Balanced Breeding,

Built on a Multi-Disciplinary Collaboration

Dr Brad Walmsley

NSW DPI has a long history of R&D into breeding for differences in carcass attributes, including the development of a 'visual muscle score' herd, where trained people use their eyes and rank animals in terms of their muscle distribution.  DPI has been conducting this research for over 30 years and have successfully created divergence in muscling distribution and carcass yield between selection lines at a given liveweight at slaughter. Different carcass yields at the same liveweight means that higher muscled animals don’t require any more feed, for example, higher-muscling keeps the overall cost of producing a carcass the same which helps increase profit.  During his first 6 years with DPI, he was involved in research developing 3D camera technology where, instead of a person visually assessing muscle score, they were using 3D cameras to create 3D computer images of animals to make visual muscle score assessments.

His job at AGBU is focussed on developing Selection Indexes, and getting these Indexes used in beef cattle breeding.  BREEDPLAN (the major Australian beef cattle genetic evaluation system) produces estimated breeding values (EBVs) relating to animal characteristics, but having these EBVs doesn't tell us which is the best way to select for increases in overall profit.  Selection Indexes put all the information together relating to production economics and animal genetic potential (through EBVs) to allow people to get an idea how animal selection will change your profit in the desired direction.  To do that you have to be able to work at the interchange between genetics and production, and that is basically what my background is.

There have been quite a few highlights since coming to work as part of the AGBU team, and one of these is being involved in the upgrade of the indexing system.  We now have the capability of fully describing what the feed costs are on-farm in an annual production cycle which gives us a lot more utility with how the indexes can be constructed and how they can work.

Another highlight is working on the Southern Multi-Breed project and being on the team of the DPI Retail Beef Project.  Brad also co­ supervised AGBU PhD candidate, Nipa Sarker, who used data from the project in her PhD looking at primal distribution in the carcass, that is, looking at the proportional distribution of parts of the carcass, in both pigs and beef cattle.  Doing projects with HDR researchers has benefits for both DPI and AGBU.  DPI gets some of its data analysed and has the results included in publications.  The benefit of Nipa's work for pig and beef genetics, is that it tells us that there is something we can do to increase the value of the carcass by changing the distribution of primals.

Brad's research experience helps bring the biology, economics and genetics of production systems together in the indexing systems used in BREED PLAN.  An emerging area of attention is the inclusion of welfare and carbon emission traits into the breeding goal, which will be areas of future DPI and AGBU focus.

More information about the Southern Multi Breed project can be found at the NSW DPI website.