In this episode of the Poultry Network podcast, Tom Woolman and Tom Willings are joined by Harrison Davies, technical manager at Aviagen, to discuss the launch of the 505 Club for Ross 308 broiler growers.
The conversation explores how the new club follows on from Aviagen’s previous 470 Club, reflecting the continued improvement in UK broiler performance. Harrison explains what EPEF — European Production Efficiency Factor — means, how it is calculated, and why it provides a useful benchmark for comparing biological performance across broiler crops.
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The episode also covers the impact of changing stocking densities, particularly the move from 38kg/m² to 30kg/m² for many retail contracts, and how this has affected performance. Harrison highlights FCR and average daily gain as key drivers behind recent improvements, while stressing that genetics only set the potential of the bird — it is consistent management, strong brooding, good environmental control and skilled stockmanship that unlock that potential on farm.
Tom and Tom also reflect on Aviagen’s wider role in supporting the sector through technical advice, training, schools and development opportunities for the next generation of poultry professionals.
This episode is sponsored by the Poultry Network Supplier Directory 2026/7.
Main talking points
Aviagen’s 505 Club
Aviagen’s 505 Club recognises Ross 308 broiler growers achieving high levels of performance. It follows the previous 470 Club, with the threshold raised to reflect the level now being achieved by leading UK growers.
Harrison explains that the club is designed to recognise what is possible when genetics, farm management, bird welfare and consistency come together.
What is EPEF?
EPEF stands for European Production Efficiency Factor. It is a single performance figure used to assess the outcome of a broiler crop.
Harrison explains that EPEF brings together several key measures:
- Livability — whether the birds stayed healthy
- Liveweight — the weight achieved by the crop
- Age — how long the crop took to reach that point
- FCR — how efficiently feed was converted into growth
Rather than focusing only on financial performance, EPEF gives producers a way of comparing the biological performance of birds across different farms, systems and markets.
Why performance has improved
The conversation looks at why UK broiler performance has continued to rise. Harrison points to the performance of the Ross 308, but also stresses that the top-performing farms are usually those doing the basics consistently well.
Lower stocking density has helped in some cases, particularly where producers have moved to 30kg/m², but Harrison notes that strong EPEF scores are still being achieved by farms operating at 38kg/m². His message is that stocking density is part of the picture, but it is not the whole answer.
The importance of the first seven days
Brooding is one of Harrison’s strongest themes. He describes the first seven days as critical to the rest of the crop, setting the bird up for later growth, feed conversion and welfare outcomes.
Good brooding, correct temperature, careful ventilation, litter management and close attention to bird behaviour all help lay the foundation for strong performance.
Technology is a tool
Tom Willings asks about the role of data, integrated shed systems and modern technology. Harrison explains that technology can be extremely valuable, especially for monitoring things that are harder to assess directly, such as air movement and temperature.
However, he is clear that technology does not replace stockmanship. The best results still come from people who can read the birds, understand what they are seeing and make the right management changes at the right time.
Stockmanship and consistency
A recurring point throughout the episode is that the best growers are consistent. Harrison says that high-performing farmers are those who watch the bird, respond to changes and adjust management as the bird develops.
Tom Woolman and Tom Willings also reflect on this after the interview, noting that performance cannot simply be bought through technology. Data and equipment can help, but they are only tools in the hands of the people managing the birds.
Stocking density and ventilation
The move from 38kg/m² to 30kg/m² has changed the way some farms need to manage ventilation. Harrison explains that reducing stocking density by around 20% can create a risk of over-ventilation if settings are not reviewed.
Too much air movement, particularly during brooding, can chill birds and affect early performance. At the same time, Harrison points out that some farms may previously have been under-ventilating, so the right approach is to look at the bird, the shed environment and the conditions in front of you rather than relying on assumptions.
What is driving higher EPEF scores?
When asked which parts of the EPEF calculation are contributing most to the uplift, Harrison identifies FCR and average daily gain as the main drivers.
That means birds are not only growing well, but also doing so more efficiently, which helps improve overall biological performance and supports poultry meat output from the existing production footprint.
Genetics and future performance
Tom Woolman raises the point that Aviagen has been able to balance progress in both broiler and breeder traits. Harrison explains that genetics set the potential of the bird, but that potential still has to be delivered on farm.
As the bird changes, management also has to keep changing. Harrison describes the best growers as those who adapt with the bird rather than remaining fixed in old routines.
Training and professional development
In the post-interview discussion, Tom Woolman also highlights Aviagen’s work around training and professional development, including its schools and next generation scholarship opportunities.
These schemes give people working in the sector the chance to sharpen their knowledge, learn from technical specialists and meet others working with the same bird in different parts of the world.
How growers can join the 505 Club
Growers achieving an EPEF score of 505 or above can submit their farm performance details through the Aviagen website. Aviagen then reviews the result, and qualifying producers can be recognised through its EPEF awards.
There is also a gold award for producers who either exceed the threshold by more than 10% or achieve three consecutive EPEF scores of 505 or above.
Key takeaways for producers
- Strong performance starts with the basics.
- The first seven days are critical.
- Brooding, ventilation, temperature and litter management need constant attention.
- Technology can help, but it does not replace stockmanship.
- Watch the bird and respond to what it is telling you.
- Lower stocking density can support performance, but it is not the whole answer.
- FCR and average daily gain are major contributors to recent EPEF improvement.
- Genetics set the bird’s potential; management determines how much of that potential is achieved.
