Producer case study: Increasing number of lambs weaned / ewe unit

Jason Stokes operates ‘Mt Erin’, a large-scale mixed farming enterprise located in Chapman Valley, WA. With a focus on maximising productivity and sustainability, Jason participated in an MLA Producer Demonstration Site (PDS) aimed at improving lamb survival through precision ewe feeding.

Jason has implemented strategic breeding, feeding and management practices to enhance flock performance while adapting to the changing market landscape. This case study outlines the integrated approach he has taken to livestock management, highlighting his commitment to using precision tools and making data-driven decisions to ensure the success and sustainability of his operation.

Operation structure

Mt Erin spans 5,200ha and operates with a 60:40 cropping-to-livestock ratio. The farm currently runs 5,600 breeding ewes and is transitioning from 4.5 to 3 full-time labour units, driving the need for greater efficiency across all areas of operation. The stocking rate is maintained at a sustainable rate of 10 DSE per winter-grazed hectare, supporting both livestock and cropping success.

Jason started the project with 600 maiden ewes and implemented split joining, with joining commencing in mid-November.

Genetics and breeding objectives

Mt Erin runs Leahcim-bloodline Merino ewes, selectively bred for early growth, easy-care traits, and high wool and meat production potential. Sires are bred in-house via an artificial insemination program, with 90% selected based on Australian Sheep Breeding Values (ASBVs), including growth and fleece traits. Visual selection continues to play a key role, with ewes evaluated for conformation, wool length and brightness, and ease of management.

The enterprise has transitioned from the DP+ index to a combination of Self-Replacing Merino and Maternal indexes to align with commercial and maternal lamb production targets.

Reproduction management

In more recent years, Jason has implemented split joining. He has found this practice allows for tighter lines of lambs to mark, wean and market, and to track ewe reproduction performance. Being a November joiner, he relies on teasers to ensure ewes are cycling and uses a joining rate of 2.5%. Pregnancy scanning has been in place since 2006.

He also introduced eID in 2018, which has allowed for tracking individual ewe performance. The type of data Jason collects includes:

• pregnancy status and litter size
• lamb marking and weaning weights
• hogget weight, fleece weight and fleece traits
• body weight and condition scoring.

Mt Erin has set weaning target weights of 20kg (singles) and 18kg (twins) at 11 weeks. Post-marking mortality is maintained at approximately 3%, aided by high-input monitoring and animal health protocols.

Flock selection and culling strategy

Post-shearing data – including fleece weights and traits, body weight and condition scores – is used to index ewe hoggets each April. The top 10% are selected for artificial insemination, the bottom 10% culled, and an additional 3–5% removed based on visual appraisal. Ewes are culled immediately if they:

• fail to scan in-lamb
• fail to rear a lamb
• present udder defects.

Feeding system and nutrition

Jason employs a diverse and structured feeding strategy across the year. Over summer, sheep graze stubbles and are either trail-fed, provided a mixed ration or have access to self-feeders. Like most mixed growers, Jason uses home-grown commodities and fodder and assesses the cost of energy and crude protein to determine the most cost-efficient feed sources. Different classes of stock receive different rations depending on the production status and the food-on-offer.

A typical ration would consist of:

• ewes: 75% wheat, 10% canola, 15% lupin stubbles (shifting toward 40% wheat, 40% lupin, 20% canola)
• weaners: 80% lupin, 20% oats/barley.

Jason confinement feeds from March to May to allow for efficient allocation of feed sources and land allocation to allow for winter crop grazing. In confinement, sheep receive a ration of 60:40 barley to lupin, with ad lib barley straw. Jason places a large emphasis on feed budgeting to ensure enough grain/hay is conserved. Each ewe is budgeted for ~45kg of grain per year.

Loose licks enriched with calcium and sulphur support pre-lambing and lambing nutrition. Causmag, limestone and salt are provided when grazing crops. Winter cereal grazing is practiced, contributing to condition recovery before lambing.

Lambing and management systems

Mobs are split 15 days prior to lambing into production status, with the emphasis on managing mob size for lambing. Single-bearing ewes have a maximum of 400 head in a mob and twin-bearing ewes have a maximum mob size of 200 head.

Lambing paddocks are sheltered and lupins are spread in grassy areas to provide 10 days of feed. Lamb growth is considered critical – the entire system is designed around ensuring continuous growth.

Animal health program

Jason’s approach to animal health programs is a preventative one, with key treatments provided at critical times to ensure the health and productivity of the flock:

• pre-lambing: long-acting drench, ADE, Glanery 7
• marking: Glanery 7, Trisulfon, Clik
• weaning: Glanery 7 booster, combination drench, lice treatment
• parasite control: monthly faecal egg count testing; treatment as needed.

Technology and tools

Jason's operation integrates a suite of tech tools, including:

• TruTest Data Link, AgriWebb
• Innovate IoT (for tank, pump, weather monitoring)
• Drought Feed Calculator, LTEM
• Safety Culture (shearing shed audits)
• Lambing Planner (paper version)
• WhatsApp for real-time team communication.

Jason has found these tools useful for planning, measuring production, reporting and managing resources. The data collected through these tools drives Jason’s production and management decisions, helping him optimise performance, improve efficiency and make informed decisions for the future of the operation.

Challenges and strategic priorities

Major challenges include labour availability, managing Barber’s Pole worm and achieving timeliness of operations. The primary improvement focus is increasing lamb growth from birth to weaning without compromising stocking rates. Under financial pressure, no components are removed from the program. The scale of the operation requires proactive rather than reactive management, especially regarding parasite control. Jason’s non-negotiables for his business’s success are:

• pregnancy scanning
• achieving target condition scores pre-lambing
• maintaining uninterrupted lamb growth.

Enterprise change: focus on store lambs

Jason is modifying his enterprise objectives to suit the evolving market, to ‘produce the best quality store lambs for the feeder market’. He has calculated that the time value of finishing lambs and the current store prices make it hard to make the math work to feed to slaughter. Currently, store lambs are more profitable per kg than finished lamb. When factoring in shearing 1.5 times a year, grain prices, losses and financing costs, $90/head in September starts to look appealing compared to $150/head finished. He believes this strategy will allow Mt Erin to run another 500 ewes.

Results from the Producer Demonstration Site (PDS)

Reproductive outcomes at the PDS on Jason’s property showed marked improvement over the project period, particularly in twin conception rates, reflecting the successful adoption of best-practice joining and nutritional strategies. The losses between scanning and marking here were the lowest across all sites included within the project, due to this site having the highest single ewe average, converting to greater lamb survival.

While fleece income remained consistent and provided some financial stability, declining lamb prices and rising input costs substantially reduced overall profitability. To ensure sustainable performance, future efforts should prioritise improving lamb survival post-scanning, particularly among twin-bearing ewes.

Conclusion

Jason's operation is an advanced enterprise leveraging precision breeding, structured feeding systems and integrated technology to drive productivity and sustainability in large-scale sheep production. The combination of rigorous data collection, targeted nutrition and strict selection delivers consistent lamb growth and reproductive success, positioning Jason's enterprise as a leader in practical genetic application within commercial systems.

With the shift to producing high-quality store lambs, Jason is poised to improve operational efficiency while adapting to market conditions, ensuring continued success in the long term.