Unit 2 - Non-Protein Nitrogen/Urea Ammoniated Forages Flashcards
What are the sources of urea for toxicosis?
Pelleted feed, premixes, and liquid mineral
Fertilizers
Normally, what does urea do in the rumen?
Urease rapidly converts urea to ammonia which is synthesized to protein
What happens to ammonia that is in the rumen when the pH is > 8?
Ammonia is absorbed into the blood stream, is converted into urea in the liver, and is excreted in the urine
What happens to ammonia in the rumen when the pH is <7?
It is cnverted into ammonium
What is the MOA of urea intoxication?
- Urease hydrolyzes urea to ammonia in the rumen
- Ammonia is absorbed into blood
- Excessive ammonia overwhelms the liver and it can’t be converted to urea
- There is elevated blood ammonia levels that cross the BBB
What species are susceptible to urea toxicity?
Ruminants; poisoning of monogastric species
At what temperature, pH, and NH3 level is optimal urease activity?
120 F
pH of 7.7-8
NH3 - 0.5-2
What are the causes of urea intoxication?
Feed associated - misformulation/excess, direct feeding of protein pellets, wrong species, and sudden introduction at high levels
Urea based fertilizers - barn-break in, application on forages
Water
What are the predisposing factors to urea intoxication?
Poor carbohydrate diet Inadequate adaptation High rumen pH and temp Hepatic insufficiency Unrestricted access to supplements
When is the onset of clinical signs for urea toxicosis?
10 minutes - hours post consumption
What clinical signs are associated with urea toxicosis?
Salivation and bruxism Muscle tremors and incoordination Polyuria (dribbling) Weakness Tachypnea Violent spasms/seizures Acute death
What biological samples can be collected for detection of ammonia in suspect cases of urea toxicosis?
Ocular fluid, rumen content, and serum
What samples can you use to detect urea in suspect toxicosis cases?
Water, feed, forage
T/F: Samples can be collected at any point for diagnosis of urea toxicosis.
False - they need to be collected ASAP, If it has been >12 hours there is no point
What rumen pH can be diagnostic for urea toxicosis?
8-9.2
How is urea toxicosis treated?
Stop further ammonia production in rumen
Decrease urease activity - cold water and acetic acid
Triage
Activated charcoal is ineffective
What do raw soybeans have high concentrations of?
Carbohydrates, proteins, urease
What does overconsumption of raw soybeans result in?
Ammonia toxicosis and lactic acidosis
What are the sources for raw soybean toxicosis?
Spills, barn-break in, and soybean field
What clinical signs are associated with raw soybean toxicosis?
Lethargy/depression, salivation, polyuria, increased respiratory rate, death
How is raw soybean toxicosis diagnosed?
History of exposure, gray/sludgey rumen with soybeans, elevated rumen or ocular ammonia
How is raw soybean toxicosis treated?
In acute cases treat the ammonia toxicosis
If >8 hours post ingestion treat carbohydrate overload and rumen acidosis
What is ammoniated forages also known as?
Bovine bonkers syndrome
What is the MOA of ammoniated forages toxicosis?
Imidazoles form from browing reaction with amino groups and a reducing compound (sugar) which are convulsion inducing compounds
What clinical signs are associated with ammoniated forage toxicosis?
Trembling Stampeding Interrupted periods of calm Dilated pupils Rapid respiration Urination, salivation, defecation Bellowing and seizures Star gazing
How is ammoniated forages toxicosis diagnosed?
Remove feed and watch for a rapid recovery
Assay for imidazoles in forage, milk, or serum
How is ammoniated forages toxicosis treated?
Sedative and thiamine
