Requirement of Magnesium to horses

Magnesium is an important partner in the optimum utilization of calcium, but it is a limiting element world wide.


Horses that have adequate magnesium are:
• More relaxed
• Can work longer in anaerobic conditions because magnesium mobilizes the calcium in the muscles
• Less likely to tie up especially heavy muscled horses like warm blood, by better utilizing the calcium in muscles
• Less likely to get colic because magnesium is a laxative, helping stimulate hind gut motility
• Less likely to founder as magnesium helps the good-keepers be less insulin resistent.


Magnesium and tying-up

• An excess of Ca or a deficiency of Mg can both cause a temporary muscle tetany in horses called tying-up or Recurrent Exertional Rhabdomyolosis
  
• In horses who suffer from RER, characterized by a chronic tying-up during work sessions, supplementation with Mg will help to prevent the symptoms.
  
• Magnesium is considered to be an "anti-stress" mineral, since sufficient supplies reduce the release of stress hormones.
  
• Magnesium is also important for maintaining normal insulin sensitivity
  
  

Feeding Magnesium

• Magnesium is non-toxic and is impossible to overdose by mouth. The GI tract absorbs what it needs and the rest is dumped.
  
• Magnesium phosphate or magnesium sulphate (Epsom salts) should not be used as a feed additive on a regular basis because this salt form can cause diarrhoea.
  
• The recommended dietary magnesium supply for horses is 20 mg Mg/kg of body weight per day, corresponding to a maintenance requirement of 10 g Mg/500 kg body weight.
  
• A calcium/magnesium ratio of 1.5-2.0:1 is ideal for the daily intake, with the higher value for maintenance and the lower for intense work.
  
  

For more information

http://www.plumcoullee.ca/documents/Magnesiuminhorses.pdf