Video analysis is a novel tool in cattle breeding and may be used to increase the proportion of valuable cuts in carcasses. The weights of different cuts can be predicted through automatic analysis of digital carcass images, and the heritability of carcass cut composition is significant. These results, based on Irish data, are presented in a thesis by Thierry Pabiou at the Swedish University of Agricultural Sciences (SLU).
Beef produced in Ireland is exported to many European countries including Sweden and Irish beef breeders aim to produce high quality beef with a high proportion of valuable cuts. In Irish abattoirs, digital images of cattle carcasses are routinely taken after slaughter to derive so called EUROP grades for classification of conformation and fat content. Thierry Pabiou at the Swedish University of Agricultural Sciences has now investigated the feasibility of using cut weights predicted from video image analysis (VIA) in the Irish beef breeding program, in order to improve beef quality and the economic value of the beef.
Evidence that genetic factors affect weight distribution among different cuts was found in a study using data from more than 1000 dissected carcasses. The influence of heritage on the variation in the weights of 14 different cuts varied between 3 and 80 per cent. The primal cuts were grouped into four wholesale cuts according to their retail values: lower value cuts, medium value cuts, high value cuts, and very high value cuts. Equations to predict wholesale cut weights were then derived from VIA image parameters. The accuracy of predicted cut weights was always higher than 70 per cent.
The prediction equations were then applied to a large national dataset of carcass digital images. Genetic analysis of predicted wholesale cut weights revealed a medium high to high heritability (18 to 40 per cent). There were moderately strong genetic relationships between the various predicted wholesale cut weights and strong genetic relationships between predicted wholesale cut weights and animal price at weaning and post-weaning age, suggesting a benefit of indirect selection when data on carcass cut weights are not yet available.
The studies that Thierry Pabiou presents show that including predicted wholesale cut weights in a breeding program increases genetic gain for carcass quality compared to the current selection practice of using EUROP conformation scores. His conclusion is that video image analysis therefore is a useful tool in breeding for improved carcass quality in Irish cattle.
Attention needs to be drawn to calving and maternal traits as they tend to respond negatively to selection for growth or carcass traits.
Studies have shown that digital grading overcomes the weakness of visual grading, where bias can occur between groups of carcasses. Classifier judgement can vary over time, and differences can be observed between classifiers. Moreover, digital grading of carcasses offer a new potential for any country willing to develop it simply because digital images store much more information than carcass weight, conformation and fat.
The studies have been performed in cooperation between the Department of Animal Breeding and Genetics, SLU, the Irish Cattle Breeding Federation, and Teagasc – the Irish Agriculture and Food Development Authority.
Thierry Pabiou, Department of Animal Breeding and Genetics at the Swedish University of Agricultural Sciences, defends his thesis Genetics of carcass composition in Irish cattle: Exploiting carcass video image analysis on Wednesday, January 24, 2012 at 9:15.
Venue: Loftets Hörsal, SLU, Ultuna, Uppsala, Sweden
Opponent: Professor Dorian Garrick, Iowa State University, USA
More information: Thierry Pabiou, tpabiou@icbf.com
Link to the complete thesis (pdf):
http://pub.epsilon.slu.se/8533/
Press images (may be published without charge in articles about the dissertation)
Digital images of carcass used to predict wholesale cut weights
Photographer: Irish Cattle Breeding Federation
Thierry Pabiou, currently working at the Irish Cattle Breeding federation in Ireland
Photographer: João Dürr
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http://www.slu.se/en/about-slu/press-room/