Effects of age and diet on the viscosity of intestinal contents in broilerchicks

1. A standard methodology was developed for the determination of the viscos ity of digesta in broiler chickens. 2. The best variables considered for use (those which gave the most consist ent results) were: digests obtained from the foregut area (defined as the r egion from the pancreas to Meckel's diverticulum) using a minimum of 6 repl icates and offering experimental diets for 5 d before slaughter at 25 d of age. 3. There was evidence that the viscosity of digesta obtained from the hindg ut (defined as the region between Meckel's diverticulum and the ileo-caecal junction) was reduced the longer the birds were fed on one diet, suggestin g possible dietary acclimatisation. Hindgut digesta viscosity from birds fe d on a barley-based diet over a longer period was 10% to 30% less than that of birds fed for 5 d. 4. There was an apparent reduction in viscosity with age of bird up ro 45 d of age, with hindgut digesta viscosity from birds fed on barley-based diet s falling from 20.6 cps at 25 d to 9.8 cps at 45 d. 5. In an assessment of the procedure developed, the following digesta visco sities were obtained at 25 d: 3.1 cps (wheat-based diet, foregut), 19.8 cps (barley-based diet, foregut), 5.7 cps (wheat-based diet, hindgut), 22.8 cp s (barley-based diet, hindgut).