Sheep management – Making good decisions in Summer and Autumn in Western Australia

Page last updated: Thursday, 6 June 2024 - 10:19am

Please note: This content may be out of date and is currently under review.

To avoid problems and take advantage of opportunities, managers need to be well informed, make good decisions and take timely action. This article is for South West Western Australia, over summer and autumn – a period of hot dry conditions, decreasing paddock feed, and decreasing water reserves.

The Department of Primary Industries and Regional Development provides the information here to help graziers focus on the important decision points for summer and autumn in South West Western Australia.

The essential steps in making good sheep management decisions

Know your constraints – feed and water reserves, livestock needs, finances, labour, personal pressures.
Have a plan and use it.
Assess your management options using real numbers.
Monitor sheep, land, water, people, supplement and budget.
Take action before problems develop.
Make use of professional advice. Seek information earlier than later.
Look after yourself and family.

Seasonal outlook

The immediate past and forecast weather will determine many of your management decisions.

Information on weather and other resources is available on the Season 2021 web page.

More information about feed and water quality and livestock requirements, nutrition management and other dry season advice is available from Department of Primary Industries and Regional Development (DPIRD) Season 2021 webpage.

Objectives for summer and autumn

Feed to achieve targets

Table 1 Feed sheep to achieve target condition and weight
Background	Ewes are the power house of the flock
Targets for pregnant ewes	Maintain ewe condition during pregnancy. Aim for high ewe and lamb survival rates. Minimise deaths from metabolic disturbances in the last 50 days of pregnancy. Minimise undernutrition and other animal welfare concerns.
Good outcomes for pregnant ewes	Profitable to provide feed to maintain condition during pregnancy Target condition score for a twin bearing ewe is 3 or more, and a single bearing ewe is 2.5 or more at the start of lambing Optimises ewe and lamb survival in environments susceptible to poor lambing conditions Ewe management targets are based on Lifetime Ewe Management (LTEM)
Feed pregnant ewes with confidence that it still pays	Example of the cost of mismanaging ewe nutrition based on 2019 prices Loss of Merino-Merino ewe: Non-scanned ewe is worth $236 Single bearing ewe is worth $214 Twin bearing ewe is worth $280 Higher value for merino-terminal sire ewe e.g. non-scanned ewe is worth $298 Sensitivity analysis indicates the cost of a dead ewe remains similar at current prices for wool and meat.
Rules of thumb	Takes less grain (3kg) to prevent one kg of loss in liveweight Takes more grain (9kg) to regain the loss of one kg of liveweight Extra wool pays for 20% to 30% of your supplement costs Estimated value of extra merino lamb alive at weaning is $55 in 2020
Confinement feeding	Class of sheep you should feed: Feed sale sheep in a feed lot - male weaned lambs (high growth rates) or male hoggets (slower growth rates) Feed merino weaned ewe lambs (gain 1.5 kg per month) Feed mated adult and hogget ewes (maintain condition with increasing days of pregnancy) See below for more details on requirements for feeding sheep in a confined paddock/pen
High (95%) survival rates in last year lambs	Weaners need to grow 1.5kg per month 25 kg merino weaner requires 7MJ of energy per day and their diet contains 12% crude protein (e.g. 520 grams/head/day of barley in confinement) Prevent and repair muscle damage in the weaner’s body by giving a vitamin E drench A preventative dose is 2000mg per head of water miscible vitamin E every 56 days until green feed is available
Metabolic disturbance in late pregnant ewes from insufficient intake of energy or sudden cessation of eating or inadequate calcium in their diet (Pregnancy toxaemia and/or Hypocalcaemia)	Need to progressively increase intake of energy with days of pregnancy Avoid over-estimating the intake of energy by ewes grazing dry paddock roughage or when fed hay Four-year-old ewes and older are more at risk from metabolic disturbances The best protective measure is to ensure pregnant twin bearing ewes are condition score (CS) 3 and single rearing ewes CS 2.5 at the start of lambing

Reduce feed demand

Table 2 Reduce feed demand in a dry season
Background	Ewes are more profitable than wethers
Reducing number of sheep on property if sheep have a strong position in the farm business	Pregnancy scan all ewes and separate into groups of twin, single bearing and non-pregnant animals Sheep to retain, with highest priority first: adult pregnant ewes (3 and 4 years old) mated hogget ewes (2 years old) adult pregnant ewes (more than 4 years old) non-pregnant ewes 2, 3 and 4 years old) weaned ewe lambs non-pregnant ewes (greater than 4 years old) weaned wether lambs wethers (2 years or older)
Ensure early sales of surplus or low priority sheep	Animals in good condition get a higher sale value. Save feed for high priority sheep. Sell lower-priority sheep if cash flow is restricted. The greater the cash flow restriction, the earlier and higher the number of sheep that should be sold.
Agistment off-farm	Reduce the number of sheep on the home property, but maintain flock size for when the season breaks. Maintain good on-farm biosecurity practices for all sheep coming back onto the property.

Medium term strategies for sheep

Table 3 Medium term strategies
Background	Keep the right flock structure to allow rebuilding of the flock when conditions improve
Rebuilding margin	The rebuilding margin for each business is different depending on the role of sheep in the business Use DPIRD online flock composition calculator to determine the impact on flock structure over six years when retaining or selling different classes of sheep
Alternatives are:	Sell surplus and low priority sheep now and buy in ewes later in the year Sell surplus and low priority sheep now but increase flock ewe numbers over the next few years Sell surplus sheep and retain all mated sheep and ewe lambs Sell all sheep and go cropping Producers that maintain their sheep will need to ensure they are still valuable and can be sold later if required
What to pay for ewes if intending to rebuild flock	The breakeven purchase price for ewes is dependent on: the difference between the sale and potential purchase price the alternative or opportunity cost of the area now grazed by sheep.

Water demand for summer and autumn

Table 4 Water demand in summer and autumn
Background	Adequate good quality water is needed for maintenance and growth
Need to provide adequate good quality water with safe access by livestock	Good quality livestock water has: Salinity within the acceptable range (EC of less than 700 mS/m or total dissolved solids (TDS) less than 4000 mg/L) Water pH between about 6.5 (acid) and 8.5 (alkaline) Freedom from toxic elements and chemicals No contamination with toxic algae or putrid materials
Cost of providing water in summer and autumn Cost of providing water has not been included in the return on investment calculations, information for the next three months listed above, or the rebuilding margin.	infrastructure and cost needed to cart water to property labour (time) to collect and distribute water on-farm additional on-farm infrastructure to provide safe access to water for all sheep restriction on paddocks available for grazing by sheep during summer and autumn length of time water carting is anticipated to continue
Reduce water demand Sell the lowest priority sheep – reduce water demand based on maximum intake of water per day	Wether hoggets or older (10 litres per day) Non-pregnant ewes (10 litres per day) Weaned wether lambs (5 litres per day) Weaned ewe lambs (5 litres per day)
Sell pregnant ewes older than 4 years old	Sale needs to occur 4 weeks before the start of lambing (10 litres per day)
Rules of thumb	Need safe access to a constant supply of good quality water so the group as a whole can drink a maximum of: Adult pregnant ewes require 10 litres per day Young sheep require 5 litres per day Lactating ewes require 14 litres per day Sheep will require 3–5 litres per day when grazing stubbles, depending on their size and ambient temperature Sheep can consume 10–15 litres of fresh water per day when grazing on a diet with a high salt content

Management of sheep in dry seasons

Information in this document is adapted from presentations by Ashley Herbert, Agrarian Management (2017) and John Young, Farming Systems Analysis Service (2017 and 2019).

Confined paddock feeding of sheep

Confinement areas may be pens or small selected paddocks. Different classes of sheep will require different designs and different rations.

Permanent confinement feeding facilities allow the removal of sheep from paddocks with low levels of feed on offer:

wind and water erosion risks are reduced
supplementary feed is used more efficiently
monitoring livestock condition is simplified
the use of equipment and labour is more efficient

There are tools available to help plan feed and water budgets before commencing confinement feeding. Analysis of feed ensures the correct rate of supplementation for each class of sheep and provides some scope for least cost diets.

Recommendations for confinement feeding:

Provide 100% of the animals’ specified restricted diet including energy, protein, minerals and roughage.
Maximum mob size per pen for adult ewes is 500 and young sheep is 200.
For 500 pregnant ewes – a confinement feeding pen needs to be a minimum of 2500 m2 (50 m x 50 m or 25 m x 100 m).
The confinement feeding area should be convenient to yards, silos, a water source and have well-drained soils.
Provide sufficient trough space to allow daily intake of feed and water.
Use the MLA checklist when selecting a site for confinement pens.
If using lick feeders, maximum mob size is 200 sheep per lick feeder.
Formulate diets to avoid acidosis. Wheat, barley, triticale, peas and faba beans have high starch content and are more likely to cause grain acidosis.
Introduce new rations gradually to the sheep, particularly grains with high starch content e.g. three-week introduction required for barley when final feeding rate is greater than 400 g/h/d.
It takes six weeks for the microbial population in the rumen in sheep to fully adapt to the high starch content of a barley or wheat diet so the feed-to-energy conversion from barley is initially less during this period, compared with lupins or oats
Conduct a worm egg count (WEC) on faecal samples taken from 10 sheep per confined pen or paddock.
If the WEC is greater than 100 eggs per gram then treat the sheep with an effective combination drench.
This drench during confinement will then act as the recommended autumn drench normally given to pregnant ewes around the first week of April.
Ewes at day 100 of pregnancy require about 11% crude protein and growing weaned lambs require about 14% crude protein in their diet.
Pregnant sheep and weaned lambs need ~15% acid digestible fibre (ADF) in their diet. Enough roughage will need to be added to rations based on wheat (3% ADF) or barley (8% ADF) to meet the 15% ADF target.
Sheep fed lupins (20% ADF) and/or oats (18% ADF) and pellets will require less roughage in their diet.
Condition score sheep on entry and draft into similar condition mobs. Continue to monitor 50 sheep per pen monthly. Use the condition score app to record and analyse this information.
Provide rations based on maintenance or growth for each class of sheep and days of pregnancy for each frame size of ewe (small, medium or large).

Table 5 Feeding barley to a large frame (60kg) Merino ewe with different days of pregnancy based on Feed Budget Tables for dry conditions (lifetime wool).
Large frame (60kg)	Maintain at CS 3	Maintain at CS 3	Maintain at CS 2.5	Maintain at CS 2.5
Days of pregnancy	Paddock (MJ)	Confinement (MJ)	Paddock (MJ)	Confinement (MJ)
Not pregnant	9.3	7.8	8.7	7.3
50	9.7	8.1	9.1	7.6
70	10.1	8.4	9.6	8.0
100	11.5	9.6	10.8	9.0
130	14.4	12.0	13.1	10.9
Large frame (60kg)	Barley	Maintain at CS 3	Barley	Maintain at CS 2.5
Days of pregnancy	Paddock (g/h/d)	Confinement (g/h/d)	Paddock (g/h/d)	Confinement (g/h/d)
Not pregnant	832	698	778	653
50	867	724	814	680
70	903	751	859	715
100	1028	859	966	805
130	1288	1073	1172	975

Cereals, like barley, oats, wheat and triticale are low in calcium and will need 1.5% of finely ground limestone to restore the animal’s calcium-phosphorous balance.
There is potential for grain acidosis with a change in batches of pellets or when introducing new source of barley or other types of grain – manage each change of source of feed carefully.
Give young sheep a vitamin E drench (2000 mg per head of water miscible vitamin E) on entry and every 8 weeks until green feed becomes available.
Remove pregnant ewes from the confinement feeding pen and return them to the paddock at least two weeks before the start of lambing. The change in diet at this time can also result in metabolic disorders leading to death.
Pregnant Merino ewes in late pregnancy can maintain condition if winter FOO is more than 800kg/ha DM and pasture growth rates more than 20 kg/ha DM.
Avoid lambing in the confinement pen as ewes tend to steal lambs from other ewes once they have a lamb, and can accumulate three or four lambs. When this happens ewes are not able to care for all the lambs.

State-specific confinement feeding resources

NSW DPI – Confinement feeding stock
Agriculture Victoria – Stock containment areas
SA Natural Resources – Stock containment areas
WA DPIRD – Confined paddock feeding and feedlotting of sheep

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Contact information

Danny Roberts

+61 (0)8 9892 8535

Email Danny Roberts

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