Breeding Objectives - setting and getting change
| Project start date: | 30 April 2020 |
| Project end date: | 10 January 2025 |
| Project status: | In progress |
| Livestock species: | Sheep, Lamb |
| Relevant regions: | NSW, Victoria, Tasmania |
| Site location: | Northern Victoria: Horsham; Yarrock; Winchelsea; Glenthompson; Violet town / South Australia: Kingston |
Summary
The aim of this PDS is to benchmark the genetic potential of six commercial Merino flocks and ensure that genetic and phenotypic potential of weaners aligned to a stated breeding objective, driving genetic progress.
Objectives
By December 2025, across 6 commercial merino flocks in Victoria to:
Objective 1) Benchmark the existing genetic and phenotypic potential of six commercial merino flocks against the Sheep Genetics database.
Key deliverables 1.
a) Undertake flock profile testing of current ewe lambs (n=20) at marking. 1.
b) Collection of key phenotypic indicators including weaning and post-weaning weight, fibre diameter and fleece weights of the latest ewe lamb drop.
Objective 2) Develop breeding objectives with group members.
Key deliverable 2.
a) Run a Bredwell/Fedwell training activity to establish breeding objectives for demonstration flocks, that address genetic strengths and weaknesses identified during the benchmarking process.
b) Group members (observer participants not directly involved in flock profiling) will undertake Bredwell/Fedwell training to develop their own breeding objective, that incorporates methods to drive genetic improvement.
Objective 3) Evaluate producer attitudes and practices to ram procurement and assess changes in attitudes and actions based on an awareness of the genetic potential of the ewe flocks, and a stated breeding objective.
Key deliverable 3.
a) Eighty Pre, Mid and Post KASA Surveys of producer attitudes to ram purchasing decisions.
b) Report outlining changes in ram purchasing decisions based on new knowledge of flock genetic potential and having a written breeding objective. We anticipate that upwards of 75% of members of the lambs alive group (core and observer producers) will have a written breeding objective at the end of this project and made changes to their breeding decisions in relation to ewes and rams.
Objective 4) Quantify the impacts of changes in ram selection on genetic merit and phenotypic performance of subsequent ewe lambs.
Key deliverable 4.
a) Flock profile report for ewe lamb drop, sired by newest cohort of rams.
b) Collection of key phenotypic indicators including weaning and post-weaning weights, fibre diameter and fleece weights of the ewe lambs sired by the updated ram team.
c) Transform the collected phenotypic data into an economic analysis (outputted as gross margin/DSE) that accounts for changes in productivity, specifically mortality rates (lamb survival) and kg production (meat and wool) per dse (calculated from weaning weights and wool production).
Progress
The online sheep discussion group ‘LambsAlive’ has been working with an MLA and Agriculture Victoria supported demonstration to test how setting a breeding objective, and then monitoring the progress towards that objective, can benefit a production system. With five sites located throughout southeastern Australia, producers have used the flock profile tool to track changes in genetic potential of their flocks. Improvements in key performance traits (that includes weaning weights, post weaning growth, reproductive rates and wool traits) have been incorporated into an economic model that demonstrates changes in Net Benefit and Net Present Value. Improvements in any one trait may drive a financial gain, however, there are likely tradeoffs between traits that need to be accounted for – the model has been used to quantify tradeoffs such as a 10% improvement in pregnancy scanning rates offsetting a reduction in weaning weights from 32 to 27.5kg, to deliver a Net Benefit of $162 in year two associated with this change. The model has also been used to investigate the relationship between increasing lamb sales and decreasing wool values to assess overall net benefit of a change in genotype. All modeled host farm scenarios where there has been a change in ram genotype have resulted in increased Net Farm Benefits and improved Net Present Values. For more details on the demonstration, contact Nick Linden (Agriculture Victoria) 0438 369 486.
