CHARACTERIZATION OF EMBRYONIC CARDIAC-DERIVED TROPONIN-T IN BROILER CHICKS BLED ONE TO 168 HOURS AFTER HATCHING

Troponin T, a cardiac-specific protein released only from damaged or i njured heart tissue and cells, was measured in the sera from fowl chic ks bled one, 12, 24, 48, 96 and 168 hours after hatching. A peak tropo nin T response was observed 12 hours after hatching in two experiments conducted six months apart. In the second experiment the heterophil/l ymphocyte (H/L) ratios were also increased at one and 12 hours after h atching. The data suggest that the troponin T response in chicks bled 12 hours after hatching, together with the raised H/L ratios at the sa me age, may indicate a physiological stress reaction to the process of hatching, rather than a process which is under direct genetic control .