The Effect of Forced Feeding and of Dietary Protein Level on Enzymes Associated with Digestion, Protein and Carbohydrate Metabolism in Geese

Abstract

Digestive and metabolic enzymes were studied in geese in which fatty livers and obesity were produced by forced feeding. The effect of different protein levels before and after the forced feeding period was investigated. The concentrations of most of the digestive enzymes in pancreas and intestinal chyme were reduced following forced feeding. Fattening caused an increase in the liver xanthine dehydrogenase (XDH) activity and a decrease in kidney arginase when expressed on a nitrogen basis. Concentrations of RNA and DNA were decreased in the fatty livers while their absolute amounts were increased due to liver enlargement. Glucose 6-phosphate dehydrogenase (G6PDH) activity in the liver decreased, while 6-phosphogluconate dehydrogenase (6PGDH) activity increased. Addition of protein during the period prior to forced feeding increased XDH activity in liver and arginase activity in kidneys. However, this difference disappeared after the forced feeding period. The addition of moderate amounts of protein during the forced feeding period had only slight effects on the enzymic activities tested.