Dairy nutrition science advances set to slash carbon emissions by up to 60%, study reveals

15 Aug 2024 --- Advances in dairy nutrition science may soon deliver a 60% reduction in ruminant livestock enteric methane emissions. According to a recently published invited review in the Journal of Dairy Science, one such method is using the feed additive CH4 inhibitor 3-nitrooxypropanol. However, the long-term effects and external factors affecting the inhibitor’s efficacy must be studied further.

“If currently available mitigation practices prove to deliver consistent results, and novel, potent and safe strategies are discovered, nutrition alone can deliver up to a 60% reduction in enteric methane emissions and pave the way for a more sustainable dairy sector,” says Dr. Alexander Hristov, professor of dairy nutrition, Pennsylvania State University, US, and author of the review.

Research about reducing greenhouse gas emissions from livestock has increased exponentially because the dairy and agriculture sectors work together toward shared sustainability and efficiency goals. The bespoke advances are in genetics, animal welfare and health and dairy nutrition for emission reduction impact.

Methane — both enteric methane produced during digestion and methane from manure — is the critical greenhouse gas that makes up most of the dairy industry’s environmental footprint. “There are two main ways to tackle enteric methane emissions through nutrition: adjusting an animal’s diet or adding in specific new ingredients,” he says.

Livestock diet reformulation

The review provides an overview of where additional research is needed and the methane-reduction pathways that offer practical and viable solutions. The review identifies the latest conclusions on diet reformulation, such as adjusting concentrate feeds, feeding corn versus grass and legume silage, and using alternative forages such as sorghum or plantain.

The researcher believes these changes can have a tangible impact on methane emissions but are not one-size-fits-all. Hristov says: “Diet reformulation depends on a farm’s unique scenario to be an effective tool. For example, if a dairy has room for efficiency and productivity improvements, balancing diets can be helpful.”

However, this approach could be more practical in intensive dairy production systems, where nutritional professionals formulate the diets and producers have efficiency dialed in. In those dairy systems, Dr. Hristov notes, “It may be difficult to find specific feeds that can have a substantial and measurable impact on methane emissions.”

Introducing feed additives in small amounts in a dairy cow’s diet reduces methane produced during digestion. Existing research claims that seaweed and 3-nitrooxypropanol (3-NOP) are the most promising additives.

Red seaweed varieties, for example, contain bromoform, an active compound that has effectively reduced methane emissions in several studies. Hristov adds: “Bromoform appears to be able to achieve a 30% to 50% emissions reduction, but whether this effect can be applied broadly and consistently needs more research.”

The strongest feed additive contender to emerge is 3-NOP. “Its efficacy has been proven in numerous controlled and independent experiments and 3-NOP is currently the only available option headed to market for dairy operations looking to use additives to reduce emissions,” says Hristov.

Pairing methane mitigation with nutrition

The researcher recommends reducing methane emissions from cow manure and studying whether nutrition strategies can be synergized. Hristov notes, “In theory, practices with different modes of reducing methanogens could work together to boost overall mitigation.”

The article cites a best-case scenario in the literature where a 20–30% reduction by a feed additive could be combined with another 10–20% reduction from a second feed additive and another 5–10% from improvements in forage quality and diet manipulation.

In addition, FrieslandCampina Ingredients and Bioiberica strive to meet climate targets to produce their nutrition portfolios. They also aim to develop active and functional ingredients for supplements and nutraceuticals transparently. We caught up with these industry leaders to find out more about their methods of reducing CO2 in their production and the circularity of their business models.

By Inga de Jong

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