Relationship Between Plasma Free Thyroxine Levels and Some Biochemical Parameters in Two Strains of Broiler Chickens

摘要

The thyroid is an endocrine organ found in all vertebrates and the avian gland is similar in manyrespects to that of mammalian. In birds as in other vertebrates, product hormones are both thyroxine(tetra-iodothyronine or T4) and tri-iodothyronine (T3). Thyroid hormones influence all major metabolicpathways and are involved in the regulation of the basal metabolism of the majority of tissues andconsequently in the metabolism of lipids, carbohydrates and proteins. In this study, the relationship betweenplasma free thyroxine, cholesterol, triglyceride, glucose and total protein in Isa 15 strain and Arbor Acres strainduring the fattening period was investigated. At 28, 35 and 42 days of age, ten birds per strain were sacrificedby decapitation and blood for analysis was collected from the jugular vein. The concentration of free T4 wasrecorded by radio- immuno- assay method (RIA) and other parameters were measured using clinical chemistrytests on the ARCHITECTci 8200 system. Our data from this study indicates that in broiler chickens, plasma lipidprofile and plasma glucose profile were not correlated to plasma free thyroxine. However, a significantcorrelation between plasma free thyroxine and plasma total protein (r=0.42, p=0.01) was described in ArborAcres strain. A significant difference (p<0.05) for plasma total protein was observed between the two strains.No significant difference between the two groups was reported for the other measured parameters. The studysuggested conducting more investigations on the dynamics of free thyroid hormone concentration changesin blood plasma and their correlations in broiler chickens.