The Korean Hanwoo system, properly modelled.

Hanwoo is Korea's domestic beef breed — small, intensely marbled, fed to 30 months on a barley-and-rice-bran ration, sold through a grading system where one marbling tier above neighbour can be the difference between an unprofitable kill and a record price. The bioeconomic shape is unlike anywhere in the Western beef world. Here's how the engine models it correctly.

The grade economics, in numbers.

The Korean Beef Quality Grading System runs on two orthogonal axes: a Yield Grade (A / B / C, based on carcass yield) and a Quality Grade (1++ / 1+ / 1 / 2 / 3, based on marbling, meat colour, fat colour, texture and maturity). The combination is what the consumer-facing market actually pays for. Marbling drives the quality axis almost entirely; the platform's bioeconomic anchor treats the MARB EBV (or KAPE equivalent) as the single most economically valuable trait in Korea.

The premium between adjacent grades is not linear, and the premium for 1++ A over 1++ (same marbling score, just better yield grade) is itself ~12% — that's a structural feature of the grid most US/AU/EU pricing tables don't have an analogue for. Producers chase the top tier hard. So does the platform's bioeconomic anchor when the producer's market is Korea.

What Korean producers actually select on.

KAPE (Korea Animal Products Quality Evaluation Service) publishes the breed evaluation for Hanwoo. The trait set is similar to BREEDPLAN or BIF in structure but with weight shifted toward carcass quality and away from growth. The platform reads it natively (Tier 1 ingestor) and re-weights for the producer's specific operation.

• Marbling score (MS / KAPE). The single most valuable trait on the rank page when the producer's market is Korea. h² ≈ 0.40 in the published reference population.
• Carcass weight (KAPE CW). Heavy enough to clear the 720 kg liveweight finish target, not so heavy that meat density and marbling drop. Sweet spot economically.
• Eye muscle area (KAPE EMA). Drives yield grade, which compounds with marbling on the 1++ A premium.
• Backfat (KAPE BF). Penalised in the bioeconomic anchor — too much subcutaneous fat reduces saleable yield without contributing to marbling.
• Growth rate (KAPE WG). Important for feed-conversion economics through the long 30-month finishing window, but always secondary to carcass quality.
• Cow fertility (KAPE STAY). Self-replacing herd economics; days-open penalties are material because every wasted cycle pushes the dam's lifetime contribution down.

The 30-month finish window.

Korean Hanwoo are typically slaughtered at 28–32 months, ~720 kg liveweight, after a long intensive finish on barley, rice bran and concentrate. That's roughly twice the time-on-feed of a US Choice-Prime finish and ~40% longer than even a long-fed Wagyu programme. The feed cost is correspondingly high — the breakeven per head is driven primarily by getting the 1++ premium, secondarily by feed-conversion efficiency over that long window.

This shapes the engine's selection objective. Growth-trait weights are softer than US systems (because the producer is paying to grow the animal for an extra year either way), but marbling-trait weights are 3–5× heavier. The production-system modifier "hanwoo_intensive" in the platform automatically applies this re-weighting; any KAPE DGV report or imported Hanwoo bull catalogue feeds straight into a Korean-shape rank page.

Trait notation, side by side.

The platform's translator handles the breed-society semantic differences. The mapping for the Korean audience reading reports across countries:

What that looks like on a real-shape Hanwoo operation.

The numbers below are derived from a real-shape 280-head Hanwoo cow-calf-finish operation in Gyeongsangbuk-do, finishing all progeny on a barley-and-rice-bran ration to 30 months, with a typical 1++ achievement rate of ~38% and a 1++ A rate of ~14%.

The pattern is consistent with what the closed-loop calibration loop is designed to find: this producer's calibration multipliers reflect their specific grid achievement, their specific feed-conversion economics, and their specific cow-cycle structure. Marbling is even more valuable here than on the national average; growth is slightly less valuable; backfat is more penalised. A KAPE-published Hanwoo bull catalogue feeds through this re-weighting on the rank page and produces a meaningfully different top-10 list than the same catalogue would on a national-average operation.

The national grading system pays for marbling. The producer's specific grid pays for marbling even more. The engine reflects both.

What's wired natively for Korea.

As of May 2026, the platform reads the following Korean sources natively:

• KAPE DGV publications — read directly from the official KAPE breed-evaluation feed. Marbling, carcass weight, eye muscle area, backfat, growth rate, calving ease, longevity.
• NongHyup / aT Center wholesale prices — daily 1++ A through 3-grade wholesale ₩/kg cwt, pulled overnight in KRW.
• KMA (Korean Meteorological Administration) climate — temperature, rainfall, humidity per producer's nearest station.
• K-ETS carbon market — Phase 4 (2026 pilot) carbon allowance prices, integrated into the methane-economics layer (see the methane economics piece).
• K-Hanwoo herd-book pedigree — Hanwoo-specific pedigree records for inbreeding control and mate allocation.

What this means in code.

The production-system modifier for Korean Hanwoo lives alongside the other 12 archetypes. Simplified shape:

// core/js/production-system-modifier.js — Hanwoo intensive overlay
SYSTEM_MODIFIERS['hanwoo_intensive'] = {
  // Hanwoo MS economic weight multiplier — 3.5× the temperate-system default.
  // Driven by the 1++/1++A grade premium dwarfing any Western marbling premium.
  marbling: 3.5,

  // Eye muscle area compounds with marbling on the yield-grade axis
  ema: 1.4,

  // Growth softens — the 30-month finish window means marginal growth
  // matters less than getting the carcass quality right
  yw_400: 0.55,

  // Backfat penalty steeper — Korean grid penalises excess fat heavily
  rib_backfat: 1.8,

  // Cow size penalty stays at default — extensive land cost is the constraint
  mcw: 1.0,

  // Heat tolerance ingestible if KAPE publishes it (R&D pilot 2026)
  heat_tolerance: 1.0,

  // Documented in: insights/korean-hanwoo.html, methodology.html
};

This single overlay tells the closed-form bioeconomic derivation that this producer's marbling is worth 3.5× what it's worth on the industry-default temperate template. The producer-fit β̂ multipliers from the closed-loop calibration sit on top, further sharpening to the producer's actual grid achievement.

Where the platform can go further for Korean producers.

• R&D-tier KAPE methane EBV. KAPE has a methane-emission research stream running with Hanwoo trial groups; once a published methane DGV becomes available, the engine ingests it natively into the methane economics layer.
• Microbiome panels on Korean feed rations. The rumen microbiome literature is dominated by temperate forage. Hanwoo on barley-and-rice-bran is a meaningfully different ruminal environment — academic teams running tropical or rice-based-feed microbiome work would find the engine's microbiome ingestion layer useful as the phenotype-side anchor.
• Cross-breed F1 ranking for Hanwoo × Angus crosses. Some Korean producers run small F1 herds for export-market beef; the composite-aware ranking on the 2027 horizon will fold these in directly.