STtalks #378 - Understanding the April 2026 TPI® Adjustment with David Kendall

In this episode of ST Talks, host Laura Demmer sits down with David Kendall, Director of Genetic Advancement at ST Genetics, to unpack the major 2026 update to the Total Performance Index (TPI), a cornerstone metric for Holstein breeding decisions. The adjustment, driven by shifting market dynamics, reweights protein and fat in the TPI formula to favor a higher protein-to-fat ratio—specifically moving toward 24% protein and 14% fat—responding to a surge in demand for protein due to the widespread adoption of GLP-1 weight-loss drugs. This shift is not a penalty on fat production but a strategic recalibration to align with evolving dairy processing needs and consumer trends. Kendall emphasizes that while the change is significant, it’s evolutionary rather than revolutionary, with minimal disruption to top bulls and continued confidence in TPI as a reliable tool. He also previews upcoming changes in fertility data, linear scoring, and the potential for more frequent genetic evaluations due to advancements like single-step genomic evaluations. Breeders are advised to maintain confidence in TPI while considering customized indexes that reflect local market conditions, especially smaller herds with fewer resources. The episode underscores the importance of adaptability in genetic selection, with Kendall stressing that past progress in fat production makes this pivot possible without undermining previous achievements. Looking ahead, the industry faces a wave of innovation—from new traits like first service to conception to potential shifts in evaluation frequency—requiring ongoing education and engagement. ST Genetics positions itself as a leader in guiding the community through these changes, ensuring breeders remain informed and empowered in an era of rapid genetic and economic transformation.