Management strategies to reduce enteric methane emissions can be categorised into three sections, forage utilisation, feed additives and improved production efficiencies. The material from this blog comes from a review of scientific research into strategies for beef cattle and was done in Canada, as such some of the strategies that they recommend are not available in the UK.
Science has demonstrated that forage quality has a significant impact on enteric methane emissions. This can be seen both in conserved forage (when stock are fed hay or silage) and in grazing systems. The research suggests that animals fed higher quality feed, so hay and silage with a higher D value or animals allowed to graze pasture early in the season, emitted less methane than those fed on lower quality forage (either fresh and conserved). Emissions seem to be influenced by pasture dry matter availability and quality. High levels of enteric emissions would be seen when the animal is presented with poor quality forage and limited ability to select higher quality forage as a consequence of reduced dry matter availability.
There is research that suggests that inclusion of legume based forages in the diet is associated with higher digestibility and a faster rate of passage, which results in a shift towards high proprionates in the rumen and reduced methane production. The study that looked at this also found that because of this improved feed utilisation within the cow, as a consequence of reduced enteric emissions, growth rates were 11% higher in the legume mix pasture.
There have been difference additives produced that claim to reduce enteric methane production. Ionophores (the technical name of a class of additives commonly fed to cattle to improve feed efficiency and rate of weight gain. They are antibiotics that alter the chemistry of the rumen by changing the bugs in the gut to produce increased amounts of proprionic acid releases more energy per unit weight to the host cow upon oxidation than acetic and butyric acids do, as such is important to global beef production (not in the UK production). There have been studies done that show that these ionophores reduce methane emissions, but not over a long time period, effects “wear off” after around 2 weeks.
Another method that has been looked at is the addition of fat supplementation into high energy finishing diets. Results have shown a reduction in methane emissions of 33% when oil was added to a high concentrate diet (85%). Fat supplementation may well effectively reduce enteric emissions for finishing cattle, although there are not consistent results for emissions in low quality forage diets.
Improved production efficiencies
Consensus amount the research community is that a good strategy that all farmers can implement for mitigation is to decrease methane loss per unit of product (in this case per kg of beef produced). Using this approach, strategies should include effective management of feed resources other than forage, for example water quality, mineral supplementation, and ration balancing.
Other than effective management of feeding programmes, there are several other ways that will improve animal productivity, which include selecting animals for improved production, breeding and fertility management.
Adoption of strategies that serve to improve production efficiency, including feed analysis, ration balancing, pregnancy testing, and provision of minerals and quality water sources will not only serve to reduce enteric methane emissions but will also prove to be economically beneficial.
For more information on strategies to reduce emissions from beef production, please click here to visit the Toolkit.