Climate change and broadacre livestock production in Western Australia

How will livestock production be affected by climate change?

Climate and livestock production models provide projections on the effects of climate change: the effects vary with location, soil type and management.

• In the higher rainfall areas of the south-west, increased temperature in winter and early spring and reduced waterlogging could benefit livestock production by:
  • increasing forage production
  • reducing livestock feed requirements (lower energy maintenance costs)
  • increasing survival of young animals or shorn sheep during cold and wet periods.
• In northern and eastern agricultural areas and during the summer months, increased temperatures could negatively affect livestock production by:
  • heat stress reducing forage growth or length of growing season
  • heat stress reducing livestock growth, reproductive success and milk production
  • increasing livestock water requirements
  • decreasing water availability and quality
  • changing livestock exposure and susceptibility to parasites and disease.
• Reduced rainfall and higher temperatures could reduce forage production by up to 10% over the agricultural areas:
  • The percentage decline in livestock productivity and profitability will be greater than the decline in pasture growth.
  • Inter-annual variability in pasture production is likely to increase.
• Increased carbon dioxide concentrations could reduce pasture digestibility and protein content if tropical (C4) plants become more dominant, but this reduction may be offset by increased growth rates of leguminous species where water is not limiting.

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How can livestock producers adapt to climate change?

In the short term, combining new technology, operations and management will be needed to offset the increasingly negative effects of climate change: this may actually improve enterprise profitability. By 2050–70, a complete change of the feed base may be required in lower rainfall areas unless there are sustained improvements to terms of trade.

Some adaptations are listed below.

Improve animal husbandry and health

Provide shade, shelter and cooling systems

Options include:

• shelter trees
• shade cover over yards and raceways
• shade cover over troughs and water sources to keep the water cool (livestock intake reduces as wtare gets warmer)
• shelter sheds (e.g. for dairy cattle).

Use livestock breeds or species that are adapted to warmer conditions

Options include:

• select within-breed for heat tolerance, such as plain-bodied rather than wrinkly skinned sheep
• select heat-tolerant breeds and crosses, such as Brahman cattle and crosses
• select more heat-tolerant species, such as sheep or goats, instead of cattle
• select for disease and parasite resistance
• develop animal welfare protocols for movement, handling and transport during hot periods
• provide access to cool, clean water and shade during hot periods.

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Maintain forage productivity and quality

Improve pasture rainfall use efficiency

Plant available water is the most limiting factor to forage production in most areas of Western Australia. In a hotter, drier climate, water-use efficiency usually decreases. There are technologies to improve water available for plant growth:

• Remove physical constraints to root growth by:

  • drainage to reduce waterlogging, such as deep drains, raised beds, surface drainage
  • deep-ripping to remove hard pans
  • applying gypsum to improve soil structure of responsive clays
  • using controlled traffic farming to reduce compaction
  • increasing soil organic carbon content with perennial pastures.
• Remove chemical constraints to root growth by:
  • applying micronutrients and macronutrients to prevent deficiencies
  • liming acid soils to increase soil pH
  • drainage to reduce soil dispersion of sodic soils.
• Use pasture varieties/species with increased ability to explore the soil profile with better:
  • root morphology (deep versus lateral roots)
  • tolerance of chemical soil constraints, such as pH, boron, aluminium and transient sodicity
  • ability to grow through soil physical constraints, such as hard pans or transient waterlogging.
• Improve soil water-holding capacity with:
  • increased soil organic carbon content
  • deep-ripping
  • gypsum to improve soil structure
  • controlled traffic farming to reduce compaction
  • claying (surface application/delving/spading) to reduce non-wetting.
• Root rip along tree lines to control tree–crop/pasture competition.
• Reduce evaporation from soil by increasing deep infiltration of rainfall.
• Reduce run-off by retaining adequate ground cover.

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Use best-adapted pasture species and varieties

• Use varieties or species with increased drought resistance, such as stay-green varieties that have:
  • physiological tolerance of hot conditions
  • physiological tolerance of dry conditions with:
    • ability to maintain cell turgor
    • stomatal resistance.
• Use varieties or species which are better able to exploit the fertilisation effect of increased atmospheric carbon dioxide to improve water use efficiency.
• Use varieties or species bred to resist current disease risks and new risks presented by changing climate.

Use grain and graze strategies

• Use dual-purpose crops, such as grazing crops.
• Sow winter crops into summer-active perennial forages.

Optimise inputs using precision farming technologies

• Use remotely sensed data to map productivity.
• Use soil testing.
• Use variable rate fertiliser application based on yield potential and soil tests.

Improve fodder conservation 

• Use hay.
• Use silage.

Use confined feeding

• Confined feeding systems use feed supplements more efficiently when paddock feed is limited, and also allow better management of ground cover and early season pasture growth.

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Use decision tools

Use tools, such as forage production models incorporating utilisation rates, seasonal and long-range weather forecasts, remotely sensed production data and soil-water calculators, to estimate livestock carrying capacity and feed requirements and assist with decisions about:

• dealing with extreme temperatures (dairy cows are at high risk)
• scheduling feed supplementation and forward-contracting feed supplies
• forward planning for agistment
• value of soil amelioration
• matching stocking rates to projected carrying capacity
• modifying timing of mating and weaning based on seasonal conditions.

Provide good quality livestock water

• Design dams and catchments to cope with current and projected rainfall and evaporation rates.
• Treat roaded catchments with chemical sealants to reduce the rainfall run-off threshold to 4–6 millimetres.
• Plan for increased investment in tanks and dams storage.

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Reduce business risk

• Use a combination of rotational grazing, supplementary feeding and fodder conservation for livestock to adapt to dry and variable seasons.
• Use systems facilitating trade cattle through alliances between pastoral and southern broadacre enterprises.
• Change enterprise mix:
  • adjust ratio of cropping to livestock according to terms of trade, land capability and long-term climate trends
  • use new markets for existing agricultural residues, such as straw for biofuel
  • diversify by growing new agricultural products:
    • carbon farming.
• Increase enterprise size to gain advantages:
  • efficiencies of scale
  • reduced local risks by farming over a wider geographical area.
• Use all-risk insurance policies.
• Increase access to off-farm income.
• Undertake training.
• Maintain information and innovation sharing networks and links.

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Reduce soil erosion risk

• Manage grazing to maintain at least 50% vegetation cover.
• Use windbreaks on very erosion prone sites.
• Use claying on suitable soils.
• Use contour farming, including drainage in high rainfall regions.
• Maintain vegetated buffers along waterways.

While many of these adaptations are considered good practice, they vary in applicability across the grainbelt.

We recommend that:

• managers assess their location-specific costs and benefits before making significant changes
• producers continue making incremental changes in the short term
• and investigate and plan for more transitional and transformative changes for the medium and longer term.

For more information

Download Bulletin 4870 Climate change: impacts and adaptation for agriculture in Western Australia