Evaluation of a Video Image Analysis system for the prediction of carcass and meat quality in genetic improvement programmes
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Date
2009Author
Rius-Vilarrasa, Elisenda
Metadata
Abstract
Video Image Analysis (VIA) is a digital camera based technology that extracts
relevant information from images using purpose tailored image processing software.
In the present work, the VSS2000 image analysis system from E+V Technology
GmbH has been used in a large lamb abattoir to determine the value of carcasses in
an objective, consistent and automated way. In this thesis results are reported of
several experiments conducted within the framework of two UK-funded projects.
The aims of the research were (i) the calibration and validation of the VIAtechnique
for the evaluation of lamb carcasses under UK abattoir conditions, with the
view to scientifically examine the accuracy and precision of information from the
VIA systems as the basis for a value-based marketing system, (ii) to investigate the
use of VIA measurements (weights of primal meat yields and carcass dimensional
measurements) in sheep breeding programmes to improve carcass and meat quality
and (iii) to evaluate the potential of this technology to reward increased carcass
quality associated with the use of breeding strategies based on the inclusion of a
quantitative trait locus (QTL) for improved muscularity.
Accuracy, precision and consistency of The Meat and Livestock Commission (MLC)
carcass classification scheme, currently used in UK abattoirs to evaluate carcass
quality, was compared against the VIA system in the prediction of various primal
joint weights. The results highlighted the advantage of the VIA system being on
average 2% more accurate (measured as coefficient of determination: R2) and 12%
more precise (measured as root meat squared error: RMSE) in predicting weight of
primal meat yields (leg, chump, loin, breast and shoulder) of the lamb carcasses than
the MLC carcass classification scheme.
The genetic analysis of VIA-based predicted primal joint weights showed substantial
additive genetic variance, suggesting that their use in sheep breeding programmes
could improve carcass quality either by an improvement of conformation or by an
increased weight of the most valuable primal cuts, without an increase in fatness.
Favourable associations between VIA primal weights and performance traits indicate that selection based on VIA traits is possible without a negative effect on average
daily gain, live weight and cold carcass weight.
Although computer tomography (CT) and dissection found in related studies
significant effects of a Texel muscling-QTL (TM-QTL) for increased muscularity in
the loin region, in the present study they could not be identified by both, the current
industry carcass evaluation system for conformation and fatness and the VIA
system. A calibration of the VIA system against CT measurements resulted in
improved VIA prediction equations for primal meat yields and also showed a
moderate potential to estimate loin muscle traits measured by CT and to detect
partially the effect of the TM-QTL on these traits.
The results of the research demonstrated that VIA is a consistent method to measure
carcass composition and that it improved the prediction (accuracy and precision) of
primal meat yields compared to the present MLC scoring system. The estimated
genetic parameters for VIA primal meat yields suggested that selection for increased
lean meat yield from lamb carcass measured using VIA can contribute to genetic
improvement of carcass quality without increasing carcass fatness. The results
suggest that VIA technology installed in abattoirs could provide the means for the
development of a value-based marketing system by paying for weights of the most
valuable primal cuts measured using VIA.