Negative energy balance

Question 1

What factors need considering in NEB?

Answer 1

• glucose
• C3 molecules (more important in ruminants than glucose)
• krebs (citric acid) cycle
• gluconeogenesis
• vitamins
• co-enzymes

Question 2

Describe glucose levels in early lactation

Answer 2

Insufficient in early lactation –> gluconeogenesis and lipolysis d/t drop in insulin. Lack of glucose –> cascade of problems

Question 3

Consequences of NEB

Answer 3

• glucose deficit
• reserve mobilisation (fat and protein)
• ketosis complex
• fat mobilisation syndrome

Question 4

Describe ketosis complex

Answer 4

• excessive build up of ketone bodies in blood d/t accumulation of acetyl-CoA (as precursors are turned into glucose?)
• increased ketones –> reduces appetite –> vicious cycle
• aka acetonaemia which is not same as acidosis

Question 5

T/F; cows don’t develop ketoacidosis

Answer 5

True

Question 6

When does ketosis complex occur?

Answer 6

• post-partum (2-10 weeks after calving)
• lactation incidence 3-7%, some farms higher
• subclinical ketosis higher, esp poorly managed farms
• RISK FACTORS: hypoCa, hypoMg, RFM, lame, twins

Question 7

How does hypoCa lead to ketosis complex?

Answer 7

HypoCa –> gut stasis –> fat mobilisation –> ketosis complex

Question 8

Categorisation - ketosis complex

Answer 8

• primary vs secondary

- wasting form vs neurological form

Question 9

Describe primary ketosis

Answer 9

• VFI cannot meet energy demands
• excessive breakdown of body fat and mm
• sometimes d/t specific nutritional deficiencies affecting energy metabolism (choline, biotin, vit B12)
  = ‘starvation ketosis’

Question 10

Describe secondary ketosis

Answer 10

• any condition causing cow’s appetite to decrease:
• LDA/RDA
• (endo)metritis
• lameness
• (mastitis)

Question 11

Describe ‘wasting form’ of ketosis

Answer 11

• gradual reduction in appetite, cows refuse to eat concentrates
• marked loss of body weight
• firm, dry faeces
• occasional bouts of staggering

Question 12

Describe ‘neurological form’ of ketosis

Answer 12

• sudden onset ‘abnormal’ behaviour
• walk in circles, aimless wandering, head pushing, apparent blindness
• develop depraved appetite, lick skin and objects, chewing
• hyperaesthesia, uncoordinated gait
  +/- 10% of ketosis cows

Question 13

Dx - ketosis

Answer 13

• CS
• blood glucose (low end)
• Beta hydroxybutyric acid (BHBA): >1.4 mmol/l subclinical, >2.5mmol/l clinical
• milk and urine ketone levels
• serum NEFAs can be elevated

Question 14

Tx - ketosis

Answer 14

• IV dextrose 100g, quick
• ** IV dextrose, 200g, slow drip (5 hours) ***
• corticosteroids sometimes
• appetite stimulants (transfaunation)
• propylene glycol 250ml, BID, until cow fights you off!

Question 15

Describe fatty liver syndrome

Answer 15

= fat cow syndrome = fat mobilisation syndrome

• excessive wt loss
• fat mobilised as NEFA (lipase) is deposited in liver (fat can also be turned into KB, ATP and VLDL but these are less preferable pathways)

Question 16

CS - fatty liver syndrome (FLS)

Answer 16

• BCS recumbent
• neuro signs
• death
• typically have concurrent condition (RFM, (endo)metritis, although low grade in severity, that doesn’t respond to tx)

Question 17

Outline relationship b/w FLS and pregnancy toxaemia

Answer 17

• start last few weeks of gestation
• most prevalent at parturition
• twins
• reduced VFI is primary cause
• fat animals are at risk
• cattle and sheep mainly

Question 18

Describe pregnancy toxaemia of cattle

Answer 18

• beef
• usually autumn calving herds (relates to feed available, palatability, quality)
• internal parasitism increases the risk
• when it occurs shortly before calving, cows/ heifers are agitated, incoordinated, have difficulty rising, scant faeces
• when +/- 6 weeks before calving, the tend to be depressed, rest the same

Question 19

Describe pregnancy toxaemia of sheep

Answer 19

• uncommon in maiden ewes
• breed and age variations relate to fecundity
• fatality approaches 100%, in clinical cases
• outbreaks in flock also have higher lamb mortality
• Associated with (sometimes): hypoMg, hypoCa

Question 20

CS - pregnancy toxaemia of sheep

Answer 20

• affected ewes separate from flock, apparently blnd
• constipation common and grinding of teeth
• periods of drowsiness and abnormal posture (‘stargazing’) and incoordination
• ewes become more recumbent, severe depression, coma
• recovered ewes show evidence of ‘woolbreak’

Question 21

Dx - FLS and pregnancy toxaemia

Answer 21

• BLOOD: NEFA, glucose, liver enzymes, fatal uraemia in sheep
• MILK; fat > 5%, protein 1.6%
• LIVER BIOPSY (research): >15% fat

Question 22

Tx - FLS and pregnancy toxaemia

Answer 22

• as for ketosis + IVFT
• consider: insulin, steroids, choline, biotin, cobalt amine, BST (illegal in EU)
• provide high quality feed, glucose precursor rich
• depends on case, usually poor response

Question 23

How does insulin with IVFT dextrose help?

Answer 23

allows glucose to enter cells faster

Question 24

Tx - sheep - FLS and pregnancy toxaemia

Answer 24

• **drench q4-8 hours with rehydration solution (like scouring calves) **
• induce parturition or CS
• affected flocks IMMEDIATELY place on supplementary concentrates/ cereal and early cases tx with propylene glycol

Question 25

Control/prevention - FLS and pregnancy toxaemia in cattle

Answer 25

• prevent overly fat or poor BCS at calving
• transition cow ration to reduce concurrent dz
• early lactation cows: balance, high energy dense (glucose) ration, aim to minimise rumen acidosis
• good quality forage, maize silage
• strategic BCS recording
• fat cows to walk moderate distance for feed/water
• consider: sodium propionate, niacin, biotin, cobalt
• high risk cows: monensin bolus (KEXXTONE)

Question 26

Control/prevention - FLS and pregnancy toxaemia in sheep

Answer 26

• BCS monitoring
• twins and triplets ID for supplementary feeding at end of gestation
• provide shelter and supplement hay/silage for ewes during inclement weather and careful planning of husbandry events to minimise stress at high risk periods

Question 27

2 features of negative energy balance (NEB)

Answer 27

• ketosis

- fat mobilisation syndrome