Food intake in the domestic fowl: effect of intrahepatic lipid and amino acid infusions.

Five experiments were conducted to determine the effect of hepatic and jugular infusions of amino acid and lipid solutions on short-term food intake of cockerels. Neither jugular nor hepatic infusions of amino acids had any effect on food intake of Single-Comb White Leghorn (SCWL) cockerels. Lipid infusions had no effect on SCWL cockerels when administered intrajugularly but decreased food intake significantly when infused intrahepatically. In contrast, no effect on food intake was observed when Rock-Cornish (RC) cockerels were infused intrahepatically with lipid. Thus, it appears that the liver of the SCWL cockerel is not responsive to plasma amino acid concentrations but is sensitive to circulating lipid levels. This lipid sensitive mechanism may be important in the peripheral control of food intake in a chicken such as the SCWL which has been bred for egg production but may be desensitized in fowl such as the RC broiler which has been selected for large body size and feed consumption.