Optimising Age of Weaning in Cattle
| Project start date: | 19 December 2022 |
| Project end date: | 01 December 2026 |
| Project status: | In progress |
| Livestock species: | Grass-fed Cattle, Grass-fed Beef |
| Relevant regions: | Western Australia, Mediterranean |
| Site location: | WA: South Coast region |
Summary
This producer Demonstration Site (PDS) project aims to demonstrate that weaning cattle 60 days earlier than each participant’s current practice has the potential to improve pasture use efficiency allowing improved stocking density, conserve high value feed stuffs for finishing weaner cattle and conserve the body condition of breeding females improving their ability to both calve successfully and rebreed at the subsequent mating opportunity.
Objectives
By May 2026, in the Esperance Region of Western Australia, Asheep will engage 11 core producers & a minimum of 20 observer producers to:
- Demonstrate across 5 demonstration sites that:
- Calves weaned 60 days earlier than their control group siblings can be managed to prevent a reduction in weight gain comparatively measured after the control calves are yard weaned.
- Cows with calves weaned earlier will gain or maintain more weight and have higher average body condition scores (BCS) than the cows from the control group to the point of traditional weaning on the same pasture, demonstrating a reduction in maintenance requirements (15.5 kg DM vs 6 kg DM per day) and apparent partitioning of resources to BCS.
- Cows with calves that have been weaned earlier will have maintained more weight, better body condition scores, and will have an improved pregnancy rate in their subsequent mating.
- Enrolled producers will realize that better utilisation of forage will improve their kgs of beef per hectare turn off for the same quantity of forage additionally reducing their net carbon contribution per kg of beef produced per hectare.
- Conduct a cost benefit analysis to determine the economic impact on weaner weight, cow repreg rate, feed efficiency and potential to increase stocking rate, as well as impact on net carbon.
- Implement skills and training development with core and observer producers via workshops, newsletter articles, field day discussion and You Tube videos.
- 75% of core producers will have intention to adopt earlier weaning practices. 50% of observer producers will be considering practice change and 25% will intend to implement.
- 100% of core producers and 75% of observer producers will have improved their knowledge, skills and confidence in relation to understanding the impacts of time of weaning
Progress
The Optimising Age of Weaning Cattle Producer Demonstration Site (PDS) project was undertaken in the Esperance region of Western Australia in response to producer interest and uncertainty about whether calves in local beef systems are being weaned at the optimal age, and whether earlier than traditional weaning could be used as a management tool without creating unacceptable production or economic trade offs. In particular, producers wanted locally relevant data on the impacts of earlier weaning on calf growth, cow body condition and subsequent management decisions under variable seasonal conditions. The PDS was hence developed to demonstrate the application of earlier weaning practices than the local norm.
The project was delivered through on‑farm demonstration sites over three breeding seasons (2023–2025). At each site, first‑calving cows were used, and calves were randomly allocated to either an earlier weaning treatment (targeting 60 days earlier than the producer’s usual practice) or a traditional weaning treatment. Calf weight gain, cow weight, and cow body condition score were measured, with management of early‑weaned calves varying by site depending on feed availability and system design. Extension activities, including field days, producer discussions and written case studies, were embedded throughout the project.
Across sites and seasons, calves that were weaned earlier were generally lighter at the traditional weaning point and often had lower average daily gain. Cows whose calves were weaned earlier consistently maintained higher bodyweight and body condition. Results varied markedly between seasons and systems, highlighting the strong influence of feed availability and management. Subsequent pregnancy and cow metric data was difficult to obtain, and the results did not show an improvement amongst cows whose calves had been weaned earlier the previous years.
The project provided producers with realistic, locally generated evidence to inform flexible weaning decisions. It demonstrated that early weaning can be a valuable tactical tool for managing cow condition and feed demand in challenging seasons; however, the results also showed that achieving minimal commercial impact on calf weights is highly dependent on feed quality, supplementation and management, and proved difficult to achieve consistently across sites.
