Maximising Dorper Reproductive Performance
| Project start date: | 13 March 2020 |
| Project end date: | 15 February 2023 |
| Project status: | Completed |
| Livestock species: | Sheep, Lamb |
| Relevant regions: | NSW, Western Australia, Victoria, South Australia |
| Site location: | Eyre Peninsula, South Australia: Penong; Ceduna; Coorabie |
Summary
This project aims to demonstrate that the adoption of best practice management can improve the conception rate, lambing percentage, weaning rate and production efficiency of Dorper (& White Dorper) flocks in mixed farming systems.
Objectives
By January 2023, on three prime lamb properties in the far west Eyre Peninsula region of South Australia:
1. Establish base line productivity measures in all participating flocks (9), but with a particular focus on the three demonstration sites (one flock with biannual mating, one with annual mating and one with continuous mating).
2. Demonstrate that the adoption of best management practice (including lambing twin bearing ewes in small mobs) can improve the conception rate, lambing percentage, weaning rate and production efficiency (kg of lamb turned off annually per ewe and per hectare) of Dorper (& White Dorper) flocks by 10% in mixed farming systems.
3. Undertake a cost benefit analysis of the use of eID to monitor individual reproductive performance and inform culling decisions.
4. Undertake a range of training and extension programs with commercial shedding sheep producers on condition scoring, pre-joining management of rams and feed budgeting etc so that:
a. 80% of core producers and 40% of observer producers will have adopted best practice management for Dorper reproduction
b. 100% of core producers and 60% of observer producers will have improved their knowledge and skills in relation to the reproductive performance of Dorpers.
5. Changes in marking and weaning percentages following the adoption of a Campyloba.
Progress
Sheep producers on the far west coast of South Australia had identified decreasing reproduction rates in their self-replacing Dorper flocks. This project was undertaken to demonstrate that the adoption of best management practices could result in an improvement in weaning percentage and turn off of kilograms of red meat per hectare.
Individual ewe performance was monitored for three years in two demonstration flocks, one joining biannually and one joining annually. In addition, four training workshops were conducted.
Monitoring of the biannually joined flock clearly demonstrated the relationship between condition score and conception rate and weaning rate. It became apparent that this was not a sustainable joining strategy for this producer’s production environment and labour model.
The adoption of improved management practices in the annually joined flock including: monitoring of ewe condition score; pregnancy scanning; differential management of single and twin bearing ewes; culling scanned empty ewes; ram soundness checking prior to joining; and timely weaning resulted in an increase in conception rate in the monitored group of ewes from 125% to 159%. Over this period, the whole of flock marking percentage increased from 99% in year 1 to 137% in year 3. Contributing to the final year result was improved seasonal conditions and treatment of some ewes with Ovastim®.
