ACTA UNIVERSITATIS AGRICULTURAE ET SILVICULTURAE MENDELIANAE BRUNENSIS SBORNÍK MENDELOVY ZEMĚDĚLSKÉ A LESNICKÉ UNIVERZITY V BRNĚ

INGR, I., BOŽEK, R., JŮZL, M.: Myopathy of slaughter chickens. Acta univ. agric. et silvic. Mendel. Brun., 2006, LIV, No. 5, pp. 49–56 High-powered means of slaughter chickens production cause on certain individuals abnormal biochemical development of postmortal changes in their muscles. It consequently lead to interferences of sensory quality of the chicken meat. So called myopathies of the chicken breast meat occur in the low extent. It is typical variation in dark colouring of breast muscle. Veterinary supervision confiscates chickens embodying myopathy by reason of sensorical unacceptable dark muscle colour. Deepness of colour is evaluated by adspection of veterinary supervisors. It is tendency leading to find out objective parameters for evaluating this sensual chicken meat colour variati on. Incidence of the chickens with myopathy has been evaluating for 3 years in big poultry slaughter, therewithal high-quality chickens and chickens with perspicuous myopathy have been taking out of slaughter-line. Electric conductivity values and pH values were measuring during 60 till 330 minutes post mortem in breast muscles. Aproximately 9 millions chicken was annually slaughtered and 13 thousands of them was confiscated out of the slaughter line by reason of myopathy. It amounts to 0.14 per cent of annually count of processed chickens. Myopatical chickens had significantly higher muscle pH values as com pared with healthy ones. Healthy chicken muscles decreased on ultimative pH values aproximately past 3 hours post mortem. It means pH 6.03, and after 300 minutes decreased to pH 5.82. However, myopatical chickens values varied from pH 6.46 to pH 6.30. Concurrently measured values of electric conductivity significantly corellated with pH values.