27 May 2024

Worth the weight

A Research Officer in Grassland Science at Teagasc Grange, Peter Doyle is at the forefront of research that’s optimising beef systems to improve lifetime animal performance while meeting crucial climate goals.

Photo by: Tony Keane

How did you get into this field of study?

I grew up on a beef and tillage farm in Co. Wexford, which laid the foundation for my passion for beef systems. I saw that there were challenges and opportunities in this area, and I wanted to be at the forefront of Ireland’s work in this field.

I studied Agricultural Science at UCD, during which time I did work placement at Teagasc Grange. In 2017, I took a PhD opportunity, which I was able to complete at Grange, discovering a love for research in the process, leading to me pursuing it as a career. 

My PhD focus was on evaluating forage-only beef systems, and how sustainable this is compared to using concentrate. This sustainability pertains to economic factors, meat nutritional value, food security and environmental sustainability.

What makes this topic relevant?

The results from the PhD research showed that, compared to concentrate-based, forage-only beef systems have increased farm profitability, don’t use human-edible food resources, and the meat produced also had improved fatty-acids profile. However, forage-only is a longer slaughter production system, which increases GHG emissions per animal and per kilogramme of carcass. On the other hand, GHG emissions per net weight of human-edible food produced is more favourable again, as forage-only systems don’t consume human food in the process.

Typically, in Ireland, forage makes up 90% of the diet in beef systems. Concentrates are an expensive feed resource for farmers and use grain that could otherwise be consumed by humans. Hence we are looking at the possibility of removing concentrate from beef systems and instead using forage-only, which is ineligible as feed for humans and our cheapest feed resource.

What research have you been doing in this field?

Our new research in conjunction with the Walsh Scholar Peter Bennett, is aiming to reduce age to slaughter, concentrate use and nitrogen use. We are validating and quantifying the role of legumes – red and white clover – and of animal genetics in helping to achieve these objectives. 

From birth through to finishing at 20 months, in a predominantly forage-based system, we’re looking at several variables: grass-only vs grass-clover, and Aberdeen Angus vs Charolais in a suckler calf-to-beef herd. This will allow us to validate the economic, environmental, and animal growth responses within the given treatment systems.

How has this research developed over time?

We’re building on the work of colleagues at Moorepark and at Solohead Farm who have examined the use of white clover in dairy systems and found that it can increase milk production by 8% in dairy herds. Our aim is to build on this research and look at animal weight gain within beef herds – in line with both government and Teagasc aims.

We began this research in 2023 and will run it for three production cycles – birth-to-slaughter for a single animal being a single production cycle. For systems-based research you need to do a few repetitions to validate results.

What are the challenges surrounding this topic?

Farmers have recently started to get more clover into grass swards. Our role is to quantify these differences. These new technologies need to be put out on-farm in collaboration with industry to reach the climate targets laid out by the government. For beef systems, the key part of the MACC is reducing age-to-slaughter, incorporating clover and improving animal genetics, so our research is about validating this technology; but we need to continue to build on the collaboration across industry to adapt this tech on a wider scale.

What has the industry response been?

Further to the point of industry collaboration is the importance of reducing nitrogen input. In 2023, fertiliser N use was 280k tonnes, the lowest it’s been in the past four decades – and below the climate action plan target of 300k tonnes. This reduction is partly attributed to use of clover in swards, but also economic factors and better slurry use practices.

The importance of clover is that red and white clover are both legumes that can fix nitrogen, i.e. reduce the need for chemical N in fertiliser. Each has its own use: white clover persists very well in grazing swards, while red clover persists for four to six years in silage swards. It’s great to see such a sales increase in clover seed across industry. We work closely with partners and key stakeholders across industry and strive to keep them up to date with the latest research results.

What results have you seen?

The results so far from 2023 are positive. We had suckler cattle assigned at 12 months of age to a mixed grass-white clover pasture or grass-only pasture. The cattle grazing the grass-white clover pasture had a 24 kilogramme greater live-weight gain, equating to a 14 kilogramme carcass weight advantage over one grazing season.

Of course, genetics also play a massive role, and we’ll start acquiring usable data towards the end of this year. Building on this work is crucial for understanding clover’s impact on animal lifetime performance.

What are your future plans for this research?

Colleagues across Teagasc are currently testing machines called GreenFeeds. These help measure enteric methane production, making them a key technology for identifying beef systems which reduce both daily and lifetime methane production.

Furthermore, the next stage in our research is that we want to develop a new suckler blueprint system for Teagasc. This would form guidelines for farmers to help achieve their GHG mitigation targets set by the Government, as well as improve farm profitability.

We’ll continue looking at other species and genetic traits to reduce age-to-slaughter and improve animal performance. After our current trials of mixed-clover swards, we’ll be further examining the potential roles of other plant species.

In addition to all that, I still farm at home every weekend with my father as well! So, I plan to carry on the family business in the future.

Up close and personal

What’s your favourite animal?

The suckler cow; they’re nice animals to work with when managed correctly and provide a lot to rural Ireland.

If you hadn’t ended up in research, what other job would you have wanted to give a go?

Probably a technical advisor or lecturer in the agricultural industry.

What are you most proud of professionally?

Being awarded Teagasc Walsh Scholar of the year in 2021, it was great seeing the team recognised for high-quality research within beef systems.

Acknowledgements 

This PhD research was conducted with Edward O’Riordan, Mark McGee, Aidan Moloney, Alan Kelly and Paul Crosson.