Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BVetMed3 - PMVPH > Macrominerals > Flashcards

Macrominerals Flashcards

1
Q

What conditions can magnesium deficiency lead to?

A

Staggers

Grass tetany

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

When does Mg deficiency arise?

Why is it more likely?

A

When high demand is combined with decreased intake

Little homeostatic regulation of magnesium in ruminants

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What management factors can result in low Mg?

A

Low Mg in the diet (e.g. fed on fresh grass)
Poor feed intakes (when raining)
Poor absorption of the Mg due to:
- increased intake of positive ions - K (DCAB) or N
- Increased passage rate through gut (e.g lush pasture, low fibre)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What clinical signs are associated with acute magnesium deficiency?

A 
Hyperaesthesia 
Ears twitching 
Sensitive to sound / hand clap 
Staggers and collapses
Champing of jaws 
Sudden death  
Increased heart rate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is meant by the term hyperesthesia?

A

Increased sensitivity to stimuli

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What clinical signs are associated with subacute magnesium deficiency?

A 
Slow onset
Spasmodic urination and defaecation 
Muscle tremor 
Staggering gait 
Increased heart rate

Could be more vocal than normal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What clinical signs are associated with chronic magnesium deficiency?

A

Few signs

Poor appetite

Depressed milk yield

Increased heart rate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How can magnesium deficiency be treated?

A

URGENT

IV Ca borogluconate with magnesium hypophosphate - SLOWLY
- typically into mammary vein

Magnesium sulphate 25% SC ONLY

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How can Magnesium deficiency be prevented?

A

Mg NOT PALATABLE

MgO in concentrates, mix w/ molasses
Mg oral bolus
Mg tablets/flakes added to drinking water

Avoid K fertiliser (or pig manure) if hypomag known problem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are some other names for hypocalcaemia?

A

Milk fever
Acute flaccid paralysis
Bovine Parturient Paresis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the relationship between Ca and Mg?

A

Mg required as a cofactor at several stages of Ca homeostasis
- D3 and parathyroid hormone release

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the biggest store of calcium in cows?

Where else is it absorbed?

A

Bone

GIT
Kidney

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the homeostatic regulators of Calcium?

A

PTH - increases Ca2+ resorption in kidney, increases D2 to D3 conversion for increased absorption in SI, increased Ca2+ from bone

Vitamin D3 (converted in kidney) - increases absorption from GIT

Calcitonin - UNCERTAIN ACTION - normally reduces blood Ca2+, rare that it is too high in a cow.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What might you observe in a cow with subclinical hypocalcaemia?

A 
Able to stand 
Hypersensitivity 
Excitable 
Tremors 
Ear twitching 
Ataxia 
Bloat
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Why is hypocalcaemia associated with bloat?

How can this progress?

A

Smooth muscle responds faster to decreased calcium concentrations

There is stasis in the gut

Therefore eats less, less calcium taken in, CLINICAL HYPOCALCAEMIA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How can the transition from dry to milking affect the calcium levels of cows?

A

Dry cows don’t need as much Ca2+ therefore there is a low rate of absorption

When she starts producing colostrum, she will quickly start draining calcium and it takes time for the rate of absorption to catch up

This leads to a NEGATIVE CA2+ BALANCE

17
Q

How might a cow with clinical hypocalcaemia present?

A 
Recumbent - sternal recumbency 
S shaped neck 
Depressed 
Dry muzzle 
Cold extremities 
Bloat
No Defaecation 
Delayed / Absent PLR
18
Q

Why might hypocalcaemic cows be slightly cold to touch ?

A

Not moving (as much) therefore don’t generate as much heat

19
Q

How would a cow with severe hypocalcaemia present?

A 
Reduced consciousness
Lateral recumbancy 
Unresponsive to stimuli
Muscle flaccidity
Reduced CO
Bloat 
Death
20
Q

How would you treat hypocalcaemia?

What do you need to be careful of?

A

20/40% Calcium Borogluconate
Maxacal
Mg, P, Glucose

IV - SLOW don’t want hypERcalcaemia, monitor heart rate

SC- deposit to prevent recurrence

(SIT ANIMAL UP)

21
Q

What are some signs that a hypocalcaemic cow is recovering ?

A

Passes dung and eructation

Shows smooth muscle is starting to work.

22
Q

Why might fat cows become hypocalcaemic?

A

Mobilising fats so eat less

Therefore less Ca2+ in

23
Q

Why might old cows be more likely to get hypocalcaemia?

A

Lower reserves in bone

24
Q

Why would you NOT drench hypocalcaemic cows?

A

Poor smooth muscle action

Don’t swallow properly

ASPIRATION OF DRENCH

25
Q

How can you prevent hypocalcaemia in the herd?

A

Low Ca in dry cow ration, high Ca in milking ration

Magnesium,
DCAB

Drench at calving,
Bolus just before calving

26
Q

What is a typical presentation for phosphorous deficiency?

A

‘Happy downer’

No response to Calcium injection

27
Q

How would you treat a phosphorus deficiency?

A

Foston IV

28
Q

What does DCAB stand for?

A

Dietary Cation Anion Balance

29
Q

What cations and anions do DCAB balance?

A

Cations: Na+ and K+

Anions: Cl- and S2-

30
Q

What is the goal of DCAB?

A

To provide excess anions over cations

(Na+K) - (Cl+2S) should = -100 to -200

Decreases pH of blood

PTH more effective

31
Q

Which cows should DCAB be fed to?

A

DRY cows

32
Q

How does DCAB work?

A

By feeding more negative ions, we create a metabolic ACIDOSIS as more H+ is produced to balance the charge.

Decreased pH causes a conformational change in PTH receptors making it more effective

Calcium homeostasis regulated more effectively so fewer problems around calving

33
Q

How can a DCAB be implemented?

A

REDUCE K+ intake - found in young grass, leafy

ADD anions - MgCl MgS CaCl2 NH4Cl

34
Q

How can neutral compounds effect the charge balance of the animal?

A

Cations stay behind in the GIT so only anions absorbed

35
Q

What issues are there with feeding an ionic salts?

How might these be resolved?

A

NOT VERY PALATABLE
- could reduce DMI and cause negative energy balance, fatty liver etc

Can be dissolved in the water (MgCl2)
Reduce grass intake to make cows more thirsty

36
Q

How could you assess the metabolic status of a cow being fed DCAB?

A

Monitor urine pH

37
Q

What is the normal urine pH of cows? Why?

A

8-8.5

Alkaline due to K+ in grass

38
Q

What Urine pH should you aim for with DCAB cows?

A

5.5-6.5

NOT ANY LOWER

39
Q

What are the main clinical presentations of macro mineral imbalance?

A

Milk fever (hypocalcaemia)

Grass staggers (Hypomag)

BVetMed3 - PMVPH (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions