Effect of nylon bag and protozoa on in vitro corn starch disappearance
Autor: | A.M. van Vuuren, Jan Dijkstra, J.T. van Zwieten |
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Rok vydání: | 2008 |
Předmět: |
dairy-cattle
degradability Rumen Animal Nutrition Starch ruminal fermentation digestion In Vitro Techniques Polysaccharide maize Zea mays chemistry.chemical_compound Botany Genetics site Animals Food science Ciliophora bacteria Incubation degradation chemistry.chemical_classification Residue (complex analysis) rumen biology Bacteria food and beverages Eukaryota biology.organism_classification Diervoeding In vitro Body Fluids extent Nylons chemistry Seeds WIAS Protozoa Animal Science and Zoology Cattle Digestion Female Wageningen Livestock Research Food Science |
Zdroj: | Journal of Dairy Science 91 (2008) 3 Journal of Dairy Science, 91(3), 1133-1139 |
ISSN: | 1525-3198 0022-0302 |
Popis: | An in vitro experiment was carried out to study whether the presence of protozoa in nylon bags can explain the underestimation of the in situ degradation of slowly degradable starch. Corn of a high (flint) and a low (dent) vitreousness variety was ground over a 3-mm screen, weighed in nylon bags with a pore size of 37 μ m, and washed in cold water. Samples of washed cornstarch were incubated in 40-mL tubes with faunated and defaunated ruminal fluid. An additional amount of washed corn, in nylon bags, was inserted in each incubation tube. Incubations were carried out for 0, 2, 4, 6, 12, and 24 h, and starch residue in tube and nylon bag was determined. In general, starch disappearance from the nylon bag was less than from the tube, and was less with faunated than defaunated rumen fluid, but corn variety did not affect starch disappearance. When no protozoa were present, the disappearance of starch from the bags was higher after 6 and 12 h incubation compared with presence of protozoa. However, in the tubes, there was no difference in starch disappearance due to presence or absence of protozoa. Estimated lag time was higher in presence (4.6 h) then absence (3.6 h) of protozoa. It was concluded that the effect of presence or absence of protozoa on starch disappearance differs within or outside nylon bags. The reduced disappearance rate of starch inside the nylon bags in the presence of protozoa helps to explain the underestimation of starch degradation based on the in sacco procedure when compared with in vivo data upon incubation of slowly degradable starch sources. |
Databáze: | OpenAIRE |
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