Source
https://www.dairynz.co.nz/media/m4knoxds/facts_and_figures_chapter_4_updated_december_2021.pdf — original source (opens in a new tab; the file is not redistributed)
DairyNZ Facts & Figures ch.4 (Dec 2021) — Cow feed requirements
The feed-demand side of a community house-cow / small-herd model — and the source of the batch's single most consequential caveat
DairyNZ’s grower-facing reference chapter giving annual dry-matter requirement per cow by breed, liveweight and milksolids production: Jersey 375 kg LW @ 300 kg MS = 3.8 tDM/cow/yr · Kiwicross 450 @ 400 = 4.8 · Friesian 500 @ 400 = 5.1, at a feed quality of 11.0 MJ ME/kg DM and including walking 4 km/day for 270 days in milk. 🔴 These are EATEN figures, not GROWN figures. Verbatim: “They do not allow for any feed offered that was not eaten (wastage).” Apply the source’s own 80% utilisation worked example and 5.1 tDM eaten becomes ~6.4 tDM grown; a low-input community pasture below 11.0 MJ ME incurs a further +5% per MJ ME on top. Taken raw, the 3.8–5.1 tDM band understates a low-input community’s real pasture need by roughly 25%.
Summary
Chapter 4 of DairyNZ’s Facts & Figures (December 2021 edition), the industry’s standard grower-facing reference. The chapter tabulates the annual dry-matter (DM) requirement of a dairy cow as a function of breed, liveweight and milksolids production, plus the adjustments that move a cow off the table’s base assumptions (feed quality, walking distance, wastage). For the Neobiome food model this is the demand side of any community dairy or house-cow calculation: how much feed a milking cow consumes in a year, which — once grossed up for utilisation and pasture quality — sets how much land a community must dedicate to feeding her. It pairs directly with OT_172, which supplies the matching breed liveweights and per-cow milkfat outputs.
The chapter’s headline numbers are attractive precisely because they are clean, and that is the trap: they are stated on an eaten basis at a feed quality (11.0 MJ ME/kg DM) that a low-input, unfertilised, non-irrigated community pasture will generally not reach. Both corrections push the land requirement up, and both are documented inside this same source.
Key claims
- claim: "ANNUAL DRY-MATTER REQUIREMENT per cow, by breed / liveweight / production, at a feed quality of 11.0 MJ ME/kg DM: Jersey 375 kg liveweight producing 300 kg MS = 3.8 tDM/cow/yr; Kiwicross 450 kg liveweight producing 400 kg MS = 4.8 tDM/cow/yr; Friesian 500 kg liveweight producing 400 kg MS = 5.1 tDM/cow/yr. The figures include an allowance for walking 4 km/day for 270 days in milk. [verified verbatim against the source]"
source_location: "Facts & Figures ch.4 'Cow feed requirements' (Dec 2021), annual feed-requirement table (breed × liveweight × milksolids). Page-level locations were not recorded by the verification pass."
- claim: "⚠ EATEN BASIS, NOT GROWN — the load-bearing caveat. Verbatim: 'They do not allow for any feed offered that was not eaten (wastage).' The source's own worked example applies 80% utilisation, so 5.1 tDM eaten corresponds to approximately 6.4 tDM grown. [verbatim caveat verified; the 6.4 figure is the draft's arithmetic on the source's own 80% utilisation example, not a printed value]"
source_location: "Facts & Figures ch.4 'Cow feed requirements' (Dec 2021), notes/assumptions accompanying the feed-requirement table, and the chapter's worked utilisation example."
- claim: "⚠ FEED-QUALITY ADJUSTMENT — add 5% to the requirement for each MJ ME/kg DM below the 11.0 MJ ME/kg DM base. Low-input pasture sits below 11.0, so a community model incurs a positive adjustment on top of the utilisation gross-up. [verified verbatim against the source]"
source_location: "Facts & Figures ch.4 'Cow feed requirements' (Dec 2021), feed-quality adjustment rule accompanying the requirement table."
- claim: "⚠ MATURE LIVEWEIGHTS stated in this chapter are Jersey 435 kg and Friesian 535 kg — ABOVE the 375 kg and 500 kg rows the upstream research report selected from the table. Choosing the lighter rows understates the requirement a second time. [verified verbatim against the source]"
source_location: "Facts & Figures ch.4 'Cow feed requirements' (Dec 2021), mature-liveweight reference figures by breed."Neobiome Intelligence relevance
Feeds d02_smart_food_systems as the per-cow feed-DEMAND constant for any community dairy / house-cow pathway. The food model already carries a pasture-supply side by land class (su_ha[LUC], OT_083 / OT_082) but no dairy-specific per-animal demand. This chapter supplies it.
How to use the number — three stacked corrections, all sourced from within OT_171 itself:
| Step | Basis | Friesian 500 kg @ 400 kg MS |
|---|---|---|
| As printed | eaten, 11.0 MJ ME/kg DM | 5.1 tDM/cow/yr |
| ÷ 0.80 utilisation (source’s own worked example) | grown | ~6.4 tDM/cow/yr |
| + 5% per MJ ME below 11.0 | grown, low-input pasture | higher again — magnitude depends on the assumed pasture ME |
The batch’s conclusion: taken raw, 3.8–5.1 tDM understates a low-input community’s real pasture need by roughly 25%. The model should therefore treat 3.8–5.1 tDM as a floor, not a planning figure, and carry the grossed-up band explicitly.
What it does NOT settle. The gross-up needs a pasture-growth figure (t DM/ha/yr) to convert feed demand into a land area, and no NZ regional pasture-growth dataset is yet in corpus — raised as a research target below and cross-referenced from URL_032. Nor does the chapter supply any liveweight/breed cross-check of its own vintage; that comes from OT_172 (2023-24 herd-test liveweights Jersey 414 / HF-J 492 / HF 537 kg), which places the real NZ Jersey between this table’s 400 and 425 kg rows and not at the 375 kg row the upstream report used. No engine cell is auto-changed by this ingest.
Notes
- Authoritative NZ industry reference, downloaded — no retrieval-provenance block required (not AI-prepared).
data_quality: highrather thanverified: the figures are DairyNZ’s own modelled requirement table, industry-standard but not independently corroborated in corpus. - Pairs with, and must not be mixed across, editions. This is the December 2021 edition. OT_172 is 2023-24. Liveweight/production rows should be read from OT_172 and looked up in this table, not averaged.
- Both corrections point the same way (upward). That matters for how the caveat is carried: this is not a two-sided uncertainty band, it is a systematic understatement of a community’s pasture requirement.
- Vintage: December 2021.
Research targets
Documents to retrieve
- RT_386 — DairyNZ Facts & Figures chapter 3, the sibling chapter to this one. Only chapter 4 (cow feed requirements, this source) was retrieved; the companion chapter is named as a hard blocker in the approved batch decisions and would complete the F&F picture around the feed-demand table ingested here.
Research gaps
- Pasture growth (t DM/ha/yr) by NZ region — the missing conversion term. OT_171 gives feed demand per cow; converting it to hectares needs a regional pasture-growth figure the corpus does not hold. Raised at URL_032 as RT_389 (not duplicated here). RESOLVED 2026-07-24 → RD_033 (DairyNZ Facts & Figures ch.3 — 49-site NZ regional pasture-growth dataset, 7.6–21.7 t DM/ha/yr; low-input planning band ~8-12 t DM/ha/yr).
- Not raised as RTs (recorded here instead, per the batch’s minimise-new-RTs decision): the exact ME content of a low-input / unfertilised NZ community pasture (needed to size the +5%-per-MJ adjustment); and a measured utilisation fraction for a hand-managed community grazing system (the 80% in the source is a commercial-system worked example). Both are modelling-judgment parameters rather than retrievable documents, and both are already carried as explicit warnings above.
Connections
Links to
Referenced by