In this contributed item, Victorian Angus seedstock producer Harry Lawson looks at just how important genetics are in driving down beef cattle methane emissions …   

 

THERE is no denying that enteric methane (CH4) emissions produced by beef cattle ruminant livestock has gained enormous global interest.

Politicians, celebrities, comedians and even influencers love to have a crack at cattle breeders: A cow fart joke when giving an impressive talk on the plight of the planet is bound to get the attention of the audience.

So as breeders, the existential crises looms; as an industry how do we reduce methane emissions and stay in business?

We strongly believe that livestock are an essential global food source that incorporates the conversion of pastures, native grasslands and other feed sources to produce high-quality protein.

The focus on beef cattle emissions should be a good incentive for all of us to be part of a global response to climate change. As an industry, we must continue to develop well thought-out science-based solutions to cattle emissions, avoid green-washing and make evidence-based change.

There is wide ranging research and a strong global scientific community working hard to find solutions and pathways for livestock producers to lower their carbon footprint.

Well-recognised and qualified academics like Richard Eckard (University of Melbourne) and Professors Frank Mitloehner and Alison Van Eenennaam (UC Davis California) and many others communicate the scientific facts in a positive and realistic way for both producers and Industry leaders to understand and incorporate into their production systems.

Whole-farm approach

University of Melbourne Professor Bill Malcolm’s ‘whole-farm approach’ to farm management and economics highlights the role that we can play in reducing our carbon footprint through the delivery of genetics (and quantitative genetic data) to improve both the productivity and sustainability of our commercial clients herds.

Our claims that we have lower emissions genetics are based on the genetic factors around emissions intensity (amount of methane produced per unit of beef).

On this journey to better understand the drivers of on-farm emissions, we have focused our attention on researching and improving the key underlying genetic factors that drive beef cattle emissions.

We have put a lot of time and resources into researching feed efficiency and beef cattle emissions and as a result made a significant investment in establishing an on-farm Vytelle feed efficiency research facility (pictured below) at our property near Yea in 2020.

The importance of measuring feed intake

There are a wide-range of views on how best to solve or reduce on-farm emissions for beef producers, from building soil carbon, reducing reliance on fossil fuels, reducing the use of nitrogen fertilisers, regenerative farming practices, planting trees, grazing practices, genetics, and farm management systems that reduce the age of turnoff.

Some even believe we should replace livestock with other plant based alternatives.

While all these approaches can potentially contribute to an individual enterprises carbon footprint one thing that is clear is enteric methane is the single biggest contributor to a beef farm’s emissions. So if you are going to keep farming livestock, then understanding and developing a solution to improve emissions intensity has to involve a strategy that incorporates methane.

It is estimated that enteric methane from beef cattle is responsible for around 9pc of Australia’s national emissions and around 70-80pc of emissions from beef farms is from enteric methane.

Feed supplement intervention Vs genetics

Methane production may be mitigated to varying degrees by a number of dietary and feed supplement intervention strategies aimed at changing microbe populations and fermentation processes that result in a more efficient rumen and thereby lowering methane outputs.

These solutions will be become more widely available and economic over the next decade, however, it does not reduce or discount the importance of genetics in improving emissions intensity.

The big advantage of genetic change is the long-term and cumulative improvement (i.e. can be improved every generation on an on-going basis).

Firstly, let’s consider the relationship between methane (CH4) and dry matter intake (DMI).

Some cattle breeders (and researchers) are trying to focus solely on methane without understanding the importance of feed intake and feed efficiency, and the direct relationship with methane outputs.

DMI has the biggest influence on both methane outputs and the cost of production.

Research has clearly demonstrated the linear relationship between dry matter intake and methane outputs (similar for cattle, sheep and dairy livestock).

The other big reason we are interested in feed efficiency is feed costs are the biggest input cost for any beef producer, estimated at 70-75pc of cost of production for most beef farmers in Australia.

The majority of that feed is utilised for cow maintenance. There is also a methane cost, as larger cattle produce more methane (there is a direct correlation between cow size, DMI and methane).

In terms of priorities, the most effective way to reduce the carbon footprint of a herd (as defined by emissions intensity) is to keep cow size moderate and ensure fertility is a priority. Mature Cow Weight (MCW) is the biggest driver of feed costs.

So having established and agreed (hopefully) that cow maintenance and fertility are the biggest factors driving both a beef farmer’s productivity and methane intensity, the next selection priority in terms of impact on emissions intensity is to reduce age of turn-off.

Hence Lawsons Angus’ long-term breeding focus on bending the curve at both ends.

Bending the growth curve is no doubt the single biggest genetic way to improve on-farm emissions.

It is important that our moderate, fertile cow herd still produces calves with the ability to grow fast and convert feed efficiently. Cattle that meet target market weights and carcase specifications at a younger age have lower emissions intensity, however we still need to consider their dam’s daily emissions.

If, for example, faster growing calves are 20pc heavier but are out of dams that are even 10pc heavier than their respective contemporaries, the benefit of the faster growing cows will be offset by the additional feed costs and higher emissions of the heavier cows.

Other factors of having larger cows also need to be considered such as how many you can carry, their fertility and drought tolerance in the tougher years. We often see a much higher reproductive crash in herds that have larger cows in tougher years.

It’s not just the overall pregnancy rates in these years, it’s when these larger cows get in calf – every cycle a cow delays on a rebreed is 25-30kg weaning weight loss the following year.

Cow size considerations

Cow size is the most important factor driving economics and emissions

Herds with Mature Cow Weight (MCW) EBVs that are significantly higher than breed average make no sense on any level.

These cows can often look fantastic and can produce wonderful looking calves (usually due to low stocking pressure) cost significantly more to feed, are at higher risk of reproductive failure in tough years and are the major contributor of methane emissions.

Many stud breeders are ignoring the fact that their cows are the biggest “fuel guzzlers” in the system. In a commercial sense, cow size often unwittingly “creeps” up over generations and the differences don’t hit hard until a tough season hits.

In terms of context, we are not talking about having small, lower productivity cows. Our cows are around +90 for Mature Cow Weight (MCW) EBV, below current breed average of +102; and are typically around 650kg in a normal spring.

They are highly productive, with the ability to produce steers at >400kg at 15-18 months. Our simple question is why would we want them bigger?

On-farm productivity, feed efficiency and lowering emissions intensity should be the priority for future farming practices.

Selective breeding traditionally has been focused on outputs with an emphasis on growth and fertility, and as an industry, we appear to be regressing back to more traditional ways where popular bulls are being sold on phenotype rather than genetic merit.

Next frontier NFI

The next frontier in beef genetics is to start to use selection for feed efficiency to improve rumen efficiency and also the many other factors that influence why some animals are inherently more efficient than others in the way they use feed.

The genetic factors influencing feed efficiency and methane outputs include differences in rumen microbe composition, metabolic and cellular efficiencies, maintenance efficiency and how some animals store and utilise fat and muscle as energy reserves. The feed efficiency measure that best summarises these differences is Net Feed Intake (NFI).

If we have two cows that are similar-sized and turn off weaners with similar weights, and one uses 25pc less feed than the other, why wouldn’t we do that?

We measure and observe these differences in feed intakes in every Cohort in the Vytelle feed efficiency testing centre.

We have the tools to make sure we improve feed efficiency over time without it compromising too much on other key economic traits. Like many other genetic challenges over the past few decades, we can get there if we measure it and have a plan.

It’s a tough decision for commercial breeders to put their faith in the data as you can’t see these differences with your eye. This is part of the reason why this critical trait (NFI) has not been widely adopted, despite the fact that it is moderately heritable and the differences we measure and observe in our tests done post-weaning are highly repeatable (in terms of animal rankings) as mature cows.

It is important to note that there is some variance in terms of the relationship between methane and DMI (so that there is the potential to find some low methane omitting animals with higher intakes).

However if we just select for low methane per se, we will select animals with lower feed intake that will not necessarily be more efficient or profitable.

Getting the balance right between animal performance, costs and emissions is critical.

Our research is essential given the high correlation between DMI and methane and the economic importance of feed costs.

Modern breeding, for those with a genuine commitment to improving commercial productivity, will encompass a multi-faceted plan involving measuring and multiplying superior animals that will have the best balance of economic traits that lift both on-farm productivity and reduce greenhouse gas emissions.

This is a lot more challenging than most breeders realise, especially given there are very few Angus sires with high accuracy feed efficiency data.

Genomics will play a major role in beef genetics going forward, however some seedstock herds will still need to do some heavy-lifting in terms of research and disciplined breeding to move the needle on Net Feed Intake (NFI) along with measuring and selecting animals with proven genetic superiority to lower emissions intensity.

Summary:

• Enteric methane from beef cattle is responsible for around 9pc of our national emissions. 70-80pc of emissions from beef farms is from enteric methane. Getting the balance right between animal performance, costs and emissions is critical.
• Genetics are a critical part of reducing GHG emissions for beef farmers:
• Cow size – cow size dictates cow costs, fertility, drought tolerance and methane outputs.
• Keeping a lid on cow size and bending the growth curve is no doubt the single biggest genetic way to improve on-farm emissions intensity.
• Growth – growth is important as faster growing calves (in the right package) reach market weights faster which reduces emissions intensity.
• Cow size has a significantly higher impact on overall feed intake, feed costs and emissions than calf growth rates.
• Feed efficiency – Net Feed Intake (NFI) is the most globally accepted trait that relates to the selection for both feed efficiency and emissions intensity. Methane output is directly related to feed intake (DMI)

 

Lawsons Sale date correction

Beef Central published an incorrect date for Lawson Angus’ upcoming Victoria spring bull sale in our Upcoming Bull Sales directory (click here to access).

The date originally published was 1 September, but this year’s sale is in fact being held on Friday, 20 September. Apologies for any confusion.

An open day for the sale, offering 110 bulls, will be held on Friday 13 September.

With more than 360 bulls sales across 14 breeds and data drawn from a wide range of sources included in Beef Central’s comprehensive national bull sales summary, we’d again ask stud managers to check the details we’ve listed for their own upcoming spring sales (click here to access), and advise us of any necessary changes via this facility.