Changes in the plasma concentration of sexual steroids in domestic hens during forced and hormonally-induced molt
Szelényi, Z.; Pethes, G.; Péczely, P.
Acta Veterinaria Hungarica 31(1-3): 57-63
1983
ISSN/ISBN: 0236-6290 PMID: 6234768 Document Number: 211492
Changes in the function of the ovary were studied in 2 groups of hens subjected to experimental molt. In the 1st group, forced molt was induced by biotechnical methods (withdrawal of feed, drinking water and light and decrease of temperature). In the other group, molt was induced by hormonal treatment (progesterone and triiodothyronine (T3)). The change of feathers was of different character in the 2 groups. The concentration of progesterone in the blood plasma increased significantly in the period of feather loss, while other sexual steroids (testosterone, 17-.beta.-estradiol) were at low levels and estrone even decreased significantly. In later stages of molting, at the time of new feather outgrowth, progesterone concentration tended to decrease. This was accompanied by a significant rise in the levels of estrone and testosterone. The level of 17-.beta.-estradiol was low also in this period. The increase of plasma progesterone at the beginning of molting may be 1 factor responsible for inducing the process. In this period, the low level of 17-.beta.-estradiol and the significant decrease of estrone concentration may have a permissive effect on progesterone, thus facilitating the initiation of molting.