Do we need to talk more about methane?

By Jen Butcher, AB Agri

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When people think about greenhouse gases, carbon dioxide (CO2) usually comes first to mind as the worst offender in terms of climate change impact. But for us in agriculture, methane (CH4) has emerged as arguably the biggest ‘baddie’ to tackle. The methane emitted by ruminants belching is one of our most widely reported contributions to global warming, responsible for over 40% of methane emitted in the UK each year*.  

There has been a lot of discussion around methane inhibitors to tackle this problem, and no doubt there is a place for them, but could there be other ways to approach this challenge? 

What are methane inhibitors, and do they work?

Methane inhibitors are feed additives designed to be included in a cow’s diet to reduce enteric production – the methane produced when a cow belches. A variety of inhibitors are available today, from essential oils and seaweeds to chemicals, nitrates and probiotics. If a feed ingredient can safely and effectively be added to a cow’s diet to reduce enteric methane, then we could and should use them more widely than we do today.

But we do need to be careful. There are claims being made that we can achieve as much as a 90% reduction in methane through inhibitors. Whilst we expect all inhibitors to be robustly trialled and proven safe – it may not always be the case. We need to be careful with seaweed, for example, as some seaweeds contain bromoform which has been shown to be toxic in some scenarios.

As with all new additives we must robustly assess all potential outcomes and interactions with other components of the diet. We must also keep in mind the principle that even though an ingredient is ‘natural’, it must still be fully trialled and tested to be sure it’s safe. We also need to consider other animal health and welfare impacts, both real and perceived,  as consumer perception matters.

In research carried out for AB Agri last year, consumers rated animal health and welfare as one of their top priorities when it comes to buying meat, eggs and dairy. They want to be reassured that the food they eat comes from an animal that’s been well cared for during its life. Whilst we don’t know how consumers will respond to the use of methane inhibitors (and if anyone has any research on this I would love to see it!) it’s possible that feeding additives that interfere with ‘natural’ processes may prove to be an issue for consumers.   

There is also the question mark over how we can be sure methane inhibitors are doing ‘what it says on the tin’. We do not feed cows individually: some cows eat more than others. Equally, how do we measure the impact of it, when we do not currently have the tools to accurately measure the methane output of an individual farm? It is difficult to quantify any reduction. 

Are there alternatives? 

Potentially, yes. We have been interested to see some recent research looking at methane capture, such as the GreenShed project in Scotland, led by SRUC. By placing cows in a housed environment, this approach aims to capture the methane produced before it can escape into the atmosphere. In this particular project, a state-of-the-art shed will use cattle waste products to power a methane capturing system and grow indoor crops. 

This approach may seem radical but if we are looking at truly removing all the emissions from dairy and beef production, it would enable us to deliver that goal – along with a number of other potential benefits. From an animal’s health and welfare perspective, being housed in a really well managed and safe environment, with good air quality, good manure quality, good nutritious feeds and maybe even temperature control, is all positive. For cows that are reared in an extensive environment, it is a little more difficult and methane inhibitors will also have a place. We just need to make sure that we can measure the impacts. 

There are solutions and opportunities whichever strategy is taken, so keeping an open mind and investigating a range of solutions makes sense.  The key is to keep collaborating through the supply chain and not be afraid to try new technology.

*DEFRA, 2021.

Jen Butcher is AB Agri’s Head of Commercial Responsibility, focusing on helping the industry to best address the biggest challenges we face today - from improving animal health and welfare to tackling climate change and ensuring we safeguard our earth and its finite natural resources for future generations.