In poultry nutrition the prescribed tendency is to maximise the nutrient density of the feed in order to achieve optimal performance. Sources of dietary fibre are excluded as they are understood to dilute the diet and to decrease digestibility. This misconception appears to ignore the fact that poultry have a biological requirement for dietary fibre and the gut physiology to benefit from the provision of the correct sources of fibre in their diets. Poultry have a hind-gut consisting of double pairedcaeca and the colon. In hens the caeca have a length of up to 25cm, the colon is up to 11cm long. The poultry's large intestine ends in the cloaca. Caeca, colon and coprodeum (part of cloaca) are known to have highly active transport system to absorb glucose, ions and water across the epithelia. It is a characteristic of the poultry's intestine that the chyme is also moved from the cloaca back to the caeca with reverse peristalsis to optimize nutrient uptake. The caeca of healthy birds have up to 1011 bacteria/g of digesta within one week after hatch. From this time the bacterial density keeps constant according to a subsequent growth of bacteria in synchrony with digesta passage rate. This microflora provides vital health effects as it produces metabolites to provide energy for the epithelial cells in the hind-gut and stabilizes the gut environment. This is of special importance to avoid dysbacteriosis and prevent colonization of pathogens. Imbalance in the hind-gut's microflora causes problems likeClostridia proliferation, non-specific enteritis or wet litter, accompanied by significant economic consequences like reduced feed conversion efficiency, poorer survivability and impaired growth.
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