A new Lincoln University study has found some cows are genetically better for the environment than others, paving the way for a significant reduction of nitrogen leaching into the nation’s waterways.
The research project found dairy cows with a certain phenotype excreted 28 per cent less nitrogen than others through their urine, diverting much of it into milk protein instead.
It’s a promising development for farmers under pressure to reduce the amount running off their land and into rivers and other waterways, where it can cause massive algal blooms.
Lincoln University doctoral student and project lead Cameron Marshall says most farmers will already have cows with the "low milk urea nitrogen gene".
“There will be animals in their herd already which will be either high or low or for this particular trait, so there will be animals in their herd already which will be more environmentally friendly,” Mr Marshall says.
“We've shown we can see the animal as the solution to one of the problems going forward.”
The trait can be identified through testing of milk, giving the farmers the option to breed from their pre-existing stock, and change the make-up of their farm over time.
Lincoln University livestock production professor Pablo Gregorini described the study as a “very significant” move forward.
“It's a massive amount, between the lowest cow and the highest cow. We reduced pretty much half of the nitrogen excreted per cow per day,” Mr Gregorini says.
It's the first independent verification of a concept, initially suggested by private companies like CRV Ambreed, and farmers are showing interest.
Dunsandel dairy farmer Tony Coltman described it as a “great idea” today.
“There are a raft of tools out there,” he says. “The breeding one, it's not a silver bullet, but it's a tool that we can use, to add to the toolbox.”
The hope is it could become a rare win-win, giving farmers a way to save the environment without burning a hole in their pocket.