Why use this calculator
Overstocking is the most expensive mistake in grazing, and it is usually made slowly rather than in one decision. Ground cover falls, the perennial grasses thin out, weeds move in and it takes years of destocked rest to get back what one hard summer removed.
A stocking rate expressed in head is almost meaningless because a 700 kg lactating cow eats roughly ten times what a dry wether eats, so this tool converts everything to Dry Sheep Equivalents first. It also separates the two ideas graziers use interchangeably and should not: stocking rate is what you are running today, carrying capacity is what the country can support year after year without going backwards. Seeing both on one page makes the trading decision obvious.
How to use it
- Enter the grazeable area, which means paddock hectares less timber, rock, laneways and dam surrounds that stock cannot eat.
- Put in your growing season rainfall from your own gauge or the nearest Bureau of Meteorology station, not the annual total, because summer rain in a winter rainfall zone grows very little.
- Choose the pasture type that describes what is actually growing now rather than what was sown.
- Select the grazing system, because rest periods change how much grown feed ends up inside an animal.
- Pick the species and the class of stock, since pregnancy and lactation lift demand far more than liveweight does. Enter the average liveweight off the scales.
- Finally enter the head you are carrying today so the tool can compare real grazing pressure with capacity.
What each result means
- Safe carrying capacity
- Dry Sheep Equivalents each hectare can carry year in and year out without eating into ground cover or pasture persistence.
- Total DSE the country can carry
- The whole property budget in DSE, which is the currency you should be trading in rather than head.
- DSE per head
- How many dry sheep one of your animals is worth. Multiply it by head to convert any mob into DSE.
- Head this country can carry
- Capacity translated back into animals of the class and weight you entered, rounded down to whole head.
- Area per head
- Hectares behind every animal at capacity, which is the number most useful when you are sizing paddocks and water points.
- Current stocking rate
- What you are actually running today in DSE per hectare, which is a stocking rate rather than a carrying capacity.
- Head over or under capacity
- The trading gap. A positive number is room to buy or agist, a negative number is feed you will have to buy or sell out of.
- Head to sit at 80% of capacity
- How many head of this class you can run while leaving a fifth of the long term capacity spare, the buffer most graziers keep so a dry year does not force a sale.
- Grazing pressure against capacity
- Current stocking rate as a percentage of long term capacity. Above one hundred means you are drawing down pasture reserves.
The formula
Potential growth is estimated with the long standing southern Australian rule of thumb, Potential DSE per hectare = (growing season rainfall in mm minus 250) divided by 25
That figure is multiplied by a pasture factor (improved perennial 1.0, sown annual 0.8, native 0.5, run down 0.3) and a grazing system factor (set stocking 1.0, rotational 1.15, cell 1.25).
DSE per head = (liveweight divided by 50) raised to the power 0.75, multiplied by a species factor (cattle 1.65, sheep 1.0, goats 1.1) and a class factor (dry 1.0, growing 1.4, late pregnancy 1.35, lactating 1.9)
Head capacity = total DSE divided by DSE per head
How this number is used in practice
Most graziers who run into trouble were not reckless, they simply kept a good season's numbers into a poor one. The practical answer is to split the herd into a core and a trading tier. Set the core to the dry year row in the season table, which is the number you can carry through a bad winter without buying feed, and take the extra capacity of a good spring as trade cattle, agistment or a later turnoff weight.
That way the decision to destock happens on a spreadsheet in autumn rather than in a saleyard in November when everyone else is selling the same stock.
The gap between stocking rate and carrying capacity is where the money is. Stocking rate is a fact about today. Carrying capacity is a judgement about the long run, and it moves with fertiliser history, perennial content, soil pH and how much bare ground you are prepared to tolerate.
Lifting capacity is a genuine investment decision: the same paddock that carries 6 DSE per hectare as run down native pasture can carry 12 to 15 after lime, phosphorus and a perennial resow, and the calculator will show you the head that extra capacity is worth before you commit to the input bill.
Rotational grazing is worth a real but modest uplift in this model, not the doubling that some sales pitches claim. Resting a paddock lets perennials rebuild root reserves and raises the share of grown feed that is eaten instead of trampled or shaded out. What it cannot do is make more rain fall.
Treat the uplift as something you earn through actual paddock moves and measured rest periods, and check it by measuring pasture rather than by trusting the multiplier.
Worked examples
240 ha of sown pasture, 500 mm growing season rain, 450 kg dry cows, 150 head on hand
About 8.0 DSE per hectare and roughly 1,920 DSE in total.
Same country improved to perennial pasture and moved to rotational grazing
Capacity lifts to about 11.5 DSE per hectare.
800 ha of native pasture on 350 mm running 50 kg dry wethers
About 2.0 DSE per hectare, carrying roughly 1,600 wethers.
When people use it
- Setting a core herd size that can be carried through a dry year without buying feed
- Deciding how many trade cattle or lambs a good spring can safely absorb
- Putting a head number on the return from lime, phosphorus and a perennial resow
- Comparing paddocks or blocks on capacity rather than on bare hectares
- Sanity checking the carrying capacity claimed in a property listing before an inspection
- Converting a mixed sheep and cattle enterprise into one comparable DSE budget
Tips
- Run the numbers in DSE, not head. A cow with a calf at foot is roughly fifteen times a dry wether and the difference decides whether feed runs out.
- Use growing season rainfall, not annual rainfall. Rain that falls outside the growing season mostly evaporates or runs off before it grows feed.
- Stock the core herd to a poor year and trade the surplus capacity, so destocking is a plan rather than an emergency.
- Measure ground cover, not just pasture height. Dropping below about 70 per cent cover on sloping country is where erosion starts.
- Check the answer against a local benchmark from your state department or a producer group before buying stock on it.
- Recalculate whenever the class of stock changes. Joining or calving shifts the whole feed budget without a single extra head arriving.
- Keep a feed budget for the late autumn gap. That is the period that decides the year in most southern Australian grazing systems.
What it assumes, and where it stops being accurate
- The rainfall rule of thumb is calibrated for temperate southern Australian pasture and will overstate capacity in the tropics and understate it on irrigated or highly fertilised country.
- Soil type, fertility, slope, aspect and paddock history are not modelled. Two neighbours on identical rainfall can differ by a third.
- Capacity assumes adequate water points and reasonable paddock layout. Long walks to water cut effective capacity well before feed runs out.
- DSE ratings are derived from metabolic liveweight and standard class factors, so they are indicative rather than a substitute for a ration calculated on actual energy requirements.
- The rotational and cell grazing uplifts assume the rest periods are actually delivered. Poorly executed rotations perform no better than set stocking.
- Supplementary feeding, fodder crops and standing hay are not counted. They add to capacity but also to cost and to risk.
Terms used on this page
- DSE
- Dry Sheep Equivalent, the feed energy to maintain a 50 kg wether at constant weight.
- Carrying capacity
- The stocking rate country can sustain long term without losing ground cover or pasture persistence.
- Set stocking
- Leaving a mob in one paddock for a long period with no planned rest.
- Utilisation
- The share of pasture grown that is actually eaten rather than trampled, fouled or senesced.
- Ground cover
- The percentage of soil surface covered by living or dead plant material, the main defence against erosion.
Questions people ask
- What exactly is a Dry Sheep Equivalent?
- A DSE is the feed energy needed to hold a 50 kilogram wether at constant weight, commonly quoted as about 7.6 megajoules of metabolisable energy per day. Every other class of stock is expressed as a multiple of that, so a mixed sheep and cattle property can be budgeted in a single unit rather than in two sets of head counts.
- What is the difference between stocking rate and carrying capacity?
- Stocking rate is what you are running right now, measured in DSE per hectare. Carrying capacity is the rate the country can sustain over the long run without losing ground cover, perennial species or soil. You can exceed carrying capacity for a season by drawing down pasture reserves, which is exactly how overgrazing happens quietly.
- Why does a stocking rate need a district context?
- Because rainfall, its reliability, soil depth, fertility and pasture species vary enormously over short distances. Eight DSE per hectare is a comfortable rate in a 600 millimetre zone on improved pasture and completely unattainable on shallow soils in a 300 millimetre zone. Always check the answer against a local benchmark from a state department or producer group.
- Does rotational grazing really increase carrying capacity?
- It can, mainly by raising utilisation and by letting perennials rebuild root reserves during rest. Published gains are usually in the range of ten to twenty five per cent where the rotation is genuinely managed. It cannot create rainfall, and a rotation that is not actually executed performs no better than set stocking.
- How does a livestock unit differ from a DSE?
- A livestock unit is the same idea with a different reference animal. European and New Zealand systems often use a stock unit based on a 55 kilogram ewe rearing a single lamb, and North American systems use an animal unit based on a 454 kilogram cow with calf. Convert carefully before comparing figures across countries.
- Should I stock right up to the calculated capacity?
- Rarely. Most graziers set the core herd near eighty per cent of long term capacity and use the remainder as a buffer for a dry finish or as trading opportunity in a good spring. That buffer is what stops a seasonal downturn turning into forced selling into a falling market.
Use this with
Stocking Rate Calculator answers one part of the question. These pick up where it stops: Livestock Feed Calculator, Livestock Weight Gain Calculator, Hay & Silage Feed Calculator, Fencing Materials Calculator and Rainfall & Soil Moisture Calculator.
Where these figures come from
Figures and rules on this page follow Australian law and ATO guidance.
- Meat & Livestock Australia. Producer research on grazing management, DSE benchmarks and growth paths
- NSW Department of Primary Industries. Primefacts on stocking rates, soil acidity, livestock nutrition and breeding
- Australian Wool Innovation. Sheep grazing management, condition scoring and feed budgeting resources
- CSIRO. Australian soil, pasture and animal science research
Stocking Rate Calculator produces an estimate for general information. It is not financial, tax, medical, legal or engineering advice. read the full disclaimer. Spotted a wrong number? Report it and it gets fixed. The form picks up this calculator and the inputs you used.