STtalks #377 - Journey of Genetics Part 5: Importance of Quality Control with Candis McCleary

In this fifth episode of the 'Journey of Genetics' series, host Laura Demmer sits down with Candice McCleary, Global Director of Quality Insurance and Quality Control at ST Genetics, to explore the rigorous quality control processes behind gender-sorted semen production. McCleary details the multi-layered checks that occur from the moment semen is collected—from initial raw quality assessments to post-thaw evaluations of motility, morphology, acrosome integrity, gender purity, and microbiology. A critical component of the process is the external DNA testing via Genetic Visions in Wisconsin, which ensures each batch contains only the intended bull’s DNA. The episode highlights the global standardization of procedures across ST’s 45+ production labs, the importance of traceability through unique animal codes, and the stringent biosecurity protocols in place during packaging and international shipping. McCleary emphasizes that even minor deviations lead to batch discards, with only 2–3% of product typically rejected. The entire process, from collection to final approval, can take up to three weeks, but ST has optimized it to rival human sequencing timelines while maintaining accuracy and integrity. The conversation concludes with a strong call to action for farmers to verify the animal code on straws to ensure they receive the correct genetics. Key takeaways include: 1) Always verify the animal code (bull code) on the sealed end of the straw to confirm the correct bull; 2) ST Genetics uses a dual-layer QC system—internal lab testing and external DNA verification—to ensure purity and traceability; 3) Batches failing any QC standard are physically destroyed to prevent contamination; 4) Traceability is built into every straw via coded databases, enabling full product history retrieval; 5) Biosecurity is maintained through physical separation, sanitation, and health monitoring from bull to shipment; 6) The entire process, though complex, is designed for speed and accuracy, with a typical turnaround of two weeks; 7) Farmers are encouraged to reach out to ST’s quality team for any concerns—support is available 24/7; 8) Consistency across global labs is achieved through standardized SOPs and continuous global oversight.