Biochemical disorders of the rumen

Question 1

Physiology of rumen function

Answer 1

Rumen juice

• Contents:
    o 80-90% water
        ▪ Feed, water and plasma
        ▪ Saliva daily is 90-160 L
            Chewing, swallowing, rumen homeostasis
            pH is 8.2-8.7 (and contains Na+, HCO3 and HPO4) 
            Recirculation of N material
            Contains fibre
    o pH: 6.3-7.1 Can degrade VFA and NH3
    o Temperature 39-40 ̊C
    o Anaerobic conditions
    o Rumen homeostasis

Question 2

Regulation of acid-base household in the rumen

Answer 2

• Natural feeding: rumen pH: 6,3-7,1
• Too much carbohydrates: many organic acid– pH decreases
• pH influences life of microbials, species content, activity
• Carbohydrate (grain) feeding pH 2.8-3.0 would be metabolic acidosis but
o Compensatory mechanism
o Saliva production: 60-180 1/day (pH:8.1), NaHCO3 1-1.2 kg/day, Na2HPO4 0.2-0.25
kg/day
o = buffering 5-6 kg volatile fatty acid daily
• NPN feeding or protein overload leads to formation of NH3 which results in metabolic alkalosis

Question 3

Examination of ruminal content

Answer 3

• Tubing
• Transcutaneous punction, rumenocentesis
• Fecal lipopolysaccharides measurement
• Ruminal fistula
• Milk Fatty Acid Pattern
• Blood Gas Analysis, Urine Netto Acid base Excretion
• Intraruminal bolus: Indwelling pH Data Logging

Question 4

Forestomach disorders

Classification

Answer 4

• Localization
o diseases affecting more forestomach compartment (rumen)
o diseases affecting one forestomach

Question 5

Forestomach disorders

Course

Answer 5

• Peracute: a few hours – 2 days
• Acute: 3-14 days
• Subacute: 2-4 weeks
• Chronic: > 4 weeks

Question 6

Forestomach disorders

Pathological process

Answer 6

• Primary
o Biochemical disorders
o Motoric disorders
• Secondary

Question 7

Forestomach disorders

Diseases of the forestomach

Answer 7

• Biochemical disorders

1. Rumen overload and dilatation
2. Simple indigestion
3. Ruminal alkalosis
4. Ruminal acidosis
5. Ruminal tympany (bloat)
6. Ruminal putrefaction

Question 8

Rumen overload and dilatation

Aetiology

Answer 8

• Suddenly much rough fodder (too tasty, much fibre or unusual)
• Running away, hunger, lack of drinking, frozen or mouldy feed

Question 9

Rumen overload and dilatation

Pathogenesis

Answer 9

• too much feed leads to ruminal dilatation and overload, obturated cardia and smooth muscle spasm and pain
• improper digestion, mixing leads to biochemical disorder
• lack of belching, rumination leads to gas accumulation which will compress the diaphragm
vena cava
• respiratory and circulatory failure occurs and then asphyxia
• prolonged biochemical disorder leads to shock

Question 10

Rumen overload and dilatation

Clinical signs

Answer 10

• Restlessness, colic
• Salivation, retching
• Dyspnea (labial) breathing, cyanosis, tachycardia
• Tense, overfilled abdomen (left flank)
• Ruminal statis, compact (thick), sedimented ruminal content

Question 11

Rumen overload and dilatation

Diagnosis

Answer 11

• History and clinical signs

* Probing shows only few gas and thick content

Question 12

Rumen overload and dilatation

Differentials

Answer 12

1. Other biochemical disorders
    o triad: feeding history
    o typical clinical signs
    o examination of the ruminal fluid
2. Diseases with sudden death
    o Cyanide poisoning, “fog fever”, methemoglobinemia
3. Diseases with abdominal distension

Question 13

Rumen overload and dilatation

Treatment

Answer 13

1. Analgesics, spasmolytics
2. Emptying the rumen with tube and lavage with rumenotomy (Götze technique)
3. Follow-up care includes dietetic feeding (see: simple indigestion)

Question 14

Simple indigestion of the rumen (indigestion simplex ingestae ruminis)

Etiology and Pathogenesis

Answer 14

• Feeding abnormalities leads to

a) quantitative-qualitative
b) change of the feed→disorder of adaptation
c) technological problems (e.g. lack of cribs or water)
d) trace elements: (--Co; ++ Mn and ++Cu)

Leads to
• Dysfunction of ruminal microorganisms
• Slow-down of biochemical processes
• Lack of ruminal protein and vitamin synthesis and VFA
Later metabolic products (NH3 and lactic acids)

Question 15

Simple indigestion of the rumen (indigestion simplex ingestae ruminis)

Clinical signs

Answer 15

• Not remarkable, but often appear as a herd problem:
o Milk: (–) amount, (–) fat content
o Anorexia; weight loss; mild, but long-lasting deterioration
o Mild digestive disorders: (–) rumination, (–) rumen motility
▪ Moderate ruminal tympany
▪ Small, firm, doughy rumen
o Inactive ruminal fluid

Question 16

Simple indigestion of the rumen (indigestion simplex ingestae ruminis)

Diagnosis

Answer 16

• Rather by exclusion of other diseases « triad

Differentials
• According to the triad (from biochemical disorders)
• Secondary forestomach disorders
• Primary motoric disorders
Other organic symptoms

Question 17

Simple indigestion of the rumen (indigestion simplex ingestae ruminis)

Treatment and Prevention

Answer 17

1. Good quality food: molasses, sugar beet, hay, grass
2. Ruminal digestive: yeast, rumen juice, Ruminogen pulv. A.U.V., Diernhofer mixture, rumen extract (Simulex A.U.V.), probiotics (Probios por A.U.V)
3. Loosening of the rumen content: water, mineral oil, salt laxatives
4. Elimination of feeding abnormalities

Question 18

Ruminal alkalosis / putrefaction

Etiology

Answer 18

RA:
(++)NH3

RP:
(++)NH3, toxic amines

Question 19

Ruminal alkalosis / putrefaction

Pathogenesis

Answer 19

RA:
    Feeding failures (too much protein NPN substance)→ alkalic ruminal content, NH3 gets into circulation

RP:
    Putrid bacteria (E.coli, Proteus) from surroundings or overgrowth in the rumen leads to alkalic ruminal content and NH3 and biogenic amines get into circulation and damages other organs

Question 20

Ruminal alkalosis / putrefaction

Clinical signs

Answer 20

RA:
General and digestive signs

RP:
Same general and digestive signs but + nervous signs

Question 21

Ruminal alkalosis / putrefaction

Ruminal fluid analysis

Answer 21

RA:
Moderate abnormalities

RP:
Expressed abnormalities

Question 22

Ruminal alkalosis / putrefaction

Diagnosis and differential diagnosis

Answer 22

According to the triad (from biochemical disorders)

Question 23

Ruminal alkalosis / putrefaction

Treatment

Answer 23

1. Controlling ruminal pH (carbohydrate) vinegar, lactic acid 2. Antihistamines and flunixin meglumine maybe
2. Antibiotics (neomycin, oxytetracycline) po.
3. Sol. contra alkalosi/putrefaction FoNoVet
4. parenteral fluid/electrolyte replacement
5. Evacuation of the rumen
   AFTER-CARE: fresh rumen juice, hay, fermentable carbohydrates, probiotics, Ruminogen pulvis A.U.V. (sugar beet, molasses)

Question 24

(Acute) Ruminal acidosis (acidosis ruminis acuta)

Etiology and Pathogenesis

Answer 24

• High carbohydrate (Streptococcus bovis and Lactobacillus) and D-lactic acid (butyric acid) and shift in microflora
• Local changes
o (–) rumen pH (butyric acid)
o Mucosal damage
o (++) osmotic concentration
o (++) carbon dioxide concentration
• Systemic changes
o Metabolic acidosis
o (–) saliva production (buffer)
o Parenchymal organ degeneration o Paralysis of medullar centre
• Other consequences
o Bacterial toxins→parenchymal organ degeneration
o Biogenic amines→(++) permeability of vessels, laminitis
o Ethylene alcohol → toxic sings

Question 25

(Acute) Ruminal acidosis (acidosis ruminis acuta) Clinical signs

Answer 25

• Course o Peracute, acute o Mild, moderate o Severe • General signs o Depression, weakness, recumbency • Basic clinical values o T: --; P: (++), R: (++) • Dehydration signs o Sunken eyes, o Skin: decreased elasticity o Mucosal membrane vascularization, CRT o +(Anuria) • Digestive symptoms o Rumen: firm→loose→tympanic + atonic o Faeces: soft, sour, greyish-yellowish, bubbles, blood, grain o +/- abdominal pain • Central nervous signs o Stupid, incoordination and impaired sight o +/- Excitement → coma o + (Kussmal type dyspnoea_ • Laboratory examinations o Blood: (++) PCV, metabolic acidosis o Urine shows decreased pH and negative NAB excretion o Ruminal fluid: ▪ Greenish-yellow, sour, pH <5.2, ▪ Weak sour cream consistency ▪ Smear will show bacteria (Streptococcus and Lactobacillus)

Question 26

(Acute) Ruminal acidosis (acidosis ruminis acuta) Diagnosis and differential diagnosis

Answer 26

* According to the triad (from biochemical disorders) * + Diseases with acute CNS symptoms * + Diseases with abdominal pain

Question 27

(Acute) Ruminal acidosis (acidosis ruminis acuta) Treatment

Answer 27

1. Correction of acid-base, fluid, and electrolyte imbalance: see table on the next slide 2. Blocking of lactic acid production and absorption 3. Restoration of ruminal digestion 4. Additional medical treatment

Question 28

(Acute) Ruminal acidosis (acidosis ruminis acuta) Treatment 1. Correction of acid-base, fluid, and electrolyte imbalance: see table on the next slide

Answer 28

o Macromineral imbalance ▪ Hypokalemia: KCL 20 to 40 mEq/L during routine fluid administration (1 gram of KCl contains 14 mEq of K+) OR 11.5 g KCl/ 1000 ml saline, 5 ml/kg/hour. ▪ Hypocalcemia is suspected, a 500 ml bottle of calcium gluconate: 20 liters of fluids iv. o Hypertonic saline: (7,4%): 4-5 ml/ttkg, in total 1000-2000 ml 54 ▪ Freshwater administration per os thereafter o Oral fluid therapy (mild dehydration): (NaCl (7 g/L)+KCl (1.25 g/L) and CaCl2 (0.5 g/L) into one litre of drinking water o Blood glucose control: iv glucose/dextrose.

Question 29

(Acute) Ruminal acidosis (acidosis ruminis acuta) Treatment 2. Blocking of lactic acid production and absorption

Answer 29

o Rumen emptying: rumenotomy o Alkalizing agents: ▪ MgO, Mg(OH)2,: cattle 500 g, prevention 100g/day, sheep-goat 100g, prevention 10-15 g/day ▪ NaHCO3: 20-30 dkg/animal, prevention 5-10 dkg/day

Question 30

(Acute) Ruminal acidosis (acidosis ruminis acuta) Treatment 3. Restoration of ruminal digestion

Answer 30

o Direct Fed Microbials ▪ Yeast (Saccharomyces cerevisiae) ▪ Enhancing lactic acid metabolism (probiotics) o Rumen juice: transfaunation o Monensin (EU forbidden) o TMR: providing Physically Effective Fiber (peNDF), sorting prevention o Close up diet: lengthen the rumen papillae o Buffers: sodium bicarbonate (0,5% DMI) o Feed additives (fumaric acid) o Phytogenics o Vaccination against Streptococcus bovis and Lactobacillus spp. (experimental)

Question 31

(Acute) Ruminal acidosis (acidosis ruminis acuta) Treatment 4. Additional medical treatment

Answer 31

o Flunixin-meglumine o Antihistamines o B1-vitamin injection

Question 32

Ruminal tympany (bloat) Etiology and Pathogenesis

Answer 32

Free gas bloat: 1. Increased gas production too much grain, low pH, No adaptation of micro flora 2. blocked belching (mechanical, reflectoric) 3. prohibited ruminal movements rumen dilatation, smooth muscle spasm, abdominal pain compression of the diaphragm, lungs and caudal v. cava acute respiratory and circulatory failure absorption of CO2, H2S asphyxia, shock Frothy bloat: 1. Increased gas and foam production Leguminosae, low pH, cold feed, predisposition, increased Streptococcus bovis 2. lack of belching (no stimulus)

Question 33

Ruminal tympany (bloat) Clinical signs

Answer 33

``` Free gas bloat: General signs (restlessness): ++ Basic clinical values (resp/pulse): ++ Digesitve symptoms: Eructation: Stops from beginning Rumen volume: +++ Auscultation: Crackles, crepitation Palpation: Tense Separation: Separated Percussion: Upper third tympanic Diagnostic probing: Successful, much gas ``` ``` Frothy gas bloat: General signs (restlessness): +++ Basic clinical values (resp/pulse): +++ Digesitve symptoms: Eructation: Soon ceases Rumen volume: ++ Auscultation: Crackles, crepitation Palpation: Tense Separation: Not separated Percussion: All over subtympanic Diagnostic probing: Unsuccessful, scanty foam ```

Question 34

Ruminal tympany (bloat) Course

Answer 34

Free gas bloat: Rapid Frothy bloat: Rapid

Question 35

Ruminal tympany (bloat) Outcome

Answer 35

Free gas bloat: Favourable Frothy bloat: Less favourable

Question 36

Ruminal tympany (bloat) Diagnosis

Answer 36

Diag: Feeding history, clinical signs Diagnostic probing (gas, ruminal fluid) Differential diag: Two types of primary acute tympany Forms of secondary tympany (meteorismus) Other biochemical disorders (going along with bloat) Diseases with abdominal distension Animals on pasture: poisonings, rabies, tetanus Diseases with sudden death

Question 37

Ruminal tympany (bloat) Treatment

Answer 37

Free gas bloat 1. Removal of the gas: stomach tube, trocarisation 2. Elimination of the cause Frothy bloat: 1. Removal of rumen content: tubing, probang, antifoaming agents 2. elimination of the cause 3. After-care rumen juice, hay

Question 38

Ruminal tympany (bloat) Control and prevention

Answer 38

Adaptation, avoiding etiological factors Enough therapeutic instruemnts, “client education” (measures) In some industries: surfactants onto skin, pasture, water (e.g. vegetable oil, poloxalane, alchol ethocylates); sustained – release techniques (capsule in the rumen); monensin:polyether ionophor antibiotics

Question 39

Ruminal tympany (bloat) Antifoaming drugs

Answer 39

• Atympan A.U.V. o timol, formaldehyde, ethylene alcohol, antifoaming agent • Bloat remedy A.U.V. o symethicone • Tympasol A.U.V. o symethicone, methyl cellulose, peppermint oil, benzyl alcohol, benzoate derivates • Traditional, home-made mixture 200 ml ethylene alcohol, cooking oil, methyl cellulose, and water → mixed and given in