Gastro-intestinal tract structure and energy metabolism in broilers

Relationships between apparent metabolisable energy (AME) of the diet and gut structure were examined in two experiments designed to expose the extent of potential variation in AME by application of treatments involving cleanliness of the rearing environment, sex of chickens and addition of mannan oligosaccharide (MOS) to the diet. It was concluded that large between-bird variation in AME reported in previous studies could not be explained by differences in the weights of duodenum, jejunum and ileum relative to metabolic body weight, or by changes in villus height or crypt depth in these sections of the small intestine. The possibility that variation in AME is associated with functional differences in gut epithelial tissue is worthy of investigation.