Dairy Grazing Rate Calculator NZ

Grazing is charged by the head by the week, and this works out what an arrangement actually costs across the mob and the season, then converts it into two units that make it comparable: cost per kilogram of liveweight gain, and cost per kilogram of milk solids. The weekly rate on its own tells you remarkably little, because it does not say what you are getting for it. A grazier delivering 0.7 kilograms of gain a day and one delivering 0.4 at the same weekly rate are selling quite different things, and the cheaper rate is regularly the more expensive arrangement once the gain is counted. Heifers that come home light cost you again later, in a first lactation that never reaches its potential, so the cost per kilogram of gain is closer to the real price than the weekly figure ever is. The per kilogram of milk solids conversion does the other useful job, which is to put a large cost line in the same unit as the income so it can be set against the payout beside everything else. A grazing bill means little as a lump sum and a good deal more when it turns out to be over a dollar a kilogram of milk solids.

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$
$
kg
kg
kgMS
$59,580
total grazing cost
Per head$851.14
Per kg of gain$3.55
Per kgMS$0.68
Gain a day0.66 kg

Cost per kilogram of gain is the figure that compares two graziers. The weekly rate on its own does not say what you are getting for it.

How it works

The grazing bill is the head count multiplied by the weekly rate and the weeks, with cartage and animal health added on top since those are part of what the arrangement costs even though they are not part of the rate. Per head divides that across the mob. Liveweight gain is the difference between the weight going out and the weight coming home, multiplied by the head count, and the cost per kilogram of gain is the total bill divided by that. Gain a day converts the same weights into the figure a grazing contract is usually written around. The per kilogram of milk solids figure divides the whole bill by the farm production, which puts it in the same unit as the payout.

Why the weekly rate misleads

Because it is a price for time rather than a price for an outcome. Two graziers charging the same rate can return heifers thirty or forty kilograms apart, and the lighter ones carry that difference into their first lactation and often never fully recover it. Weighing at both ends is what turns a grazing arrangement from a matter of trust into a measurable one, and it is the only way the cost per kilogram of gain can be calculated at all. A contract that specifies target weights and gets weights taken on both dates is worth more than a slightly lower rate.

Worked example

Seventy heifers grazed for 52 weeks at $14.50 a head a week costs $52,780, and $6,800 of cartage and animal health takes it to $59,580, or $851.14 a head. If they leave at 180 kilograms and come home at 420, each has gained 240 kilograms, which is 16,800 kilograms across the mob and works out at $3.55 a kilogram of gain, or 0.66 kilograms a day. Against a farm producing 87,000 kilograms of milk solids the grazing is $0.68 a kilogram of milk solids. A grazier charging $13.50 a week but returning them at 390 kilograms would bill $55,940 all up and deliver 14,700 kilograms of gain, which is $3.81 a kilogram: cheaper by the week and dearer by the kilogram.

Related calculators

Data sources: no market grazing rate is supplied, because rates differ by region, season, class of stock and what the contract requires of the grazier. Every figure here is one you enter, and the weights are the ones worth insisting on in the agreement.

Frequently asked questions

How is dairy grazing charged in New Zealand?

Usually as a rate per head per week, sometimes with a target liveweight gain written into the agreement and sometimes not. Winter grazing for milking cows is often quoted the same way over a shorter block of weeks. The rate on its own is not comparable between graziers, because what it buys differs: a grazier who delivers 0.7 kilograms of gain a day is providing something quite different from one delivering 0.4 at the same weekly rate.

What does grazing cost per kilogram of liveweight gain?

Divide the total grazing cost by the total liveweight the animals actually put on. That converts a weekly rate into the unit that lets you compare one grazing arrangement with another, or with keeping the stock at home. A cheaper weekly rate that produces less gain is often the more expensive option once you look at it this way, and the difference can be substantial.

Why express grazing per kilogram of milk solids?

Because it puts the cost in the same unit as the income. Grazing is one of the larger lines in a dairy budget and expressing it per kgMS lets it be set directly against the payout, alongside every other cost expressed that way. A grazing bill of a hundred thousand dollars means little on its own and a great deal when it turns out to be over a dollar a kilogram of milk solids.