3. Methylene blue reduction test ( Redox potential)


        It reflects the anaerobic fermentative metabolism of the bacterial population.




Mix 20 ml ofrumen fluid with 1 ml of 0.03 % methylene blue in a test tube and let to stand at room temperature.

Measure the time needed for the color of the mixture to be changed.

Normal rumen fluid from cattle fed on a hay and grain diet needs 3 mm. to decolorize leaving a narrow ring of blue color at the top of decolorizing mixture.

Abnormal reduction of time up to 15 mm indicates:

o   Indigestible roughage.

o   Anorexia of several days.

o Rumen acidosis.

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