Submitted to: Physiology and Behavior
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 20, 1999
Publication Date: N/A
Interpretive Summary: It has been known for years that lipid stores are well regulated. Recently a new hormone termed leptin, which is secreted by liver and fat tissue has been identified in birds. It is known that leptin is involved in appetite regulation as well as energy metabolism in mammals. When administered into the brain of mammals, food intake is inhibited. Whether similar functions can be attributed to leptin in poultry is unknown. The study reported herein investigated the effect of centrally administered leptin on food and water intake in meat-type and egg-laying chickens. It was observed that leptin injected in a dose-dependent manner inhibited feed intake in both types of chickens. This effect was specific for food as water intake was unaffected. The results of this study strongly support the hypothesis that leptin is an important integrator of appetite in birds. The results are of interest to other scientists.
The effect of intracerebroventricular (ICV) injection of leptin was investigated using broiler and Single Comb White Leghorn type chickens. These represent relatively fast and slow growing birds, respectively. The ICV injection of leptin decreased food intake both broilers and Leghorns in a dose-dependent manner. The most efficacious dose appeared to be 10 ug in nboth types of chickens. Water intake was generally not affected by leptin indicating that this effect was not due to general malaise. It appears that leptin can act within the central nervous system of birds to decrease food intake.