Magnesium is essential for ___ activation.
Most body Mg is found in __ & ___. Only 1% is in ___.
bone & soft tissue
There is __ ____ hormonal regultion of Mg. ___ ___ is key to homeostasis
Mg is primarily absorbed in the ___, no compensation occurs in the __ or ___. No absorption from ____.
no sm or lg intestine compensation
Minimum ___ ___ is necessary for net absorption.
Mg ____ is mainly driven by small __ ___ and a large __ ___ ___.
small chemical gradient
large electrical potential difference
__ % dietary Mg absorbed
A cow producing 20-30lgs requires ___ g/d of Mg.
Mg ___ such as ___, ___ are poorly absorbed.
salts MgO, MgSO4
How can Mg absorption be altered:
___ deficient intake
High ___ concentration
Low ___ concentration
Very high ___ ___ eg ____
__ ___ enhance absorption
Very high crude protein eg nitrogen
High K intake alters ____ forces and reduces luminal Mg uptake.
Decreases in Na stimulates ____ which enhances ___ secretion of K.
aldosterone --> stim salivary secretion
Very high crude protein eg Nitrogen:
Acute elevation vs slow increase
acute: decreases Mg
slow: no effect
Fermentable Carbs ___ Mg solubility by:
increase absorptiive surface area
T/F There is specific hormonal control of Mg
but it can be influenced secondarily by other hormones.
What are 3 excretion patterns?
Kidney: glomerular filtration, tubular reabsorption
Fecal: unabsorbed and endogeouns
Mammary: lactational drain - can trigger hypomagnesemia alone
Endocrine regulation of Mg
Mostly ___ _____, minimal ____.
Inc absorption slightly:
Increases renal loss, dec absorption:
Consistently decreases serum mg:
inc - PTH
inc loss: aldosterone
Dec serum Mg: Vit D
Tetany reflects ____ demonstrated. The other word reflects the ___ ___ eg:
grass tetany, transport tetany, winter tetany, wheat pasture tetany, milk tetany
Mg involved in basic functions:
____ formation & use
Hormone activation via ____
___ ____ (Mg deficiency increases ___)
ATP form & use
Hormone action via cAMP
Ach Esterase --> inc ACH
Grass tetany occurs during ___ (___ season grasses) during periods of ___ growth of grasses.
Wheat pasture poisoning occurs when ___ wheat is grazed by cattle, and occurs with other ___ crop pastures.
Lactation teany: ___ cases occur in lactating cows.
Winter tetany. Most feed for beef cows in winter are ___. They are harvested during ___ or ___ during times of ___ Mg. They are also ___ digestable. Supplment with:
deficient in Mg
spring/fall - low Mg
Mollases licks, protein blocks supplemented with Mg
Calves fed milk become deficient after ___ weeks because the GI tract becomes less efficent in ____
Cattle on ____ diets are tranpsorted. Combine with the ___ of transport and ____ feed intake for transport and confinement.
stress & lack of feed
Where does hypomagnesemic tetany occur?
it is a disease of ____ and improved ____.
What kind of diet?
dz of prospertity and improved productivity - fertilization
What are predipsosing factors in the spring/fall?
roughage diets <.2% mg
periods of fasting
High K diet
High protein diets
Clinical signs are ____ may wax and wane but can be ____ (speed)
Progressive - rapid
Belligerent, bellowing, running, Incoordinated, recumbent
Pyrexia (muscle contractions)
Elevated resp rates
Convulsions, seizures, opithotonus
serum associated with clinical signs:
Do all animals have subclinical vals?
compared to serum
Ionized compared to serum
remains same for how long post mortem?
Tissue to collect?
1.7-3.3 mg/dL normal
<0.8 clinical signs
No, Some have normal serum
CSF = serum
same for 24hrs
Vitreous humor - good for 36-48hrs
The lower Ca the ____ ____.
Serum K :
low normal to hypocalcemia <6mg/dL
K - often, but not consistently elevated
milk fever - any stage
DFDX all cattle
Lead poisoning - act crazy
Infectious dz - rabies, listeriosis
IV soln of Mg salts include:
Mg hypophosphite, sulfate, lactate or calcium salts
In emergency: behavior:
ER: recumbent convlusing animals
IV dosing if save, or rectal suppository,
Feed __ gm/hd/day
Feed how often:
give what free choice?
Give 100lb/ton ___ ___
Give ____ free choice
Dust pastures with ___
Soil tx with ___
Feed daily - immediate effect
salt free choice
protein supplment - 2lb/hd/day
MgO 25lbs/acre dust
Soil tx: limestone, MgO
Be careful and get Mg back into them
Can't give huge ___, but must give ____. If give too much concentration in _____ don't _____.
Usually ___ ____ _____ so severe you can't get back. Often some ___ ___ going on.
total body defecit
T/F: treating with mineralocorticoids is safe. When and why was it given.
Common after calved to reduce udder edema. Animals on this would tank and looked incompatible with life.