Possible AVT Involvement in Regulation of Body Water Balance during the Incubation Period in the Chabo Hen

Abstract

Plasma concentrations of arginine vasotocin (AVT), pituitary prolactin messenger RNA (PRL mRNA) and weights of ovary and oviduct were measured at different reproductive stages in the Chabo hens. Concentrations of plasma AVT dropped significantly at the laying stage but increased at 1-week of incubation stage and was sustained during the whole incubation period. The concentration decreased markedly at the brooding stage of rearing chicks. At the laying stage weights of ovary and oviduct were the highest while it remained at other stages. Pituitary PRL mRNA expression was high during the incubation period as previously observed in the Chabo hens. The present results may indicate the sustained level of plasma AVT is involved, at least in part, in the regulation of body water balance.