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Preventing Grass Tetany In Cattle

As the days start to get longer and spring nears, it's time to start guarding your herd against grass tetany. Most frequently occurring in the spring, grass tetany incidents often follow a cool period (45-60°F) when grass is growing rapidly. Early grass growth may be high in potassium and low in magnesium. This excess potassium can interfere with magnesium absorption in cattle resulting in tetany.

Signs of Tetany

Unfortunately sometimes the first sign of a problem with grass tetany is finding dead cows in your pasture. Symptoms of tetany include cows staggering, excitability, involuntary muscle contractions, convulsions, frothing at the mouth, and vocalization. Tetany can strike quickly, leaving the animal dead within hours of the onset of symptoms, making detection and treatment that much more difficult. In the battle against grass tetany it's best to try to prevent it rather than treat it.

Preventing Grass Tetany

Luckily grass tetany can be highly preventable if you follow the tips below:

Provide Magnesium Supplementation

To avoid potential magnesium deficit issues we suggest feeding Mag-O-Min® or other high magnesium mineral products prior to and during tetany season. "Palatability of the mineral is crucial," explains Harry Walker, Southern States® Feeds Sales and Technical Representative. "Cattle do not like the taste of magnesium and will not consume a high magnesium mineral that is not palatable." High magnesium minerals should be available to your herd 24/7 during tetany season.

Proper Location & Number of Mineral Feeders

It is very important to have an adequate number of mineral feeders in each pasture. Walker says, "A general rule of thumb is one mineral feeder for every 25-30 cows." Not only is number of feeders critical, so is their location. If the mineral feeder is located too close to the pasture water source, cattle may over consume the mineral. Likewise if the feeder is located too far away from water, the cattle may not consume enough. Ensure your feeder is properly stocked at all times during tetany season. An empty mineral feeder, even if just for a few days, is asking for a tetany problem.

Keep Offering Hay

Just because the grass is growing doesn't mean you should rely solely on pasture as a food source. Continue to offer hay so the cattle have another food source other than new growth in the pasture. Keep hay available until they completely stop consuming it.

Add Variety to your Pasture

Variety is the spice of life. Did you know the risk of grass tetany decreases on pastures that contain over 30% legumes? At next seeding think about incorporating clovers and alfalfas into your pasture mix.

Avoid High Risk Pastures

If at all possible, avoid letting your herd graze on pastures known to be at high risk for grass tetany.

Avoid Fertilizing with Nitrogen in the spring

Nitrogen fertilization contributes to rapid plant growth which in turn can lead to low magnesium in the plants.

Prevention is Key

As Benjamin Franklin once said, "An ounce of prevention is worth a pound of cure." This definitely rings true when it comes to grass tetany, as it is easier to prevent tetany than treat it. By keeping vigilant to pasture changes you can be one step ahead of grass tetany.

Visit your local Southern States location for all your cattle care needs.

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