Michael (Mike) Barnas defended his thesis, “The Study of Broiler Gut Health with a Focus on Digesta Viscosity, Coccidiosis and Supplementation with Butyrate,” on April 10. Barnas, a resident of Delmar, Maryland, now holds a doctorate in food and agricultural sciences from the University of Maryland Eastern Shore.
The primary objective of Barnas’ study was to determine the utility of existing methods for measuring digesta viscosity. To date, he said, most published methods centrifuge the sample before analysis—a practice that is required to remove the particles and produce a supernatant that can be measured on the viscometer.
“Using the Discovery HR-2 Rheometer, both whole and centrifuged digesta were measured for viscosity,” Barnas said. “Although the thickness of the whole digesta was dramatically different in the various areas of the GI tract in 21d old broilers, after centrifugation, the viscosity of the supernatant from the upper (3.302±0.44 cP) and lower (3.391±0.48 cP) GI tract were not significantly different (P > 0.05).”
This result, he said, questions the utility of existing methods used to quantify digesta viscosity after centrifugation of the sample, because the process does not simulate the physical movement of digesta in vivo. Measuring the viscosity of digesta whole without centrifugation, he found, resulted in low viscosity in the duodenum (3.241±0.657 Pa-s), moderate viscosity in the jejunum (633.1±173.8 Pa-s) and high viscosity in the ileum (7,013.5±137.2 Pa-s) of straight-run Cobb-500 broilers at 21 days of age.
“Opportunities exist to employ rheology in poultry science, but the utility of measuring supernatant, rather than whole digesta viscosity, appears limited,” Barnas said. “One potential use for measuring the viscosity of whole, uncentrifuged digesta could be to predict oocysts per gram in digesta as oocysts occupy space like a feed particle and create internal friction.”
“Mike’s work provides valuable insight to poultry gut health. Ultimately, the health of the intestinal tract contributes to the health and performance of the bird,” said Dr. Jennifer Timmons, assistant professor in UMES’ Department of Agriculture, Food and Resource Sciences and Barnas’ research advisor.
Barnas is vice president of business development at AHPharma Inc. in Hebron, Maryland. He also holds a bachelor’s degree in information systems from Salisbury University.
