Objective evaluation of lean meat yield and EUROP scores for Icelandic lamb carcasses by video image analysis

VIAscan®. The best single predictor of LMY% (R2: 30%) and FAT% (R2: 74%) was the GR-measure. The agreement in classification between VIAscan® and a panel of expert classifiers showed that 82% of carcasses were classified identically for conformation and 73% for fat which is within the minimum limit set by the Icelandic authorities. The heritability for VIAscan® yield prediction as proportions was generally high, ranging from 0.39 to 0.63,lowest for Shldr% and highest for Loin%. Heritability of viaEUROPc was 0.32 and 0.29 of viaEUROPf while heritability was 0.35 for pEUROPc and 0.31 for pEUROPf. For weight related traits (Leg (kg), Loin (kg), Shldr (kg), HCW and LW) the direct heritability ranged from 0.17 to 0.21, maternal heritability from 0.09 to 0.11 and maternal environmental effects (c2) from 0,21 to 0,23. For traits evaluated in vivo the heritability ranged from 0.27 to 0.52, lowest for UMS and highest for ML. The genetic correlation between viaEUROPc and pEUROPc was 0.94 and 0.82 between viaEUROPf and pEUROPf. It was concluded that this correlation was sufficiently high to define EUROP scores assessed by these two methods as identical traits. The correlations between LMY% and in vivo traits were favorable and not unexpected except for the positive correlations between Loin% and traits measuring fat. This was explained by unsuitable methods used for deboning loin and flanks. Genetic and phenotypic correlations between EUROP scores and in vivo traits were similar for both grading methods ranging from -0.53 to 0.70 for viaEUROP and -0.56 to 0.77 for pEUROP. The results indicate that VIAscan® is capable of predicting LMY% and classifying in EUROP classes with sufficient accuracy for the Icelandic sheep industry. Results for genetic parameters also indicate that the technology can replace the current grading system. Objective carcass grading by the VIAscan® technology is thus an option for the Icelandic sheep industry. However, the costs of implementing the method need to be evaluated before it can be put into practical use.

Author dc:creator

• Eyþór Einarsson 1976-

Contributors dc:contributor

• Landbúnaðarháskóli Íslands

Language dc:language.iso

en

Handle dc:identifier.uri

http://hdl.handle.net/1946/23658

OAI identifier oai:identifier

oai:skemman.is:1946/23658