Chapter 8.3 Match animal demand to feed supply and minimise risk

The maximum number of stock that can be carried all year is usually limited by pasture availability during the period of lowest feed supply. This is generally in the autumn/winter in both summer and winter rainfall zones. It is critical to get the time of lambing right to optimise the number of ewes that can be carried through the period of lowest feed supply (see Chapter 8.2).

Matching animal demand to feed supply requires a flexible enterprise structure that allows you to respond to seasonal conditions in a way that works for you, whether that be through buying in or selling off stock, retaining an older age group of ewes or more wethers or retaining key breeding stock and supplementary feeding when necessary. This is particularly important to be able to respond and capitalise in “better years”. In this way, the annual stocking rate may not change but there will be larger seasonal differences. Focus on seasonal adjustment of stock numbers to suit the conditions.

The major risks associated with increasing stocking rate and pasture utilisation are:

• Poor persistence of desirable pasture species.
• Bare paddocks.
• Reduced stock health.
• Damage to sensitive areas such as water courses and embankments.
• More need for supplementary feeding.
• Increased impact from droughts.

All of these risks are real but they can be managed using stock assessment, grazing management, feed budgeting and working towards a more flexible enterprise structure. The above risks will be reduced significantly if stock numbers are seasonally adjusted at pre-defined trigger points (feed available, ground cover, condition score, etc.).

Review the match between your pasture supply and animal demand curves then align these curves to minimise production, financial and environmental risk. Ask yourself:

• Am I lambing when my pasture supply is most reliable?
• Can I increase stock numbers during a one-in-five or one-in-ten year early break?
• Can I easily sell or find agistment for the livestock classes I carry through the months where pasture growth is not reliable?
• In general, how closely does the feed demand of my flock match my pasture growth?
• What options do I have for increasing feed supply in the slowest growth period, e.g., supplementary feeding, deferred grazing, etc.?
• Can I do anything to lengthen the periods of good pasture growth or move them forward or back?
• Do I store enough feed to cover bad seasons?
• Can I use cash reserves to cover bad seasons?

The tools that follow will help you measure, manage and monitor any mismatch between pasture supply and animal demand and minimise exposure to changing seasonal conditions, both within a year and between years.

They can help you make both strategic (i.e., 1-5 years) and tactical (short term within the current year) decisions that relate to managing stocking rates, and answer the questions like ‘do you have enough stock? Too few or too many?’

Stocking rate is the major determinant of pasture utilisation and profitability. A conservative stocking rate may be a sound, low risk choice for a sheep enterprise in a variable climate, but it may also be less profitable. Sustainable stocking rates are achieved when animal demand is actively managed to fit pasture supply.

Plan your feed year

A feed year plan recognises the range of stock classes, pastures and forage crops across your farm and brings all the annual decisions on pasture utilisation together in one plan. Tool 8.4 provides a feed year plan template and contains an example plan for the Central West Slopes of NSW.

Develop your own plan using the template in Tool 8.4 to identify in advance when you will have high quality feed available on your farm.

Does pasture supply meet animal demand?

Use Tool 8.2 MLA feed demand calculator to assess how well current animal demand matches your average pasture curve. You can calculate the percentage of pasture being utilised and liveweight produced per hectare, then test opportunities to better align feed supply and animal demand, e.g., growing a winter active fescue, running more stock at peak pasture supply periods, changing your lambing date, etc. You can have two grazing systems with the same pasture stocking rate and utilisation but the system that better aligns feed supply with animal demand will be more productive and less risky.

What animal factors can I change?

The four main ways that you can change animal requirements and better match feed demand with feed supply are:

• Overall farm stocking rate – consider regional benchmarks for stocking rates or seek advice from local advisors on what is a realistic overall stocking rate for your farm and locality given the pasture species, soil types and soil fertility.
• Time of lambing – during pregnancy, feed requirements of ewes’ doubles. At 30 days lactation, energy requirements of ewes rearing twin lambs are over 3 times that of dry ewes. Match mid-lactation with peak pasture growth to better match feed supply and demand.
• Time of sale – when surplus stock are sold can markedly effect feed demand. For example, sale of cast for age ewes prior to summer-autumn. Lamb or wether sales can be varied depending on seasonal conditions.
• Reproductive rate – when making breeding and selection decisions to improve the reproductive performance of your flock and having a higher twinning percentage can be a way of using peaks in spring feed supply. Feed demand of ewes rearing twins is 25% higher than for those with single lambs.

Complete regular feed budgets (measure and monitor)

Use feed budgets to see if you can meet your pasture supply targets (and nutritional demands) for different classes of stock with your current or proposed stocking rate. Feed budgets also answer more tactical (short-term) questions like:

• How long will a paddock last with a certain number of sheep in it?
• How many sheep can I graze in a paddock for a certain length of time?

Short term feed budgets (daily, weekly, fortnightly) ensure production requirements can be met for a given stock class. Use the pasture benchmarks in table 8.1 (Chapter 8.2) to identify the minimum pasture supply and quality required by your sheep classes.

Calculate a feed budget three months ahead when planning your lambing or weaning paddocks, or for stock marketing (forward contracts).

Doing a feed budget for lambing lets you know if there will be 1,500 kg DM/ha available for lactating ewes, or if you should be taking further action now to meet the nutritional demands of your sheep.

Tool 8.3 sets out how to calculate three month and shorter-term feed budgets on paper. It includes examples to help guide your feed budget calculations.

Manage the grazing system to control stock intake

Stock intake and performance can be managed by grazing. Allocate a certain amount of pasture to stock, on a daily or weekly basis to:

• Ration intake: conserve feed from autumn to winter (when pasture growth rates slow down) in order, for example, to build up a feed wedge for lambing. Stock must either be above target condition when rationed (autumn) or supplementary fed to maintain condition. It may also be desirable to ration the intake of pregnant ewes if higher than condition score 3.5 to limit lambing difficulty, particularly in single bearing ewes. This is best done in mid pregnancy (following pregnancy scanning) to avoid metabolic disorders.
• Increase intake: rationing intake by some classes of stock to create an opportunity to allocate higher quantities of pasture to other classes, such as weaners or twin bearing ewes. Preferential allocation of green feed to priority stock on a regular basis also gives a better measure of pasture growth rates and feed consumption. 

It is often desirable to increase the intake of pregnant ewes or ewes rearing twin lambs. These ewes can be given preference for the highest quality pasture and in a rotational system grazed ahead of the stock with lower feed requirements, e.g., dry ewes or those with single lambs.

Add or remove paddocks from the grazing rotation to increase or decrease paddock rest periods. If pasture growth rates are fast, speed up the rotation by moving stock on quickly. Fast moves during periods of fast pasture growth give livestock access to the best feed before it goes rank or hays off. When pasture growth is slow, slow the rotation down, then reduce stock numbers or supplement stock to allow time for pastures in rested paddocks to re-grow before grazing. In a winter rainfall system, remove paddocks from the grazing sequence in spring and consider fodder conservation options. In a summer rainfall system, remove paddocks from the grazing sequence in autumn and consider fodder conservation options.

Regularly monitor pasture and animal condition. Monitoring helps you track changes in pasture quantity and quality or animal demand to ensure pasture and animal production targets are met. Tool 7.6 in MMFS Module 7 Grow More Pasture contains pasture assessment techniques. Tool 10.1 and Tool 10.4 in MMFS Module 10 Wean More Lambs contain condition scoring guidelines and targets for sheep.

Manage the grazing system to maintain optimum pasture levels

Not detecting a change in pasture quantity and quality or animal demand will increase the risk of missing pasture and animal production targets. Regular monitoring of pasture and animal condition is critical to success because:

• An increase in predicted pasture growth, leading to higher pasture mass and total pasture energy supply, may be wasted if additional pasture is not utilised.
• A decrease in predicted pasture growth, or unplanned events that decrease pasture availability, may lead to declining pasture mass, lowered intake by animals and eventually overgrazing.
• Repeated overgrazing without adequate rest can reduce ground cover, damage soil and reduce the ability of the pasture to “bounce back” with rain, rest or fertiliser.

Implement tactical grazing

Tactical grazing focuses on applying grazing techniques that best meet animal, pasture and environmental targets. Consider:

• Set stocking at a conservative stock density to maximise the intake of quality pasture by lactating ewes.
• Rotationally grazing perennial pastures to ensure persistence.
• Using high density, short duration rotations to ration intake or control weeds.

Review the grazing management guidelines in Tool 7.5 in MMFS Module 7 Grow More Pasture.

Are paddocks unevenly grazed?

If you can see obvious signs of patch grazing in paddocks (e.g., bare hilltops, sheep camps and rank grass in other parts), then utilisation can be improved. The issue of uneven grazing often has to be dealt with before stocking rate is increased. Running more stock will increase pasture utilisation, but any areas that are already overgrazed will be grazed even harder. Some short-term options include:

• Fencing paddocks to land class to reduce the variability within them. Land classes are based on soil type, slope, aspect and land use (see Tool 6.1 in MMFS Module 6 Healthy Soils)
• Reducing selective grazing by either reducing paddock size/using bigger mobs to graze the paddock in a rotation. Boxing existing mobs and using existing paddocks for rotational grazing is the cheapest way to get started on evening up utilisation within paddocks.

Uniformity of pasture utilisation is affected by:

• Paddock size: smaller paddocks are generally grazed more evenly than large paddocks, but there is no ‘rule of thumb’ for optimum paddock size as it depends on flock size, the livestock production system and other factors (such as cropping requirements).
• Paddock uniformity: flat paddocks will be grazed more evenly than hilly paddocks, north-facing slopes will be grazed harder than south-facing slopes, saline areas will be preferentially grazed, etc.
• Grazing method: using large mobs of stock for short periods in a paddock will reduce the opportunity for selective grazing by stock and result in more even utilisation but may lower performance per animal.
• Type of stock: sheep are more selective grazers than cattle and they tend to create bigger camp areas. Cattle can be used to complement sheep grazing.
• Watering points: pasture utilisation will tend to be highest close to watering points. This is especially noticeable in large paddocks with a single watering point.

Compared with set-stocking, implementing a more intensive rotational grazing system will give more precise control of stock intake and more even pasture utilisation. Tool 8.6 outlines a method for getting started with rotational grazing and is further developed in the MLA Tips & Tools “Getting started in simple time-based rotational grazing”. Intensive rotational grazing systems can help you implement a simple four paddock rotation (see signposts).

Increase pasture utilisation on part of your property

When trying to increase pasture utilisation, start off with one or two paddocks as a trial, to practise pasture and stock assessment skills and feed budgeting. It may be the better land classes or paddocks where there are obvious signs of poor utilisation (too much dead pasture, low legume content).

It is often best to make incremental lifts towards your stocking rate target which will allow you to increase confidence and build skills. For example, you might decide to increase the stocking rate in winter by 10% this year, based on analysis of the average pasture supply curve and the amount of dead pasture left in paddocks. One option could be to retain an older age group of ewes or more wethers, rather than purchasing stock if the risk of introducing disease is a concern.

Plan for drought

Determine what constitutes a drought or ‘dry year’ for you in your environment. For example, it may be a failed spring followed by a failed autumn.

Set trigger points for action, for example “If certain weather conditions occur, I will take this action by this date”. This could include selling surplus stock, conserving fodder or buying in grain, beginning supplementary feeding in containment, turning off lambs earlier, etc.

Be ready for a drought or dry year – they are inevitable. This will include keeping adequate feed reserves, having containment areas/drought lots, and a plan to determine which stock will be sold and which will be kept and fed in the drought lot. Decisions about which stock to keep or sell will depend on their value at the time, the probable cost of feeding, the value of any production that would be gained if they are kept and their future replacement value, should that be necessary. There are several publications and tools which can help you prepare such a plan (see signposts).