ImmuneDEX – Select for Disease Resilience in Merino Sheep

ImmuneDEX is a genomic tool that helps Merino breeders select for immune competence alongside productivity traits.

It provides genomic insight into an animal’s ability to respond to disease and environmental stress, supporting more resilient and consistent flock performance over time.

Developed by Neogen in partnership with CSIRO, Sheep Genetics (MLA), Animal Genetics and Breeding Unit (AGBU), and supported by The MLA Donor Company, as part of the National Livestock Genetics Consortium (NLGC), ImmuneDEX builds on data from the AWI-funded Merino Lifetime Productivity (MLP) projects.

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Exclusive to Neogen, ImmuneDEX is built directly into the Neogen GGP platform as an add-on to Smart Flock Elite.

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Disease costs money
Research commissioned by MLA in 2022 on sheep industry estimated the annual cost of the top five sheep diseases to the Australian sheep industry to be ~$1.5 billion. The biggest contributors include:

• Internal parasites (~$436 million)
• Weaner ill-thrift and mortality (~$188 million)
• Flystrike (~$173 million)

These costs are particularly significant for Merino producers, where survival, growth and welfare strongly affect enterprise profitability.

Why does immune competence matter?
When seasonal conditions become tough genotyping early, focusing and investing wisely counts. Using genomic Immune Competence values (ImmuneDEX) lets you focus on the top animals and avoid spending time and money on the bottom end that won’t contribute to your breeding or product goals. Removing the underperforming animals from your flock lifts the whole average of your flocks’ productivity.

Strong commercial proof from the beef industry 
Feedlot studies in Angus cattle, show immune competence has hard-dollar benefits:

Low immune-competent animals

• Cost around $105/head in health related costs
• Represented 12% of animals
• Accounted for 35% of total health costs

High immune-competent animals

• Cost around $5/head in health related costs
• Had lower disease-related mortality
• Stayed healthier and more productive

This proven model shows what’s possible for sheep: healthier animals cost less and perform better.

Direct benefits for Merino stud and commercial producers
Selecting for immune competence can deliver:

• Improved lamb survival and weaner performance
• Reduced impact of parasites and flystrike
• Lower labour and treatment costs
• Improved welfare outcomes, aligning with consumer and market expectations
• Increase whole-of enterprise profitability
• Stronger, more resilient sheep suited to commercial production environments and supply chains