Fewer, better-fed cows can deliver methane cuts – Technology – Emissions – Farmers Weekly – Gerald Piddock Nov 18, 2022
New research shows that improving feed conversion efficiency in dairy herds could see them thrive while still meeting methane reduction targets.
The research by Te Awamutu-based Headlands Consulting found that by using a moderate amount of concentrate feeds on fewer but better cows, the total amount of feed required per farm reduces dramatically – and total milk production per farm is retained.
Using the system could reduce a farm’s greenhouse gas emissions by 15.6%.
Headlands managing director Warren Morritt said the research helps to provide some principles for farmers switching to lower-emissions farming.
“It’s really a case of we can become more efficient at what we’re presently doing, and in doing so will hit the GHG targets and remain more profitable as an industry, whereas the alternative with what the government is proposing – the only lever is to reduce milk production,” Morritt said.
He was critical of both the Climate Change Commission’s and the government’s recommendations. The latter’s modelling in its response to He Eke Waka Noa’s proposals does not take into consideration feed conversion efficiency when calculating GHG emissions in cows.
The research used modelling based on an average Waikato farm’s DairyNZ statistics for the 2018/2019 season as a control. Five scenarios were then modelled against this control farm.
“There’s things we wanted to achieve here: Hold the milk production at a farm level, maintain or improve profitability, and hit greenhouse gas targets – and ideally stay within Fonterra’s Co-operative Difference [framework],” he said.
The study found there are better ways of achieving and even exceeding the government’s climate change targets.
Of the five scenarios, the one with the greatest environmental benefit showed that dairy farmers can continue to achieve the same total farm milk production levels with a 36% reduction in cow numbers per hectare, coupled with 8.5% of dairy-farm land being retired for alternative use, delivering a 22% increase in operating profit.
Total GHG emissions were reduced by 15.6% – well in excess of the government’s 10% reduction target for 2030. Nitrogen leaching was also reduced by 15.5% under this model.
Included in the modelling was concentrated supplementary usage made up of grain or grain byproducts, amounting to 20% each of maize grain and dried distillers’ grain. The remaining 60% was soya bean hull.
These concentrates drove the feed conversion efficiency required for the model to work.
“You’re feeding each cow a lot more, but at a total farm level, a lot less feed is used to produce the same amount of milk.”
Using these concentrates enabled more feed to be consumed by the cow compared to forage feed. Summer feed crop planning and usage was also unchanged under the modelling.
The model also stacked up from an economic perspective, despite the huge increase in input costs over the past 12 months, Morritt said.
The initial modelling was at a $6.50/kg MS and $550/t blended feed costs. That feed cost was closer to $700/t at the current $9.25/kg MS midpoint milk price forecast.
“It’s surprisingly robust,” he said.
“But the key is we’re able to use substantially less feed to produce the same amount of milk and we’re not disputing the fact that every kilogram of drymatter fed is going to produce methane.
“The key driver of this is, can we produce less feed and maintain milk production, that’s the critical bit, but the only way we can do that is to drop the stocking rate – but feed every individual cow more.”
That feed-to-milk efficiency is what drives GHG reductions.
The imported feed amounted to about 18.5% of total feed, with the rest being home-grown pasture or grass silage, pushing this farming scenario closer to a medium intensive system 3 style farm.
He acknowledged that bringing such a system onto a farm is not without its challenges – variable pasture quality, animal genetics, the pasture management skill level of the farm and its staff being at the top.
“And you wouldn’t do it overnight. The good thing about what we’re saying here is that it requires minimal investment because the only thing we’re talking about is an in-shed feeding system – no feedpads, none of that is required.”
That system was costed into the model at $80,000.
The 36% fall in stocking rate would mean a more regular pasture surplus. Keeping on top of that and maintaining pasture quality by knowing the right time to cut for silage is critical for the success of the model.
The key to achieving that is proper monitoring by the farmer, he said.
“When it comes to farming, it’s all about timing and the good ones are good at their timing.”
He is reasonably confident the research’s principles could be extrapolated to other regions in New Zealand.
The research has been peer-reviewed by DairyNZ former principal scientist Dave Clark and former principal animal scientist at DairyNZ Dr Eric Kolver.
The findings have also been presented to Agriculture Minister Damien O’Connor, who urged those involved to make them public as soon as possible.