Ante-mortem detection of PSE and DFD by infrared thermography of pigs before stunning.
Using water-holding capacity and colour measurements (L and b values) as objective quality parameters, we have observed an increasing incidence of meat quality defects with the increasing skin surface temperature of pigs by infrared thermography prior to stunning. Below 32·2°C, 50% of the 32 pigs measured had normal meat while the other half showed meat quality defects. Above 32·2°C, however, 71% of the 49 pigs showed meat quality problems classified as moderate PSE (6%), PSE (30%), moderate DFD (22%) and DFD (37%). At this temperature level, meat quality of the remaining pigs was normal and decreased to 29%. Although infrared thermography of live animals cannot predict whether the meat will be PSE or DFD, it seems to be a practical and rapid method to detect pigs who will yield a significant proportion of meat quality defects. An early post-mortem identification of meat quality could supply the missing information.
Thermographic Applications in Veterinary Medicine
Veterinary infrared thermography is a term indicating in vivo digitally imaging an animal with an infrared camera using computer interpretation of thermal maps. Various trials were performed with different species (horse, pig and cows)1,2,3,4,5 to assess the validity of thermographic instrument. Infrared thermographic systems are capable of seeing energy emitted by most objects at a temperature above -35°C. Therefore colour or visible light does not interfere with the possible images seen by thermographic system. The maximum heat emitter is considered a black body which have an emissivity of 1 because it adsorbs all radiated heat. The emission factor of skin is approximately 0.93-0.98 depending on coat quantity and length. Heat is the primary sign of inflammation process and different disease processes affect the microcirculation of the skin. Therefore variations of the skin temperature become interesting indicator of such conditions that can range from specific vascular alterations to referred conditions also physiologically. Since skin temperature may be used in order to estimate tissue integrity because it reflects the underlying circulation and tissue metabolism.
Porcine malignant hyperthermia. I: Metabolic and physiological changes.
Porcine malignant hyperthermia was studied in seven Pietrain pigs under standardized experimental conditions. In five animals malignant hyperthermia was triggered with suxamethonium and halothane, but in two pigs suxamethonium alone was used. Characteristic metabolic and physiological changes were found and these are discussed with regard to a possible mechanism to explain the malignant nature of the syndrome.