Effects of Fasting, and Estradiol-17β and Progesterone Injections on Serum Transferrin, Iron Binding Capacity and Iron Levels in Chickens

Abstract

Effects of fasting and hormone injections on serum transferrin (Tf), total iron binding capacity (TIBC) and iron levels were studied. The egg-laying of hens paused by fasting and the serum vitellin level decreased rapidly. After refeeding, hens began to lay and serum vitellin increased to the similar level as before fasting at 1 week before egg-laying. Serum Tf, TIBC and iron in egg-laying hen decreased rapidly with pause of egg-laying by fasting and showed the similar levels as cocks. By refeeding, these levels recovered to those before fasting. The vitellin appeared in serum of castrated cockerels by estradiol injection and its contents reached to the highest value on the 6th day after injection. By stopping injection of estradiol, the serum vitellin decreased and disappeared on the 5th day after the last injection. Serum Tf, TIBC and iron in castrated cockerels injected with estradiol reached to the highest value from the 6th to 8th days after injection, which similar values as those of egg-laying hen. Those levels decreased rapidly by stopping of estradiol injection and showed the similar levels as before injection. Progesterone had no effect on the changes of these characteristics.