Last month we discussed the coming of spring and the importance of scouting our pastures and hayfields for buttercup. Along with that, this month, we will discuss grass tetany and what producers need to know going into the spring.
Sunshine and lush new growth on pastures will most definitely be a welcome sight after all the weather we have had with multiple days of rain. Along with that also comes the concern of grass tetany, or the disturbance that takes place in the gut of cattle that are grazing those lush new growth pastures. It is thankfully mostly season specific, so once cattle have had time to get adjusted to their new diet they are OK.
This disturbance seems to come as a result of consuming forages with low levels of magnesium. While this seems to be the main culprit there are studies which suggest that phosphorus deficiency in the soil may prohibit plants from utilizing their available magnesium.
Regardless, grazing cattle are affected. Cattle suffering from grass tetany will appear nervous, lack coordination and may be easily excited. They may also have muscle tremors and/or seizures followed by coma and death. Cattle that exhibit these signs need immediate veterinary attention.
To avoid losses due to grass tetany, producers have several options. Producers can limit the amount of grazing cattle can do when the grass is lush and young during early grazing. Top dressing pastures with a source of magnesium is another option. A major source of magnesium is dolomitic limestone Routine soil testing can help determine when lime and fertilizers need to be added to pastures to keep everything at the appropriate levels.
One of the very best ways to avoid grass tetany is to provide magnesium through a mineral supplement or Hi-Mag mineral. There are many Hi-Mag mineral options available to producers. The key is to look on the tag of your supplement to make sure that it contains at least 14-15 percent magnesium.
By planning ahead now, producers can reduce losses due to grass tetany this spring whether by top dressing with magnesium or providing a Hi-Mag mineral, and ensure that their herds can capitalize on spring forage growth.
For more information producers can contact me at the Jackson County Cooperative Extension Office at 586-4009 or the Swain County Cooperative Extension Office at 488-3848 or by email at kendra_norton@ncsu.
Kendra Fortner is N.C. Cooperative Extension agent for livestock in Jackson and Swain counties.