Lipogenesis in turkeys and chickens: a study of body composition and liver lipogenic enzyme activities.

1. Carcase composition, fat deposition and the activities of three liver lipogenic enzymes were compared in turkeys and chickens fed ad libitum on two different isocaloric diets, respectively adapted to chickens (C) and to turkeys (T). Diets differed in their protein content, being higher by 60 g/kg in diet T. 2. Chickens were much fatter than turkeys and exhibited higher activities of acetyl-coenzyme A carboxylase (EC 6.4.1.2) and malic enzyme (EC 1.1.1.40). 3. The carcase composition of turkeys was not influenced by the type of diet administered, while chickens fed on diet C were fatter than chickens fed on diet T. Compared to diet T, diet C enhanced malic enzyme activity, whatever the species and age. 4. A good correlation between abdominal fat and total fatness was observed in both species but especially in turkeys. 5. In conclusion, hepatic lipogenesis is much lower in turkeys than in chickens.