A 12 year old Belgian Blue dam and her 8 month old son from Sire Lockwood Smith's stud Woodleigh Belgian Blue. Photo / Sir Lockwood Smith - Supplied
A 12 year old Belgian Blue dam and her 8 month old son from Sire Lockwood Smith's stud Woodleigh Belgian Blue. Photo / Sir Lockwood Smith - Supplied
Opinion: Recent research into marbling in meat is confusing and not actually all that new, Dr Jacqueline Rowarth writes.
New research to show that marbling in meat is improved from an all-grass "regenerative" system is causing confusion for many New Zealand scientists and breeders.
They have been focused on production of high-quality meat for least environmental impact and life cycle analysis (cradle to grave) suggests they have done a good job.
AgResearch scientists calculated that the greenhouse gas (GHG) emissions from New Zealand beef ranged from approximately 7-14 kg carbon dioxide equivalents per kg live weight, in comparison with the OECD average of just over 15.
In Italy, the range was over 17 to over 26. The research was published in 2020 in a highly ranked peer-reviewed journal.
The results are solid. They show that New Zealand beef, including transport to Europe, is associated with lower GHG production than European beef.
The range in New Zealand beef GHG reflects the conditions how and where we farm.
Steeper/harder country can be associated with lower feed quality and more exercise to find it than flatter/easy country. Cattle may be slower growing, with more energy and thus GHG associated with just maintaining their metabolism than on easy country.
The new research on marbling in New Zealand has been stimulated by research from overseas suggesting that cattle finished on diverse mountain pastures, with nearly 40 different species, have improved meat quality and taste compared to pastures on the flats with few species.
This is not new. In the 1820s, Thomas Love Peacock's poem (The War Song of Dinas Vawr) stated that "The mountain sheep are sweeter but the valley sheep are fatter…".
"Marbling is increased by starch in the diet, especially at an early age," Lincoln University's Professor Jon Hickford said.
"Increasing starch intake in an all-grass system is challenging. To improve marbling, grain or crops can be used, but the production of those has its own GHG cost and creates nutrient management issues too."
Cropping land could also be used to grow human food directly, so "nothing comes for free", Hickford said.
In any feeding system, growth is critically important. Reduced growth leads to increased GHGs because to get beef cattle to slaughter weights the energy required for their maintenance increases proportionate to the energy they need for growth.
"Slow-growers are simply less carbon-efficient," Hickford said.
"Most cattle producers are trying to finish their animals in 18 months, with obvious GHG benefits".
Dr Jacqueline Rowarth. Photo / Supplied
Sir Lockwood Smith, ex-speaker of the House, ex-NZ High Commissioner in the UK and a Belgian Blue breeder, concurred.
"We forget the fundamentals of energy metabolism," Smith said.
"Fat requires more energy to lay down than muscle, so the GHGs associated with fat are greater than those from protein."
Smith was a ruminant physiologist before taking up politics. He is also still involved with trade negotiations.
"An increasing number of New Zealand's trade deals have clauses which include the environment and intention to reduce impact'" he said at a recent He Waka Eke Noa meeting in Northland.
"We must continue to make progress in reducing GHGs associated with food."
The economic impacts for the farmer must also be considered. Hyper-diverse pastures are frequently not as productive as pastures that are grown to optimise growth.
In mountain pastures, the herbs are there because they have a life cycle that enables survival – placing reserves into storage organs for surviving winter, rapid flowering and seed set.
If vegetation per hectare is reduced through regenerative farming practices and harvesting of that vegetation by the animal is reduced, fewer kilograms of beef per hectare will be produced.
Input costs might be lower, but huge meat premiums will be required to produce the same net financial returns.
Although there is probably some potential to develop grass-fed brands, farmers generally receive a very small slice.
"A bit like organics, you need to get a lot more for your product to offset the lower productivity," said an overseas industry expert (and Lincoln University graduate) recently.
Listen to Jamie Mackay interview Dr Jacqueline Rowarth on The Country below:
"Regenerative farmers are focused on increasing soil organic matter, but their increased GHG emissions can be greater than advantages gained from increased soil carbon."
Further, meat experts point out that although farmers can achieve good marbling scores from grass and "mountain pastures", it's very hard to do so consistently, which is what is required to build a supply chain and brand.
The United Nations' Global Methane Assessment of 2021 reported that animals are responsible for 32 per cent of the human-created methane emissions.
The Assessment identified the potential for improved animal management in some countries through changes in feed and supplements, breeding to improve productivity and animal health/fertility improvements.
The important factors are time to reach maturity (or slaughter weight) and longevity in herd or flock.
In both cases, the GHGs associated with production are spread over the time as a juvenile.
Life Cycle Analysis takes these factors into account and shows that New Zealand is ahead of the game.
But trade deals require us to do even better. Research investment is required – but not in areas where the answers are already known.
Hickford's warning is clear "We might be taking a giant step backwards for both GHG production and income".
- Dr Jacqueline Rowarth, Adjunct Professor Lincoln University, is a farmer-elected director of DairyNZ and Ravensdown. The analysis and conclusions above are her own. jsrowarth@gmail.com
