Inside the Merino Wether Trials: Benchmarking Bloodlines with Dr. Sue Hatcher and Phil Graham

About this episode

The episode explores the significance of wether trials in Merino genetics and their impact on sheep production.

Join us for another thought-provoking episode of Genetics in the Paddock with Emily, as we dive into one of the longest-running and most influential sources of independent Merino genetics information: wether trials. In this episode, Emily is joined by Phil Graham from Graham Advisory and Dr Sue Hatcher from Makin Outcomes to unpack why this decades-old approach is re-emerging as a powerful decision-making tool for today’s sheep producers. Together, they explore the origins of the combined wether-trial analyses stretching back to the 1990s, why producers have consistently driven demand for independent data, and how these trials continue to provide deep genetic insights beyond what you can see from on-farm performance alone. From benchmarking bloodlines and understanding genetic variation in key traits like fibre diameter and clean fleece weight, through to navigating the well-known trade-offs between production traits, Phil and Sue break down what the results really mean for flock improvement. We also step through how a wether trial actually works, from entry to final data collection, and discuss why the analysis is done on a ewe-flock basis, how producers should interpret results…

People in this episode

Host: Emily Johnston

Guests: Dr. Sue Hatcher, Phil Graham

Topics covered

• Merino genetics
• wether trials
• sheep production
• genetic benchmarking
• fleece weight
• breeding objectives

Keywords

• Merino
• wether trials
• genetic insights
• fleece weight
• breeding objectives
• sheep producers
• independent data

Mentioned in this episode

Organizations: Graham Advisory, Makin Outcomes

More episodes of Genetics in the Paddock with Emily

• The Genetics Behind the Microbiome: Predicting Performance with Microbes with Dr. Andrew Lakamp (Pt.2) · November 9, 2025 · 27 min
• The Genetics Behind the Microbiome: Why Your Livestock’s Microbes Matter with Dr. Andrew Lakamp (PT. 1) · October 26, 2025 · 21 min
• Gene Editing in Livestock: What, Why, and What’s Next? with Dr. Gus McFarlane · June 9, 2025 · 31 min
• 30 Years of Proof: Why Muscular Cows Mean More Meat, More Profit with Dr Linda Cafe and Brett Littler · April 6, 2025 · 37 min
• Double Trouble or Double Profit? The Science of Twinning in Cattle with Dr. Leo Cummins · March 2, 2025 · 30 min
• Wrinkles, Weather, and Wool: The Genetics of Breech Strike in Merinos with Tracie Bird-Gardiner · February 2, 2025 · 21 min