"It's been my passion to maintain the purity of the breed. You won't find too many herds left like that," he said.
Ian milks about 120 cows on his rolling 54ha farm on Opunake Road.
The herd produced 68,000kg of milksolids (kgMS) in 2018-19. It was one of the highest producing fat herds, of registered Holstein Friesians, in the country.
His top cow, Bushview Braxton Hazel VG89, produced 12,525 litres or 828 kgMS last season.
Bushview Holsteins was founded in 1980, when Ian and his brother Gerald were herd-owning sharemilkers on their parents' Rowan Road farm.
"The stud really kicked off in 1988 with the purchase of a heifer named Snowline Poppy," he said.
"She was from the well-known Snowline 'P' family, which traces back to the cow Egmontdowns OG Peggy."
Poppy had six daughters, five were reared as replacement heifers.
"A number of her descendants are still in the herd and have all classified as very good (VG) or excellent (EX) for traits other than production," he said.
Bushview Windbrok Picture VG89, who's a six-year-old, produced 712 kgMS last season. Bushview Braxton Petal VG88, a five-year-old, produced 701 kgMS.
Ian bought his current farm in 2005.
A major focus of his breeding has been cow families, production and type. He strives for a well-balanced cow with longevity.
Ian's used mainly North American genetics from World Wide Sires, Semex and Genetic Enterprises.
"You'll see I have a few old cows in the herd that don't look their age. They look young. I don't think I've done too badly," he said.
Bushview Holsteins currently has 17 cows classified as excellent.
The largest cow family in the herd descends from Okains EC Vrai.
"I bought my first cows from that family when Nouveau Holsteins in Dargaville and Chrislerae Holsteins in Palmerston North held dispersal sales," he said.
He later purchased another member of the family, Ruaview Star Rosemarie EX2. Her descendent, Bushview Selvino Marie EX, is for sale.
Bushview Bolton Hottie VG88 was named the senior champion cow and took out the Burkitt Family Trophy at the Stratford A&P Show in 2015.
Bushview Bolton Sassy VG87 won champion cow at the Egmont A&P Show in 2013 as a four-year-old.
In recent years Ian has used several Italian sires, such as Heavenly Golden Dreams-ET, to help reduce the stature of some of his cows.
One of the bull's daughters, Bushview Heavenly Heidi EX, produced 761 kgMS last season as a four-year-old. She has a two-year-old daughter Bushview Solomon Hayley in the herd.
Bushview Shottle Heidi VG87, who produced 680 kgMS in 2018-19 as an 11-year-old, will have several descendants in the sale.
One of her daughters, Bushview Danilo Heidi VG89, sold to Waipiri Holsteins in the Waikato in 2013 for $3,700.