A new carbon sub-index to be introduced to the EBI

A new carbon sub-index is set to be introduced to the Economic Breeding Index (EBI) in the near future.

Some of the details of this new sub-index, and how it could work, were revealed by Teagasc’s Donagh Berry who spoke yesterday, January 8, at the Irish Grassland Associations (IGA’s) dairy conference.

Firstly, drawing the attendees’ attention to the Teagasc marginal abatement cost curve (MACC), he explained how it “shows the massive potential EBI has to reduce our carbon footprint in dairying”.

The width indicates the potential the technology has in reducing our greenhouse gas (GHG) emissions and the EBI, he said, has a “massive potential” to do this. It is also below the line which indicates that you are also making money by adopting this technology.

Image source: Teagasc

However, the added benefit the EBI has, Donagh pointed out, is how “the EBI is cumulative and permanent”.

Explaining this, he said: “If you stopped using low-emissions slurry spreading (LESS) or protected urea tomorrow you go back to the base line; but if you decide you are not going to use the EBI for the next two years you are still maintaining permanence in your population.

“By 2050, I would argue that that bar should be much wider because we are building on it year-on-year. Whereas, the other technologies are not; so, I think the EBI is going to be crucial to reducing our emissions in the future,” he added.

The good news is we are already doing it. Year-on-year we have been improving our EBI and at the same time reducing our carbon footprint, he further noted.

Image source: Teagasc

This, he said, has been equating to a 14% reduction in carbon footprint per kilogram of fat and protein produced.

But can we build on this success?

Donagh went on to describe what he referred to as “the new carbon sub-index”.

Similarly to how the EBI is calculated – using exactly the same principles – but instead of the output being profit, in this new sub-index the output would equate to carbon.

“So if we increase milk kilograms by one per lactation, what is the change in carbon output for that herd? Then the one in the middle is, what is that cost of carbon going to be in the future?” he said.

Continuing, he displayed data where he plotted different bulls based on their EBI against what their carbon index would be.

He said: “What you see is a negative correlation, which is good. The higher the EBI the lower the carbon footprint.

“A correlation of -0.87 exists which is really good. This means the EBI is strongly pushing down our carbon footprint.

Image source: Teagasc

“If you do the math on that, each €10 improvement in EBI is associated with a reduction of 61.7kg of CO2 equivalents per lactation. But remember it is cumulative and permanent.”

Inclusion of additional traits in the EBI

However, Donagh stressed that any change to the make up of the EBI would have to be strongly considered.

For a trait to be considered in the EBI, Donagh noted that it must fulfill the following criteria:
  • It must be important – which he said “carbon clearly is”;
  • Must exhibit genetic variability;
  • Must be (ideally easily) measurable or correlated with a measurable trait.

Teagasc, Donagh explained, is currently working with a number of technologies to more easily measure methane from animals.