On-Farm Emissions Mitigation – Are We Doing Enough to Improve Animal Efficiency?
Updated: Jun 23
I recently attended a Rural Professionals Seminar on Greenhouse Gas (GHG) Emissions on New Zealand Farms. This seminar covered the science behind GHG emissions and gave a good rundown of the policy and economics involved. But as a farm consultant, what interested me the most was the section on options for emissions mitigation on-farm.
On-farm mitigation largely revolves around reducing enteric methane emissions. This is the methane emitted from the ruminant digestive system and it makes up about 71% of agricultural GHG emissions in NZ. The total enteric methane emitted by an individual animal is directly related to their DM intake, so it follows that by improving animal efficiency (getting more production per kg DM eaten) we can reduce our emissions per kg of production (liveweight or milk solids). And as long as we’re not increasing stock numbers, we can also lower our total emissions.
Whether it’s dairy or drystock we’re talking about, the generally accepted view is that most gains in animal efficiency will be made through improved feeding (i.e. Offering better quality pastures though improved grazing management). And while I agree that this is a big part of the method, is it enough?
The fundamental thing we need to understand and that consistently gets overlooked, is that optimal pasture quality does not automatically equal optimal mineral content. The assumption that high quality ryegrass pastures meet the nutritional requirements of our grazing livestock stems from a focus on non-mineral nutritional parameters. If the mineral nutrition of the feed is considered, then this becomes a less reliable assumption.
Have you ever had a flock of well fed, well grown, healthy looking ewes that struggle to get in lamb? Or a herd of Dairy Cows that BCS well but have a persistently high empty rate? This happens more often than you think, and it’s not because they aren’t being fed well.
We are often so focussed on feed quantity and quality, that we forget to consider if the mineral content of the diet is meeting the production requirements of our animals, rather than just avoiding a deficiency. Mineral supplementation is much more common these days; however, the devil is in the detail.
And you may argue that we need to focus on “feeding” before we even consider minerals but an in-depth understanding of the full nutritional profile of the diet you’re offering allows you to make smarter and more sustainable decisions around feeding and supplementation that are to your benefit. The good news is that this information is available now and it starts with taking a pasture sample.
It’s estimated that we could achieve about a 10% reduction (below baseline) in absolute agricultural emissions through enhanced animal performance and while it may not seem like much, along with reducing stock numbers to plant trees it’s one of the only existing and proven options we have. In this time of uncertainty, we need to focus on what we can control, and animal efficiency is something we can improve on right now. So, let’s take a pasture sample and get on with it!
Find out how taking a pasture sample can help you improve animal efficiency on your farm.
Read More on the important role of minerals in improving Animal Efficiency.