Study On The Rheological Characteristics Of The Digestive Tract Of Poultry

In this paper,the rheological properties of poultry intestinal chyme under different kinds and physiological conditions were firstly investigated by means of physical properties test.The rheological characteristics were analyzed and discussed from the angle of rheology,which provided basic data for feed processing and animal nutrition.The main research contents include the following aspects:(1)Comparative study on intestinal chyme rheological characteristics of different breeds of poultry.The rheological properties of chyme in different intestinal segments of meat ducks,broilers and layers were studied.The results showed that the chyme in each intestinal segment presented pseudoplasticity of shear thinning,and its apparent viscosity,shear stress and linear viscoelastic zone were different during shear rate scanning and stress scanning.The dynamic rheological test shows that chyme is viscoelastic,and the elastic modulus of chyme is larger than the viscous modulus,showing the rheological characteristics of semi-solid.Within the range of 39.6-43.6?,chyme dynamic modulus changes little,indicating that temperature has little influence on its internal spatial structure within this range,and normal physiological activities of poultry have little influence on the rheological characteristics of chyme.In the frequency scanning process,the duodenal consistency index K value is small,the flow characteristic index n value is large,the chyme fluidity is good,the strength is small,the viscosity is good,the fluid type is close to Newtonian fluid.(2)Comparison of rheological characteristics of intestinal chyme of the same breed of poultry at different age.Rheological properties of intestinal chyme in broilers and layers aged 14 days,broilers aged 35 days and layers aged 180 days were studied.The results showed that the apparent viscosity of duodenum and jejunum in the intestine of broilers and layers in the adult stage was higher than that in the young stage.With the increase of shear rate,intestinal chyme of broilers and layers showed thinning shear phenomenon and belonged to pseudoplastic fluid.The flow characteristic index of duodenum and jejunum of broilers and layers was larger than that of adults,indicating that the chyme was more fluid and closer to Newtonian fluid.(3)Comparison of rheological properties of intestinal chyme in broilers and layers aged 15 days.The rheological properties of broiler and layer chickens aged 15 days were studied.The results showed that the apparent viscosity of duodenum in the intestines of broilers aged 15 days was higher than that of layers aged 15 days,while the viscosity of jejunum was the opposite.With the increase of shear rate,intestinal chyme of 15-day-old broilers and 15-day-old layers showed shear thinning phenomenon and belonged to pseudoplastic fluid.The viscoelasticity of duodenum and jejunum in the intestines of broilers aged 15 days was less affected by temperature,while that of layers aged 15 days was more affected by temperature.During frequency scanning,the viscoelasticity of the sample increases with frequency.The duodenal flow characteristic index of layer aged 15 days was higher than that of broiler aged 15 days,indicating good fluidity.