Greener grasses are on the horizon as winter nears its end and makes way for warmer spring weather. But before you let your cattle mosey about on your freshly-grown pastures, understand the hidden danger of grass tetany that lies in newly-grown grasses, and take precautions to ensure you’re protecting your herd’s health.

Grass tetany is a metabolic disorder caused by a lack of sufficient magnesium in cattle’s bloodstream. Also known as grass staggers and wheat pasture poisoning, this disease occurs more frequently in April through early-May when grass is growing rapidly following the cold winter months.

Early grass growth is typically high in potassium and low in magnesium. The excess potassium interferes with the absorption of magnesium in the cattle, causing an often deadly mineral deficiency. Cattle need a sufficient supply of magnesium in their bloodstream in order for their central nervous system to function properly. Older cows that are in peak lactation are the most susceptible, but it can occur in young cows and growing calves, as well.

Livestock feed specialists and nutritionists at Southern States Cooperative, a large farm supply cooperative, have a number of suggestions on different approaches that you can take to help prevent grass tetany and keep your herd happy and healthy.

Implement Grazing Management
Forages have high moisture levels during the early growing season, resulting in lower, diluted nutrient levels. The grass is high in potassium and low in magnesium and calcium, which can cause digestive issues in your herd. Resist the temptation to let your cattle graze on newly grown grass. Immature forages have less available magnesium, so it’s best to wait until grass is at least 4-to-6 inches tall before letting cattle graze.

Add Legumes to Pasture
Adding a pasture blend of 30% legumes during seeding can encourage grass growth. Legumes like clover and alfalfa have high magnesium levels and will compensate for the magnesium shortage often found in new grass growth. You get the added benefit of nitrogen, as legumes pull nitrogen from the air and “fix” it to the soil. The added nitrogen also encourages grass growth and can ultimately save you on nitrogen costs.

Provide Magnesium Supplementation
According to Southern States Cooperative’s livestock feed sales manager, Mike Peacock, the key to preventing tetany is starting early enough to get intake up on a ‘hi-mag’ mineral at least 30 days prior to the anticipation of issues.  Any cows that will be calving within 30 days should already be getting extra magnesium supplementation from their pre-calving mineral.

Ensure Magnesium Availability
Hi-mag minerals must be available to your herd around the clock during tetany season. Even one day without mineral availability can put your herd at risk. Place mineral feeders where they will get optimum consumption by the herd — you don’t want the herd to over or under consume the magnesium mineral. Southern States makes a 20% high mag cattle breeder block that contains high levels of magnesium.

Identify High Risk Pastures
If you’ve had episodes of tetany in specific pastures in the past, use these areas to graze less susceptible animals. Generally speaking, heifers, dry cows or cows with calves over 4 months old, and stocker cattle are less likely to develop tetany and can graze higher risk pastures.

As the old adage goes, “an ounce of prevention is worth a pound of cure.”  When it comes to your herd—and many other things in life—it’s easier to try and stop something from happening before it happens, rather than wait and try to repair the damage after it’s done. For more information on products and tips on herd health, visit your local Southern States Cooperative or visit www.southernstates.com.

Southern States Cooperative is a Richmond, Virginia-based farm supply retailer and service cooperative. As one of the nation's largest agricultural cooperatives, it provides a wide range of farm inputs, including fertilizer, seed, livestock feed, pet food, animal health supplies, and petroleum products, as well as other items for the farm and home. Founded in 1923, the cooperative is owned by more than 200,000 farmer-members, and serves its members and non-member customers through 1,200 retail outlets in 23 states.