Matching stocking rate to carrying capacity

Optimising your stocking rate is closely linked to profitability because it helps to utilise feed on offer without exceeding the land’s carrying capacity or relying too heavily on imported feed.

Stocking rate is a key indicator promoted by the Grazing Matcher Program, which currently supports 32 livestock enterprises in the South West and on the South Coast.

Calculating stocking rate doesn’t sound too complicated until you realise that energy requirements, and therefore feed demand, varies throughout the year depending on the animal class and stage of reproduction. To help standardise “stocking rate”, numbers are converted to a dry sheep equivalent (DSE), the maintenance energy requirements for a dry 50-kilogram merino wether (or 45 kg wether in some low rainfall publications).  For example, 50 kg ewes in late pregnancy (single bearing) need more energy than a dry wether and have a feed demand equivalent to 1.3 dry sheep. Alternatively, a cow with a body weight of 500 kg and also in late lactation is equivalent to 21.5 DSE.

These conversions can be easily done with a stocking rate calculator that converts different animals into an annual and monthly DSE figure per hectare.

Grazing matcher co-facilitator Dan Parnell says measuring DSE gives producers an idea of their productivity and the energy they’re harvesting from their farm.

“DSE is really a measurement of energy. One DSE will need about 8.1-8.7 MJ of energy per day,” Dan said. “That is how much energy producers need to provide. So, if we estimate the average energy of a pasture, we can see how much pasture is being utilised per hectare, or how much needs to be made available.

“I like to do these calculations because it helps me understand where a business is at. So, if they want to make some changes to either grow more pasture or run more stock, you can see how that might play out.

“A business with a relatively low DSE with surplus feed and surplus forage in most years should be able to support a higher stocking rate in most years. However, if they don’t have a lot of surplus forage with their current stocking rate but want to lift numbers, they need to figure out how they will achieve that.

“Once you understand your numbers you have a baseline to work from. So, if you want to run more numbers, how much extra pasture do you need to grow and utilise. That guides management. If it doesn’t mean providing much more feed then it’s not too hard, whereas if it’s a big change you might be more wary. Maybe you can grow more by getting a good rotational grazing system in place, control weeds better or sow new varieties or species.  So, it gives that context and confidence.”

Another benefit is to compare your DSE with costs.

“When managers invest to improve a pasture composition  they also tend to spend money on other things like weed control, lime and more fertiliser, which can increase pasture yield and quality but also adds to costs, so they need a relatively higher stocking rate to make a profit from this investment.

“Optimising DSE is a big profit driver for most farms. The tipping point is where you have such high stocking rates that you’re having to utilise more imported feed, which is more expensive compared to home-grown pasture. It’s generally the businesses with a higher stocking rate, but where energy demands are met by home-grown pasture, that are most profitable.”

One manager involved in this year’s Grazing Matcher program is Brendon Giudici who farms east of Donnybrook. He has found value in calculating his stocking rate since being introduced to the tool in April this year.

“Before I started using the DSE calculator I knew how many sheep I ran per hectare, but not the nutritional demand, which is where DSE comes into it,” Brendon said. “The big thing is working backwards to work out what pasture you need to provide to carry what you’re trying to run.

“I found it good to quantify your total operation and analyse what different lease blocks provide. Some blocks might have lower DSE but also lower cost. It’s good to be able to measure that and consider your management options such as time of lambing and pellet or lupin inputs.

“I used it to run scenarios such as adding extra weaners to see how it changed DSE – will we have enough energy, or do we need to drop a few animals on a hard year, how much does it actually change things.  I might look at doing DSE graze days on certain paddocks, then break down what certain pasture species are doing.”

Stocking rate calculators are available online, including here. For more information, contact South West Catchments Council’s Peter Clifton on 9724 2400.

The Grazing Matcher program is a joint initiative of the Western Beef Association and South West Catchments Council, through funding from the Australian Government’s National Landcare Program, Meat and Livestock Australia’s Profitable Grazing Systems, Revitalising Geographe Waterways, Healthy Estuaries WA and producer subscriptions.