Re: Magnesium

Kirsten Rasmussen

Hi Jackie,

The NRC requirement for minimum Mg is 0.015g Mg per kg body weight, at Maintenance (mature, non-exercising horse).  If Rose weighs 700 lbs, she is 318 kg.  318 kg x 0.015 g/kg = 4.77 g Mg.  Because that is a minimum, we add 50% because feeding minimum amounts is not optimal.  4.77 g × 150% = 7.155g.  As per Dr Kellon above, Rose's hay is supplying twice this amount so she is getting enough Mg and there is no frank deficiency in Mg.  However, you should also look at Ca and ensure the Ca:Mg ratio is 2:1.  Ideally the Ca in her hay will be approx 2x the Mg.  If it is not, then you might need to add Ca or Mg because a relative deficiency might still be present.  This is where paying the one time fee to have someone balance your hay for you is well worth it, because there are numerous ratios to check.  Or taking Dr Kellon's NRC Plus course, here:

Kirsten and Shaku (IR + PPID) - 2019
Kitimat, BC, Canada
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