Effects of Dietary Fat and Protein Sources on Performance, Lipid Content and Mixed Function Oxidase in Liver, and Fat Deposition and Adipocyte Cellularity in Abdomen in Broiler Chickens.

Abstract

Abdominal fat deposition and the cellularity, and lipid content and mixed function oxidase (MFO) activity in livers were studied in broiler chickens fed isoenergetic and isonitrogenous diets which were different in the fat and protein sources.Feeding corn oil (CO) or chicken oil (CH) tended to decrease abdominal fat content compared with feeding yellow grease (YG) at 56 days of age, although no significant differences were observed in general performance. In female chickens, the decrease in the abdominal fat pad was associated with decrease in the adipocyte volume. At 21 days of age, lipid and triglyceride contents in the liver of chickens fed CO or CH were numerically lower than those in YG-fed chicks, and hepatic MFO activity was elevated by feeding CO.Feeding high fat diet (HF) increased liver triglyceride content at 21 days and tended to increase abdominal fat content at 56 days of age. Feeding fish meal (FM) as a major protein source increased the abdominal fat content in comparison with feeding soybean meal+fish meal (SFM), irrespective of dietary fat content, at 21 days of age. In chickens fed low fat diet (LF) for 21 days, FM decreased lipid and triglyceride contents in the liver and the decrease was associated with an activation of the hepatic MFO activity.