Glucagon and Neuromedin U Suppress Food Intake in Broiler Chicks

Several peptides show different effects on food intake between broiler and layer chicks. For example, the central administration of R-melanocyte-stimulating hormone decreased food intake in layer chicks but not in broiler chicks. The central administration of agouti-related protein increased food intake in layer chicks but not in broiler chicks. We previously reported that glucagon and neuromedin U (NMU) suppress food intake in layer chicks when administered centrally. However, the effects of these peptides on food intake in broiler chicks have not been examined. In the present study, we thus examined whether these peptides also show anorexigenic effects in broiler chicks. The intracerebroventricular administration of glucagon significantly suppressed food intake and increased plasma glucose concentration in broiler chicks. The hyperglycemic effect of glucagon had been shown in layer chicks in our previous studies. Intracerebroventricular administration of NMU significantly suppressed food intake and induced wing-flapping behavior in broiler chicks as well as in layer chicks. All our findings demonstrate that glucagon and NMU function as anorxigenic peptides in both broiler and layer chicks.