Ketosis

What is ketosis?

Metabolic disorder; primarily dairy cattle; small ruminants and camelids also

When does ketosis most commonly occur?

parturition to 6 weeks postpartum

What can the presentation of ketosis be?

Subclinical and Clinical

What is the incidence of subclinical ketosis?

15-60%

What is the incidence of clinical ketosis?

2-15%

What cows are more likely to have ketosis and why?

Holsteins and older cows because of high milk production demands and greater body fat mobilization during the transition period

What are some risk factors for developing ketosis?

• Excess BCS at calving

• Other post-partum diseases

• High milk production

• Poor cow comfort

• Stress

• Nutritional imbalances

Ketosis can be _____ or __________?

Ketosis can be the primary disease (severe negative energy balance or obesity) or secondary to another condition such as lower energy intake or cause systemic inflammation, most commonly metritis, mastitis, displaced abomasum, retained placenta, and lameness

What are clinical findings in ketosis?

• Drop in Dry Matter Intake

• Abnormal stool
• Depression

• Decreased BCS

• Ketotic breath

• Neurologic signs = circling, staggering, licking, chewing, bellowing, compulsive walking, head pressing

What causes ketosis?

Combination of high glucose demand and adipose mobilization

Why is ketosis more common in early lactation?

• Early lactation = negative energy balance = adipose mobilization NEFAs released from Triglycerides

• Milk production = high glucose demand

• Negative energy balance results in gluconeogenesis

What are NEFAs metabolized to?

Acetyl-CoA in the liver

What are the four fates of acetyl-CoA?

• Complete oxidation through the Krebs cycle

• Incomplete oxidation through ketogenesis

• Triglyceride synthesis into VLDL and exported out of the liver

• Triglyceride synthesis for storage in the liver

What is the Complete oxidation of Acetyl-CoA is dependent on?

The presence of oxaloacetate.

What is excess Acetyl Co-A shunted to?

Ketogenesis

What does excess triglyceride storage results in?

In fatty liver

What ketones are produced in ketosis?

• acetone

• Acetoacetate

• β-hydroxybutyrate (BHB) Most common ketone

How is ketosis diagnosed?

• Production Stage

• Clinical Signs

• Ketones in urine/milk/blood

Cow side test

Urine/Milk tests only detect acetoacetate

Blood test necessary to detect BHB

How is ketosis treated?

• Provide glucose precursors

Dextrose

Propylene Glycol goes to propionate

• Corticosteroids -controversial, older vets use it but most recent data says don't use

• Vitamin B12 - Important for the Krebs cycle

How do you prevent ketosis?

• Proper nutritional management in the transition period

Additives such as niacin and rumen protected choline may prevent ketosis if fed during last 2-3 weeks of the dry period and into early lactation

• Prevention of overconditioned cows in late lactation - Energy from digestible fiber sources as opposed to starch