Negative Energy Balance

When is NEB of highest concern in dairy cows?

3 weeks pre calving through 6 weeks post calving

How much energy does a dairy cow need in their dry period?

100-120MJ

How much energy does a dairy cow need after parturition?

300MJ or more

What cows are most susceptible to NEB in early lactation?

Fat cows

How does a cow utilize energy from forage?

Rumen fermentation of CHOs and ruminants use Volatile fatty acid (VFA) by products

What is the typical VFA ratio (Acetate:propionate:butyrate) in high forage diets?

70:20:10

What is the typical VFA ratio (Acetate:propionate:butyrate) in high starch diets?

60:30:10

What is the first step of energy metabolism that “braks down” to cause the spiral into ketosis?

Propionate is blocked from entering the Krebs cycle and Fat deposits are broken down to accomodate for necessary energy

When are beef cattle more likely to suffer from fatty liver disease?

Prepartum

When are sheep more likely to suffer from fatty liver disease?

Prepartum

When are dairy cows more likely to suffer from fatty liver disease?

Postpartum

Which of the following is the most severe metabolic disease: Fatty liver disease, clinical ketosis, or subclinical ketosis?

Fatty liver disease

Which of the following is the least severe metabolic disease: Fatty liver disease, clinical ketosis, or subclinical ketosis?

Subclinical ketosis

What are the major ketone bodies produced by/within the cow?

Acetone, Acetoacetate, and Beta hydroxybutyrate (BHB)

When does fatty liver occur in cows?

rate of FA esterification to Triglycerides exceeds the rate of disappearance by hydrolysis and export

When should you consider a fatty liver diagnosis?

When liver triglycerides >30mg/g (liver sample I believe)

What is the epidemiology of ketosis?

1-50% incidence among all dairy cows in UK

More common in high producing cows and older cows

What is the etiology of ketosis?

Over conditioned dry cows

Primary ketosis: Patho-physiological in high yielding dairy cows, poor dry cow management, poor fresh cow management,

Secondary ketosis: RFM, metritis, hypocalcemia, other PP diseases

What are the clinical signs of ketosis?

Inappetence or anorexia, milk drop and rapdi weight loss, feces ± firm and dry

Depression, reduced rumen contraction frequency and strength

TPR normal

± acetone breath

How common is nervous ketosis?

<1% of ketotic conditions

What clinical signs could be seen during nervous ketosis?

Delirium, cricling, leaning and crossing legs, licking and chewing manias, blindness

What are the main effects of ketosis that are most commonly seen?

Decreased milk production, decreased submission rate, decreased conception rates

How can you diagnose ketosis?

Determine if individual or herd problem

History/signalment

Clinincal exam

Test via Biochemistry (Ketone bodies ± NEFA ± glucose)

What ketone body/bodies is/are of primary concern when diagnosing ketosis?

BHB

What is the clinical range of BHB in a normal, healthy cow?

1.2-1.4mmol/L fresh cows

How can you diagnose ketosis via urine?

Acetoacetate levels (+++)

How can you diagnose ketosis via milk?

test with Rothera’s reagent to test for BHB in the substance (semi-quantitative)

To monitor ketosis rates at a herd level, how should sampling be done?

15-20 cows/month

3-9 days postpartum

extend sampling up to 24 DIM

Less than 15% of values should be >1.2mmol/L

What level of ketones indicates subclinical ketosis?

1.2-2.9mmol/L

What level of ketones indicates clinical ketosis?

>3.0mmol/L

How can you diagnose fatty liver disease in cows?

Clinical signs, Liver biopsy, Liver enzymes, PMI

What is the recommended treatment for ketosis?

Oral propylene glycol, 300mL drench SID for 5d

How does oral propylene glycol help with ketosis?

It is absorbed directly in the rumen or converted to propionate → gluco-neogenesis and stimulates insulin release

elevated blood glucose in 4h

What are some benefits to treating ketosis with oral propylene glycol?

Easy to administer, higher cure rate, lower odds of displaced abomasum or to be culled by 30 DIM, milk production icnreased by 1.3-1.6kg/d

What is the normal level of NEFAs in dry cows?

300mmol/L or less

What is the normal level of NEFAs in fresh cows?

600mmol/L or less

Why may we not want to treat ketosis with glucose/dextros IV?

LArge proporiton excreted in urine, reduced insulin response to glucose in ketotic cows, labor intensive

When is glucose/dextrose IV recommended as a treatment for ketosis?

Rec as 2nd line treatment for animals presenting nervous signs or severe hypoglycemia

What traditional method of ketosis treatment is NOT recommended anymore?

Glucocorticoids (steroids)