Here’s one simple step to reduce straining, collapse or death at calving or lambing.
Don’t graze springing cows or spread out ewes on too high potassium pastures. Heard it before? But how do you know and what level is high anyway?
Grazing any pasture with potassium levels over 3.0% dramatically increases your risk of metabolic disease. This is not just downer cows or dead sheep but extends to difficult births, slow suckling (low colostrum intake), reduced milk production and a whole list of related issues including mastitis, metritis and ketosis (sleepy sickness). And while you think you’re safe by adding plenty of magnesium to the diet (dusting pastures, water treatment, or in-shed feeding), when your pasture potassium increases by just 10% you nearly double your dietary magnesium demand.
Grazing pasture with potassium levels over 3.0% dramatically increases your risk of metabolic disease in the animals
What Are Your Typical Risky Paddocks?
Effluent Block: Everyone knows about this but still farmers take the risk. Why? Because calving closer to the shed is easier and the risk is not usually known in advance. Grazing management in autumn may leave these as the paddocks with the best cover and temptation is high.
Paddocks Fertilised with Potassium: The cause is very similar to effluent blocks, but because the potassium source comes in the form of a commonly recommended fertiliser regime, the risk is not connected. Potassium may be an essential part of your fertiliser program, but consideration of animal health must be given to time of application, strategic use of pastures for calving or lambing and keeping good fertiliser and management records.
For example when silage, baleage or hay is taken, standard practice is to add back potassium fertiliser. Harvesting your supplement from the effluent blocks and feeding out into other paddocks can shift nutrient effectively around your farm. Similarly, if hay was harvested late and autumn potassium support fertiliser was applied, consider avoiding these paddocks at ewe spread out. Make sure you understand your underlying soil types and their potassium reserve status. This is important because if natural mineral cycling will replace nutrient removed, then applying potassium fertiliser might be a cost and an animal health risk you can avoid.
Cereal Green Feed: Plant potassium levels vary widely and cereals are commonly high – often climbing over 4%. At this level the active magnesium pump in the rumen has all but stopped and magnesium absorption is totally reliant on passive transport, i.e. the concentration of magnesium in the diet.
Very few pastures we test have magnesium levels over 0.3%, most in the low 0.2’s and some lower than this. Ah “But I’m dusting and have mag in the water!” or “I’ve got a high magnesium lick/block or tub” we hear you say. While these help, the better strategy is to avoid the challenge.
Not only do you not want to have to drive the ambulance to the bottom of the cliff, you might consider putting up a fence 100 meters back from the cliff edge.
So How Can You Avoid The Stress?
Know your pasture levels.
Yes pasture levels change. Yes there is a cost. And yes it takes some time.
But the information is invaluable. You can go from using boxes and boxes of high pressure stressful ambulance delivered electrolyte bags to driving around the farm with a more relaxed grin.
And What If The Results Come Back High?
There is an optional emergency plan. Foliar application of salt is the most economical way of reducing foliar potassium but the science is not exact and high pasture sodium can also be a metabolic risk factor in its own right. Please call if you find yourself in this situation – 0800 765 854.