This episode of the American Sheep Industry Association’s Podcast breaks down what the New World Screwworm means for sheep producers on the ground. Host Jake Thorne sits down with Dr. Rosie Busch, UC Cooperative Extension and UC Davis, School of Veterinary Medicine, to discuss current cases, official regulations, and practical management strategies.

Key Topics Covered

• Outbreak Status: The current state of New World Screwworm cases in Texas and neighboring regions, including the distinction between active and inactive cases.

• Eradication & Tech: How the Sterile Insect Technique (SIT) works, how AI is improving sterile fly distribution, and updates on USDA breeding facility capacities.

• Regulations & Movement: Rules for infested/surveillance zones, inspection protocols, and direct-to-slaughter requirements.

• Treatment Options: The role of systemic treatments like injectable Dectomax (and its EUA status) versus topicals, plus guidance on proper herd management to minimize wound risks.

The American Sheep Industry Association podcast with host Jake Thorn features guest Tom Murphy Ph.D., a sheep geneticist with the USDA/ARS Meat Animal Research Center in Clay Center, Nebraska. Dr. Murphy explores how breed and age impact lamb performance, carcass characteristics, and meat quality.

While producers focus on traits like growth rate and parasite resistance, industry success relies on creating a positive eating experience for consumers. Surveys indicate that consumer satisfaction is largely tied to eating satisfaction, particularly lamb flavor.

Dr. Murphy defines how heritability varies across traits, explaining that:

• Lamb survival has low heritability (less than 5%).

• Weaning weight is moderately heritable (20–30%).

• Carcass traits like loin muscle area are highly heritable (~40%).

• Flavor profiles are on the lower end (10–20%).

While terminal sire breeds (e.g., Suffolk, Texel) provide growth and carcass advantages over maternal breeds, research shows no clear, consistent breed differences regarding eating quality and flavor. Dr. Murphy emphasizes that improving these traits requires consistent performance recording, phenotypic data collection, and leveraging genetic tools.

Flushing Ewes: Nutrition and Reproductive Success
Dr. Richard Ehrhardt,  Michigan State University