Magnificent Maidens

Summary

Maiden ewes represent about 30% of the breeding ewe flock. However, the scanning percentage of maidens is often about 20% lower than adult ewes. More robust recommendations for liveweight and condition score targets at joining have recently been generated for maiden ewes and therefore the Magnificent Maidens Producer Demonstration Site aimed to demonstrate the current best-bet management guidelines for maiden ewes on-farm. The project included five demonstration sites across southern Australia where producers compared managing the nutrition of maiden Merino ewes based on ‘best-bet’ management versus ‘normal’ management for the farm on their reproductive performance at the maiden joining at 19 months of age and examined carryover benefits at the second joining.

Ewes managed in the best-bet group were heavier and in higher condition score at joining and gained more weight during joining as a maiden than those in the normal group (P<0.001). Ewes in the best-bet group had higher conception rates (93.5% vs 89.1%; P<0.001) and scanning percentages (124.6% vs 113.8%; P<0.001) as a maiden than those in the normal group. Ewes that were heavier and in greater condition score at joining and that gained more weight during joining were more likely to conceive (P<0.01) and be scanned as twin-bearing (P<0.001). Ewes that were in higher condition score at their second joining were more likely to achieve higher conception rates (P<0.01). Ewes that were heavier at their second joining were more likely to be scanned as twin-bearing (P<0.001). Ewes that were pregnancy scanned as twin-bearing as a maiden were more likely to be scanned twin-bearing than ewes scanned dry as a maiden (P<0.01).

Economic modelling showed that producers should aim for maiden Merino ewes to be at a joining weight of 96-98% of standard reference weight and to maintain weight during joining. If producers are currently using established best-practice guidelines, such as Lifetime Ewe Management, these new targets are projected to increase whole-farm profit by 0.5%, income per ewe by $4.90 and weaning rates by 10%. Further work across a range of Merino genotypes and environments is needed to validate the findings and confirm the revised joining targets for the Australian Merino industry. Further analysis would also be valuable to assess the economic importance of achieving these targets.

The ability to evaluate practice change as a result of participating in this project has been limited by the number of producers who completed both pre- and post-project surveys. The project findings have been packaged into best-bet guidelines for extension to industry to help producers improve the reproductive performance and profitability of maiden ewes.

Objectives

By the 30-June 2025 we will:

1. Demonstrate on eight host properties the impacts of adopting ‘best bet’ management of maiden ewes on their reproductive performance and carryover effects on subsequent performance. This will include ewe selection, nutritional management to joining, pregnancy scanning and differential management of singles and twins and lambing group size where appropriate.

2. Implement a series of activities to develop the knowledge, attitudes and skills of ‘core’ and ‘observer’ producers to enable them to more confidently improve the reproductive performance of their maiden ewes by 10% and 5% respectively.

3. Conduct a benefit cost analysis to determine the relative economic performance of ‘best bet’ compared to ‘normal’ management of maiden ewes, and modify the ‘best-bet’ management guidelines to develop a legacy product that would be available for wider distribution across the sheep industry.

4. Extend outcomes, learnings and experiences relating to management of maiden ewes amongst core and ‘observer’ producers within the wider neXtgen Agri network using the neXtgen Agri members site, the neXtgen Agri facebook group and Zoom (Group Video conferencing) calls throughout the project resulting in:

• 100% of core producers and 50% of observer producers adopting or intending to adopt ‘best bet’ management of maiden ewes; and
• 100% of core producers and 80% of observer producers with increased knowledge, skills and confidence in relation to ‘best bet’ management of maiden ewes

5. Present findings at sheep industry forums and extend results through at least eight field days/field walks at host properties and via other grower group networks and consultants.

Key findings

Demonstration site results

On average, ewes in the best-bet group gained more weight before joining, were 1.8 kg heavier and 0.1 condition score higher at joining and gained more weight during joining compared to those in the normal group. Ewes in the best-bet group had higher conception rates (93.5% vs 89.1%; P<0.001) and scanning percentages (124.6% vs 113.8%; P<0.001) as a maiden than those in the normal group. Ewes that were heavier at joining and in higher condition score were more likely to conceive. The magnitude of these effects were greater when ewes were joined lighter and in poorer condition (P<0.01). Ewes that gained more weight during joining were also more likely to conceive (P<0.01). Ewes that were heavier and in higher condition score at joining and that gained more weight during joining as a maiden were more likely to be scanned as twin-bearing and less likely to be scanned dry as a maiden (P<0.001).

Ewes that were in higher condition score at their second joining were more likely to achieve higher conception rates (P<0.01). Ewes that were heavier at their second joining were more likely to be scanned as twin-bearing and less likely to be scanned as single-bearing or dry at the second joining (P<0.001). Ewes that were pregnancy scanned as twin-bearing as a maiden were more likely to be scanned twin-bearing and less likely to be scanned single-bearing or dry at the second joining compared to those ewes scanned dry as a maiden (P<0.01).

Economic analysis

Economic modelling showed that producers should aim for maiden Merino ewes to be at a joining weight of 96-98% of standard reference weight and to maintain weight during joining. Profitability is sensitive to these targets, with higher joining weights and maintaining weight during joining generally leading to greater returns. However, profitability can decline sharply when joining weight exceeds the standard reference weight, due to the inefficiency of weight gain when ewes are in higher condition. Changes in the cost of supplementary feed do not significantly alter optimal nutrition targets, provided that producers can respond to rising feed costs by adjusting the stocking rate (e.g. through destocking) and/or the amount of supplementary feed fed.

The economic impact of implementing the revised targets for maiden ewes will depend on each farm’s current nutritional management. However, under a scenario where producers are currently using established best-practice guidelines, such as Lifetime Ewe Management, the new targets are projected to increase whole-farm profit by 0.5%. Income per ewe would rise by $4.90 and weaning rates would increase by 10%.

Extension and communication

The project utilised online and face-to-face extension and communication activities to foster skill development and adoption across core and observer producers. These included a project webpage and online community, online workshops, blog articles, an online course, field days and webinars. The online ‘Magnificent Maidens’ community on the neXtgen Agri Hub grew to 1211 members by the end of the project. Significant engagement was also seen via social media, including a post reach of up to 13,000 for one of the case study videos. Updated best-bet guidelines for the management of maiden ewes to optimise reproductive performance and profitability have been developed for extension to industry.

Monitoring and evaluation

The ability to evaluate practice change and impact on production efficiency, reproductive performance of maiden ewes and profitability of producers as a result of participating in this project has been limited by the number of producers who completed both pre- and post-project surveys. Many participants who completed the post-project survey had already adopted key practices for managing maiden ewes to maximise reproductive performance before participating in the project, including weighing and condition scoring maiden ewes, setting weight and condition score targets for maiden ewes, calculating the energy requirements of maiden ewes, pregnancy scanning for multiples in maiden ewes, separating single- and twin-bearing maiden ewes in late pregnancy and lambing them separately. Most producers who had not adopted these practices before participating in the project had either implemented them or intended to implement them.

Benefits to industry

This project has extended knowledge related to improving the reproductive performance of maiden ewes and built the skills of sheep producers that have engaged with the project as a demonstration site or observer. The project has enabled ‘best-bet’ guidelines for the management of maiden Merino ewes to be updated with new targets at joining. These guidelines will help producers to improve the reproductive performance of their maiden Merino ewes, increasing the productivity and profitability of Merino enterprises across Australia.

Future research

  This project has identified optimal nutrition targets for maiden ewes based on updated relationships derived from the Producer Demonstration Site findings. Further work across a range of Merino genotypes and environments is needed to validate the findings and confirm the revised joining targets for the Australian Merino industry. Further analysis would also be valuable to assess the economic importance of achieving these targets and which targets are of greater economic importance. Further work is required to understand the reasons behind the carryover benefit of being scanned as twin-bearing as a maiden and whether the performance of twin progeny born to maiden Merino ewes is poorer than that of progeny from ewes scanned with singles. This also influences culling decisions for ewes that are scanned dry as a maiden and the nutrition strategy for the remaining flock, which could be explored with further economic modelling. More comprehensive guidelines for managing maiden Merino ewes could be developed with further work involving larger numbers of maiden Merino ewes and a broader range of Merino genotypes, to understand whether the response to better nutrition or the optimal management targets vary between genotypes.