Dairy KB

One concept per page: definition, formula, how to pull it from DairyComp 305, typical ranges with herd context, and common mistakes.

Reproduction

Conception rate — Share of inseminations with a known outcome that result in a confirmed pregnancy. A per-service measure of breeding success.
Heat detection rate (insemination rate) — Share of breeding-eligible cows inseminated in each 21-day period, whether from detected heat or timed AI.
Pregnancy rate (21-day) — Share of eligible open cows that become pregnant in each 21-day period. The main speed-of-getting-pregnant reproduction KPI.

Calves

Passive transfer of immunity — How well a calf absorbed colostral IgG, graded from serum IgG, serum total protein or Brix at 1-7 days old.

Feed

Income over feed cost (IOFC) — Milk revenue minus feed cost, per cow per day or per cwt of milk. The core margin metric for the lactating herd.