Climate Impacts on Dairy Farms

The Australian dairy sector is already seeing and will increasingly experience the impacts of climate change, including physical risks.

Australian dairy farmers have already seen the impacts of climate change on their businesses, including:

In Gippsland and Northern Victoria, where pasture growth patterns have changed, and spring now starts about four weeks earlier.
In the Murray region irrigation area, where reduced water availability has favoured annual pastures over perennial pastures. Farmers are investigating pastures such as lucerne, which have deeper root systems and can tolerate longer periods of water deficiency.
In response to more competitive land and water use in South Australia, as well as reduced availability and quality of water, some farmers are already making changes to their systems, while others are relocating.

You can get information on climate and weather risks for the next few days and months from the Bureau of Meteorology and expected changes over coming decades from Climate Services for Agriculture.

Impacts on livestock

Climate change will lead to more extreme hot days and higher temperatures overnight – all of which can impact the health and welfare of a cow. At temperatures above 25 degrees Celsius, the animal begins to feel uncomfortable, reducing its ability to produce milk and get in-calf. Cows have evolved to possess a range of mechanisms to off-load heat, but problems can occur if temperatures and humidity remain high. Heat load accumulation can occur when hot nights simply do not allow animals to recover.

Impacts on pastures

Depending on the dairy region, hotter climates may lead to farms experiencing heat/moisture stress over summer while shortening the peak of spring growth and delaying the start of autumn. Short rotation pasture systems and winter fodder crops may become more attractive than irrigating pasture over summer.
Increased temperatures may make tropical pasture species like paspalum, kikuyu, maize and forage sorghum more competitive at the expense of the nutritious temperate species like ryegrasses.
Irrigation requirements will increase with higher temperatures and lower rainfall. Irrigation availability is likely to decrease, magnifying the impact on pasture production.

Impacts on farm water supplies

Climate change projections indicate farm water supplies will decrease due to lower rainfall, higher evaporation, changes in seasonal patterns as well as more frequent and longer droughts.
These factors generally cause run-off to be reduced at more than double the rate of rainfall reduction. As a result, farmers who rely on surface run-off for irrigation or dairy supplies could face more severe water shortages.
Groundwater is recharged by rainfall and farmers using this water source could also face availability challenges such as declining water levels.

Impacts on biosecurity

Future climate changes will influence the spread of livestock and pasture pests, disease and weeds. See the Biosecurity page for more on managing this risk.