VPT 421: Veterinary Toxicology (2+0)

PROPERTIES OF TOXICOLOGICAL IMPORTANCE

• Urea and other commonly used non-protein nitrogen have the ability to liberate ammonia.

• Urease is present in many plants and microorganisms and hence is present in the rumen.
• Hydrolysis of urea is speeded up by urease and an alkaline pH.
• Excess urea can liberate sufficient ammonium ions to make the rumen contents more alkaline which in turn speeds up further hydrolysis of urea.
• Toxicosis results from the accumulation of ammonia in the animal.
• Other factors, which enhance urea toxicosis, are
  • Rapid ingestion
  • A diet low in energy and protein and high in fiber
  • Ingestion of palatable urea concentrate such as urea molasses mixtures
  • High pH in the rumen
  • High body temperature
  • Water deficiency and
  • Feeds rich in urease like soyabeans
  • Stress
  • Hepatic insufficiency