In situ and Other Methods to Estimate Ruminal Protein and Energy Digestibility: A Review

Nutrional value and antinutritional components of whole and ethanol extracted Moringa oleifera leaves

In vitro gas measuring techniques for assessment of nutritional quality of feeds: a review

Comparative evaluation of non-toxic and toxic varieties of Jatropha curcas for chemical composition, digestibility, protein degradability and toxic factors

https://www.uky.edu/Ag/AnimalSciences/instruction/asc684/PDF/JDS75_2618.pdf

Markers for quantifying microbial protein synthesis in the rumen.

A method is described for the determination of protein degradation based on measurements of ammonia concentration and gas production (Menke et al. 1979) when a feedingstuff was incubated with rumen fluid in vitro. NH3 liberated during incubation is in part used for microbial protein synthesis. Production of carbon dioxide and methane can be regarded as a measure of energy available for protein synthesis. The ratio, gas production: incorporation of NH3-nitrogen was estimated by addition of starch to the substrate. The response in gas production was linear in the range 0-200 mg starch, when starch was added to 0-200 mg feedingstuff dry matter and 30 ml rumen fluid-medium mixture. Linear regression between NH3-N concentration (y, mg) and gas production (x, ml) yielded an intercept (bo) representing that amount of NH3-N which would be released when no fermentable carbohydrates were available and consequently no bacterial protein synthesis took place. The difference between this intercept bo and NH3-N content in the blank (rumen fluid without substrate added) indicated the amount of NH3 liberated from protein and other N-containing compounds of the feeding-stuff incubated. In vitro-degradable N (IVDN) was calculated as a proportion of total N by the equation: (formula; see text).

/pdf/rumen-protein-degradation-and-biosynthesis-i-a-new-method-2oe6cbtv8m.pdf

B. Cafantaris

Papers

Rumen protein degradation and biosynthesis. I. A new method for determination of protein degradation in rumen fluid in vitro.