A survey of pre-slaughter conditions, halothane gene frequency, and carcass and meat quality in five Spanish pig commercial abattoirs

A total of 116 deliveries, comprising 15,695 commercial pigs delivered to f ive abattoirs, were surveyed during winter and summer. Information about on -farm fasting, transport duration and stocking density, and lairage time wa s collected. Cortisol, creatine phospho-kinase (CPK), and lactate, and DNA for halothane genotype were analysed in a subsample of pigs at exsanguinati on in every journey. Electrical conductivity (PQM) in semimembranosus muscl e (SM) and carcass characteristics (Fat-o-Meater and skin damage) were meas ured in each carcass. pHu of SM was analysed in the laboratory in a subsamp le in every journey. Carcasses were identified as PSE or DFD based on PQM a nd pHu, respectively. The n gene frequency ranged among abattoirs from 54 t o 8%. Mean lean content was 58.9% for nn, 57.3% for Nn, and 55.8% for NN pi gs, though a difference of 2.5% lean was observed between two abattoirs wit h the same n gene frequency. A straight relationship of the incidence of se rious PSE carcasses and n gene frequency was found. The overall incidence o f serious PSE and DFD carcasses was 6.5 and 12.5%, respectively. A higher i ncidence of PSE carcasses was found in summer; in deliveries with < 12 h on -farm fasting; with transport stocking densities > 0.40 m(2)/100 kg pig; an d in transports of < 2 h duration. A higher incidence of DFD carcasses was found in winter; with transport stocking densities < 0.40 m(2)/100 kg pig; transports of > 2 h duration; and lairage times > 9 h. Cortisol level in bl ood increased in winter and decreased after 12-18 h fasting time. A rise in the lactate concentration was observed in pigs transported in high stockin g density (< 0.40 m(2)/100 kg pig) and for a longer time (> 2 h). All blood stress indices increase as increasing lairage time. Carcasses with more sk in damage had higher levels of cortisol, CPK and lactate, and higher incide nce of DFD meat, compared with non and low skin damage carcasses. (C) 2000 Elsevier Science Ltd. All rights reserved.