9. Biochemical disorders of the rumen Flashcards
Rumen juice?
Rumen juice
- 80-90% water
- pH 6.3-7
- 39-40°c
- Anaerobic conditions
- Rumen homeostasis
Regulation of acid-base household in the rumen?
Regulation of acid-base household in the rumen
• Natural feeding
o Rumen pH6.3-7
• Too many carbohydrates
o Many organic acid- pH decreases
pH influences
- Life of microbials
- Species content
- Activity
Carbohydrate (grain) feeding
- pH 2.8-3 would be metabolic acidosis but
- compensating mechanism
o saliva production= buffering 5-6kg of volatile fatty acids daily
NPN feeding or protein overload
• NH3 forming = metabolic alkalosis
Carbohydrate feremntation in the rumen?
Carbohydrate fermentation in the rumen
- Sugars, starch, cellulose, hemicellulose, pectin, and protein enter the pentose pathway
- Converted into
- Methane, acetate, butyrate, and propionate
Volatile fatty acid production in the rumen?
Volatile fatty acid production in the rumen
- Propionic acid is the most useful VFA, produced in high amounts at optimal pH
- Acetic and Butyric acid are produced in lower amounts at optimal pH
Examination of the ruminal content?
Examination of the ruminal content
- Tubing
- Transcutaneous punction, ruminocentesis
- Faecal lipopolysaccharide measurement
- Ruminal fistula
- Milk fatty acid pattern
- Blood gas analysis, urine netto acid base excretion
- Intraruminal bolus
o Indwelling pH data logging
Sara?
SARA= subacute ruminal acidosis
- Occurs rarely, 1 degree decrease in pH of rumen
- Usually when it is between 5.5-6.3
Classification of biochemical disorders?
Classification of forestomach disorders
Localization
- Diseases affecting more forestomach compartment
- Diseases after one forestomach
Course
- Peracute: few hours-2 days
- Acute: 3-14 days
- Subacute: 2-4 weeks
- Chronic >4 weeks
Pathological process
- Primary biochemical disorders + motoric disorders
- Secondary
Biochemical disorders?
- Rumen overload and dilation
- Simple indigestion
- Ruminal alkalosis
- Ruminal putrefaction
- Ruminal acidosis
- Ruminal tympany
Rumen overload and dilatation Pathogenesis?
Rumen overload and dilatation
• Sudden much rough doffer, hunger, lack of drinking, frozen or mouldy feed
Pathogenesis
• Too much feed: there is ruminal dilatation and overload, there is obturated cardia which causes smooth
muscle spasm and pain.
• This then leads to improper digestion and mixing (biochemical disorder), there is belching and rumination
causing increased gas, resulting in compression of the diaphragm and c. vena cava.
• Finally in serious cases there is respiratory and circulatory failure leading to asphyxia. If the animal survives
there is a prolonged biochemical disorder resulting in diarrhoea.
• Ruminal overload caused by extremely rough feed and binding rope
Clinical signs of rumen overload?
Clinical signs
- Restlessness, colic
- Salivation, retching
- Dyspnoea (labial) breathing, cyanosis, tachycardia
- Tense, overfilled abdomen (left flank)
- Ruminal stasis, compact (thick), sedimented ruminal content
Diagnosis of ruminal overload?
Diagnosis
- History and clinical signs
- Probing, only a little gas and thick content
Differential diagnosis of ruminal overload?
Differential diagnosis
• Other biochemical disorders
o Triad: feeding history
o Typical clinical signs
o Examination of the ruminal fluid
• Diseases with sudden death
o Cyanide poisoning “fog fever”, methemoglobinemia
• Diseases with abdominal distension
o Simple indigestion
o Free-gas bloat
o Caecal dilatation
o Hoflund syndrome- functional pyloric stenosis
Treatment of ruminal overload?
Treatment
- Analgesics, spasmolytics
- Emptying the rumen
o With tube and lavage
o With rumenotomy
§ Götze technique
o Follow up care
§ Dietetic feeding
Simple indigestion?
. Simple indigestion
Feeding abnormalities
- Quantitative-qualitative
- Change of feed- disorder of adaptation
- Technological problems
o Lack of cribs or water
• Trace elements
o Co, Mn, Cu
• These result in dysfunction of ruminal microorganisms, slow-down of biochemical processes. There is a
decrease in ruminal protein and vitamin synthesis, leading to a decrease in VFA. Later metabolic products
such as NH3 and lactic acids
Clinical signs of simple indigestion?
Clinical signs
- Milk: decreased amount and fat content
- Anorexia; weight loss, long lasting deterioration
- Mild digestive disorders: decr rumination and rumen motility
- Moderated ruminal tympany
- Small, firm, doughy rumen
- Inactive ruminal fluid
