Opening Summary Everyone talks about chasing the highest LPI. But what if the sires driving nearly a quarter of Canadian Holstein registrations are actually dragging down fertility, health, and long‑term profit? In this episode of The Bullvine Podcast, we dissect Lactanet’s new subindexes and reveal how Canada’s 20 most‑used Holstein sires can sit at the 96th percentile for LPI while averaging only the 31st percentile for fertility — and what that disconnect is really costing in dollars per cow. If you’re still picking bulls off the front page of a catalog, this conversation will change how you read proofs and how you build your next sire list.

Key Takeaways

· Why 17 of the 20 most‑used Holstein sires rank below the breed midpoint for fertility — despite “elite” LPI proofs.

· How Lactanet’s six new LPI subindexes expose hidden weaknesses in health, fertility, milkability, and environmental impact.

· What an average inbreeding level of 11.9% (vs. 9.99% in heifers) really means for milk, components, and cow survival.

· The barn‑math cost of inbreeding: how $80–$110 per cow in lifetime profit drag quietly adds up across a 200‑cow herd.

· How casein and polled genetics have shifted fast (70% A2A2, 50% BB, 15% PP) — and why that doesn’t automatically fix fertility.

· Practical thresholds for using subindexes: where to draw the line on Reproduction, Health & Welfare, and inbreeding in your breeding program.

· How to use Compass, pLPI, and Lactanet’s Inbreeding Calculator to build a sire lineup that fits your market, not the semen catalog’s agenda.

This episode goes beyond “here are the new proofs” and into the structural problem at the heart of modern Holstein breeding: we’ve optimized heavily for LPI, production, and type, while quietly accepting below‑average fertility and health from the very bulls we use the most. Using the latest Lactanet data, we walk through how Canada’s 20 most‑used sires hit the 96th percentile for LPI, average 92% for production and 97% for Longevity & Type, yet stumble badly on subindexes that actually keep cows in the herd.

For links to the full analysis, charts, and the supporting research discussed in this episode, visit TheBullvine.com and look for the article on Canada’s 20 most‑used Holstein sires and Lactanet’s subindexes. While you’re there, subscribe to The Bullvine Weekly to get future genetics breakdowns, proof‑run reactions, and on‑farm strategies delivered straight to your inbox.

If this episode challenged how you think about LPI, fertility, or inbreeding, hit follow or subscribe in your podcast app so you don’t miss the next one. Share the episode with a fellow breeder, nutritionist, or vet who’s serious about data‑driven progress, and join the conversation on The Bullvine’s social channels — we want to hear what you’re seeing in your own proofs and your own cows.