Making More from Sheep Australian Wool Innovation Limited Meat & Livestock Australia
MODULE 8: Turn Pasture into Product
Procedure 8.2
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Background
information

Now that pasture growth and variability are known (procedure 8.1), you need to estimate your annual animal demand for the enterprises in your business.

Flexibility with stock numbers during the year and between years is a key element of matching animal demand to pasture supply and managing risk. How flexible you can be with stock numbers will depend on your enterprise structure and goals, value of stock, disease risks if agisting or trading stock, and your willingness to conserve or purchase fodder and concentrates.

At a Glance
pt Define the feed requirements for your classes of sheep

pt Set condition score or liveweight targets for different stages of the year

pt Identify opportunities to modify the annual animal demand curve and enterprise mix to suit your pasture supply curve

pt More variable rainfall and pasture production between years requires more flexibility to manipulate stock numbers during and between years

pt Set trigger points for action to cope with the yearly seasonal variation and more extreme drought conditions

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Key decisions, critical actions and benchmarks

Determine feed requirements for sheep classes

Most sheep producers run a range of sheep classes on the farm, and these classes will have different nutritional needs throughout the year. Describe your classes of sheep according to:

  • Sex
  • Liveweight and condition/fat score
  • Stage in reproductive cycle and pregnancy status (empty, single, twin)
  • Growth target: to gain or lose weight at a specified rate (kg/day).

Scanning and separating ewes based on condition score and pregnancy/ lambing status enables better allocation of paddocks/pasture to sheep. It is more efficient to run 3-5 year old ewes together and draft on ewe condition and pregnancy status than age groups. Suggested drafting for these mature ewes are;

  • Dry ewes
  • Pregnant or lactating ewes single lambs, condition score >3
  • Pregnant or lactating ewes, single lambs, condition score <3
  • Pregnant or lactating ewes, twin lambs, condition score >3
  • Pregnant or lactating ewes, twin lambs, condition score <3

Information in Table 8.1 or the Grazfeed program can then be used to match pasture resources to feed requirements.

Weaners and lactating ewes rearing twin lambs should get the best pastures, followed by single lambing ewes, pregnant ewes, hoggets, and then wethers and dry ewes.

Estimate feed quality

Digestibility is a useful measure of pasture quality. Digestibility is:

  • Directly related to the energy content-Metabolizable Energy (ME) of the pasture. Energy is needed by animals for body functions. Tool 7.6 in Grow More Pasture shows the relationship between the digestibility of temperate pastures and their energy content as they mature.

Energy content is:

  • Positively related to protein content. When digestibility is high, protein content will also be high, although pasture species vary in their protein content, eg, clovers are generally higher in protein than grasses.
  • Directly related to the rate of feed moving through an animal. Pastures with higher levels of digestibility move more rapidly through the digestive system, allowing for greater intake and so greater animal production.

Table 8.1 describes the pasture quality (digestibility) and quantity benchmarks required to meet production targets of various classes of livestock. Use the benchmarks in table 8.1 as “trigger points” to better match feed supply with animal demand and so improve the likelihood of meeting your production targets.

Table 8.1 Minimum pasture supply benchmarks to maintain satisfactory production levels in sheep using herbage mass. For Feed on Offer, add 300kg DM/ha to the pasture targets.   (Source: PROGRAZE® manual).

Sheep Class Pasture targets** (kg green DM/ha) to meet animal demand at three levels of pasture digestibility (%)
75% Digestible
(mainly sown species, actively
growing, 30% legume <10%
dead)
68% Digestible
(volunteer or native species, 15%
legume, 20% dead)
60% Digestible
(dried off pasture in early summer
or mature volunteer/native
species)
Dry Sheep  
400
600
1200
Pregnant ewes Mid pregnancy
500
700
1700

Last Month
700
1200
Not suitable
Lactating ewes Single Lambs
1000
1700
Not suitable

Twin Lambs
1500
Not suitable
Not suitable
Growing weaned lambs(% of potential growth) 30% (75g/day) *
400
700
1700

50% (125g/day) *
600
1000
Not suitable

70% (175g/day) *
800
1700
Not suitable

90% (225g/day) *
1600
Not suitable
Not suitable
* Predicted growth rates in brackets are based on a weaned 4-month old crossbred lamb of approximately 32kg from a ewe with a standard reference weight of 55kg.
** Add 300kg DM/ha to convert herbage mass pasture targets to Feed on Offer pasture targets.
 

If the pasture targets in table 8.1 are not met, then animal production targets will not be met. A decision will be needed to accept a lower production level, change paddock, reduce stock numbers, or supplement to meet the energy and protein requirements of the stock.

Tool 11.1 in Healthy and Contented Sheep lists the energy and protein requirements of a range of sheep classes. Tool 11.4 in Healthy and Contented Sheep can help you calculate the cost of energy and protein supplements to meet animal demand where pasture supply does not meet the benchmarks in table 8.1.

Estimate pasture mass

At priority stages of the year (eg, joining, two months before lambing, lambing and managing weaners), use table 8.1 to set pasture targets for different classes of stock.

Monitor pastures regularly to ensure you meet your production targets

Set targets for dead pasture at the end of the growing season. Using every kilogram of dry matter produced is not only unrealistic, it will quickly undermine the sustainability of your enterprise. Some pasture will always be trampled and fouled. A significant amount of pasture must remain uneaten to provide carry-over feed for stock, and maintain groundcover. Carry-over feed and groundcover are usually most critical over late summer/autumn, at the break of the season in southern regions and over summer in the north (see procedure 6.2 and tool 6.2 in Healthy Soils).

Monitoring pasture mass every 1-2 weeks lets you identify and fill any impending feed gaps, or feed excesses that can be used. Tool 7.6 in Grow More Pasture and the MLA Pasture Ruler (tool 8.6) contain information to help you assess pastures.

Set annual targets for livestock classes and pasture

Plan how you want the pastures and stock to look throughout the year. An example is shown in figure 8.5 for a winter rainfall area but the principle is the same for all environments.

Managing the risk of increasing pasture utilisation is all about planning ahead

Figure 8.5 Managing the risk of increasing pasture utilisation is all about planning ahead. Set targets, monitor and have trigger points for action when things deviate from your plan. Example for northern Victoria.

Managing higher pasture utilisation is all about planning ahead (see figure 8.5.) Set targets, monitor, and have trigger points for action when things deviate from your plan.

Setting targets for pasture supply and animal demand through the year gives you the decision framework for taking action if stock condition or pasture mass deviate significantly from the plan.

Assess stock condition

Set condition score targets for mature stock and growth rate targets for lambs and weaners. Monitor stock at critical times during the year (eg, ewes at the end of spring, pre-joining and pre-lambing; rams pre-joining) to ensure you will meet your targets or can take appropriate action well before stock drop below their target score.

Condition scoring is described in tool 10.1 in Wean More Lambs. Target condition scores for different classes of sheep are shown in tool 11.2 in Healthy and Contented Sheep.

Set trigger points and plan to meet your targets

Trigger points spark action well before critical feed shortages. For example, if it hasn’t rained by a certain date, or pasture availability drops below your targets, you might change your weaning time, sell stock, purchase grain for ewes and weaners, or plan to use nitrogen and rotational grazing in order to boost pasture availability leading up to lambing.

Setting targets is one thing. Putting a plan in place to meet those targets for animals and pasture is another, but it is achievable. This planning requires:

  • Identification of a pasture quality and quantity target on a particular date (a trigger point), eg, 1,500kg green DM/ha at 70% digestibility on 5 November (weaning)
  • A grazing plan to build feed reserves in the identified paddock, and ensure the required pasture will be available when needed. For example:
    • Identify the November weaning paddocks at joining
    • The grazing plan will allow autumn grazing of the weaning paddocks to manage weeds and encourage clover growth; a light grazing over winter, perhaps by cattle or wethers to reduce worm larvae; then a rest from mid spring to allow pasture to accumulate
    • Given the pasture mass at the end of winter, you can calculate how much pasture will accumulate each month towards the target of 1,500kg green DM/ha by 5 November
    • 400kg DM/ha at the end of winter + 30 days in September at 30kg DM/ha/day + 31 days in October at 45 kg DM/ha/day = 2,695kg DM/ha by the end of October
    • 2,695kg DM/ha is well above the November 5 target for the weaning paddocks. You may not need to lock up the paddock until the start of October (500kg DM/ha at the end of winter + 31 days at 45 kg DM/ha/day = 1,895kg DM/ha by 5 November).
  • Plan paddock allocations using the benchmarks in table 8.1 to check that animal demand can be met by pasture supply
  • Use feed budgeting (see procedure 8.3 then tool 8.4 ) for short and long term planning
  • Take appropriate action once you have reviewed the situation at your trigger point. For example:
    • If stock meet your condition/fat score targets and the feed budget predicts you will have enough feed do nothing, but continue to monitor pasture supply
  • If stock meet your condition score targets, but the feed budget predicts that pasture supply will not meet their nutritional demands in three months’ time, your options include:
    1. Grow more pasture: put on nitrogen to boost pasture supply; assess availability of other paddocks for grazing
    2. Consider the option of grazing crops
    3. Reduce stocking rate: re-allocate stock to another paddock, draft off dry ewes, seek agistment for your sheep elsewhere, or sell some stock
  • If stock are below your condition score targets and you will have less than your target feed in three months’ time, your options include:
    1. Feed supplements now (see procedure 11.1 in Healthy and Contented Sheep) and grow more pasture (see procedure 7.1  in Grow More Pasture).
    2. Reduce stocking rates
    3. Accept a lower production level and potential damage to the pasture or soil base.
  • If stock meet target condition score and the feed budget predicts you will have a feed surplus in 3 months time:
    • Can you agist or trade extra stock now, or conserve fodder later?

Monitor your plan

Revisit your targets for pasture quality and quantity and livestock condition/ growth to ensure you make your decisions:

  • Before feed runs out
  • Before paddocks become bare and
  • To meet all animal wellbeing requirements (see procedure 11.5 in Healthy and Contented Sheep).

De-stock paddocks before groundcover falls to levels that expose paddocks to erosion (see procedure 6.2 in Healthy Soils). Put stock into another paddock where there is still adequate cover or, if this is not an option, put them into a containment area for feeding (drought lot). De-stocking will also prevent overgrazing and death of perennial grasses and so minimise the need for resowing.

GrazFeed® can help you decide if the pasture in front of stock will meet their nutritional requirements. Being able to assess pasture objectively, in terms of quantity and quality is critical to making management decisions using GrazFeed®. PROGRAZE® can help you develop objective pasture assessment skills (see signposts).

Modify the annual animal demand curve

The primary objective is to fit the pasture supply curve to the animal demand curve. Five options are available:

  1. Improving the proportion of pasture grown that is utilised for animal production (pasture utilisation). Higher pasture utilisation means having more stock on when surplus pasture is available, but not when supply is low. Increasing pasture utilisation does not have to mean increasing stocking rate all year round. As well, utilisation can be increased by pasture conservation for example, making silage to feed back to stock at a time when green pasture is limiting
  2. Change your enterprise mix to better meet feed supply. A higher proportion of trading stock may present more options when feed becomes limiting. Use tool 8.3 to test ‘what if ’ scenarios with varying proportions of ewes and wethers
  3. Modify animal demand by changing the management calendar
  4. Change pasture supply by using different pasture species, eg, summer active as well as winter active species. Tool 8.3 can be used to assess the change in feed supply and to explore livestock options required to capture the feed grown into product
  5. Do all of the above.
Plan for your Merino flock

Sowing pastures species (option 4) is generally a costly option, but can be very beneficial to address natural resource issues (eg, to increase groundcover, reduce salinity), production outcomes (eg, growing weaners) or when targeting new markets (eg, heavy weight lambs). The primary focus is to make better use of what is currently growing.

Modifying animal demand by changing the annual livestock management calendar will help match existing animal demand to pasture supply. It may also highlight opportunities for increasing stocking rate, or a need to reduce stock numbers during periods of the year.

It is more important to match supply and demand within seasons than for the entire year. This ensures animal demand is met and pasture resources are not degraded by over or under utilisation.

Time of lambing

This is the most important decision in the management calendar. Lambs provide a major boost to animal demand that can be aligned to peak pasture supply to increase total production and reduce risk and costs.

Guidelines for the optimum time of lambing have been developed (see procedure 10.1 in Wean More Lambs) and can be related to the length of the growing season:

  • Self-replacing Merino flocks: lambing 3–4 months before the end of the reliable growing season is about the optimum. Lambing later allows more ewes to be run, but weaner management has to be excellent as they will be lighter when the feed quality falls. If the decision to lamb later is made, feeding supplements to weaners is more cost effective than feeding pregnant or lactating ewes during the low pasture growth periods
  • Prime lamb flocks: lambing 4–5 months before the end of the reliable growing season gives a better result because it maximises the chance of finishing the lambs on pasture which is often the cheapest source of energy and protein.

The AWI Lifetime Wool project has ewe management guidelines, tools and tips and background research results with economic analyses for sheep producers across southern Australia (see signposts).

Many farms run sheep and cattle as well as a cropping enterprise. In such cases, the feed demands of the beef enterprise and the labour demands of the cropping program need to be factored in, which may alter the optimal time of lambing.

Stock sales and purchases

Aim to sell surplus stock (culls, cast for age) when the stock are still in good condition. Typically this will be late spring–early summer in the south and later in the north.

In a good year, delay stock sales to improve pasture utilisation and animal liveweight at sale. In a bad year, bring stock sales forward to reduce stocking rate and conserve feed for other stock. Similar flexibility can be applied to the timing of lamb sales and the target market, eg, feeder, finished or yearlings (see procedure 3.1 in Market Focused Lamb and Sheepmeat Production). Timing stock sales and purchases is a constant trade-off between current and expected future prices, and current and expected future feed supply.

Time of shearing

Decisions about timing of lambing and stock sales have an impact on shearing time. Timing of shearing can have important consequences for wool quality (see procedure 2.2 in Market Focused Wool Production), but it should be a secondary decision to time of lambing.

Signposts Signposts

Read

MLA Tips & Tools: 

Improving pasture use with the MLA Pasture Ruler: explains how to use the MLA pasture ruler ( tool 8.6 ) to estimate pasture mass (quantity) and quality and the performance you can expect from your grazing animals.

Get your free copies of these MLA Tips & Tools by:

Managing sheep in droughtlots, a best practice guide.

Managing fodder prices for drought, a guide to help sheep producers.

Which sheep do I keep? A guide to assist producers in droughts.

Order your free copies of these three publications from AWI by:

Drought feeding and management of sheep (2015): a practical guide on sheep feeding and management during a drought from Vic DPI. Download at: http://agriculture.vic.gov.au/agriculture/farm-management/drought-preparedness/managing-resources-in-drought 

MLA’s More Beef from Pastures – the producer’s manual: eight modules and practical tools to build a more profitable beef business. The principles presented relate to using animals to convert pasture to liveweight be they sheep, cattle of goats. Purchase a hard copy or CD version of the manual by:

View

Lifetime Wool Regional Guidelines: a series of guidelines and recommendations for managing ewe flocks throughout the year. Visit the Lifetime Wool website: www.lifetimewool.com.au/guidelines.aspx

Lifetime Wool – Tools for Management: view feed budget tables based on Feed on Offer (FOO) for annual clover based pastures and mixed perennial and annual pastures. Visit the Lifetime Wool website at: www.lifetimewool.com.au/toolsmgt.aspx

GrazFeed®: a decision support software tool to help graziers improve the profitability of livestock production, through more efficient use of pastures and supplementary feeds. GrazFeed® can be purchased by contacting Horizon Agriculture on www.hzn.com.au/grazfeed.php

GrassGro®: a decision support software tool used to examine variability in pasture and animal production for sheep and beef enterprises. GrassGro® can be purchased by contacting Horizon Agriculture on www.hzn.com.au/grassgro.php

Attend

The MLA EDGEnetwork® program is coordinated nationally and has a range of workshops to assist sheep producers.
Contact can be made via:

Apps

Drought Feeding Calculator: available for ios and Android. Develops a drought feeding strategy for sheep (and cattle) by determining feed requirements for different sheep age groups and pregnancy/lactation status.

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