Ruminant Metabolic Disorders

What is the normal rumen pH range?

5.6-7

What is the pH range for subclinical rumen acidosis?

5.2-5.6

What is the pH range for clinical acidosis?

<5.2

What bacteria is mainly associated with ruminal acidosis?

Streptococcus bovis

At what pH do Lactobacilli become the dominant microbes in ruminal acidosis?

<4.5

What are the three major ketone bodies?

Acetone, acetoacetate, and beta-hydroxybutyrate

Which ketone body is responsible for the "pear drops/fruity" breath in ketotic cows?

Acetone

What is the primary source of glucose for ruminants?

Gluconeogenesis

What is the main substrate for gluconeogenesis in ruminants?

Propionate

What hormone inhibits lipolysis in ruminants?

Insulin

What is the main cause of clinical rumen acidosis?

Excessive consumption of rapidly fermentable carbohydrates

What is the process called when milk and colostrum are transferred directly to the abomasum in young ruminants?

Oesophageal or reticular groove

At what age does the transition from pre-ruminant to ruminant typically begin?

Around 4 weeks

By what age is the rumen usually fully functional in lambs?

8 weeks

What are the main volatile fatty acids (VFAs) produced in the rumen?

Acetic acid, propionic acid, and butyric acid

Which VFA is absorbed from the rumen as a ketone body?

Butyric acid

What is the primary cause of ketosis in dairy cattle?

Negative energy balance

What are the two main types of clinical ketosis in dairy cows?

Type I and Type II

What is homeorhesis in the context of early lactation?

Coordinated changes in metabolism to support a physiological state

What is the main source of energy for ruminants during periods of negative energy balance?

Non-esterified fatty acids (NEFAs)