Three Profit Equations and Three Denominators

#Two gross margins per hectare, and only one of them is real

The Land Bank's own budget book prints a Merino enterprise returning R10 843.73 per hectare (Land Bank 2023/24 v2). Put the same book's beef budget onto Highveld veld and you land near R467 per hectare — the arithmetic is worked further down this page. Twenty-three times the money, from sheep.

Put those two numbers side by side and you will make the single most expensive mistake in this module. The Merino figure is an irrigated lucerne pasture carrying 13 sheep units per hectare. It is a forage-crop enterprise that happens to have sheep standing on it. The beef figure is veld at roughly 6.8 hectares to the Large Stock Unit — near eleven hectares for a cow and her calf. They share a unit and nothing else.

Gross margin per hectare is only comparable between enterprises competing for the same hectares. That is not a footnote — it is the whole discipline this lesson exists to install, and it applies just as hard to the three denominators you will use on your own farm.

#The equations, written properly

Gross margin = gross production value, including inventory change, minus the variable costs directly attributable to that enterprise. It excludes land, loan principal, depreciation, tax and your drawings. It is a tool for comparing enterprises on the same land — beef against sheep against goats — and it is not profit. Anyone who calls a gross margin "profit" has forgotten the four biggest bills on the farm.

Net farm income = the sum of your gross margins minus the fixed and overhead costs: land or its interest, non-attributable labour, insurance, admin, licences, depreciation.

Cost of production per kilogram — per kilogram weaned, per kilogram clean wool, per litre — is the one KPI that survives price volatility, because it is the only one you can hold up against a price forecast and get a sell-or-hold answer out of.

Now the denominators, and what each one hides.

#Per animal: it rewards the wrong cow

Profit per hectare = margin per animal × animals per hectare

Read that identity slowly, because a per-cow target only ever optimises the first term. A bigger cow weans a bigger calf and earns a bigger margin per cow — and eats more, so fewer of her fit. The ARC's own conversion arithmetic makes the cost visible. Both cows below carry a calf at foot, which is the physiological stage the figures are published for: a 450 kg small-frame cow is 1.32 LSU; a 450 kg large-frame cow is 1.60 LSU, with dry matter intake of 12 against 15 kg a day at identical liveweight (Mokolobate et al. 2017). Say which stage you are converting, every time — the ARC publishes separate equations for lactating cows, heifers, weaners and bulls. Say which figure, too: that paper's narrative gives 1.60 for the large-frame cow while its own table gives 1.66 at that weight, so the penalty is a fifth or a quarter depending on which line you read. Either way, swap a Nguni herd for a Simmentaler herd at the same head count and you have raised your stocking rate by at least a fifth without buying an animal.

The market says the same thing from the other end. In the feedlot decomposition most quoted in South Africa, weaning weight carries a relative economic value of −15.3%, and the authors call it "surprising that there are still breeders that aim to wean calves that weigh 260 kg" (Scholtz & Jordaan 2025). Be careful how you use that figure: it comes from a United States study re-estimated for South African conditions after two variables were deleted, not from an SA feedlot dataset. The direction is the useful part; the number is borrowed.

A 10% fall in margin per animal against a 25% rise in animals per hectare is a 12.5% rise in profit per hectare. That trade is the entire economic case for a moderate-framed veld cow, and per-cow reporting makes it look like a loss.

#Per LSU: it cannot see your land

Margin per LSU is a genuinely useful efficiency number — it asks whether the enterprise converts forage demand into money well. But it is blind to how much forage demand your farm can actually supply. A farm can be excellent per LSU and bankrupt per hectare, because it carries too few LSU to pay for itself. The Delta Farms case below is exactly that shape.

#Per hectare: it can be faked for years

Per hectare is the honest headline for a land-based business, and it is the easiest to inflate. Overstock and it goes up immediately. It stays up for several seasons while species composition shifts, basal cover thins and the Decreasers walk out of the sward. By the time the number falls, the repair is a decade of rest you cannot afford. That is capital destruction presented as productivity.

#The three-legged scorecard

The resolution is not a better single number. It is three numbers reported together, every year, in the same units.

1. Kilograms weaned per hectare — production.
2. Cost per kilogram weaned — efficiency, and it must trend down.
3. Veld condition — species composition and basal cover — capital.

Any two of these without the third will lie to you. Kilograms per hectare and cost per kilogram, with no veld condition leg, is exactly what an overstocked farm reports in the three good years before it discovers what it has spent. Veld condition on its own is a nature reserve.

The third leg has to be measured, not eyeballed. South African practice scores species composition against a characterised benchmark using the Ecological Index Method: Decreasers count 10, Increaser I count 7, Increaser II count 4, and Increaser III and forbs count 1, expressed against a benchmark value (Vorster, AJRFS 14(3), 1997). Step-point sampling gives you composition; it does not give you basal cover, so budget a separate method for that.

Treat all three as trends, not scores — calculated the same way at the end of each production year and compared over time (Herdscape, 22 July 2026). One year's kilograms per hectare tells you about last year's rain. Five years tells you about your management.

#The Delta Farms base case, worked as an upper bound

Delta Farms is 100 hectares of Highveld grassland near Meyerton. Gauteng's published long-term grazing capacity norms run 4–20 ha/LSU with a provincial mean of 6.8 (Avenant, DALRRD), inside a Grassland biome mean of 6 ha/LSU (DALRRD 2016).

At the provincial mean:

• 100 ha ÷ 6.8 ha/LSU = 14.7 LSU
• At the Land Bank's LSU factor of 1.6 for a cow with calf, plus bulls, that is roughly 9 breeding cows
• At the Land Bank's beef gross margin of R5 186.69 per cow: about R46 700 a year
• Over 100 hectares: about R467 per hectare

Before land, interest, overheads, drawings, theft and drought.

#Why a one-legged improvement usually moves a cost

Here is the pattern to watch for. A farm reports a jump in kilograms per hectare after a management change. Cost per kilogram is not reported. Veld condition is not measured. What has almost certainly happened is that a cost has been moved, not removed — off the income statement and onto the balance sheet, where the veld is.

Two South African findings make the point from opposite directions.

A survey of 48 working SA farms found them stocked 59 ± 12% above extension-recommended rates, whether or not they rotated (Venter, Cramer & Hawkins 2019). Every one of those farms is reporting a better per-hectare number than the recommendation implies. Some are genuinely within capacity. Some are spending capital. The per-hectare figure cannot tell you which, and neither can the farmer.

And in the only whole-farm South African model of a regenerative transition located for this course, raising the stocking rate from 4.5 to 5.5 small stock units per hectare produced an expected increase of 4.17% in internal rate of return and a decrease of 1.82% in net present value (Hayward 2021). Better return on capital; worse long-run cash. That is one leg up and one leg down inside a single decision, and a farm reporting only the first leg would have called it a success.

#What to do with this before the next lesson

Write your three equations tonight, on one page, with the denominator named on each line. Then write the fourth number — the date of your last veld condition survey. If that date is blank, you do not currently have a profit figure you can trust; you have a cash-flow statement with a hole in it where the capital account should be.