for us to register the calves each year and has increased the value of the animals if we ever wanted to sell them."
The couple has two young sons Campbell, 12, and Lachie, 10.
"Both boys are really interested in showing calves and the farm," Bassett said.
"It's a driving factor behind how we operate. We'd like to do further expansion in the future to help both of them get into farming."
Farm facts: Owners- Rob and Nicola Bassett Location - Carterton, Wairarapa Farm size - 100 hectares and a 129 hectare support block Cows - 410 Holstein Friesians, plus 50 December calvers Production - 228,300 kgMS 2019-20 Stud name - Manukorihi Holsteins