Age-Related Differences in Levels of Blood Chemistry Parameters and Cardiac Marker Proteins in Commercial Broilers

ABSTRACT The effect of age on levels of blood biochemical parameters in broiler chickens is largely unknown. The purpose of the present study was to investigate physiological alterations of blood chemistry variables in renal, liver, lipid and cardiac profile in commercial broilers at the age of 2(n=20) and 7 weeks (n=40). The results showed that compared with broiler chicks at the age of 7 weeks, those at the age of 2 weeks had significantly higher levels of blood urea nitrogen, creatinine, uric acid, triglycerides and the enzymes alanine aminotransferase and alkaline phosphatase. Older chicks, on the other hand, displayed significantly higher levels of total protein, albumin, total cholesterol and the enzyme gammaglutamyl transferase. Although a significantly higher activity of cardiac enzyme aspartate aminotransferase and a significantly lower activity of lactate dehydrogenase were observed in older chickens, younger broilers exhibited a significantly higher concentration of the cardiac-specific marker troponin T. There was no significant age-related difference either in the levels of cardiac enzymes creatine kinase, creatine kinase MB or in glucose level. Cardiac troponin T concentration correlated significantly with that of CK-MB in both groups of animals studied. These results underline the importance of age as a significant contributor of variation in levels of several blood chemistry parameters and cardiac marker proteins, especially cardiac troponin T in broiler chicks