Reflux of digesta and its implications for nutrient digestion and bird health

Reflux is the anti-peristaltic induced, retrograde movement of digesta in the gastrointestinal tract (GIT). Previous research has characterized the occurrence and frequency of reflux, as well as the possible effects it has on the well-being of the chicken. Reflux may be both beneficial or harmful depending on the general health of the bird. In a healthy bird, it may present the opportunity for prolonged exposure of digesta to the enzymatic and mechanical systems of the GIT, thus leading to an increase in digestion and absorption time in the upper intestine. On the other hand, pushing caecal contents up into the intestine may increase the chance of undesirable organisms colonising the intestine, possibly resulting in subclinical infections. Another important implication of digesta reflux in chickens may relate to the use of the marker technique for determination of ileal digestibility of nutrients since the technique assumes constant, one-way flow of digesta throughout the GIT. This paper presents a brief review on the digesta reflux phenomenon and speculates how reflux could affect the general health of the chicken and how it may be manipulated by diet.