DROUGHT FEEDING AND MANAGEMENT OF BEEF CATTLE - A GUIDE FOR FARMERS AND LAND MANAGERS 2018 - Agriculture ...
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DROUGHT FEEDING
AND MANAGEMENT
OF BEEF CATTLE
A GUIDE FOR FARMERS
AND LAND MANAGERS
2018
Published by the Victorian Government Department of Economic Development, Jobs, Transport and Resources, April 2018. © The State of Victoria, Department of Economic Development, Jobs, Transport and Resources, Melbourne 2018. This publication is copyright. No part may be reproduced by any process except in accordance with the provisions of the Copyright Act 1968. Authorised by the Victorian Government 1 Spring Street, Melbourne Victoria 3000 Australia First edition 2002 Revised and reprinted March 2007 Revised and reprinted September 2015 Revised and reprinted April 2018 ISBN 978-1-74199-055-3 (print) ISBN 978-1-74199-035-5 (internet) For more information about Agriculture Services visit the website at www.agriculture.vic.gov.au or call the Customer Service Centre on 136 186 Disclaimer This publication may be of assistance to you but the State of Victoria and its employees do not guarantee that the publication is without flaw of any kind or is wholly appropriate for your particular purposes and therefore disclaims all liability for any error, loss or other consequence which may arise from you relying on any information in this publication.
Drought Feeding and Management of Beef Cattle
CONTENTS
List of Tables 4
Acknowledgements 5
Abbreviations 5
Chapter 1 – Preparing for drought 6
Drought Action Plan 6
Tips from past droughts 7
Management options to consider 7
Other considerations 9
In summary 9
Drought Action Plan template 10
Drought action planning check list 14
Chapter 2 – Water during a drought 15
Will you have enough water? 15
How to calculate how much water you have 16
Water quality 17
Salt content 17
Pollution 17
Algal blooms 17
Options to reduce water requirements 18
Reducing stock numbers 18
Relocating stock 18
Minimising evaporation 18
Reticulating from dams rather than allowing animals direct access 18
Protecting dams from wind-borne contamination 18
Actions to address a water shortage 18
Carting water 18
Sinking bores 18
Digging new dams 18
When seasonal conditions improve 19
Farmer tips from past droughts 19
Water testing 19
Online resources 19
Chapter 3 – Pasture management during drought periods 20
Assessing pasture availability 20
Pasture quality 21
Stock and pasture management at the end of a drought 22
Feeding management 22
Pasture recovery 22
Opportunity to improve pastures 23
Opportunity to control weeds 23
Need for fertiliser 23
Fodder crops 23
Estimated pasture survival 23
Assessing the need for resowing a perennial pasture 23
1
Agriculture Victoria
CONTENTS
Chapter 4 – Monitoring stock condition 25
Fat score descriptions 26
Visual assessment 26
Muscling 26
Target fat scores 26
Managing cattle condition 27
Chapter 5 – Choosing feeds 28
Understanding the components of a feed 28
Energy 28
Protein 28
Fibre 29
Dry matter 29
Other components of a feed analysis 29
How to sample for a feed analysis 30
Costing fodders on energy value 32
Other factors to consider when buying fodder 34
Grain processing 34
Storage, handling, feeding out 34
Availability 34
Cost of freight 34
Noxious weeds 34
Tips for buying hay 34
Drought feeding of stock – the risk of chemical residues 35
Chapter 6 – Feeding cattle 36
Nutritional requirements of beef cattle 36
Energy and protein requirements of various classes of cattle 37
Using the figures – feed budgeting 40
Tactical feed budget for use when some pasture is available 40
Pearson’s Square – for use when no pasture is available 43
Other considerations 45
Minerals 45
Calcium 45
Sodium 45
Buffers 45
Vitamins 45
Improving the feed value of low-quality feeds 45
Treating straw with urea to improve the protein level of the diet 45
Molasses as an energy source 46
Chapter 7 – Feeding grain to cattle 47
Introducing cattle to grain 47
Frequency of feeding 47
How to feed – trough or on the ground? 47
Changing a ration 48
2
Drought Feeding and Management of Beef Cattle
CONTENTS
Roughage (fibre) 48
Other grain additives 48
Processing grain 48
Grain poisoning 48
Other grain feeding problems 49
Calcium deficiency 49
Vitamin A deficiency 49
Urolithiasis 49
Polioencephalomalacia 49
Chapter 8 – Feeding in stock containment areas 50
Why use stock containment areas 50
When to use a stock containment area 50
Site selection 51
Design 52
Construction 53
Water 53
Feed 53
Stressful weather conditions 54
Releasing cattle 54
Animal health 54
Other considerations 54
Chapter 9 – Animal health and welfare 55
Health and welfare problems in beef herds in a drought 55
Classes of livestock affected 55
Grain feeding problems 56
Poisoning and chemical residues 56
Urea poisoning 56
The effect of disease on drought-affected cattle 56
Internal parasites (worms and fluke) 56
Lice 56
Bottlejaw 56
Coccidiosis 56
Pulpy kidney (enterotoxaemia) 57
Pneumonia and calf diphtheria 57
Pinkeye 57
Welfare considerations of drought 57
Chapter 10 – Options for young stock management 58
Early weaning of beef calves 58
Deciding when to wean 59
Pre-weaning 59
Weaning 59
Post-weaning 59
Creep feeding of beef calves 60
The type and level of feed 61
3
Agriculture Victoria
CONTENTS
Chapter 11 – The feed value of unusual feedstuffs 62
Types of feeds 63
By-product energy concentrates 63
By-product protein concentrates 65
By-product roughage 65
Appendices 69
Appendix I – Weight of hay and silage bales 69
Appendix II – Energy tables and calculations 69
Appendix III – Tactical feed budget 70
Appendix IV – Pearson’s Square worksheet 71
List of Tables
Table 2.1 Animal water requirements, litres/animal/day 15
Table 2.2 Salt tolerance in drinking water for various classes of cattle 17
Table 3.1 Metabolisable energy (MJ ME/kgDM) supplied by different pasture qualities 21
Table 4.1 Fat score descriptions for manual fat scoring 26
Table 4.2 Minimum and desired fat scores for different classes of stock 27
Table 5.1 Energy and protein compositions of common livestock feeds 31
Table 5.2 Energy and protein compositions of common grains (whole and processed) 32
Table 5.3 Quick lookup table for costing fodder based on energy value 33
Table 6.1 Energy and protein requirements of steers and heifers (after weaning) 37
Table 6.2 Energy and protein requirements of cows, pregnant mature 38
Table 6.3 Energy and protein requirements of cows, with suckling calves 1-4 month old 38
Table 6.4 Energy and protein requirements of bulls 39
Table 6.5 Quantities for full hand feeding for common classes of stock 39
Table 7.1 Digestibility of whole versus processed grain 48
Table 10.1 Energy and protein requirements of calves of various liveweights 60
Table 10.2 Example diets for early-weaned calves 60
Table 11.1 Mean and range of canola hay and silage samples from the 2006-2007 season 66
Table 11.2 Energy and protein compositions of unusual feedstuffs 67-68
4
Drought Feeding and Management of Beef Cattle
Acknowledgements Abbreviations
Agriculture Victoria thanks the following people BoM Bureau of Meteorology
and organisations for their contribution to this cm centimetre
publication:
CP crude protein
Phil Franklin, Fiona Baker, John Gibney,
John Bowman, Heather Field, Belinda Pritchard, CS condition score
Ralph Behrendt, Dr Robert Suter, Kate Sargeant, DM dry matter
Dougal Purcell, Cheryl Graham, Ross Batten, DSE dry sheep equivalent
Tim Hollier, Dr Karin Morgan, Dr David Champness,
Emma Weatherly, Meat & Livestock Australia. EC electrical conductivity
FOO food on offer (in kg DM/ha)
g gram
IOD Indian Ocean Dipole
kg kilogram
L litre
m 2
square metre
ME metabolisable energy (energy units)
MJ megajoule
MLA Meat & Livestock Australia
mm millimetre
NDF neutral detergent fibre
NLIS National Livestock Identification Scheme
PIC Property Identification Code
ppm parts per million
SOI Southern Oscillation Index
t tonne
5
Agriculture Victoria
CHAPTER 1
Preparing for drought
Droughts are part of life for farming communities. Drought Action Plan
Early planning and decision making is important. Think about the following questions when
If decisions are left until a drought worsens, many developing your Drought Action Plan.
of the management options available early may
no longer be possible. What is your current financial situation?
This chapter looks at how to prepare your farm, • Cost out various feeding or selling scenarios.
including:
• Prepare a 12-month cash flow budget.
• making plans early
• se partial budgeting to explore various
U
• knowing feed supplies and stock requirements options.
• u
nderstanding farm water levels and stock
Do you need financial advice?
needs
• ee a rural financial counsellor (see
S
• d
iscussing your drought strategy with your
www.agriculture.gov.au/ag-farm-food/drought/
family.
assistance/rural-financial-counselling-service).
The first step is to prepare a Drought Action Plan.
• Discuss your plans with your accountant.
By listing the farm’s financial and physical
• Contact your bank manager.
resources the effects of various strategies, both
short and long term, can be calculated. How widespread is the drought?
The next step is to estimate when you think the • Is suitable agistment available? You need to
weather pattern is likely to change. This will affect check fences, water supplies and health status
your calculations on how long you will be feeding of potential agistment properties.
cattle, how much it will cost and whether you will
• Is droving an option? What are the regulations
decide to sell stock or not. It is best to over-
on droving in your local councils?
estimate the time you expect to hand-feed stock
to be on the safe side. For example, you need to Water supplies (see Chapter 2)
add a few weeks beyond an expected autumn
• hat is your farm’s current water storage
W
break to allow for the new pasture to germinate
capacity?
and grow, plus continue supplementation to allow
for the transition from dry feed to green pasture. • hat are the stock water requirements over
W
In previous droughts, cattle have survived the dry the summer months?
summer months only to be lost with the sudden • o you have adequate water supplies to
D
change to a green feed diet after the autumn survive a drought?
break.
• an you seek water from other sources before
C
For long-term weather predictions see the supplies dry up (e.g. creeks, bores or outlying
following Bureau of Meteorology link: dams)?
www.bom.gov.au
Useful information can also be found at Will you feed for maintenance or production
agriculture.vic.gov.au/agriculture/farm- targets (see Chapters 4, 5 and 6)?
management/newsletters-and-updates/the- •
What are your fat score targets for the cow
break,-the-fast-break-and-the-very-fast-break- herd for joining, calving and weaning?
newsletters
• hat are the feeding needs of various classes
W
of cattle?
• Which are the priority mobs for the best feed?
• Which classes of cattle do you consider selling?
6 Chapter 1 / Preparing for drought
Drought Feeding and Management of Beef Cattle
Can you feed cattle for long periods? Tips from past droughts
(see Chapters 7, 8, 10)
Farmers who successfully survived the 1982 and
• o you have the equipment to feed cattle: silos,
D 1994 droughts were asked what they did to ensure
feed wagons, grain feeding equipment or can they got through. In summary, they:
you improvise, borrow or buy equipment?
• made plans and took actions early
• Do you have the labour or time to feed?
• id simple budgets for various feeding and
d
• ow long will you have to feed and what will it
H selling options
cost? Are grain, hay, silage, pellets or other
feedstuffs available? • new their hay supplies and were prepared to
k
ration roughage
• an you construct a stock containment area
C
for some or all of your cattle? • prepared cash flow budgets for 2-3 years
• Do you have the feed budget skills? • btained advice on current market prices for
o
fodder, grain and livestock to enable them to
Should you reduce your cattle numbers? make informed decisions
• What prices are cattle making now? • reviewed decisions regularly
• What prices will cattle be after the drought? • acted quickly and decisively
• hat effect will reduced stock numbers have
W • looked for opportunities
on your overall feeding costs and your long- • remained positive
term restocking costs?
• planned a holiday
Sustainability and protection of pastures • looked out for family and friends
and soil (see Chapter 3) • ere prepared to use stock containment areas
w
• hat effect will your strategy have on your
W to preserve their pastures and soil.
pastures and soils?
• hat effect will your action plan have on your
W Management options to consider
long-term viability?
Agistment
• ow do you protect native vegetation from
H
Sending cattle away on agistment can be a cheap
cattle damage during the drought?
solution to the feeding problem; any cattle left at
Cattle need to be adequately fed, have continual home will have less competition for feed.
access to clean fresh water, have access to shelter
Before agisting cattle check that the property
if required, be kept healthy and allowed to express
they are going to has:
their natural behaviour. Allowing stock to starve is
not an option and is an offence under Victorian • secure fencing and cattle-handling facilities
law. • a good quantity of quality feed
Your Drought Action Plan should be flexible to • good water supply
allow for changes in circumstances. For example,
• upervision to minimise theft and identify
s
you may sell a certain class of stock or buy fodder
health problems.
only if conditions do not improve by a certain date.
Only cattle strong enough to travel should be
Having a plan of action will greatly reduce the
agisted. It is an advantage to have the agistment
stress on you and your family as you will all be
area close to markets so cattle do not have to be
working towards specific aims.
brought home again.
Sell stock
If you choose this course of action, the crucial
management decisions will be the timing of the
sale and the type and number of cattle to be sold.
Any drought inevitably triggers a period of intense
selling with large saleyard yardings and resultant
depressed prices. Plan to sell as early as possible
to avoid the most depressed prices and while the
cattle are still in good condition.
The best policy is to sell the less-productive
animals, so that at the end of the drought you will
still have a herd of high-producing animals.
Chapter 1 / Preparing for drought 7
Agriculture Victoria
Generally, the best cattle to retain through a Feed stock
drought are young breeders of good quality Drought feeding of cattle is most efficient if the
because these will be difficult and expensive to stock are segregated into various classes so that
replace at the end of a prolonged drought. They they can be fed according to their nutritional
will also provide the basis for bringing a beef herd requirements.
back into production.
These classes could be:
The following sets out the steps of a selling policy
to retain a breeding herd: • early-weaned calves (less than six months)
• regnancy test and sell all empty, late-calving
P • weaners (6-12 months)
and low-producing cows. • yearlings (12-18 months)
• Sell inferior bulls. • cows with calves at foot
• ell aged cows, aged bulls and lightweight
S • dry cows
heifers.
• bulls
• ell non-breeding cattle: weaners, yearling
S
• steers and bullocks (over 18 months).
steers and bullocks. Growing stock can be
expensive to feed because of their high energy Stock requirements are discussed in Chapter 6.
and protein demands. Developing feed budgets before and during a
• ean calves over three months of age and sell
W drought is key to minimising the financial impact
or feed separately. on your enterprise.
• rogressively reduce the breeding cow herd.
P It is usually more efficient to maintain stock at a
Reassess the cow herd and sell the poorest productive level than feed to increase their weight
performing cows and heifers. Young breeders and fat score. Cows maintained in fat score 3 or
(2-5 years) are the most important to retain. better will be more fertile come joining time and
result in more live calves on the ground when the
Feed costs, saleyard prices and expected stock
season improves.
water supplies need to be assessed each time you
decide how many stock to sell. Short-term finishing rations may be justified for
stock suitable for sale, such as weaners or steers
Vendor declarations must be provided with all
for domestic markets. However, budgets need to
cattle sold. Vendor declarations are available from
be carefully calculated as the profit margins are
Meat and Livestock Australia and can be ordered
generally small during droughts.
online at www.mla.com.au
Monitoring and recording cattle liveweight and fat
Taxation can have an important bearing on your
scores gives a guide to the success of your
selling plans. Its impacts, especially if a large part
feeding program and allows for ration adjustment
of the herd is to be sold, need to be determined
and cost savings.
before the stock are sold, particularly where low
‘cost price’ valuations are used for taxation Planning is needed for when the drought finally
purposes. Speak to your accountant about the breaks to ensure the cattle are slowly transitioned
possibility of spreading the income over a five- from a drought ration to the emerging green feed
year period if the cattle sale was forced due to diet. For the benefit of both the cattle and the
drought conditions. emerging pastures, the drought ration should be
maintained for a few weeks, gradually
transitioning the stock to the green feed, which
allows the rumen microbes and the animals’
digestive systems to adjust to the new diet.
8 Chapter 1 / Preparing for droughtDrought Feeding and Management of Beef Cattle
Other considerations Purchasing cattle after the drought
To minimise the risk of introducing disease, cattle
Requirements for stock leaving the farm should be accompanied by an animal health
All cattle in Victoria must be tagged with an NLIS statement. completed by the person you are
cattle tag before leaving their property of birth. All buying the cattle from. The animal health
movements must be accompanied by a properly statement pro forma can be downloaded from
completed National Vendor Declaration www.farmbiosecurity.com.au/toolkit/declarations-
(www.mla.com.au/lqs or ring 1800 683 111). and-statements/ The statement will give you
information on the cattle’s pestivirus and Johne’s
Property-to-property movements need to be
disease status, treatments they may have
recorded on the NLIS database.
received such as worm and liver fluke drenches
Fit to travel and any current vaccinations they have received.
Stock must be in a fit condition if they are to be
transported, whether for slaughter or to another
In summary
farm. An animal is not fit if it: It is your legal responsibility to ensure that
livestock do not starve or become distressed
• is not strong enough to undertake the journey
during a drought. Doing nothing is not an option
• cannot walk normally, bearing weight on all legs open to you in the long term. Even in the short
• is severely emaciated or visibly dehydrated term, it is of questionable value.
• is suffering from severe visible distress or injury You may be tempted to do nothing in the hope
that a poor season will not turn into a drought. In
• is blind in both eyes
the meantime, paddock feed diminishes, the
• is in late pregnancy. condition and value of stock slip and feed prices
For the full publication ‘Is it fit to load’ go to: soar. These changes close off many of the options
www.mla.com.au/News-and-resources/ available to you earlier in a drought.
Publication-details?pubid=5873 The message is to plan early and set deadlines to
activate specific actions.
Droving
Remember, it is better to plan ahead. If the season
Another source of off-farm feed is along roadsides.
happens to improve or was not as dry as
Only some councils allow droving stock. Legal predicted, you can always put the plan to one side
restrictions and local environmental considerations and continue with a normal season program.
applying to this practice vary between councils
and may change. The risk of disease spread also
needs to be considered. Check with the councils
involved before starting this option.
Humane destruction
If some classes of stock are unsaleable, and no
other option is feasible, the animals should be
humanely destroyed. In past droughts, councils
have made facilities available to dispose of
carcasses.
Information on appropriate methods of
destruction can be obtained from animal health
staff from your local Agriculture Victoria office.
Chapter 1 / Preparing for drought 910
Drought Action Plan template
Use this template to clarify your farm situation and help develop your Drought Action Plan
Farm Name Farm area (ha) Month/Year
Locality Time of calving Time of lambing
Cattle
Class of Herd Name Number Current DSE Total High priority Medium Low priority Market Comments
stock fat score rating DSE (feed for priority (hold or sell) options
(number production) (feed for
Chapter 1 / Preparing for drought
x DSE) maintenance)
Weaners
Calves at
foot
Heifers
Steers
1st calf
heifers
3-5 year-old
cows
6-year-old
plus cows
Bulls
Total
Agriculture VictoriaSheep
Class of Mob Name Number Current DSE Total High priority Medium Low priority Market Comments
stock condition rating DSE (feed for priority (hold or sell) options
score (number production) (feed for
x DSE) maintenance)
Weaners
Lambs at
foot
Wethers
Maiden
Ewes
Adult (>2 yr)
Ewes
Old age 6 yr
plus Ewes
Rams
Total
Other livestock
Class of Group Name Number Current DSE Total High priority Medium Low priority Market Comments
stock condition rating DSE (feed for priority (hold or sell) options
score (number production) (feed for
x DSE) maintenance)
Horses
Goats
Alpaca
Chapter 1 / Preparing for drought
Other
Total
11
Drought Feeding and Management of Beef Cattle12
What feeds are on hand
Storage Feed type Quantity: Weight of Total Estimated Crude Fibre NDF % Comments
type and (grain or (number of bales (kg) quantity energy (ME) protein %
location hay) bales) (tonnes)
Silo 1
Silo 2
Silo 3
Chapter 1 / Preparing for drought
Hayshed 1
Hayshed 2
Hayshed 3
Silage pit 1
Silage pit 2
Silage pit 3
Total
Paddock feed on hand
Paddock name Area Average kg/DM/ha Estimated quantity Comments
Total of farm
Agriculture VictoriaPaddock feed summary
Number of hectares X Quantity of pasture = Total kg pasture on hand divide by 1,000 = Tonnes DM/farm
X = divide by 1,000 =
What water supplies are on hand
Water Source Current Access Quality Salinity Estimated Estimate Estimated Comments
Volumn Yes/No suitable suitable weekly use number of run out date
(ML) Yes/No Yes/No weeks
Dam 1
Dam 2
Dam 3
Dam 4
Bore 1
Bore 2
Creek
River
Town supply
Neighbouring
supply
Chapter 1 / Preparing for drought
Total
13
Drought Feeding and Management of Beef Cattle14
Weekly water consumption
Number of cattle X Daily consumption X 7 days = Weekly consumption for cattle
X litres/day X 7 days = litres /week
Number of sheep X Daily consumption X 7 days = Weekly consumption for sheep
X litres/day X 7 days = litres /week
House and garden X Daily consumption X 7 days = Weekly consumption for house
Chapter 1 / Preparing for drought
X litres/day X 7 days = litres /week
Total weekly water consumption litres/week
Drought action planning check list
Discuss options with:
Family members Yes/No
Accountant Yes/No
Bank manager Yes/No
Stock agent Yes/No
Farm staff Yes/No
Neighbours Yes /No
Meat and wool extension staff Yes/No
Feed merchant Yes/No
Agriculture VictoriaDrought Feeding and Management of Beef Cattle
CHAPTER 2
Water during a drought
This chapter will help you determine stock water Animal requirements
needs across a year and the options for The amount of water an animal requires will
managing on-farm water resources. depend on a number of factors, including:
Key messages • t he class of animal (a lactating cow will require
• D
o water budgets early, based on your significantly more water than a dry cow or
experience with water supplies, how much yearling steer)
water you have available and how much your • t he temperature and season (cattle consume
stock will need. significantly more water in summer and during
• H
ave a water plan that considers the worst high temperatures)
case scenarios. • t he feed on offer (grains are a dry feed, while
• E
vaporation rates can be very high over dry pasture contains some moisture)
summers and small dams are inefficient water • t he quality of the water (water with higher salt
storages. levels will increase consumption).
• C
onsider water reticulation systems and Periods of high temperatures (>38°C) will increase
transfer requirements between storages, an animal’s water requirements beyond the levels
particularly for containment areas. in Table 2.1.
• T
he major threat to water quality during
drought is high levels of salt, although algae
and animal manure can foul water following Table 2.1: Water requirements, litres/animal/day.
heavy summer rains or strong winds.
• W
ater can be tested for salinity and other Stock type Consumption
minerals to check suitability for various (L/day)
classes of stock, as well as for toxicity of algal
Sheep
blooms.
• Cows will drink up to 100 litres of water a day. Weaners up to 4
Water is essential for animal survival and Adult dry sheep up to 6
performance. Poor water quality is a common Ewes with lambs up to 10
cause of under-preforming animals. Cattle must
be provided with access to good quality water Cattle
(preferably from troughs) at all times. Weaners (250-300 kg) up to 55
Will you have enough water? Dry stock up to 80
Knowing your property and how water supplies Lactating first calf heifers up to 90
perform in times of drought is essential (350-400 kg)
information for the planning phase.
Lactating cows (500 kg) up to 100
Calculating the total water available and the total
required by stock will tell you how many stock, and Horses up to 50
of what class, you can carry through a dry period.
To do a water budget, list all the dams by paddock For daily average and yearly as well as winter and
and calculate the water available in each one. Add summer stock drinking requirements for cattle
these quantities together to find out the total water and other livestock types refer to ‘Managing farm
available on your farm. Using this figure and the water supplies’ agriculture.vic.gov.au/__data/
total water required by stock, based on Table 2.1, assets/pdf_file/0003/319386/2016-DEDJTR-Farm-
determine how many animals you can carry through. Water-Supplies-A5-web.pdf
Chapter 2 / Water during a drought 15Agriculture Victoria
How to calculate how much water you have
Step 1
Calculate the surface area of the dam. For both rectangular and round dams, surface area can be
estimated by multiplying the length by the width of the dam. Example: 40 m wide x 20 m long = 800 m2.
For triangular-shaped dams, surface area can be estimated by (width x length) ÷ 2.
Picture source – www.water.nsw.gov.au/__data/assets/pdf_file/0010/547237/licensing_rights_harvest_
dams_what_size_are_your_existing_dams.pdf
length
length length
width
width width
width x length
Surface area =
2
triangular rectangular round
Step 2 hold water for long and it may be worthwhile to
Use the following formula to calculate the volume graze paddocks with unreliable water storage
of the dam in cubic metres. early. Regular monitoring or prior knowledge of a
dam’s capacity to hold water is necessary to
Volume (m3) = 0.4 x Surface area x Depth accurately estimate how long your dam water will
The 0.4 conversion factor takes into account the last. More depth may need to be taken off to
slope of the sides of the water storage. account for this seepage.
Example: Volume = 0.4 x 800 m2 x 5 m = 1,600 m3 Example: 1.6 ML dam less 43% in evaporation (not
including seepage) as 688,000 litres (0.69 ML) lost
To convert this to megalitres (ML) divide by 1,000 =
= 912,000 litres (0.91 ML) available.
1.6 ML
Step 3 Step 4
Use Table 2.1 to calculate the daily requirements of
Evaporation can be one of the biggest losses from
all animals that rely on the dam for their water.
farm dams, especially small or shallow dams. For
example, average annual evaporation figures for Example: 200 spring-calving cows consuming
farm dams based on Ballarat evaporation data 100 litres a day will consume 20,000 litres/day.
are: Divide the total dam capacity by the daily water
• small farm dam 3 m deep would lose around
a usage.
60% Example: 912,000 litres/20,000 litres = 46 days of
• small to medium-sized dam 4 m deep would
a water available.
lose around 43% An online farm water calculator can be used to
• a medium dam 5 m deep would lose around 37% calculate stock water requirements and water
available on farm. See www.agriculture.vic.gov.au/
• a large dam 7 m deep would lose around 27%
watercalculator
In the hotter northern parts of the state, these
figures could be higher. Although these are annual
estimates, most evaporation will occur between
October and April. Seepage into the water table
may also need to be taken into account. Variation
between dams can be significant; experience will
guide you as to which dams cannot be relied on to
16 Chapter 2 / Water during a droughtDrought Feeding and Management of Beef Cattle
Water quality Pollution
Having water of a quality that is ‘fit for purpose’ is During the 1982-83 and 2015-16 droughts, many
important. Water quality can affect plant growth, dams in Victoria were severely polluted by manure
livestock health, soil quality, farm equipment and and dried vegetation blowing from bare paddocks
infrastructure and domestic use. or by summer rainfall run-off. The water turned
black and gave off a putrid smell. Stock stopped
The quality of a water source depends on the
drinking it.
season and weather conditions. Evaporation
increases the concentration of salts while a flush Retention of ground cover on paddocks adjacent
of water dilutes salts but may increase sediment, to dams will help avoid this problem developing.
and runoff of fertilisers, manure or nutrients.
Algal blooms
Water quality should generally be visually
monitored weekly to check for any algal blooms, Algal blooms are common over summer months
clarity of the water (how cloudy or muddy the when water temperatures rise as dams become
water appears) and dead wildlife (such as ducks) shallow and the levels of phosphorus and nitrogen
or livestock that may have become stuck in in the water build up.
unfenced water sources. In hotter weather or Most algal blooms are not toxic. Some blue-green
periods of prolonged moisture stress, daily visual algae, however, produce toxins that can have
checks are preferable. serious health implications for humans, animals
The major threat to water quality during drought and birds drinking or coming in contact with the
is high levels of salt, although algae and animal water. It can kill animals within a few hours of
manure can foul water following heavy summer ingestion.
rains or strong winds. Blue-green algae forms a scum that looks like
green acrylic paint and leaves sky blue marks on
Salt content rocks or plants around the edge of the dam.
Salinity is a major water quality issue in areas If you suspect you have a blue-green algal bloom:
where accumulated salts are mobilised in the
• Isolate all stock from the dam or water supply.
landscape and make their way into waterways
and dams. Salinity refers to all the mineral salts • ollect a sample for testing by a water
C
present in the water, including sodium, calcium, laboratory (use gloves – don’t allow the water
magnesium, chloride, sulphate and carbonate. to come in contact with skin).
Evaporation of water sources increases the • ontact a veterinarian if animals show
C
concentrations of salts and the problems symptoms of poisoning (sudden death, loss of
associated with them. During a drought year, low appetite, breathing difficulties, muscle twitches,
water levels can result in doubling of salt weakness, scours, photosensitisation – any
concentrations over summer. white areas of skin become swollen and
Table 2.2 lists salt levels in drinking water that can reddish). In cases of blue-green algal
be tolerated by various classes of stock. In general, poisoning, green staining may be seen on the
the salt content of water should not exceed muzzle, feet or legs of poisoned stock.
9,600 ppm and the magnesium level should not
exceed 600 ppm.
Table 2.2 Salt tolerance in drinking water for various classes of cattle presented as parts per million
(ppm) and units of electrical conductivity (EC units).
Water Classes of stock EC Units Total Magnesium
Category (µs/cm) soluble (ppm)
salts (ppm)
1 Suitable for cattle of all agesAgriculture Victoria
• ontact Agriculture Victoria for further advice
C Once material is in the dam, aeration of the water
on controlling the algal bloom. See agriculture. is necessary to improve its condition and make it
vic.gov.au/agriculture/farm-management/ more acceptable to stock. This is best done by
blue-green-algae-issues/managing-blue- pumping to a tank and reticulating to a trough. If
green-algae-in-farm-water-supplies for further aerated water is returned to the dam, the
information. organisms growing on the organic material will
quickly use all the oxygen again.
Options to reduce water
requirements Actions to address a water
shortage
Reducing stock numbers
• What are your core stock numbers? Carting water
• How many do you want to keep? Due to the volumes of water required and the
frequency it needs to be supplied (usually daily),
• How many do you need to keep? carting water is a labour-intensive operation.
• How many can you afford to keep? Consider whether you have the labour, equipment
and time available to commit to this option.
• Can you agist some?
Seepage and evaporation from earthen dams
Relocating stock during extended dry periods means it is not
Reducing the energy stock expend accessing feed generally feasible to put carted water into these
can reduce their water requirements. To reduce dams. It is best to put carted water into a tank
this energy expenditure, it may be necessary to system and reticulate the water to troughs for the
relocate the stock to a smaller paddock or a stock stock to access.
containment area where movement is more Be aware of the quality of the water source the
restricted and deliver the herd’s daily feed water is being carted from. During droughts, water
requirements to them. If water is not troughed to sources such as bores and streams may become
this area, you will need to provide enough water quite salty, affecting the stock’s willingness to
daily for stock requirements – use Table 2.1 to drink the water. Stream sources may also become
calculate stock water requirements. quite stagnant resulting in contamination from
algae and animal manures, particularly following
Minimising evaporation heavy summer rains.
To conserve water and maintain good water A dam that cannot provide enough drinkable
quality, one large deep dam is better than stock water five or more years out of 10 is not
numerous shallow dams. considered a reliable water source.
It may be advantageous to pump the contents of
a number of smaller dams into a single larger dam Sinking bores
to minimise evaporative loss and save water. Investigate likely water yields and quality before
drilling emergency bores. Consult your relevant
Reticulating from dams rather than water authority if you are considering sinking a
allowing animals direct access bore as you will need a bore construction licence.
Reticulating from dams avoids pugging and For more information and to apply for a licence
bogging problems and allows a more efficient use and permission to take and use ground water, visit
of the water. Reticulation systems must be simple, waterregister.vic.gov.au/water-trading/my-water
reliable and have sufficient capacity to meet peak or contact your relevant Rural Water Corporation.
demands.
Digging new dams
Site new troughs, tanks and pipes to suit future
Do not dig a new dam when soil moisture is low.
needs.
Only build earth dams when soil is moist enough
Protecting dams from wind-borne for maximum compaction. A permit is required to
contamination dig a new dam on a waterway.
If possible, keep adequate ground cover on Seek advice and permission before construction
adjacent paddocks to prevent material blowing from your Catchment Management Authority.
into the dam.
If ground cover is already low, fencing can be used
to trap blowing material before it reaches the
water. A close-wired fence on the windward side is
a worthwhile investment.
18 Chapter 2 / Water during a droughtDrought Feeding and Management of Beef Cattle
Water Quality Laboratory
When seasonal conditions
(NATA accredited)
improve
Deakin University, Warrnambool
Build a contingency plan for the next dry period
so you don’t get caught unprepared. Take steps to (03) 5563 3481
drought-proof your property and its enterprises. Email: wql-info@deakin.edu.au
Water testing service – Water chemistry (NATA
Farmer tips from past droughts accredited) and blue-green algae (not NATA
• ave a water plan and undertake a water
H accredited).
audit, taking into consideration the worst case
ALS Water Resources Group
scenario.
(NATA accredited)
• alculate stock water requirements and water
C
available using the online farm water 22 Dalmore Drive, Caribbean Business Park,
calculator www.agriculture.vic.gov.au/ Scoresby
watercalculator (03) 8756 8000
• ssess reliability of all your water sources. A
A Email: melbournewrg@alsglobal.com
dam that cannot provide enough drinkable
stock water five or more years out of 10 is not (Regional laboratories in Wangaratta, Bendigo,
considered reliable. Traralgon and Geelong – basic water testing only).
• ave a large, fenced catchment dam on your
H Domestic, stock and irrigation packages available
property and reticulate from this to troughs. (includes pH, electrical conductivity, turbidity,
calcium, potassium, magnesium, hardness,
• et up your reticulation system properly from
S sodium, iron, manganese, nitrate, chloride, sodium
the start. Do it in stages if necessary. absorption ration) and blue-green algae.
• repare early and ensure you have any
P
necessary permits in place well before summer. Online resources
• lant trees strategically to reduce evaporation
P Water
from dams.
Farm Water Solutions (Package) at
Water testing www.agriculture.vic.gov.au/farmwater
The best way to be certain about the quality of Dams
your water is to have it tested. The following
agriculture.vic.gov.au/agriculture/farm-
laboratories test water, but there may be others.
management/managing-dams/how-long-will-my-
Check that the laboratory you use is accredited
dam-water-last
by the National Association of Testing Authorities
(NATA) for the test you are requesting. NATA is the agriculture.vic.gov.au/agriculture/farm-
authority that provides independent assurance of management/managing-dams/organic-pollution-
technical competence through a network of best in-farm-dams
practice industry experts.
Farm water calculator
SGS
www.agriculture.vic.gov.au/watercalculator
(NATA accredited)
Water quality
10/585 Blackburn Road, Notting Hill
agriculture.vic.gov.au/agriculture/farm-
(03) 9574 3200
management/soil-and-water/water/farm-water-
Irrigation and stock water analysis available solutions/technical-resources/managing-farm-
(salinity (EC), calcium, magnesium, sodium, iron, water-supplies-in-drought
total oxidised nitrogen, pH, chloride, total hardness
and other chemistry). Blue-green algae testing is Water supply for stock containment areas
also available at an additional cost. agriculture.vic.gov.au/agriculture/farm-
Microbiological testing for human consumption is management/managing-dams/water-supply-for-
available in Shepparton (03) 5821 1708 and stock-containment-areas
Mitcham (03) 9874 1988.
Chapter 2 / Water during a drought 19Agriculture Victoria
CHAPTER 3
Pasture management
during drought periods
This chapter looks at methods of assessing
pasture quantity
Pasture height (cm)
pastures to determine how much feed is available
(kg DM/ha)
and also at management considerations to get the
Approx
best from the pasture system during tough times.
Key Messages:
• A
vailability of pasture needs to be assessed in
kg DM/ha for use in feed budgets. 14 3000+
• D
efer grazing after the drought breaks. 12 2500
Grazing too early further damages the grasses 10 2200
and will affect their persistence. 8 1900
• W
eed management is important in the first few 6 1600
months after the drought breaks, otherwise 4 1200
they may significantly reduce future pasture 2 700
production.
• A
ssess perennial pastures after the drought
Figure 3.1: The relationship between green pasture
breaks for the percentage of perennial grass,
height and pasture availability.
annual grass, broadleaf weeds and bare
ground. This will give an indication of whether
pastures need resowing. The pasture quantity figure can then be used in
• I f sowing into pasture, apply a small amount of feed budgets. Feed budgets allow you to use the
phosphorus fertiliser, 10-20 kg/ha phosphorus, energy content (or quality) of the pasture to help
the equivalent of 114-227 kg super/ha. determine if enough feed is available to meet
The need for supplementary feeding and the production targets (maintenance or growth or
quantity required will depend on the availability lactation, etc).
and quality of the pasture. The following section Another way to assess pasture quantity is the ‘cut
provides a simple guide to help you estimate and dry’ method. This will give the most accurate
pasture quantity and quality to determine the estimate of quantity.
contribution of the pasture as part of a ration. • ake a square 33 x 33 cm (you could use wire
m
or PVC pipe or small gauge poly pipe using
Assessing pasture availability corner joiners)
The quantity of pasture in a paddock is measured • t ake 10, 33 x 33 cm pasture cuts (to the ground)
in kilograms of dry matter per hectare (kg DM/ha). from the paddock
It is the weight of pasture from a hectare if it was
cut to ground level and completely dried to • ry each sample in a paper bag in the
d
remove all moisture. microwave – place a glass of water in the
microwave during the drying process to stop
Pasture quantity is determined by measuring the bag/sample from burning
average height of the pasture in centimetres
(using a stick or ruler) and calibrating the height • dry sample for 1 minute, remove and weigh
to kg DM/ha using Figure 3.1 as a guide. When • dry for another minute, remove and weigh
using this method, the first 0.5 cm should be
• ontinue drying and weighing until there is no
c
excluded from the measurement.
change in weight
• ultiply the average weight (g) of the sample
m
by 100 to get the kg DM/ha.
20 Chapter 3 / Pasture management during drought periodsDrought Feeding and Management of Beef Cattle
Pasture quality
Pasture quality is determined by the digestibility
of the green and dead herbage, clover content
and the proportion of dead herbage.
Digestibility is the proportion of the pasture eaten
that is retained by the grazing animal. For example,
if green pasture has a digestibility of 70%, it
means 70% of the pasture eaten will be used by
the cattle and 30% will pass out as faeces, so if the
cattle eat 10 kg of pasture, 7 kg will be utilised and
3 kg excreted. A highly digestible feed will be
digested faster, allowing for greater intake and
greater animal production.
Protein content of the pasture is also important. If
it is too low it can limit the performance of some
classes of stock. The protein level of dry pasture Figure 3.2: 1,700 kg dry matter, 55% digestibility.
will range from 5% to 8% of dry matter. The protein
level of green pasture ranges from 12% to 30% of
dry matter (depending on the stage of growth and
the amount of clover present).
Pastures with high digestibility will also be high in
energy (see Table 3.1). Other factors that influence
quality of pasture include:
• proportions of dead and green herbage of the
same species (quality gradually declines as
pasture ages from the vegetative to
reproductive state
• differences between pasture species.
There is often little difference between annual and
perennial grasses early in the growing season.
Towards the end of the growing season, however,
annuals such as silver grass and barley grass
quickly decline in quality when they produce seed
heads and die. Perennial grasses maintain higher Figure 3.3: 1,000 kg dry matter, 60% digestibility.
quality longer and usually have some green
material present.
Legumes are particularly high in protein and
usually have roughly the same energy value as
perennial grasses. Animals gain weight faster
when grazing legume pastures compared to a
grass pasture with the same pasture availability.
Table 3.1: Metabolisable energy (MJ ME/kgDM) supplied by different pasture qualities.
Pasture Description Digestibility Energy (MJ ME/kgDM)
Dry stalks 50% 6.5
Dry grass and leaf 55% 7.5
Late flowering 60% 8
Mid flowering, green and dead 65% 9
Late vegetative 70% 10
Active green growth 75% 10.5
Chapter 3 / Pasture management during drought periods 21Agriculture Victoria
numbers of viable seeds to germinate or there are
Stock and pasture management drought-tolerant perennial species present.
at the end of a drought Sufficient follow-up rains are needed to keep
In previous droughts, some of the worst stock pastures growing vigorously. A delayed break, or
losses have occurred immediately after the drought lower-than-average rainfall in the autumn, will
has broken. It is important that the feeding impair the pasture recovery rate. The effect of
management of sheep and cattle is carefully drought on irrigated pastures will depend on the
planned and supervised over the weeks following availability and frequency of watering.
the end of the drought.
Annual species
Stock will spend a lot of energy roaming around
Annual grasses, such as annual ryegrass, will have
paddocks chasing the short ‘green pick’ that
reduced seed set during a drought, resulting in
quickly appears. Although this green pick is highly
lower density in pastures the following year.
nutritious, the quantity that stock can eat soon
after germination is not great and may be far less Lack of competition from favourable species may
than their maintenance requirements. allow undesirable annual grasses such as silver
grass and barley grass to come back strongly,
Stock need time to adapt from grain feeding to
even if there is less seed available for germination.
eating pasture. It takes 2-3 weeks for the
population of digestive organisms in the rumen of Spray programs later in the year may be required
cattle to adjust to digesting pasture rather than to control undesirable annual grasses.
grain. Sudden changes from high grain rations to Sub clover or medic should have sufficient
green pasture can cause digestive disturbances. residual hard seed in the soil to produce a good
There may be stock problems if the pasture is sward after drought, unless the clover or medic
dominated by particular weeds. Nitrate poisoning content has been poor for some years before.
is common in pastures dominated by capeweed Bare soil conditions and an early break will favour
and clover early in the season. Do not allow their germination and it is not uncommon for
hungry stock free access to these types of these annual legumes to return to a similar or
pastures. Strip graze the paddock where practical greater percentage of the sward than before the
and ensure stock have ad lib access to hay. drought.
The arrival of drought-breaking rains can also be Annual weeds such as capeweed, erodium,
accompanied by cold and windy weather. These Patterson’s curse and thistles will be more
conditions place added stress on stock that are prominent after a drought. These broadleaf weeds
already suffering from a lengthy drought. tend to grow bigger with less competition. If
capeweed is dominant, there is a possibility of
Feeding management nitrate poisoning of stock. This can be prevented
Feeding should be continued for 2-3 weeks by not introducing hungry stock to capeweed-
beyond the end of the drought. Stock should be dominant pastures.
restricted to small areas for that time to allow a These species are favoured by bare ground at
wedge of feed to grow ahead of them. germination and reduced competition from other
Wean stock off grain over 2-3 weeks and give species. They also cope better with ‘false’ breaks
them access to some green pick to enable their than more favourable species.
digestive systems to readjust to the green feed. Perennial species
Cold and windy conditions associated with Perennial grass species are likely to suffer
drought-breaking rains may increase the considerable reductions in plant numbers during
maintenance requirements of the stock. The a drought. The longer the dry conditions last, the
rations fed over the 2-3 week period should be more severe the effect.
increased by about 20% above drought rations.
Perennial ryegrass is the least tolerant of drought,
Pasture recovery followed by cocksfoot, tall fescue and phalaris. A
dormant bud in the phalaris plant is its
The effect of drought on a pasture will depend on
mechanism for survival, supplying the plant with
the management and grazing pressure to which it
water and nutrients throughout the dry period. By
is subjected relative to the rainfall. There are
allowing phalaris to set seed in spring, the
significant differences between species in their
dormant bud can be fully developed, enhancing
ability to withstand the combined effects of heavy
the chances of survival.
grazing pressure and reduced rainfall.
Take care when grazing phalaris pastures soon
The extent to which pastures recover after a
after the autumn break. Short phalaris pastures
drought depends largely on when the drought-
can produce a toxin that causes phalaris staggers
breaking rains are received. If the drought breaks
and death. The risk can be minimised by allowing
with a ‘normal’ autumn break, the pasture should
plants to establish three leaves before grazing,
recover quickly – providing there are adequate
22 Chapter 3 / Pasture management during drought periodsDrought Feeding and Management of Beef Cattle
and feeding the animals hay before they are Need for fertiliser
introduced to phalaris.
There may be a larger-than-usual residual effect
Paspalum is relatively drought tolerant and will from fertiliser applied at the start of the drought
increase its dominance in under-irrigated as a consequence of reduced leaching of
pastures. nutrients because of the dry conditions and
Lucerne has a deep taproot and can survive reduced pasture growth.
drought, provided it is given regular spells from Areas that have been used for intensive feeding
grazing to allow it to recover. will have increased in fertility due to the nutrients
White clover survival is likely to be severely supplied by the feed and recycled through the
affected, particularly in marginal areas (which animal. Soil testing post-drought is the key to
includes ‘irrigated’ areas where the watering has ensuring the correct nutrient applications.
been stopped). In circumstances of reduced stock numbers and
restricted finances, it may be necessary to defer
Opportunity to improve pastures or reduce fertilisers for the year.
Pasture productivity will not necessarily fall Nitrogen fertilisers can be used early after the
drastically after a drought, even though some autumn break to boost autumn/winter feed
species will have declined. A ‘wait and see policy’ availability. Nitrogen fertiliser is best used on
for up to two years after the drought can allow improved plant species and may be wasted if
sufficient time to gauge the actual effects and pasture composition has been seriously
allow some species, for example perennial compromised by the drought.
ryegrass, to thicken up from seed produced in the
post-drought year. Fodder crops
For the best result, a good weed control program In some circumstances, it is useful to grow a winter
should precede all pasture establishment work. fodder crop to boost feed supplies after the
Broadleaf weeds, for example, are likely to be a drought. In most cases there is no need to do so,
problem in newly germinated pastures unless they particularly if there is a good early break and
are controlled. stock numbers are down, or if water is available to
irrigate pasture.
Opportunity to control weeds
Fodder crops can help control weeds prior to
For any weed control program to be successful, it re-sowing pasture in the following year and can
must include a method for replacing the weeds provide feed more rapidly than a newly sown
with more desirable species. Methods may include pasture.
chemical control followed by re-sowing and/or
grazing management programs. Grazing Estimated pasture survival
management combined with chemical control can
It is important to assess what recovery might be
be successful if the desirable species makes up
expected when rain falls so early action can be
50% or more of the pasture composition.
taken.
The following spray programs may be considered.
A simple procedure is to water (with a watering
Always read the product label and follow all
can) a square metre in several places within the
directions. Product labels contain helpful
paddock and see what grows. In previous
information and critical precautions for the safe
droughts, the results of this procedure have shown
and responsible use of these techniques.
a close relationship to what subsequently
• pray grazing for broadleaf weeds. Conducted
S germinates.
in autumn or early winter after the break. Spray
If stock are in the paddock, it may be necessary to
with a broadleaf herbicide such as MCPA, wait
use a fence to protect the watered areas.
two weeks and graze off the pasture.
• Winter cleaning for annual grasses (particularly Assessing the need for resowing a
silver grass). Conducted in late winter. Spray perennial pasture
with simazine, which prevents the annual
grasses from seeding. Resowing does not always mean a total
renovation of the pasture. If there is still a
• pray-topping for annual grasses such as
S reasonable amount of desirable species present,
barley grass. Conducted in mid-spring (when but it needs to be thickened up, direct drilling into
plants are in the ‘milky dough’ stage). Spray the existing pasture is generally the best method.
with sub-lethal dose of glyphosate and graze
off the pasture. Ryegrass seed, for example, is generally drilled in
at lower rates, such as 15 kg/ha for an oversow,
• re-sowing knock down spray. Spray with a
P while a full resow generally has sowing rates of
lethal dose of glyphosate before sowing a new 20-25 kg/ha. Other seed types will have different
pasture or fodder crop. recommended rates.
Chapter 3 / Pasture management during drought periods 23Agriculture Victoria
Assessing composition of the perennial pasture When assessing perennial pastures before the
can be completed using the stick method. Walk break has arrived, a significant amount of bare
across the paddock in a diagonal transect. ground may be encountered. If this bare ground is
Randomly throw a pen or stick in front as you 30% or lower, this will not significantly affect
walk. Note what the end of the stick is touching pasture production across the year. Clover will
and record. Complete this 50 times along the germinate and fill some of the bare ground areas,
transect. Record whether it touches a perennial but weed control may be needed to control
grass, annual grass, weed or bare ground. If 50 capeweed growth early in the season (generally
records are collected, simply multiply the number about six weeks after the break).
in each category by two to get a percentage If reseeding, it is a good idea to apply a small
composition for the paddock. amount of phosphorus-based fertiliser to ensure
If desirable perennial grass species are above new emerging pasture can readily access
70%, the pasture will still be productive. If the phosphorus from the soil. Phosphorus is important
desirable grass species are below 50%, reseeding for healthy, strong root formation, giving the
will increase yields, increase the feed value on pasture a kick start to life.
offer to stock and increase the response that Rates of 10-20 kg/ha of phosphorus will be
pasture will have to applications of nitrogen adequate (114-227 kg super/ha). The phosphorus
should you choose to use it. can either be drilled in with the seed (best
response) or broadcast around the time of sowing.
24 Chapter 3 / Pasture management during drought periodsYou can also read
