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.
Avian infectious bronchitis.
Avian infectious bronchitis (IB) is caused by the gammacoronavirus infectious bronchitis virus (IBV). The virus causes infections mainly in chickens and is a significant pathogen of commercial meat and egg type birds. IB is an acute, contagious disease characterised primarily by respiratory signs in growing chickens. In hens, decreased egg production and quality are often observed. Some strains of the virus are nephropathogenic and produce interstitial nephritis and mortality. The severity of IBV-induced respiratory disease is enhanced by the presence of other pathogens, including bacteria, leading to chronic complicated airsacculitis. Diagnosis of IB requires virus isolation or demonstration of viral nucleic acid from diseased flocks. Demonstration of a rising serum antibody response may also be useful. The widespread use of live and inactivated vaccines may complicate both the interpretation of virus isolation and serology findings. The occurrence of antigenic variant strains may overcome immunity induced by vaccination.