Use of electronic probes for classifying lamb carcasses

Area of Science:

• Animal Science
• Meat Science
• Agricultural Engineering

Background:

• Objective lamb carcass classification is crucial for trade and quality assurance.
• Current manual GR (Gr) measurements have limitations in speed and objectivity.
• Electronic probes offer potential for automated, on-line grading systems.

Purpose of the Study:

• To evaluate the accuracy and suitability of commercial and developmental electronic probes for on-line lamb carcass grading.
• To compare probe measurements with manual GR and Toland probe measurements.
• To assess the prediction of carcass water and fat content using probe data.

Main Methods:

• Four electronic probes (Hennessy, AUS-Meat, Swedish FTC, Ruakura) were tested on approximately 300 lambs over six trials.
• Probe measurements were compared against manually measured GR (total tissue thickness over the 12th rib) and Toland probe measurements.
• Statistical analysis (R-squared values) was used to determine the accuracy of predicting GR, carcass water, and fat percentages.

Main Results:

• All probes, combined with carcass weight, explained over 70% of the variation in GR on the right side.
• GR measurements from the left side predicted GR on the right side with 92% accuracy.
• Commercial probes with carcass weight predicted 36-49% of the variation in carcass water and fat percentages; manual GR probe achieved 55-58% accuracy on chilled carcasses.
• Chilled carcass measurements yielded better prediction accuracy than hot carcass measurements.

Conclusions:

• Electronic probes, particularly when combined with carcass weight, provide a viable method for objective lamb carcass grading.
• While prediction accuracy for carcass composition is moderate, it shows potential for on-line application.
• Further refinement and validation on chilled carcasses could enhance the utility of these electronic grading systems.