Canterbury dairy farmer John Tanner has been working hard to improve sustainability on his Leeston farm, Dunlac Dairies Ltd.

The farm is located in the Selwyn Waihora catchment and is just 20km from Lake Ellesmere (Te Waihora), which is considered one of New Zealand's most important wetland areas. On either side of the catchment are the Rakaia River and the Selwyn River.

"In Canterbury we have to lessen our nitrogen footprint on the farm," says Tanner, who milks 730 dairy cows during the peak of the season on 260ha.

"In our catchment, we farm on environmentally sensitive land." Tanner is one of many farmers turning to genetic solutions to help him farm well.


In recent years Lake Ellesmere has been plagued by water quality issues related to intensive farming practices. Nitrogen leached from farms on the Canterbury Plains will eventually make its way into Lake Ellesmere, therefore farm activities in the catchment are carefully regulated by Environment Canterbury, with set nitrogen limits per farm.

The Canterbury Water Management Strategy, introduced in 2012, aims to rejuvenate and restore the ecosystem of the Selwyn Waihora catchment. It requires dairy farms in the catchment to reduce their property's nitrogen limits by 30 per cent by 2022.

"We have 730 cows, and if we can lessen the nitrogen from the herd by 20per cent, then that makes a big dent."


Tanner has made significant improvements with water management and fertiliser use. The farm was a finalist in the Dairy Business of the Year 2016, and Tanner takes pride in doing his bit for the environment.

However, he feels pressure.

"We are trying to milk at our current numbers, but lessen our nitrogen footprint. So you are trying to do the same, but with less environmental impact," says Tanner.

He believes that science will offer a solution for farmers. When he heard about CRV Ambreed's genetic discovery, and its LowN Sires bull team, Tanner was very interested, purchasing more than 200 straws.

A world-first

In March, CRV Ambreed announced a genetic discovery, thought to be a world-first, which could reduce nitrogen leaching on New Zealand farms by 20per cent within 20 years.

CRV Ambreed identified and selected bulls genetically superior for a new trait related to the amount of urea nitrogen in milk. Farmers are now able to breed cows using straws of semen from CRV Ambreed's LowN Sires, and those daughters will have reduced concentration of Milk Urea Nitrogen (MUN).

Cows bred for lower levels of MUN are expected to excrete less nitrogen in their urine which will, in turn, reduce the amount of nitrogen leached from grazed pasture. This could potentially save New Zealand 10 million kilograms in nitrogen leaching a year, based on the national herd number of 6.5 million dairy cattle.

"When CRV Ambreed came up with their LowN bulls, we thought 'we'll have a go'," says Tanner. "We have 730 cows and, if we can lessen the nitrogen from the herd by 20per cent, then that makes a big dent."

Tanner is interested to see how his herd's genetics will improve over time.

"I know it's going to take a few years but, if it's something that does improve nitrogen leaching from my cows, I will probably buy more straws in the future," he says. Tanner was also pleased with the other traits. "We wanted the best in genetics, and CRV offered that. To also have the option to reduce nitrogen leaching is an added bonus."

Canterbury regional councillor John Sunckell is also a big fan of the LowN Sires programme.

He's a third-generation farmer from Leeston, in the Selwyn/Waihora zone.

"Technology and information is vital - that's why I'm so excited about [CRV Ambreed R&D scientist] Phil Beatson's work and CRV's work," says Sunckell. "It will enable us to still farm and meet environmental regulations."

Dairy farmers in his catchment have to reduce their nitrogen loss by 30 per cent "which equates to getting rid of every third cow".

"However, if LowN Sires can have an impact by reducing nitrogen by up to 20 per cent, and with other new scientific developments (like Agricom's Ecotain plantain) we able to reduce nitrogen in the cow's urine patch, then all - of a sudden - with these two bits of science, we are getting there."