Grass tetany in cattle


This is one of three Primefacts about grass tetany. This Primefact describes the causes of the disorder. Primefact 421 focuses on treatment and prevention. Primefact 785 examines some ways to predict the likelihood of the disorder occurring.

The cost to producers is greater than most estimate, as many different forms of prevention are used, sometimes with ineffective results.

Most veterinary texts define 'grass tetany' as a deficiency of magnesium (Mg). Though grass tetany is expressed as a magnesium deficiency, the reasons for this expression are complex and varied. This Primefact includes information on:

  • grass tetany;
  • symptoms;
  • why grass tetany usually occurs in late autumn/winter;
  • magnesium absorption in the animal;
  • phosphorus and calcium effects;
  • effects of age of the cow;
  • effect of breed;
  • high production demand;
  • starvation and interference from other elements;
  • other factors contributing to the risk of grass tetany;
  • facts to note;
  • notes on supplementation.


Primefact 420 First Edition

Published: Apr 2009