SERUM TROPONIN T VALUES IN 7-DAY-OLD HYPOXIA-TREATED AND HYPEROXIA-TREATED, AND 10-DAY-OLD ASCITIC AND DEBILITATED, COMMERCIAL BROILER CHICKS

Troponin T is a cardiac-specific protein forming part of the contracti le apparatus of striated muscle, and in humans it is a new, sensitive and highly specific indicator of early myocardial damage in 'at risk' patients. Serum troponin T values were investigated in 7-day-old hypox ia- and hyperoxia-treated and 10-day-old ascitic and debilitated comme rcial broiler chicks. The results showed that there was a significant increase in troponin T values in the hypoxic chicks (P< 0.05) compared with their normoxic flockmates. There was also a small, but insignifi cant rise in the troponin T values of the hyperoxia-treated chicks. Th e results confirm previous studies that myocardial damage in these you ng chicks is associated with hypoxia and that the injury caused permit s the measurement of troponin T released from the cardiomyocytes. Sign ificant increases in troponin T were also measured in 10-day-old ascit ic (P<0.05) and debilitated (P<0.02) broiler chicks compared with age- matched control broilers. In both age-groups of birds, the arterial pr essure index, a measurement of right ventricular hypertrophy caused by chronic pulmonary hypertension, was similar with the respective contr ol values and yet the troponin T concentrations were significantly dif ferent. These results demonstrate the importance of this assay in youn g broiler chickens as a marker of early myocardial damage in these bir ds. It is proposed that this assay for troponin T could be a valuable prognostic tool in future genetic selection programmes to reduce the d egree of susceptibility to hypoxia and with it the incidence of ascite s in young broilers.