Prediction of lamb carcase C-site fat depth and GR tissue depth using a non-invasive portable microwave system versus body condition scoring

This study compared portable ultra-wide band microwave system (MiS) versus body condition score to predict C-site fat depth, GR tissue depth and eye muscle depth (EMD) in lambs. Experiment 1 assessed MiS and condition score to predict ultrasound measured C-site and EMD (n = 1549). Precision and accuracy was greatest for the MiS measurement with liveweight included in the model, with a C-site predicted RMSEP of 0.58 mm, R2 0.60 and bias of 0.021 mm and an EMD predicted RMSEP of 2.27 mm, R2 0.72 and bias of 0.088 mm. Experiment 2 (n = 900) assessed pre-slaughter MiS scanning and condition scoring to predict carcase GR tissue depth, C-site fat depth and EMD. MiS performed better than condition score for all three carcase trait predictions, regardless of the inclusion of liveweight, with the highest precision and accuracy for GR tissue depth determination with a RMSEP of 3.68 mm, R2 0.63 and bias 0.072 mm.