Interest in once-a-day (OAD) milking is rising, says DairyNZ senior scientist Dr Paul Edwards.
Ten years ago, Matthew and his parents Peter and Elizabeth moved to dairy to diversify the family farm.
They first built a small shed to milk 100 cows and rear 1500 calves annually, with a plan to eventually milk 450 cows; now they milk on two farms in two herds, with each block about 260ha effective, supporting 625 cows each.
The Darkes at first took a fair bit of ribbing from their neighbours, who found it interesting that they were converting to dairy, and with Jerseys on OAD. It turns out the Darkes are trailblazers in their area, with many of the local dairy farms following suit and adopting OAD.
They credit Malcolm Ellis of LIC for the inspiration to move to Jerseys. And they’re in an OAD discussion group at Massey University started by the late Colin Holmes, who saw OAD as the future for dairy farming in NZ.
“We weren’t ‘proper’ dairy farmers in the early days; we didn’t have our beliefs and systems firmly in place, so we were prepared to try new concepts on farm,” says Matthew.
An average farm with average infrastructure, the new (upper) block has previously supported a crossbred herd that produced 90,000kgMS in the year purchased, with a farm record of 103,000kgMS.
In 2014, the Darkes purchased the neighbouring 135ha property, increasing the total land area to 500ha.
“In our first year of operation on OAD, with a predominantly Jersey herd, we averaged 115,00kgMS,” says Matthew.
“This season we changed it. We split the two herds and farms into equal land and herd sizes, with 450 cows in each herd,” he says.
“On the lower (original) block, the longest walk to the shed was 4km but that paddock was only 2km from the upper block’s shed, so it made sense to swap them around.”
In the 2016-17 season, the upper block averaged 850kgMS/ha -- 330kgMS/cow in 250 days from the mostly Jersey herd. The lower block produced 750kgMS/ha on hillier country from a mainly crossbred herd.
Having weighed the cows, the 400kg Jerseys were averaging 330kgMS/cow, making them the most efficient converters of feed (82.5% of liveweight). At other discussion groups the Darkes attended, the averages were 360kgMS from 460kg cows, with extra feed required for maintenance.
Last season the Darkes’ production totalled 406,000kgMS, just 1% less than their record season.
Matthew comments on the hard spring in 2017, then five weeks without rain.
“Now that it’s raining, the grass is bolting,” he says. “We’re now about 2000kgMS (0.5%) behind last season’s production but we’re well into catch-up mode and we’re looking at producing 400,000kgMS.”
With onfarm costs of $3.25/kgMS they’re taking advantage of the OAD premium.
Both herds are now mated to Jersey, with the exception of one crossbred bull (about 150 straws). The lower 10-15% get a beef straw.
Emma Darke mates each cow and selects bulls based on their breeding values, matching the requirements of each dam.
“We’re using the elite LIC and CRV Ambreed bulls,” says Emma. “More recently we’ve used some overseas bulls from Genetic Enterprises to address a slight issue with inbreeding.”
Coming from a stud breeding background, Matthew says the ‘bull of the day’ philosophy is not for them. “We can improve the herd more quickly by nominating semen,” he says.
For the Darkes, the Jersey breed meets so many of their goals for their herd.
“They deal well with the heat in summer,” says Matthew. “You see them eating well while the crossbreds are panting.
“Their fertility rate is also much better, and in a normal year we don’t have to do premate heat checks.”