Seasonal rotation trial shows sheep resilience and adaptation

 

Gains and lessons: what our grazing sheep taught us this season

 

By Dr Danica Parnell 
Research Fellow, Farming Systems Research
School of Agriculture, Food and Ecosystem Sciences

 

The long-term trials at Dookie are investigating drought-resilient farming practices, especially focusing on mixed farming systems that integrate sheep grazing with crop production. In these systems, pastures and dual-purpose crops are used in multi-paddock rotations. Monitoring sheep growth on the various forages is an important component of the overall project.

 

 

 

This project is led by Victoria Drought Resilience Adoption & Innovation Hub partner The University of Melbourne and is part of the Long-Term Trials (LTT) for Drought Resilient Farming Practices grants scheme, supported through the Australian Government’s Future Drought Fund (FDF).

 

Monitoring daily sheep-growth rates in the paddock was made easier this season with the introduction of two automatic portable livestock scales from Optiweigh ®. These units, purchased with funding from NorVicFoods and the Dookie Future Farms Trust Fund, provide the ability to collect precise, real-time live weight data of sheep in the paddock, and gain clearer insights into flock and pasture performance.

The trial has two mixed farming systems with livestock compared with an intensive cropping control (canola-wheat rotation). One system replicates a mixed farm with annual pastures (vetch-canola-wheat) where livestock are brought in seasonally when forage is available to simulate a trade-lamb enterprise. The other replicates a mixed farm with ley pastures (clover-clover-canola-wheat) with sheep remaining in the system all year to simulate a self-replacing merino flock. The grazing pressure expected in the trade-lamb system and the self-replacing system are simulated on trial using merino wethers. The grazing rotation schedule for both trial systems wrapped up with steady weight gain trends, despite long dry spells in April-May and August-October.

 

Annual pasture system: rotation results

• In the mixed-farming annual pastures system (rotation of canola, wheat, vetch), sheep did not graze canola due to insufficient plant growth (known as ‘biomass’).
• On dual-purpose wheat, sheep averaged gains of 160g/day over 37 days.
• Vetch pasture supported average gains of 173g/day over 72 days, though growth rates varied: in one group, sheep gained 190g/day for 62 days; in two other groups, gains were 160–180g/day over 81 days.
• Average wool yield for this system was 5.62kg (range 4.6–6.6kg).

Ley pasture system: rotation results

• In the ley pasture system (canola, wheat, sown clover), canola was again not grazed due to limited biomass.
• Sheep on dual-purpose wheat gained 125g/day over 21 days.
• Second-year clover saw gains of 170g/day over 42 days.
• First-year clover yielded strong short-term gains of 208g/day (across 10 days before shearing).
• Average wool yield here was 5.45kg (range 5.4–5.5kg).

Our “trade” lambs have now been moved off trial, to rest on farm pasture until next season. In the ley system, sheep have begun grazing permanent pastures, including lucerne.

 

 

 

 

Learn more about Dr Parnell’s work in “The secret life of sheep: how technology and animal behaviour research are shaping agriculture” in a Faculty of Science Masterclass, as part of National Science Week 2025.

 

 

 

 

 

Resources and further reading

• See our earlier trial update, about quantifying water use by summer weeds.
• Learn more about Long-Term Trials via the 2023 media release announcement.

 

Contact for further information: Prof James Hunt, Professor & William Farrer Lectureship in Agronomy, School of Agriculture, Food and Ecosystem Sciences (email james.hunt@unimelb.edu.au) or Prof Michael Tausz, School of Agriculture, Food and Ecosystem Sciences (email: michael.tausz@unimelb.edu.au)

 

Caption: The trials at Dookie are designed to measure outputs, while also helping producers to plan for variable rainfall and make informed decisions about feed, rotations and flock management.