Influence of stimuli from chicks on behavior and concentrations of plasma prolactin and luteinizing hormone in incubating hens
Résumé
Removal of eggs from the nests of incubating birds or substitution of eggs for chicks disrupts incubation behavior and induces changes in the secretion of prolactin and luteinizing hormone (LH). The aim of the present study was to determine how different stimuli, such as physical contact with eggs and tactile, visual, and/or auditory cues from chicks, interact to control the transition between incubation and brooding and to induce changes in prolactin and LH plasma concentrations. Physical contact with chicks, in the presence or absence of eggs, induced brooding behavior and an immediate fall in plasma prolactin concentration and a gradual increase in LH concentration. Vocalizations, particularly clucking and food calls, increased rapidly while incubation and nest attachment disappeared slowly. No change in plasma prolactin or