Predicting live and carcass lean using bioelectrical impedance technology in pigs

Bioelectrical impedance technology was used to evaluate 36 pigs (103 +/- 1.5 kg) and their cold carcasses (75.5 +/- 1.9 kg) with a four-terminal plethysmograph. Pigs were transported to the abattoir, weighed, and live impedance measurements recorded. The whole carcass and right side were weighed and cold carcass resistance and reactance measurements were obtained on the right half. Length (cm) was measured as the distance between the detector terminals, The right carcass half was separated into lean, fat, bone, skin and inseparable (inseparable lean and fat) portions and individually weighed. Lean and inseparable components were each ground three times and two samples from each component were collected and stored at - 20 degrees C until analyzed. The right carcass sides averaged 38.2 kg (S.D. = 1.1). Live and carcass resistance, reactance, and lengths were 38 Omega, 5.4 Omega, 87.5 cm, and 221 Omega, 60 Omega, 76 cm, respectively. Total carcass lean and percent lean averaged 40 kg and 53%, respectively. Carcass impedance measurements (weight, resistance, carcass reactance, and carcass length) accounted for 88.4% of the variation with a RMSE = 1.26 kg for total carcass lean. However, live resistance, reactance and length explained only 62.6% of the variation (RMSE = 2.04 kg) of the total carcass lean. Bioelectrical impedance has potential as a robotized procedure in an online system in a commercial plant with a minimum of perturbation for estimation of total lean of pork carcasses. (C) 1999 Elsevier Science B.V. All Fights reserved.