"Donald used to calve a couple of times a year, so his pens were perfectly adequate for his needs," said Pirie.
"But we calve the entire herd in the spring, which means we needed more space to cope with the larger volume of calves."
Students from nearby Manurewa High School helped construct the new rearing pens.
The herd produced 26,370 kilograms of milksolids in the 2018-19 season. Production was hampered by a wet winter and a dry summer.
This season is off to a promising start.
"Milk production is up 50 per cent on the same time last season," said Pirie in early August.
"The new heifers are settling in well. The herd is being fed a blend of pellets with added minerals through the in-shed feed system."
The farm's manager Tom Ruki is using the covered stand-off pad to feed grass silage to the cows and protect pastures from damage.
"Tom's using that facility really well. The cows are in good condition and things are looking a lot better than they were at this time last year," said Pirie.
"Our focus now is on getting as much milk in the vat as possible before the farm dries out in the summer."