Holstein USA and Lactanet both shifted toward protein in the same proof round. Your mating list doesn’t know yet.
Executive Summary: HORSESHOE is the kind of bull most people had buried in the middle of the list; under the 2026 TPI formula, he jumps an estimated 10 spots while GARZA, the current #2, slides down the rankings on the same December proofs. Holstein USA is shifting TPI to 24% protein and 14% fat at the April 2026 run, and Lactanet is flipping Holstein LPI production from 60F:40P to 40F:60P, so both major indices are now paying more for protein than fat at the same time. Bullvine reran the December 2025 top‑25 daughter‑proven TPI sires through the new weights and found that fat‑heavy bulls like GARZA, RICHE, and RIVERA lose ground, while high P/F bulls like POWERHOUSE, HORSESHOE, and CAPN MIGUEL pick up points and rank before a single new daughter is added. If more than two of your top five service sires have P/F ratios under 0.5 and weak PL or DPR, you’re effectively breeding for the old formula while semen companies and processors are already repricing around protein and longevity. The immediate risk is over‑exposure to fat‑dominant sires you’re sitting on by the 100‑unit cane; the opportunity is to quietly pivot toward bulls whose component mix and PL match where TPI, LPI, and casein markets are actually headed. The article walks through the full “winners and losers” table, a simple P/F check you can run in five minutes, and a 30‑day plan to talk with your AI rep and adjust spring matings without panic.
Last Friday, GARZA sat comfortably as the #2 daughter-proven TPI sire in the Holstein breed — 3464 TPI, fat pounds through the roof, the kind of bull that makes a lineup card look impressive. By the time you read this, the formula that produced that ranking may no longer exists. Holstein Association USA’s board just moved PTA Protein from 19% to 24% of TPI and dropped PTA Fat from 19% to 14%, effective with next week’s April 2026 genetic evaluation.
That’s a 10-percentage-point swap between your two component traits. And it lands two weeks before proofs.
If you bred heavy to bulls like GARZA and RIVERA this winter, this is the week your stomach does a little flip. Nothing about their daughters changed. No new genes appeared. But the TPI formula 2026 update just tilted the math away from fat-dominant profiles and toward protein, Productive Life, and fertility — and it did it right before spring mating decisions lock in.
Across the border, Lactanet picked the same proof round to flip Holstein LPI’s production subindex from 60% Fat / 40% Protein to 40% Fat / 60% Protein. Two different countries. Two different committees. One unmistakable direction.
| TPI (Holstein USA) | LPI Production (Lactanet) | |
|---|---|---|
| Index owner | Holstein Association USA | Lactanet (Canada) |
| Effective date | April 2026 evaluation | April 2026 evaluation |
| Fat weight — before | 19% | 60% |
| Fat weight — after | 14% (↓5pp) | 40% (↓20pp) |
| Protein weight — before | 19% | 40% |
| Protein weight — after | 24% (↑5pp) | 60% (↑20pp) |
| Net direction | Protein > Fat | Protein > Fat |
| Stated rationale | Align with processor demand for casein; protein lags fat in pipeline | Milk pricing signals; butterfat doesn’t need more genetic push |
| Correlation with old formula | “Very highly correlated” (Holstein USA) | Structural, not incremental shift |
| Risk to fat-dominant programs | Moderate (−5pp swing) | High (−20pp swing on LPI) |
| Opportunity bulls | P/F ratio > 0.60 + strong PL | Same profile; protein-dominant cows stick around |
Bullvine pulled the December 2025 top-25 daughter-proven TPI sires and ran their existing PTAs through the new 2026 weights. Same proofs. New formula. This isn’t a prediction of April proofs — new daughter data will still move bulls when those drop on April 7. But it’s a clean look at where the formula alone is pushing your favorite sires before that data even hits.
What Changed in the 2026 TPI Formula?
Strip it down to the parts that hit your tank.
Holstein USA’s board approved these changes for the April 2026 TPI formula:
- PTA Protein weight jumps from 19% to 24% (+5 points).
- PTA Fat weight drops from 19% to 14% (−5 points).
- The Health & Fertility block maintains strong emphasis on Productive Life (PL) and the Fertility Index (FI)— which rolls up DPR, CCR, HCR, and EFC — carrying forward the longevity and reproduction tilt that’s been building since 2020.
Holstein USA says the new formula is very highly correlated with the old one. Across all bulls, TPI values barely budge. Single-digit points for the average sire.
But your top-25 list isn’t “average.”
Up at the top, bulls are bunched within a handful of points. Their component profiles — how much of their genetic value comes from protein vs. fat — are wildly different. When you crank protein up and pull fat down, some names that felt untouchable suddenly have the wind in their face. Others catch a tailwind they didn’t have last week.
The TPI Ranking Table Nobody Else Will Publish
Press releases are safe. They’ll tell you “more emphasis on protein” and “continued focus on health and fertility.” They won’t tell you what that does to GARZA, POWERHOUSE, HORSESHOE, RIVERA, and the rest of the short list you’ve been breeding to.
Bullvine did the part nobody else will print right now.
We took Holstein USA’s December 2025 top-25 daughter-proven Holstein sires by TPI and reran their December PTAs through the April 2026 TPI weights. That isolates the formula pressure — the shift caused by the new weighting alone — before any new daughter data moves anything on April 7.
Quick methodology: Base list is the top-25 daughter-proven Holstein sires by December 2025 TPI (Holstein USA). Inputs are December 2025 PTAs for protein, fat, and TPI. Outputs are the estimated rank and TPI shift under the 2026 formula. This is Bullvine internal modeling, not official April proofs. Treat every estimated number as directional.
Top 25 TPI Sires: December 2025 vs. 2026 Formula Pressure
| Bull | Stud | Dec Rank | Est. Rank* | Move* | Dec TPI | Est. Shift* | PTA Protein (lb) | PTA Fat (lb) | P/F Ratio |
| SHEEPSTER | Select Sires | 1 | 1 | — | 3572 | +5 | 70 | 133 | 0.53 |
| DOMINANCE | STgenetics | 3 | 2 | ↑1 | 3458 | −6 | 65 | 131 | 0.50 |
| CAPTAIN | STgenetics | 4 | 3 | ↑1 | 3428 | +8 | 67 | 120 | 0.56 |
| GARZA | STgenetics | 2 | ~4 | ↓2 | 3464 | ~−40 | 51 | 145 | 0.35 |
| ZURI | Alta | 5 | 5 | — | 3375 | −7 | 54 | 108 | 0.50 |
| POWERHOUSE | Alta / Peak | 7 | ~6 | ↑1 | 3329 | ~+39 | 81 | 104 | 0.78 |
| TROOPER | Select Sires (CRI) | 6 | 7 | ↓1 | 3334 | +16 | 53 | 90 | 0.59 |
| BOLT ACTION | Select Sires | 9 | 8 | ↑1 | 3324 | −11 | 38 | 93 | 0.41 |
| JULIUS | STgenetics | 11 | 9 | ↑2 | 3299 | +10 | 64 | 110 | 0.58 |
| UNDERTONE | Select Sires | 10 | 10 | — | 3304 | −2 | 54 | 108 | 0.50 |
| POSITIVE DELUXE | STgenetics | 8 | ~11 | ↓3 | 3325 | ~−25 | 56 | 129 | 0.43 |
| POWERSTAR | Semex | 14 | 12 | ↑2 | 3275 | +22 | 49 | 79 | 0.62 |
| MATTERHORN | Alta / Peak | 12 | 13 | ↓1 | 3296 | −2 | 45 | 98 | 0.46 |
| HORSESHOE | GENEX | 24 | ~14 | ↑10 | 3262 | ~+27 | 70 | 93 | 0.75 |
| CAPN MIGUEL | STgenetics | 21 | ~15 | ↑6 | 3263 | +21 | 57 | 86 | 0.66 |
| INNOVATION | ABS Global | 19 | ~16 | ↑3 | 3266 | +17 | 70 | 111 | 0.63 |
| EVENT | Semex | 20 | ~17 | ↑3 | 3265 | +18 | 50 | 83 | 0.60 |
| PERKY | Semex | 13 | ~18 | ↓5 | 3292 | −12 | 35 | 92 | 0.38 |
| PIPELINE | STgenetics | 18 | ~19 | ↓1 | 3268 | +11 | 62 | 105 | 0.59 |
| CAPN ELEMENT | STgenetics | 23 | ~20 | ↑3 | 3263 | +7 | 56 | 99 | 0.57 |
| BENEFIT | ABS Global | 15 | ~21 | ↓6 | 3273 | −7 | 48 | 108 | 0.44 |
| T REX | Select Sires | 22 | 22 | — | 3263 | −9 | 44 | 99 | 0.44 |
| RICHE | Select Sires | 16 | ~23 | ↓7 | 3272 | ~−24 | 35 | 100 | 0.35 |
| RIVERA | STgenetics | 17 | ~24 | ↓7 | 3269 | ~−31 | 35 | 111 | 0.32 |
| CRUSHER | Select Sires | 25 | 25 | — | 3250 | ~−24 | 42 | 118 | 0.36 |
Est. Rank, Move, and Est. Shifts are Bullvine’s internal projections that apply April 2026 TPI weights to December 2025 PTAs. They are not official April 2026 proofs. New daughter data on April 7 will further move these numbers.
Which Bulls Does the New Formula Lean On?
Start with the P/F Ratio column. It tells the story faster than anything else in the table.
GARZA (STgenetics) carries 51 lb protein and 145 lb fat — a 0.35 P/F ratio — with a December TPI of 3464. In the formula-only rerun, he gives back roughly 40 TPI points and slides from #2 to about #4. That’s exactly what a fat-heavy profile looks like when protein picks up 5 percentage points of weight.
RICHE (Select Sires) is the same math problem: 35P, 100F (0.35) — an estimated ~24-point drop and a seven-spot slide from 16th to around 23rd. RIVERA (STgenetics) is even more exposed: 35P, 111F (0.32, the lowest P/F ratio in the top 25) with a projected ~31-point loss and a similar seven-spot fall.
None of them suddenly became bad bulls. Their daughters are the same cows they were last month. But if your winter breeding list was built around fat-dominant profiles because the old 19:19 fat/protein balance made it look smart, the new math is less forgiving.
In the middle of the pack, PERKY (Semex) at 35P/92F (0.38) drops an estimated 12 points and falls from 13th to about 18th. BENEFIT (ABS Global) at 48P/108F (0.44) takes a smaller −7-point hit and moves from 15th to around 21st. Not dramatic. But enough to change who’s on your short list and who isn’t.
The Quiet Bulls Who Just Caught a Tailwind
Flip the lens.
POWERHOUSE (Alta/Peak) is the poster boy for this formula shift: 81 lb protein and 104 lb fat — a 0.78 P/F ratio, the highest in the top 25 — with a December TPI of 3329. Under the April 2026 weights, he picks up roughly +39 TPI points and edges into about 6th. That’s a bull whose protein strength was always there. The formula just started paying for it.
HORSESHOE (GENEX) is the sleeper worth watching. Sitting down on the 24th in December with 70P and 93F (0.75), the new formula gives him roughly +27 points and a 10-spot jump to around 14th. Ten spots. On formula alone. Nobody was talking about HORSESHOE as a top-15 bull two weeks ago.
CAPTAIN (STgenetics) — already a known story to Bullvine readers — has 67P and 120F (0.56) and quietly adds about +8 points, moving from 4th to around 3rd. Then there’s the cluster of CAPN MIGUEL, INNOVATION, EVENT, POWERSTAR, and PIPELINE — all carrying P/F ratios north of 0.6 — all picking up points and rank spots. (Read more: CAPTAIN: The Bull That Rewrote the Rules for Modern Breeding)
The pattern isn’t subtle: higher P/F ratios climb under this formula; lower P/F ratios slip. Before we even talk about how PL and DPR interact with April’s new daughter data.
Does the CAPTAIN/HOMECOMING Story Repeat Here?
If you’ve followed Bullvine through the last few proof runs, you know formula changes can set off ranking earthquakes that compound over time.
In our look back at the April 2020 genomic class, GENOSOURCE CAPTAIN gained 369 TPI points between April 2020 and December 2025 as his daughters came in and multiple formula tweaks, plus a base change, played in his favor. AOT HOMECOMING lost 414 points over that same window as fertility, health, and type corrections piled up.
Those swings didn’t happen in one proof run. They were biology — real daughters, real performance — combined with three or four rounds of index adjustments and a base reset.
The 2026 TPI update won’t blow 300 points off a bull overnight by itself. What it does is set the direction of the wind.The CAPTAIN profile — strong components tilted toward protein, respectable PL, workable type, and fertility — is now more aligned with where TPI is heading. The HOMECOMING profile — production without the backside to support it — faces a tougher formula and a tougher biological test as daughters age.
Why Did TPI and LPI Both Move Toward Protein at the Same Time?
You can write off one index committee as a quirk. You can’t shrug off two.
Lactanet’s April 2026 update is blunt about the rationale: Holstein LPI’s production piece is moving from 60% Fat / 40% Protein to 40% Fat / 60% Protein. They tie it directly to evolving milk pricing signals and the message from national pricing bodies that butterfat doesn’t need more genetic push. The Canadian dairy market is telling breeders: give us protein-dense milk from cows that stick around.
Against that, TPI’s shift to 24% Protein / 14% Fat looks like the US reading the same tea leaves. Processors want casein. Consumer products are shifting toward high-protein formats. And the genetic pipeline has been quietly overdelivering on fat for years, while protein gains have lagged.
This isn’t two committees having the same idea by coincidence. It’s a structural repricing signal. If your program has been aggressively stacking fat % and shrugging at protein, the formula change isn’t a one-off nuisance — it’s an early warning that your genetics are drifting from where both indexes, and probably your processor, are headed.
Should You Change Your Spring Matings — or Wait for April 7?
This is the real question. Not what changed in the formula. What do you do about it?
If you adjust now:
- You start correcting a fat-heavy lineup before you add another crop of calves conceived under a formula that no longer exists.
- You can steer semen orders toward bulls whose protein strength and PL fit the new incentives.
- But you’re still working off December 2025 PTAs. Some bulls will move on April 7 because their daughter data changed — not just because the formula did.
If you wait until after April 7:
- You get the combined effect of new proofs + new formula before making shifts.
- You won’t overreact to an estimated shift that doesn’t match what actually happens.
- But you spend another month of matings optimized for a world that TPI and LPI have both moved on from.
A realistic rule that won’t blow up your program: if your own rerun under the new formula shows three or more of your top five sires losing more than about 50 TPI points, book time with your breeding advisor before April proofs to identify some protein-plus-PL alternatives. If the shifts are smaller, mark the exposed bulls and let the April proofs settle before swapping anything wholesale.
What This Means for Your Operation
- Run a P/F check on your top five sires. Divide each bull’s PTA Protein by PTA Fat. If more than two of your top five sit below roughly 0.5, your lineup leans fat-heavy relative to how both TPI and LPI now reward protein. Circle any that also carry weak PL or negative DPR — they’re taking a double hit. lactanet
- Sort your semen inventory by exposure. Any bull with an estimated >50-point drop and a P/F ratio in the 0.35–0.4 range deserves a hard look if you’re holding 100+ units of him. That doesn’t mean dump him. It means ask yourself whether you want to keep stacking that profile into 2026 heifers.
- Have a specific conversation with your AI rep. Don’t ask “what’s hot.” Show them your list. Ask: “Which of your bulls look more like POWERHOUSE and HORSESHOE on P/F and PL, and which look more like GARZA and RIVERA in this table?” Use the formula pressure as a starting point — then let April’s proofs confirm or contradict it.
- Don’t chase every shiny name in April. The bulls that deserve more use are the ones that align with the new formula and show solid daughter performance under the new weights after a couple of proof runs. Use 2026 as the year you test which sires hold up under this TPI version, not the year you jump every time a list shuffles.
- If you already bred this winter, don’t panic. Calves conceived in January and February don’t retroactively become worse animals because a formula changed. But do note which sires you used heavily and track how they land on April 7. That data tells you whether to continue or pivot for summer breeding.
Key Takeaways
If more than two of your top five sires carry P/F ratios under 0.5, your lineup is leaning into fat in a world where both TPI and LPI just shifted toward protein and longevity.
Bulls like POWERHOUSE (0.78 P/F) and HORSESHOE (0.75 P/F) are exactly the profiles the 2026 TPI formula rewards — even before new daughter data hits on April 7.
This table is a formula-only stress test on December 2025 proofs, not a crystal ball. Use it to see which bulls in your tank face a headwind or a tailwind, then let April proofs tell you which ones actually held.
The synchronized TPI and LPI protein shift isn’t a coincidence. It’s a structural market signal. Fat-dominant genetic programs that don’t adjust aren’t just chasing last year’s formula — they’re building toward a component mix that processors and pricing are moving away from.
The Bottom Line
When you rerun your own sire list under the new weights on April 7, how many of your “can’t-miss” bulls are still where you thought they were? And how many of the bulls you’d never considered just climbed into the conversation? That gap — between the list you had and the list you need — is the real story of this formula change. We’ll be tracking it through April proofs and beyond.
Complete references and supporting documentation are available upon request by contacting the editorial team at editor@thebullvine.com.
Learn More
- The $900/Cow Hit You Can’t Outbreed by April: Western Canada’s 70/25/5 Reckoning – Arms you with an immediate triage plan to survive the 70/25/5 pricing flip. It delivers specific nutrition and culling tactics that protect your cash flow before the April component shift drains $900 per cow from your margin.
- Bred for $3 Butterfat, Selling at $2.50: Inside the 5-Year Gap That’s Reshaping Genetic Strategy – Reveals a methodical approach to hedging against the brutal five-year lag between genetic selection and bulk tank reality. You’ll gain the strategic foresight to align your current sire roster with 2030’s projected component premiums.
- CAPTAIN Gained 369 TPI Points. HOMECOMING Lost 414. Inside the 59% Failure Rate of April 2020’s Top Genomic Sires – Exposes the 59% attrition rate of elite genomic sires and breaks down why “spreadsheet giants” often crumble. It delivers a massive advantage by identifying the biological traits that actually hold up against formula rewrites and base resets.
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