L12 Ruminants | nutrition exam 2

Feed, water, and saliva are delivered to the reticulorumen through what orifice

esophageal orifice

What is the medium for fermentation in ruminants and why

saliva

• provides lubrication and hydration to the rumen

• acts as alkaline buffer

What part of the non-glandular stomach in ruminants is the fermentation vat

rumen

In young ruminants, milk reaching the rumen rots so what is the solution (anatomically)

a reflex closure of musclular folds → creates esophageal orifice toward omasum

What enzyme curdles milk

rennin

Which VFA is metabolized into glucose

propionate is metabolized into glucose via hepatic gluconeogenesis

What is the purpose of acetic acid in ruminants

generation ATP

source of Acetyl CoA for synthesis of lipids

What is butyric acid metabolized into by rumen epithelium

ketone beta-hydroxybutyric acid

What is the result of mammary epithelial production of glucose and galactose

lactose

If the ruminant is lactating, what does the liver require and why

liver is in a state of constant gluconeogensis → requires constant supply of propionate

When does cows requires much glucose

3rd trimester of gestation

Increased gluconeogenesis from low/negative energy balance stems from

dec insulin

inc glucagon

With negative energy balance in ruminants, what results from a dec insulin and inc glucagon

inc gluconeogenesis

When glucose is in short supply in the ruminant what acts as a substitute

fats (triglycerides) as a substitute

What enzyme facilitates lipolysis

Hormone sensitive lipase (HSL)

What are the four factors that promote lipolysis

1. negative energy balance

2. high glucagon and low insulin

3. stress from cortisol

4. stress from epinephrine release

In ruminants, FFA beta-oxidation leads to what

FFA oxidation leads to formation of acetyl CoA

What does acetyl-CoA combine with in fat oxidation in ruminants

Acetyl-CoA combines w oxaloacetate

What are the three main ketones

• acetoacetate

• acetone

• beta hydroxybutyrate

During long term neg energy balance (or fast), acetyl-CoA is metabolized in ____ into ____

hepatocytes, ketones

What is the difference between primary or secondary ketosis

• primary ketosis: diet is too low in carbohydrate

• secondary ketosis: animal is in a prolonged fast

ketones in high amount = ketosis

What are the clinical signs of ketosis

• dec rumen motility

• dry feces, dehydration

• behavioral changes - dullness OR nervousness

How is ketones detected during PE in ruminants

• ketones can be detected in breath

• reagents and tablets can detect ketones in milk

• ketonuria can be diagnosed w/ urine dip stick

With ketosis, how does that affect milk production and energy requirements in ruminants

dec milk production

dec energy requirements

How can you change feed to treat ketosis

feed high quality carbohydrate:

• fresh forage

• molasses in water

What is transfaunation

transferring rumen fluid from a healthy cow to a sick cow can stabilize microbiota | fluid transferred from orogastric tube

What is the purpose of propylene glycol in ketosis treatment

propylene glycol metabolized by liver to propionate as a source of glucose

Propylene glycol overdose results in

• diarrhea

• sever cases

  • ataxia

  • coma

What is the purpose of glucose IV of ketosis treatment

Glucose IV:

• spares oxaloactate

• dec ketone body formation

What are the results of corticosteroids in ketosis treatment

• enhance gluconeogenesis

• dec milk production

• improve how animal feels

• stimulates hormone sensitive lipase → inc FFA → inc VFA

What can corticosteroids used for if rumminant is pregnant

as abortion drug

What tx combination reduces lipolysis (and what should not be given on its own)

glucose IV + insulin SQ

insulin should never be given by itself

How is B vitamins important for energy metabolism in ketosis treatment

• low in sick animals

• niacin supprress lipolysis

• choline forms lipoproteins and transport fat from liver in fatty liver disease

What helps monitor fat mobilization in transition cows

blood NEFA measurements

When does fatty liver disease usually occur in ruminants

result of prolonged negative energy balance in

immediate period before and after calving

What causes fatty liver disease in ruminants

fatty liver disease more common in obese animals:

• decreased appetite

• high energy needs during lactation

• prolonged ketosis even in normal BCS cows

What are the clinical signs of fatty liver disease

• shortly after calving

  • depression

  • anorexia

  • weight loss

  • dec GI/rumen motility

  • weakness

What is the difference of care between fatty liver disease and ketosis tx

fatty liver dz: long, intensive care (1-2 weeks)

What is the tx of fatty liver disease

• tube feeding/rumen fistula feeding

• IV fluid therapy w dextrose ± insulin

• propylene glycol

What is the prevention of fatty liver disease

cows at high BCS should be segregated and encouraged to lose weight

What species commonly experiences pregnancy toxemia

small ruminants (more common)

bovines

In pregnancy toxemia, more embryos result in

higher metabolic strain

What are the clinical signs of pregnancy toxemia

• illness in last trimester

• poor appetite

• separated from flock

• star-gazing

• weakness

Pathophysiologically, pregnancy toxemia can be fatal to fetus and dam, why

glucose is unrelenting → ketone bodies become acidic leading to ketoacidosis

What is the treatment of pregnancy toxemia

• terminating the pregnancy

• Alternative → IV glucose, propylene glycol, transfaunation, high carb diet