6th July 2021

How breeding and feeding can help meet the methane debate head-on

By Beth Alexander, QMS Cattle and Sheep Specialist

There is no denying that beef production emits methane. We could debate how the cycle of methane is less damaging in comparison to exhaust emissions but, in the long term, how much time can we afford to spend changing a sold story?

Methane is a waste product, so ultimately it is in our best interests as beef producers to reduce methane produced by cattle to improve efficiency. Approximately 6 to 8% of the energy from feed consumed is emitted in the form of methane. There are two main approaches we can take to reducing emissions: breeding or feeding, genetics versus diet.

There is a lot of research being carried out in Scotland by SRUC and around the world on the effect feed additives have on methane emissions. Altering the composition of the diet, by increasing proportion of concentrates and reducing fibre content can reduce methane output by up to 30%.

Research in Canada has looked into the effect of methane inhibitor 3-NOP which has the potential to reduce emissions by 40% plus. Increasing fat content of diet is another method albeit with varying results. Much of this research has been carried out on uniform feedlots or on animals with a supplemented diet.

The majority of our suckler herd in Scotland is grass or pasture based and is not supplemented for a proportion of the year, so how can we apply these principles? One easy win for the industry is better quality feed. The better quality the silage, the more digestible, with less fibre requires less work for the rumen to digest therefore less methane emitted, win – win scenario?

In a growthy season like we have been experiencing this year, taking more cuts of better-quality fodder is certainly achievable. Opting for a range of grass varieties or legumes rather than perennial rye is another veritable option worth considering for grazing animals. When accounting for reduced requirement for nitrogen the effect could be confounding.

On the other side of the coin, we have breeding. Selecting for feed conversion ratio seems to be the big hitter for reducing methane through genetics. Studies by Rainer Roehe and colleagues from Scotland’s Rural College and the Universities of Edinburgh and Aberdeen has paved the way for an approach to reducing methane produced by cattle farming using modern breeding approaches. By linking bovine host genetic variation and the influence on rumen microbial methane production is a step towards selecting for low methane emitting and efficiently feed converting cattle.

But really, we need to take it back one step further. By improving the number of calves reared per cow we can produce the same number of calves with less cows. Less inputs and the same, if not more, outputs, good for the bank and good for the environment.

Reducing emissions and improving profitability are not mutually exclusive! This sounds simple in theory but requires farmers to sit down and scrutinise their business to find out where the outliers are to put it into practice.

These outliers are unproductive year on year offering nothing saleable to the business, apart from herself, and emitting methane. A focus on maternal traits to breed productive replacements is worth serious consideration when looking further down the line past the kill sheet.

It’s finding the optimal cow, big enough and productive enough to produce marketable progeny but not too far that she costs too much to maintain. More input does not always correlate to more output or more profit.

There is no one solution for reducing methane emissions for Scottish beef farmers but the important thing is there are achievable solutions there for Scotland’s farmers, on any scale. While adding to or altering diets offers an immediate reduction, breeding can give small but cumulative gains allowing the industry to advance for the next 20, 30 years and beyond. But still the number one way of reducing emissions is by improving efficiency of kilograms of beef produced.


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