Plasma triglyceride and glucose clearance in broiler-type and White Leghorn chickens with different degrees of adiposity

Broiler-type and White Leghorn chicks were given diets containing 30.5, 26.2, or 22.3% protein with and without addition of 5% corn oil during an 8- to 9-week conditioning period. The absolute weight of the abdominal fat pad was greater in the broiler-type birds on all dietary treatments. As a percentage of body weight the abdominal fat pads were similar in broiler-type and White Leghorn birds only when the diet contained 30.5% of protein without added oil. Following a 16-hr fast, plasma glucose was higher in the broiler-type than in the White Leghorn birds, whereas plasma triglyceride concentrations were higher in White Leghorns. In birds refed a high-fat meal, plasma glucose showed little change except in the broiler chickens previously fed the 30.5% protein diet without added oil. In these birds plasma glucose declined over a 5-hr period to reach a mean value of 130 mg/100 ml. Plasma triglyceride concentrations in both breeds were markedly elevated within 45 min of refeeding with a high-fat meal, but the peak concentrations were higher in the White Leghorns than in the broiler-type birds. Previous consumption of the high-oil diet increased postprandial triglyceride concentration in the plasma of the broiler-type but reduced it in the White Leghorn chickens. The difference in response of the chickens of the different genetic stocks is attributed to differences in the development of the activities of the systems associated with 1) fatty acid absorption and movement of triglycerides from the intestinal mucosa to the circulation and 2) clearance of plasma triglycerides to the adipocytes as a result of lipoprotein lipase activity.