Improving the climate resilience of the Australian Sheep Flock

Date: Wednesday 20th December 2023

By MFMG Admin

Project code: DN4_23_17

Project manager: MFMG Team

Project duration: November 2023 to December 2024

About the project

Working within five farming systems groups and one Landscape Board, across South Australia, the project will demonstrate practical and easily adoptable strategies which improve productivity of sheep during periods of heat and nutritional restriction.

The objectives of this project are:

to extend the demonstration site work conducted in 2022 / 2023 to generate an additional year of data (2023/2024), and extend the scope of the trial work to measure the impact of the chosen strategies on flock marking and weaning rates.
demonstrate the impact of betaine supplementation and higher doses of Melatonin on thermoregulation and heat tolerance in sheep. Overall, we aim to develop a robust data set demonstrating and quantifying the benefits of the chosen strategies on flock productivity, thus facilitating greater uptake and adoption of practices designed to increase the resilience of the sheep industry during periods of drought and extreme climate.

Project activities

We have selected cost-effective, readily available interventions which, based on our previous on-farm research, are very likely to improve the productivity of sheep during periods of nutritional and climate induced stress.

These management strategies include Melatonin (Regulin®, implant) and supplementary Vitamins ADE (oral drench). We will quantify and demonstrate the benefits of using these supplements with the members of five farming systems groups and one Landscape Board across South Australia.

The project will be implemented on between 20 and 25 commercial farms across a range of environments throughout South Australia, and will also demonstrate treatments at a research farm; the University of Adelaide’s Roseworthy Campus (The Roseworthy Trial Site).

At the Roseworthy Trial Site, we will determine the impact of Betaine supplementation on thermoregulation and water intake of ewes during periods of heat, as well as the impact of different doses of Melatonin on thermoregulation and fertility, with the objective of developing the data required to demonstrate the efficacy of these strategies on producer sites as part of follow on project work in summer of 2024 / 2025.

At the Turretfield Trial Site, we will quantify the benefits of implanting rams versus ewes with Melatonin on thermoregulation and fertility, as well as the impact of Melatonin on ewe oestrous behavior, with the objective of developing the data required to demonstrate the efficacy of these strategies on producer sites as part of follow on project work in summer of 2024 / 2025.

The chosen strategies are designed to improve thermoregulation and anti-oxidant status during periods of extreme heat, increase the efficiency of feed utilisation, increase fertility of heat stressed ewes and rams and increase lamb birthweight and survival. Working within commercial systems, we will quantify the improvement in flock productivity (increased conception rates, pregnancy rates and twinning rates) that occur following their implementation within commercial farming systems, whilst also establishing and demonstrating ease of implementation.

Working within a sub-set of the commercial producer sites, we will also achieve the following:

quantify the impact of Regulin and Vitamin ADE on the number of lambs marked and weaned with monitoring of weight gain and survival (at least 4 sites); and
determine the impact of shade use on ewe fertility, fecundity and body condition change during joining and pregnancy on at least one site.

To increase understanding of the physiological, behavioural and reproductive responses to the treatments demonstrated, this project will also support two student projects (1 honours and 1 PhD) to work within the demonstration sites. The additional data collected as part of these projects will include, detailed thermoregulation and activity measures, hormonal changes and how social hierarchy impacts resource use.

This project builds on work conducted as part of the Innovation Hub, demonstrating a positive impact of Regulin and Vitamin ADE on pregnancy rates and fertility of ewes joined during summer of 2022/2023, as well as evidence that Betaine supplementation improves ewe thermotolerance.

By repeating this work in a second summer and joining period we aim to provide producers with a more robust data set with which to make decisions around their use, as well as a first year’s worth of data demonstrating and quantifying the improvement in marking and weaning rates. Where possible the chosen strategies will be tested on the same producers as 2022/2023, with additional producers also recruited to the project. This project will, therefore, involve between 3 and 5 producers from each of the farming systems groups and landscape boards involved in the project, with additional work conducted on at least one pastoral site.

This provides extensive coverage across a broad range of environments and sheep enterprises in South Australia.