ANN 111: Principles of Animal Nutrition and Feed Technology (2+1)

PROCEDURE

• Weigh 10g of test sample and add 100ml of distilled water. Stir and filter with Whatman No.4
• Pippette 2ml of standard solution and test sample into white porcelain spot plates.
• Add 2-3 drops of cresol red indicator and add 2-3 drops of urease solution.
• Let it stand for 3-5 minutes, if urea is present, it will form a deep red-purple spreading like a spider’s web appearance, in contrast to the yellow color of the indicator.
• Compare the test sample with the standard urea sample. This test should be read within 10-12 minutes.

Hoof or horn:

• Reagents
  • Glacial acetic acid (1:1)
• Procedure
  • For quick test, place 2-3 particles of amber color test sample into an evaporating dish.
  • Add 5 ml of glacial acetic acid into the evaporating dish and let it stand for 60 minutes.
  • If hoof and horn are present, the test particles will still remain hard and tough. Gelatin will be become soft and swollen.

Leather meal:

• Reagents
  • Ammonium Molybdate solution – Dissolve 5g of Ammonium Molybdate in 100ml of distilled water and pour into 35ml of concentrate nitric acid.
• Procedure
  • Pick up brown to black test sample particles and place in petridish.
  • Add 3-5 drops of ammonium molybdate and let it stand for 5-10 minutes.
  • Leather meal will give no color change. Meat and bone meal gives a greenish yellow color.