New equation powers feedlot decision making

The Department of Climate Change, Energy, the Environment and Water (DCCEEW) has adopted the new Australian-specific equation to calculate enteric methane emissions from feedlot cattle. What does it mean for those in the yards? 

Developed by the University of New England (UNE) and funded by Meat & Livestock Australia (MLA) for the Australian Lot Feeders’ Association (ALFA), the revised equation shows emissions are more than 50% lower than previously estimated.

Dr Rob Lawrence, Consulting Nutritionist at Integrated Animal Production, spoke about the equation’s practical impacts for lot feeders at the recent Grainfed R&D Symposium hosted by ALFA and MLA.

“In essence, the equation is simple. So much simpler than the previous 1979 Moe and Tyrell equation that was being used.

“The great thing about it is that all the components needed for the equation, feedlots already have access to.

“It will now be an easy calculation and reporting for feedlots, similar to average daily gain and feed conversion,” Dr Lawrence said.

With feedlots already reporting on feed intake, the rations being fed to each pen and the nutrient components that make up that ration, the revised equation is easier to use and offers greater accuracy for lot feeders.

“Feedlots already report on average daily gain and feed conversion on their performance summaries. Now they will be able to report on methane as well because they have all the information.” Dr Lawrence said.

Maintenance energy level

Dry matter intake is a key driver of methane emissions and production and is one of the equation's components.

“As you increase dry matter intake, you’re going to increase fermentation, therefore resulting in more methane,” Dr Lawrence explained.

He further added the more cattle eat above their maintenance energy level, the greater the performance.

“When you are looking at methane production on a weight gain basis (per kilogram), higher dry matter intake and the resulting production is a good thing.”

Keeping maintenance energy levels as low as possible is a great actionable step for feedlots. Dr Lawrence went on to give the example of ensuring pens are kept clean, reducing mud levels cattle are exposed to.

“If you’re getting cattle to walk through mud, it’s a high energy activity, increasing the maintenance energy level.”

Shade and shelter were other examples Dr Lawrence listed, as when the animals have those options available, it reduces the requirement to regulate body temperature.

Methane-reducing additives

The new equation also allows feedlots to determine the breakeven of introducing methane-reducing additives.

“These products are very effective and have been proven to work. You’ve got over 80% methane mitigation when they are used.”

The additives currently face some adoption barriers including cost and ease of inclusion.

“In my opinion, the current cost of some of the additives, when broken down to a per head per day figure, can be hard to justify.”

While ease of inclusion isn’t quite where it needs to be at this stage, it is being explored.

“Currently, you can’t just add the ingredients to your liquid supplement.”

“The products are also highly susceptible to degradation. They don’t fare well with heat, moisture, and even exposure to air can reduce effectiveness.” Dr Lawrence said.