Impacts of heatwaves on dairy production

Photographer: Rachelle MeyerBackground

Milk production in dairy cows is sensitive to ambient conditions, with declines observed during periods of heat stress. Australian dairy farmers are subjected to substantial climatic variability including heatwaves that will increase in frequency and severity as climate change progresses. This research aims to determine the extent of the heat stress affect generally, differences across regions and farms of Australia, as well as the effectiveness of potential responses to alleviate the impacts of heat stress.

Project outline

The project includes two major research activities. The first is a review of the literature and the second is analysis of milk-tanker pickup data. Dr. Rachelle Meyer is conducting both activities under the Forewarned is Forearmed project led by Prof. Richard Eckard and Dr. Ann-Maree Graham at PICCC, University of Melbourne. The analysis of dairy company milk-pickup data is a collaboration with Dr. Debra Hudson and Dr. Catherine de Burgh-Day at the Bureau of Meteorology (BOM) and representatives from Fonterra, Lactalis and Norco dairy companies.

Bibliographic network analysis and systematic literature review:

A bibliographic network analysis of the heat stress and milk production literature was done with VOSviewer. The systematic review focused on literature with data on the impact of heat stress on milk production in dairy cows using the PRISMA framework. The protocol used in performing the systematic review is available here. The review aims to gain a general understanding of the heat stress and milk production literature, synthesize the currently available information and detect trends; and identify research gaps. The synthesis of data addresses the sources of variability in the response to heat stress, including methodological differences, cow and farm characteristics, as well as summaries of the effectiveness of management options to alleviate heat stress impacts on production.

Analyses of milk tanker pick-up data:

A database was created comprising milk tanker pickup data over the period 2000 to 2017 inclusive from three dairy companies and BOM weather station data. The database includes 1- and 2-day pickups from over 2,500 farms across eastern Australia with data on milk volume, percent fat and protein, and cell count.


Further information and related resources

Links to the resulting publications will be included here when available.

Quantifying the impact of heat stress on milk production in eastern Australia in a changing climate Meyer, R.S.- Presentation for 3rd Climate Change and Agricultural conference Budapest, Hungary, March 2019
Systematic literature review protocol file Meyer, R.S.- PRISMA framework protocol used for the above systematic literature review
Heat Stress and Milk Production: a literature review and analysis of eastern Australian Data Webinar AgVIc (DJPR) Use password to access: Heatstress19.
Heat stress impacts and responses in livestock production Meyer, R.S., Graham, A-M, Eckard R.J. (2018) Heat stress impacts and responses in livestock production. Reducing Heat Stress, AGBU Breeding Focus 2018 (Chapter 4).

This project is supported by funding from the Australian Government Department of Agriculture and Water Resources as part of its Rural R&D for Profit program in partnership with rural Research and Development Corporations, commercial companies, state departments and universities. Meat &Livestock Australia (MLA) is responsible for the overall management of the project.