With spring well and truly upon us in most regions of Southern Australia, grass growth is starting to take off. When this occurs, obviously we aim to try and take advantage of it by maintaining quality along with taking paddocks out for silage to create a surplus for the summer months. Things may seem to be running smoothly until the cows start becoming aggressive or restless.
Grass Tetany (Hypomagnesemia) commonly occurs during late winter/spring period when the magnesium levels in pasture reduce therefore resulting in cows not receiving their adequate levels of magnesium. Symptoms of this include restlessness, staggers and convulsions resulting in possible death if not treated early enough. Common factors which cause grass tetany are:
– High amounts of grass or cereal crops
– Cold, wet weather
– Nitrogen/potash fertiliser usage
– Dairy cows in peak production
Obviously during the spring period, most of these factors can’t be avoided, and like always we need to take maximum advantage of any grass we have available. If grass tetany does occur, a 4-in-1 pouch injected under the skin is the quickest way to get magnesium back into the cow. Hay and shelter also need to be provided so she can recover.
Prevention is better than cure as grass tetany can occur without warning so supplementation with magnesium sources is the best way to prevent this. Many different ways can be used to help including:
– Magnesium Oxide (causmag).This is the easiest way to ensure cows receive supplementation to help prevent grass Tetany. This can be included in your dairy feed at 30 – 50 g/cow/day.
– Grass Tetany Licks can be used for dry cows or beef cattle. The major disadvantage of this is that the cows may not consume enough.
– Magnesium Chloride can be added to the cow’s drinking water but again intake can vary due to weather and conditions.
Magnesium needs to be fed in a balanced diet containing other essential macro minerals such as Calcium, phosphorus, sodium and potassium along with other micro minerals. If you have any questions about Grass Tetany or any other problem you may have with your herd, please get in touch with your Reid Stockfeeds representative to discuss this through a professional approach to feeding.