Lecture 5: Rumen acidosis, simple indigestion, and rumen drinker

Normal rumen fluid pH range of animal on grain is?

A. <5

B. >8

C. 5.8-7

D. 7-8

C. 5.8-7

What is the VFA?

Highest amount, fat synthesis by adipose tissues and extra hepatic tissue energy. Decreases with high carb diets.

Acetate

Normal rumen pH of animals on forage diet

7

What is the VFA?

Gluconeogensis by liver, 60% of glucose used by animal

Proprionate

What is the VFA?

Ketone bodies always by extra hepatic tissues

Butyrate

Etiology of rumen acidosis

• Excessive consumption of readily fermentable carbs

• Increase production of latic acid

• Decreased in rumen pH

What is rumen acidosis associated with?

• Cereal grains

• Potatoes, beets

• Fruit

Etiology of rumen acidosis

1. Glucose and organic acids produced

2. S. bovis proliferate

3. Metabolize the CHO and produce lactic acid

4. VFAs produced as pH decreases, act as buffers

5. Osmolality increases. Pulls in water.

6. Lactic acid damages rumen wall. Mycotic rumenitis

Why do grains and other fine compounds increase risk for rumen acidosis?

Decreased fiver, less saliva, less buffering and scratch factor. D lactate produced and not easily metabolized. Histamine results in vasodilation, arterioconstriction, increases vascular permeability leading to laminitis.

CS of acute rumen acidosis

• Rumen distension

• Diarrhea (discolored by grain)

• Dehydration

• Recumbency

• Tachycardia

• Tachypnea

• Decreased palpebral reflex

CS of long term rumen acidosis

• Polioencephalomalacia

• Liver abscesses

• Rumen hyperkeratosis, mycotic rumenitis

• Hoof wall changes and laminitis

• Clostridial overgrowth (endotoxemia)

An animal presents with the following CS. What is your diagnosis?

A. Listeria

B. Trauma

C. Polioencephalomalacia

D. Toxin

C. Polioencephalomalacia

Excessive carbs or low forage diets over long times causes high rate of termination (pH 5-5.5) and high VFAs . Observed as low butterfat, increased abomasal disease and decreased DMI

Subacute Rumen Acidosis

How do you diagnose subacute rumen acidosis?

Rumenocentesis of group of cattle

Septic thromboemboli secondary to liver abscesses secondary to rumenitis from SARA.

Caudal Vena Caval Syndrome

Acute rumen acidosis pH

<5.5

How can you diagnose acute rumen acidosis?

• Rumen pH

• Acid base venous sample

• urine pH low

Treatment of rumen acidosis

• Empty with large tube or rumenotomy

• Magnesium hydroxide to neutralize

• Fluids (IV)

• Thiamine for q8 hours

• CD antitoxin

• NSAIDs for acute laminitis if no renal changes

• PPG or tylan for liver abscesses

• SLOW reintroduction to grain

• 1 week on forage then slow stepping up

• Transfaunate (cud snatching for goats)

How much bicarbonate does he need

• Base deficit = 34 – ECO2

• Bicarb requirement (mEq) = BD x body weight x 0.3

• mEq bicarbonate to grams = /12

• Isotonic bicarb = 1.3%

• Correct half over a few hours, rest in 24 hours

• BD = 24-8 = 16

• Bicarbonate requirement = 16 x 0.6 x 50kg

= 480 mEq

• 480mEq/12 = 40g

• Therefore needs 40/13g/L = 3 liters isotonic

• Replace half initially

• 10% dehydrated

• Fluid deficit = 5L

• On going losses approx. 0.5 liter

• Maintenance 60ml/kg/day = 3 liters • In first 24 hours. 1.5 L Na bicarbonate followed by 0.9% NaCl at 300ml/hour

Why do you use Mg hydroxide over bicarb?

• Mg hydroxide is cheaper

• Bicarb may make the bloat worse

Making isotonic bicarb calculations

• Isotonic 1.3% = 13g/L

• Commercially available is 8.4%

• V1C1=V2C2 • 1000 1.3 = x 8.4 • X = 154ml

What can magnesium hydroxide cause?

Hypermagnesemia, alkalosis if excessive

A 700lb show heifer that the clients just purchased and

switched feeds rapidly present with bloat, diarrhea. She is

depressed. Bloodwork reveals a base deficit of 8. What is her

TOTAL bicarbonate requirement to correct her acid base

imbalance

• 2545mEq

Case 1:

Signalment: 6 month old show lamb Presenting complaint Progressive anorexia of about five days duration.

Diarrhea and bloating

• His attitude has not been significantly altered during this time. • No other sheep are showing similar symptoms of disease

• Purchased 2 weeks ago at sale

• Diet is 2 lb of grain with 1 handful alfalfa in evenings

• Wears polowraps as has been known to pick at legs

• Housed in barn/dry lot

PE findings:

• HR: 180bpm, RR: 70bpm, Temp: 104.7F, Wt: ~101#,

• BCS: 3.5/5

• Mucous membranes were dark pink

• Hydration status was ~5% dehydrated.

• Bronchovesicular sounds were increased bilaterally.

• Grunting and signs of discomfort were noted during examination

• No rumenal contractions were noted and there was obvious distension of the left flank.

• Diarrhea passed on digital rectal exam

• Passed NG tube

  • pH of rumen fluid sample was estimated to be 5 and microscopic examination showed no microflora present.

BW results included

Simple indigestion

What causes simple indigestion?

Abrupt changes in feed abruptly causes an imbalance in microflora and its fermentation products. Mouldy feeds, sour silages, frozen fed

CS of simple indigestion in cattle

• Mild and self limiting

• Decreased intake

• Diarrhea

• Rumen motility decreased

• Mild pH changes

How do calves inoculate microflora?

Environment or reflux from abomasum

What is responsible for rumen mucosal development in calves?

VFAs

What rumen disorders are calves on a finely ground feed without forages?

• Chronic rumen acidosis

• Parakeratosis

• Rumen hypomotility

• Poor BCS

What rumen disorders are calves on excessive long stem forage at risk for?

• Hay belly

• Poor rumen microbes

• Firm on palpation

• Poor motility

Closes in response to milk suckling and diverts milk to abomasum

Esophageal groove

In calves <12 weeks what stimulates esophageal groove?

Bucket and nipple

In bottle calves >12 weeks what stimulates esophageal groove?

Only nipple

What can cause rumen drinkers?

• Failure of groove to close (Non-whey milk)

• Calves on milk for >3-4 months

• Over feeding neonates large volumes

• Increased abomasal emptying times

• Abomasal ulcers or inflammation

What kind of rumen bloat often occurs in calves?

Free gas (type 1 vagal)

What is the normal rumen fluid pH range of animals on grain?
a. <5 b. >8
c. 5.8 - 7
d. 7 - 8

1. c. 5.8 - 7

What kind of milk replacer is more likely to cause rumen drinkers?

Soy based milk replacers

Which of the following is NOT a synonym for rumen acidosis?
a. Lactic acidosis
b. Grain overload
c. Rumen drinker syndrome
d. Carbohydrate overload

1. c. Rumen drinker syndrome

What is the approximate percentage of feedlot cattle that suffer from digestive disorders?
a. 1-2%
b. 4.4%
c. 10%
d. 20%

1. b. 4.4%

Which of the following feeds is commonly associated with acute rumen acidosis?
a. Hay
b. Cereal grains
c. Grass silage
d. Straw

1. b. Cereal grains

What clinical sign is NOT typically associated with acute rumen acidosis?
a. Rumen distension
b. Diarrhea
c. Increased appetite
d. Tachycardia

1. c. Increased appetite

What is the primary cause of subacute rumen acidosis (SARA)?
a. Excessive fiber intake
b. Low protein diets
c. Excessive carbohydrates or low forage diets
d. Sudden changes in environmental temperature

1. c. Excessive carbohydrates or low forage diets

Which of the following is an important treatment for rumen acidosis?
a. Increase grain intake
b. Administer magnesium hydroxide
c. Provide only water
d. Feed high amounts of forage

1. b. Administer magnesium hydroxide

What is the role of volatile fatty acids (VFAs) in the rumen?
a. Decrease rumen motility
b. Act as buffers
c. Decrease absorption
d. Increase lactic acid production

1. b. Act as buffers

Which clinical sign indicates a longer-term consequence of acute rumen acidosis?
a. Rumen distension
b. Polioencephalomalacia
c. Tachycardia
d. Depression

1. b. Polioencephalomalacia

What is the main consequence of D-lactate production in the rumen?
a. Improved fiber digestion
b. Increased gluconeogenesis
c. Metabolic acidosis
d. Enhanced microbial growth

1. c. Metabolic acidosis

Which of the following clinical signs is associated with rumen drinker syndrome?
a. Pot bellies
b. Increased rumen motility
c. Bright red mucous membranes
d. Increased milk fat content

1. a. Pot bellies

What is the main reason for rumen drinker syndrome in calves?
a. Too much exercise
b. Failure of the esophageal groove to close
c. Insufficient water intake
d. Excessive fiber consumption

1. b. Failure of the esophageal groove to close

What is the typical pH range for subacute rumen acidosis (SARA)?
a. <5

b. 5 - 5.5

c. 5.5 - 6.5

d. >7

1. b. 5 - 5.5

1. c. Decreased intake

Which of the following factors can lead to chronic rumen acidosis in calves?
a. High fiber intake
b. Finely ground feed without forages
c. Increased water consumption
d. Adequate protein levels

1. b. Finely ground feed without forages

What is the first step in the treatment of acute rumen acidosis?
a. Administer antibiotics
b. Perform a rumenotomy
c. Provide IV fluids
d. Empty the rumen using a large tube

1. d. Empty the rumen using a large tube

Which bacteria is primarily responsible for the production of lactic acid in the rumen during acidosis?
a. S. bovis
b. E. coli
c. Lactobacillus
d. Clostridium

1. a. S. bovis

What is the primary diagnostic method for identifying acute rumen acidosis?
a. Fecal analysis
b. Bloodwork
c. Rumen pH measurement
d. Ultrasound imaging

1. c. Rumen pH measurement

Which of the following is a key prevention strategy for rumen acidosis?
a. Rapid feed changes
b. Adequate fiber in the diet
c. High grain diets
d. Restricting water access

1. b. Adequate fiber in the diet

What is the expected outcome for an animal diagnosed with severe rumen acidosis if not treated?
a. Rapid recovery
b. No significant effects
c. Increased production
d. High mortality risk

1. d. High mortality risk