The Net Zero Pilot Dairy Farm is lifting its reproductive performance

When it comes to ways to lift a farm’s production efficiency and lower its emissions intensity, reproduction is near the top of the list.

That’s why the Co-op’s Net Zero Pilot Dairy Farm in Taranaki has made reproduction a priority. Mags Bremer, Head of Science at the farm’s operational partner, Dairy Trust Taranaki, has been closely involved in this focus on reproduction, and says it matters beyond production gains.

“Getting cows in-calf early isn’t just a production win; it’s one of the most direct ways we can reduce emissions intensity on the Net Zero Pilot Dairy Farm,” she says.

“Earlier conception means more cows calving earlier, more milk produced over the season and making better use of every kilogram of feed we grow.”

The farm tracks its performance against two key New Zealand dairy industry benchmarks: a six-week in-calf rate (6WICR) target of approximately 78%, and an empty rate of no more than 10%.
 

Where the farm system was getting stuck

The Net Zero Pilot Dairy Farm has faced its share of challenges in this space, and being honest about those has been part of what’s driven its improvement:

• Cow condition and energy balance weren’t consistent enough – the farm learned that a cow can cycle but still not have the energy balance to support good conception and early pregnancy.
• Seasonal pasture quality created hidden repro risk – a difficult season, such as a very wet autumn, can knock pasture quality and intake, quietly pushing cows into an energy deficit that undermines conception.
• A longer tail of late calvers – calving spread matters because late-calving cows shorten their milking season and often struggle to recover condition before mating begins.
• Body Condition Scoring (BCS) low before calving – the empty rate and management of low BCS at calving became a sharper focus.

The key thread across all of these was the need for earlier identification of cows likely to fall behind, and faster action when conditions changed.

Lesson one

Heat Detection is not the same as ready to conceive

One of the biggest shifts for the farm’s reproduction plans has been moving from simply trying to spot heats to assessing whether cows are in the right place to conceive and hold a pregnancy.

Technology has helped in this area. The farm adopted Halter and CowSmart, which improved heat detection and reduced missed mating opportunities. But while submission rates were already strong, the team saw that the main lever for improvement was not getting more cows submitted. It was ensuring those cows conceived and maintained their pregnancies.

“We got to a point where our submission rates were solid, but submission is just the first step,” Mags says.

“The real question is whether cows are in good enough condition and energy balance to conceive. That’s where we shifted our focus and it changed how we think about almost everything else we do on farm.”
 

Lesson two

Data and vet input turn good intentions into timely decisions

The team learned reproduction improves faster when the farm gets serious about data and puts structure around decisions.

Better data use, paired with strong vet input, helped the team identify at-risk cows earlier, intervene sooner and make clearer calls on cows that were sliding toward empty status.
 

Lesson three

Early mating focus matters but conception still rules

The farm’s early mating focus helped lift already strong submission rates and supported 6WICR performance. That’s still important, because early submission creates more opportunities to get cows in-calf within the key reproductive window.

But the big lesson was submission doesn’t compensate for poor conception. The farm has increasingly put most improvement effort into what drives conception – stable energy balance, appropriate body condition at mating, managing feed quality dips quickly, and early identification of cows at risk of falling behind.

Lesson four

Hitting those body condition scoring targets

BCS became an anchor for the farm’s reproductive management. The Net Zero Pilot Dairy Farm uses BCS as an ongoing indicator of whether cows have the stored energy needed to return to cycling strongly after calving, conceive and maintain pregnancy.

The farm has been targeting a BCS of 5 at calving.

“That target tells us whether a cow is in the right shape to cycle, conceive and carry a calf,” Mags says. “If we’re not on track for that number, we change something, such as the diet or the dry-off date.”

Levers used to manage that target include: late lactation feeding decisions to build condition in cows that need it; dry-off decisions timed to match each cow’s individual condition needs; dietary changes during the dry period to avoid under- or over-conditioning; and early lactation strategies to minimise BCS loss during the important post-calving period.
 

Lesson five

Pasture quality can make or break conception – so move fast

High pasture quality supports higher intakes and better energy balance. That flows straight through to faster return to cycling, improved conception rates, and higher pregnancy rates overall.

The farm learned that when pasture quality drops, repro risk climbs quickly unless the feeding plans change just as fast. One of the farm’s biggest improvements was being more responsive with nutrition adjustments, including increasing supplementation when pasture quality fell, to protect energy balance during key reproductive periods.
 

Lesson six

Breeding worth is a long-term engine for reproduction emissions efficiency

The farm is also investing in genetics as a permanent, cumulative lever for improving efficiency and reducing emissions intensity over the long term.

Breeding Worth (BW) is used as a core selection tool, with the farm using high BW sires to progressively lift herd performance. Higher BW cows typically produce more milk solids from lower inputs, making them more efficient converters of feed into milk and reducing the emissions generated per kilogram of milk solids produced.

“Genetic improvement through Breeding Worth isn’t a quick fix, but every generation, we’re selecting cows that are a little more efficient, a little more suited to our system,” Mags says. “This directly supports the farm’s net zero goals over time.”

What success looks like from here

The farm’s repro plans are not about chasing one-off good results. It’s about building a system that performs year after year with steady improvement.

Success over the coming seasons looks like:

• A consistent, efficient, data-driven reproduction programme
• Approximately 78%+ 6WICR as a reliable benchmark
• ≤10% empty rate, with fewer cows slipping into non-productive status
• More cows calving early, with fewer in the late tail
• Continued productivity gains (including BW lift) that reduce emissions intensity

Net Zero Pilot Dairy Farm

The Net Zero Pilot Dairy Farm is a project within the Fonterra and Nestlé partnership, working with Dairy Trust Taranaki to trial emissions reduction solutions on a 250ha (210ha effective) farm in Taranaki. The pilot aims to create New Zealand’s first commercially viable net zero dairy farm in 10 years and is in its fifth season. Everything trialled and used on the farm needs to be scalable or already available to all dairy farmers in New Zealand.

Strong reproductive performance can support a more productive, efficient herd. Visit our Reproduction & efficiency page for more information.