What are macrominerals?
Those minerals that have a high requirement in an animal.
What are some examples of macrominerals?
What are some other names for hypomagnesemia?
When does a deficiency in magnesium occur?
Increased demand combined with a decreased intake.
What are some clinical signs of hypomagnesemia?
Sensitive to sound/hand clap
Clamping of jaws
(normally all types have an increased HR)
Sudden death :(
What are some subacute signs of hypomagnesemia?
Slow onset over 3-4 days
Spasmodic urination and defecation
What are some chronic signs of hypomanesemia?
Depressed milk yield
What is the cause of hypomagnesemia?
Low Mg levels in the diet (fresh grass, hence 'grass tetany')
Poor feed intakes (rain)
Poor absorbtion of Mg
What is the treatment of hypomagnesemia?
1.Bottle calcium borogluconate with magnesium hypophosphate, i/v, slowly
2. Magnesium sulphate, 25% sub-q only
How can you prevent hypomagnesemia?
1.MgO in concentrates mixed with molasses
2. Mg oral bolus
3. Mg tablets/flakes added to drinking water
4. Avoid potassium fertilizer when hypomag is a known problem
What are some other names for hypocalcemia?
Bovine parurient paresis
Acute flaccid paralysis
Milk fever (big one)
What is normal calcium concentration in the blood?
Where is calcium absorbed in the body?
What mineral is a co-factor in PTH and vitamin D3?
What are the subclinical signs of calcium deficiency?
Bloat/gas in the gut
Able to stand
Blood calcium 1.8-2.3
What can be mistaken with subclinical calcium deficiency?
What are the clinical signs of moderate calcium deficiency?
Recumbent - sternal recumbency
Bloat/gas in the gut
Delayed/absent pupil responses
Blood calcium 1.2-1.8
What are the clinical signs of severe calcium deficiency?
Unresponsive to stimuli
Reduced cardiac output
Blood calcium less than 1.2
Name some treatments for calcium deficiency.
20% or 40% CaBorogluconate 400ml given slowly i/v
Low volume treatments of maxacal 100ml
*Need to give slowly to avoid killing the cow; need to monitor HR as well and keep within a normal range
*Can give calcium sub-q to prevent recurrence
How do you know when a cow is starting to recover from calcium deficiency?
(Sit the animal up)
When is a cow most susceptible to calcium deficiency?
Around 6 hours post-calving
High BCS, low VFI
Retained placenta can give hint if a cow is deficient (inadequate amount of Ca to expel placenta after birth).
What is the cause of calcium deficiency?
Demand not met by supply!
-Decreased absorption from kidney
-Decreased absorption from GIT (feed intake and amount of Ca in dry cow ration)
-Low bone reserves (old cows)
How do we prevent calcium deficiency?
Low calcium in dry cow ration, high calcium in milking cow ration
Maintain magnesium supply
Drench at calving
Bolus just before calving
What groups of cows are at a high risk of developing calcium deficiency?
What can occur with high soil calcium?
What type of symptoms do you see in a phosphorus deficient cow?
Unable to rise, but not having a painful process
What does DCAB stand for?
Dietary cation anion balance/diet
What are the cations in DCAB? Anions?
Cations: sodium and potassium
Anions: chloride and sulfur
What is the formula used to determine DCAB? What should the sum be lower than?
(Na+K) - (Cl + S); sum should be lower than -200 mmol/kg DM. Provides an excess of anions over cations
How do you adjust a diet for DCAB?
Reduce K in diet, and add anions to the diet (magnesium chloride or magnesium sulfate are most popular)
What is the effect of anionic salts on DMI? Why?
Reduces DMI because they are not very palatable. Can cause negative energy balance, fatty liver, and other metabolic problems.
How do you monitor DCAB?
Urine pH; it is a good reflection of blood pH.
What is your aim for blood/urine pH?
If urine pH is dropping below 5.5, what is happening?
Absorption of excess anions