
Selecting for Worm Resistance in Low-Challenge Systems with Swabtec
21/12/2025 | 37 mins.
What if measuring worm resistance didn't require high parasite burdens and ALSO delivered double the heritability of egg counts?Sarah Preston, Lecturer at Federation University and cofounder of Swabtec, explains the development of their saliva-based test designed to measure immune responses to gastrointestinal worms in sheep, allowing resistance to be assessed without relying on high worm egg counts.She and Mark discuss why egg counts often fail to reflect adult worm burden, particularly in mixed infections and with species that regulate egg production, and how this affects breeding and management decisions in well-managed, low challenge systems.They also discuss where they are with the development and validation of Swabtec. They are currently working to validate the test across breeds and environments and are planning to develop breeding values as the data builds. The test has been found to have a heritability of 0.4 compared to the WEC of 0.2 meaning flock improvements based on insights and data from Swabtec can occur twice as fast!Find out more below:https://swabtec.com/Head Shepherd is brought to you by neXtgen Agri International Limited. We help livestock farmers get the most out of the genetics they farm with. Get in touch with us if you would like to hear more about how we can help you do what you do best: [email protected] to our sponsors at MSD Animal Health and Allflex, and Heiniger Australia and New Zealand. Please consider them when making product choices, as they are instrumental in enabling us to bring you this podcast each week.Check out Heiniger's product range HERECheck out the MSD range HERECheck out Allflex products HERE

Individual ewe performance and the future of sheep productivity with Tara Dwyer
14/12/2025 | 43 mins.
What limits ewe productivity in current sheep systems?Our guest this week, Tara Dwyer is breeding manager at Headwaters Genetics and a farm manager within the Lone Star Farms group. Her work covers stud breeding, commercial supply chains, and large-scale sheep systems, and in amongst all of that, she found time to do a Kellogg report, "A New Fleece on Life: How the Sheep Farming Sector in Aotearoa Can Halt Terminal Decline to Secure a Sustainable and More Secure Future"Starting with her "day job", Tara and Mark discuss the value of genetics within a value chain, and how Headwaters is focusing on eating quality traits alongside maternal performance, resilience, and low-input efficiency. Tara explains how and why Headwaters selects for intramuscular fat and fatty acid profiles while still prioritising reproduction, lamb survival, and health traits.Mark and Tara then discuss her recent Kellogg report, which looks at why lambs weaned per ewe have barely shifted for decades, why carcass output improved while reproduction stalled, and why relying on ram breeders alone is not a reproductive strategy. Tara explains her findings on where current systems have plateaued, what existing technology already allows producers to measure, and why individual ewe performance will be one of the next major productivity levers.If you're interested in getting involved in the Head Shepherd TwentySix2000 campaign, click the link below:https://fundraise.curebraincancer.org.au/fundraisers/markferguson/twentysix2000Strava link:https://www.strava.com/clubs/1858801Head Shepherd is brought to you by neXtgen Agri International Limited. We help livestock farmers get the most out of the genetics they farm with. Get in touch with us if you would like to hear more about how we can help you do what you do best: [email protected] to our sponsors at MSD Animal Health and Allflex, and Heiniger Australia and New Zealand. Please consider them when making product choices, as they are instrumental in enabling us to bring you this podcast each week.Check out Heiniger's product range HERECheck out the MSD range HERECheck out Allflex products HERE

Results from the 'Genetics of foot health in Merinos' project with Gus Rose
07/12/2025 | 32 mins.
Gus Rose shares the recent results from the 'Genetics of foot health in Merinos' project, which is looking at footrot and foot structure in sheep in Australia. Gus shares what the data shows on the heritability of foot shape and its relationship with footrot, as well as other foot structure traits. Gus Rose explains how the dataset is being built, which traits are proving to be correlated, and where the current limits sit. Gus and Mark discuss the project's future and the significance of the results for the industry. If you would like to know more about how to get involved, please email Amy at [email protected] project is funded by Australian Wool Innovation, Animal Health Australia and collaborating Merino breeders, and is being conducted by Murdoch University and neXtgen Agri in collaboration with AGBU and SheepMetrix. You can view our webinar here:https://thehub.nextgenagri.com/c/articles/live-genetics-of-foot-health-in-merinosHead Shepherd is brought to you by neXtgen Agri International Limited. We help livestock farmers get the most out of the genetics they farm with. Get in touch with us if you would like to hear more about how we can help you do what you do best: [email protected] to our sponsors at MSD Animal Health and Allflex, and Heiniger Australia and New Zealand. Please consider them when making product choices, as they are instrumental in enabling us to bring you this podcast each week.Check out Heiniger's product range HERECheck out the MSD range HERECheck out Allflex products HERE

Proactive sheep management strategies with Tim Gole
30/11/2025 | 46 mins.
On this week's episode, Tim Gole shares how sheep farmers can increase their profits by shifting from responding to problems to preventing them in the first place.Tim runs ForFlocksSake, a vet-based sheep consultancy company. After a lightbulb moment during the drought, Tim became a self-confessed sheep fanatic.With both Tim and Mark clearly in their element, they spend nearly an hour talking all things sheep. They discuss lifetime ewe programs, scanning strategies, the use of genetics to make production easier and more profitable, and the benefits and drawbacks of EID. They also cover reproductive efficiency, worm control lessons and lots of other sheep-related topics. Head Shepherd is brought to you by neXtgen Agri International Limited. We help livestock farmers get the most out of the genetics they farm with. Get in touch with us if you would like to hear more about how we can help you do what you do best: [email protected] to our sponsors at MSD Animal Health and Allflex, and Heiniger Australia and New Zealand. Please consider them when making product choices, as they are instrumental in enabling us to bring you this podcast each week.Check out Heiniger's product range HERECheck out the MSD range HERECheck out Allflex products HERE

How Do You Breed Short-Tailed Sheep? with Marnie Hodge
23/11/2025 | 31 mins.
What do the genetics of tail length and the genetics of semen quality have in common? Not much, except that our guest, Marnie Hodge, Sheep Genetics Senior Development Officer, has researched them both.Tail length is moderately to highly heritable, but in her research, Marnie found that measuring tail length in centimetres versus a scored system gives you far more accuracy and picks up significantly more genetic variation, which means faster rates of genetic gain if you're selecting for it.But what's actually changing when tails get shorter? Are we dropping vertebrae or just shortening bones? And what about correlations with body structure? Marnie explains what we know, what we don't, and why we don't have a tail length breeding value quite yet. On the opposite end of the scale, as with all reproduction traits, semen quality is lowly heritable. Marnie's research, "Heritability and Genetic Parameters for Semen Traits in Australian Sheep", showed that most of the variation in AI success wasn't down to motility, but more down to the variation in ewe management on each farm. So what does that mean for the establishment of a potential future breeding value? Marnie explains on the podcast. Plus Marnie gives us some updates on what's coming from Sheep Genetics and the combined analysis.Head Shepherd is brought to you by neXtgen Agri International Limited. We help livestock farmers get the most out of the genetics they farm with. Get in touch with us if you would like to hear more about how we can help you do what you do best: [email protected] to our sponsors at MSD Animal Health and Allflex, and Heiniger Australia and New Zealand. Please consider them when making product choices, as they are instrumental in enabling us to bring you this podcast each week.Check out Heiniger's product range HERECheck out the MSD range HERECheck out Allflex products HERE



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