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
Diagnosis and differential diagnosis of simple indigestion?
Diagnosis
• By exclusion of other diseases
Differential diagnosis
• According to the triad (from biochemical disorders)
o Secondary forestomach disorders
o Primary motoric disorders
Treatment and prevention of simple indigestion?
Treatment and prevention
• Good quality food
o Molasses, sugar beet, hay, grass
• Ruminal digestives
o Yeast, rumen juice, rumen extract, probiotics
• Loosening of the rumen content
o Water, mineral oil, salt, laxatives
• Elimination of feeding abnormalities
Ruminal alkalosis?
Ruminal alkalosis
- NH3
- Feeding failures
- Too much protein
- NPN substances
o Alkalic ruminal content, NH3 gets into
circulation
Ruminal putrefaction?
Ruminal putrefaction
- NH3, toxic amines
- Putrid bacteria (E. coli, proteus)
o From surroundings, overgrowing in
the rumen
§ Alkalic ruminal content, NH3
gets into circulation +
biogenic amines + damage of
other organs
Clinical signs and rumen fluid analysis of alkalosis and putrefaction?
Clinical signs Rumen alkalosis v putrefaction
• General and digestive signs • Same + nervous signs
Rumen fluid analysis
• Moderated • Expressed
Diagnosis, DD treatment and after care for alkalosis and putrefaction?
Diagnosis and differential diagnosis
- According to the triad
- Biochemical disorders, ammonia toxicosis
Treatment
- Controlling of ruminal pH (carbohydrate) vinegar, lactic acid
- Antihistamines, flunixin meglumine
- AB
o Neomycin, oxytetracycline PO
- Parenteral fluid/ electrolyte replacement
- Evacuation of the rumen
After-care
- Fresh rumen juice, hay, fermentable carbohydrates
- Probiotics, sugar beet, molasses
Ruminal acidosis?
Ruminal acidosis
• Increase in carbohydrate intake means there is more bacteria such as str. Bovis and lactobacilli. They
produce more lactic acid and there is a shift in microflora of the rumen.
Ruminal acidosis local and general consequences + other consequences?
Local consequences
- Decr rumen pH (butyric acid)
- Mucosal damage
- Incr osmotic concentration
- Incr carbon dioxide concentration
Systemic consequences
- Metabolic acidosis
- Decr saliva production (buffer)
- Parenchymal organ degeneration
- Paralysis of medullar centers
Other consequences
- Bacterial toxins= parenchymal organ degeneration
- Biogenic amines= incr permeability of vessels, laminitis
- Ethylene glycol= toxic signs
Clinical signs of ruminal acidosis?
Clinical signs
- Depression, weakness, recumbency
- Increased HR and RR
- Signs of dehydration
o Sunken eyes
o Decr skin elasticity
o Anuria
• Digestive symptoms
o Rumen= firm- loose- tympanic + atonic
o Faeces: soft, sour, green
o +/- abdominal pain
• CNS
o Stupor, incoordination, impaired sight
o +/- excitement, coma
• Lab exam
o Incr PCV, metabolic acidosis
o Decr pH of urine
o Ruminal fluid= green, pH <5.2, weak sour cream consistency
