Genetics of Merino meat value and lifetime performance Final Repor
Did you know, this project aimed to provide more data to improve the accuracy of genetic parameters estimates and increase the number of Merino sheep with ASBVs for meat yield and meat quality traits.
| Project start date: | 28 February 2018 |
| Project end date: | 29 July 2021 |
| Publication date: | 29 June 2022 |
| Project status: | Completed |
| Livestock species: | Sheep |
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Download Report
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Summary
Sheep producers managing dual-purpose Merino enterprises aim to diversify their businesses by producing both meat and wool. However, to achieve that through selection there is a need for more information on the ‘right genetics’ for components of meat and wool production, and reproduction. Using data from several Merino Lifetime Productivity Project sites, performance for a range of key meat production and quality traits was recorded and genetic parameters estimated for carcass value, its component traits and meat quality traits.
Objectives
This project aimed to provide more data to improve the accuracy of genetic parameters estimates and increase the number of Merino sheep with ASBVs for meat yield and meat quality traits. With this data contributing to analyses across resource flock data sets, design of selection indexes for dual-purpose production systems in Merinos would be able to be revisited and predicted rates of gain reviewed. The project also aimed to calculate carcass value for a range of Merino sires.
Key findings
Heritability estimates confirmed that genetic variation for many carcass composition and meat quality traits of Merinos is available to be exploited through selection to improve these traits.
· There is scope to improve intramuscular fat, retail colour stability (defined as retoxy/met) and iron and zinc contents of Merino lamb loins and pH of the topside in order to meet consumer preferences for eating quality and freshness and recommended dietary guidelines.
· Selection to improve lean meat yield in Merinos will need to be balanced with improving meat quality traits due to unfavourable genetic relationships with intramuscular fat, shear
force and iron content. Carcass fatness, based on its association with higher reproduction, would also need attention.
· Selection to improve either intramuscular fat or tenderness of Merino lamb will result in redder fresh meat and less dark meat after 2 days of retail display, but the meat will be less red and discolour more after 2 days of retail display. Selection to increase fresh meat lightness would have little impact on meat redness and yellowness, but would increase the rate of discolouration after 2 days of retail display.
· Carcass value was found to be heritable. Increasing carcass value was associated with increases in dressing percentage and carcass fatness, favourable changes in pH and meat redness under retail display, but darker and more discoloured meat after 2 days of retail display. This pattern of responses would also follow selection for increased hot carcass weight.
· Preliminary economic analyses demonstrated that carcass value among Merino sires had a range of $31.33/hd under a mixed farming system while the range under a fine wool production system was $62.48/hd.
Benefits to industry
This project has increased the number of records within the MERINOSELECT database for carcass composition and meat quality traits from Merino carcasses and increased the number of Merino sires with ASBVs for these traits reported by Sheep Genetics. The data is now available to be combined with Merino data from other carcass reference populations to enable more accurate estimation of genetic parameters for meat production and quality, including relationships with wool production, reproduction and growth traits, across breeds and specific to the Merino breed. Subsequently, ASBVs of higher accuracy will be reported by Sheep Genetics, which will increase the accuracy of selection and lead to increased rates of genetic gain from dual-purpose selection indexes applied in Merino breeding programs.
MLA action
Implementation of the recommendations and future research highlighted in the final report.
Future research
Combined analyses of Merino data across resource flocks (Information Nucleus flock, MLA Resource Flock, MLP Flock) are planned in collaboration with the Animal Genetics and Breeding Unit to improve the accuracy of genetic parameters for carcass composition, meat quality and eating quality, including genetic correlations with wool production, reproduction and growth traits. Further expansion of the genomic reference population for hard to measure traits such as reproduction and eating quality is required to underpin industry genotyping.
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For more information Contact Project Manager: Peta Bradley |
