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Manage grass tetany this winter with WeatherPro MagPlus 

Grass tetany can affect all livestock, and while it can occur at any time, it’s more susceptible during winter, when cold and wet conditions are more frequent.


As we transition into the colder months of the year, it’s crucial that livestock managers are aware of the effect that frosts, and wet conditions have on their livestock’s feed and grazing pastures. Each year, the seasonal change to winter creates a high risk of feed losing its nutrient quality, and this can lead to significant challenges in maintaining the health and productivity of livestock. One particularly concerning health condition during this period is grass tetany, a metabolic disorder caused by a deficiency of magnesium in the blood.  

Grass tetany can be fatal if magnesium levels drop too low in the animal. Magnesium is a vital mineral for optimal function in animals, and it plays a vital role in ensuring muscle and nerve function, the activation of enzymes and the production of hormones, and a stabilised metabolism. It also plays a key role in the breakdown of carbohydrates and fats, and the maintenance of an animal’s structural integrity, ensuring strong bones and teeth.  

Grass tetany can affect all livestock, and while it can occur at any time, it’s more susceptible during winter, when cold and wet conditions are more frequent. It’s during this time that grasses and cereal crops often struggle to absorb adequate magnesium from the soil.  

Magnesium levels can also be compromised due to fertilisation practices, for example, using potash or nitrogen fertilisers can alter the soil chemistry making it difficult for plants to absorb magnesium. Magnesium can be lost in inputs such as feed but also through animal outputs such as urination, faeces, and milking. This makes cows in peak lactation and ewes 4-6 weeks after lambing particularly susceptible to grass tetany due to their increased physiological demands.  

Like any deficiency, supplements are an efficient and effective solution to restore optimum mineral or vitamin levels. Our feed supplement WeatherPro MagPlus offers extra magnesium, in a form that is readily available to the animal, plus the right ratio of calcium and sodium to combat high pasture potassium levels. Other benefits include improved live-weight gain for stock grazing forage cereals, assistance with calming nervous stock and preventing and treating stress illness during transit. 

A common concern when using feed supplements is their susceptibility to spoilage due to rain and wet conditions. However, WeatherPro MagPlus features a unique weather-resistant formulation. This ensures that the supplement remains effective and can be safely distributed to livestock even in adverse weather conditions. By using WeatherPro MagPlus, livestock managers can provide consistent and reliable support to their animals and ensure they remain healthy whilst mitigating the risk of grass tetany during the challenging winter months.  

Get in contact with your local territory manager here about incorporating WeatherPro MagPlus into your livestock operation this winter.  

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