Professor, School of Biology, Institute of Science, Suranaree university of Technology, Nakhon Ratchasima, Thailand

Biograph
Dr. Chaiseha, Professor in Biology in School of Biology, Institute of Science, Suranaree university of Technology, Nakhon Ratchasima, Thailand. She earned her Ph.D. in Animal Physiology at the University of Minnesota, USA. Her research interest is in reproductive neuroendocrinology with emphasis on the roles of vasoactive intestinal peptide, gonadotropin releasing hormone, dopamine, mesotocin, prolactin, leptin, neuropeptide Y, and other hormones/neurohormones/neuropeptides upon the regulation of maternal and feeding behaviors in birds. She was awarded the Hy-Line International Research Award from the Poultry Science Association. She has published book chapters and 48 original research papers in peer-reviewed international journals.

Speech Title: Roles of neuropeptide Y and leptin during the reproductive cycle in the native Thai chicken

Abstract: The growth rate of native Thai chicken is low when compared with that of imported chicken and it is noticeable that they change their food intake during the reproductive stages. During incubation, the hens eat less and stop laying, resulting in low production of eggs and chicks. Neuropeptide Y (NPY) and leptin involved in food intake regulation in birds and mammals. The distributions of hypothalamic NPY-immunoreactive (-ir) neurons and fibers and plasma leptin concentrations were investigated during the reproductive cycle in the native Thai chickens utilizing an immunohistochemistry technique and an enzyme-linked immunosorbent assay, respectively. The results revealed that NPY-ir neurons and fibers were distributed throughout the hypothalamus with the greatest density located in the paraventricularis magnocellularis (PVN). Differences in the number of NPY-ir neurons in the PVN were found across reproductive stages. The numbers of NPY-ir neurons were lowest in non-egg laying (NL) and egg laying (L) hens and significantly higher in egg-incubating (INC) and chick-rearing (R) hens. Plasma leptin concentration was high in NL hens, lowered to a minimum concentration in L hens, and increased gradually in INC and R hens. Changes in body weight were inversely related to the number of NPY-ir neurons across reproductive stages. Low plasma leptin concentrations were observed in chickens having relatively greater ovary and oviduct weights. These findings suggest that the NPYergic system in the PVN and leptin plays an important role in the regulation of food intake during the reproductive cycle in this non-seasonal breeding tropical species.

Key words: Birds, Food intake, Hypothalamus, Leptin, Native Thai Chicken, Reproductive Cycle