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Basic Cations (1)
Written by John Turner Consultancy for Agifert
Potassium, Calcium, Magnesium and Sodium
Basic Cation major nutrients are all essential for animal nutrition and also for plant nutrition with the exception of sodium. The problem is that these nutrients inter-act with each other in the soil, plant tissue and in the animals ' digestive system, the content of each of these nutrients in lush pasture is different to ruminant animal dietary requirements.
Calcium, Magnesium and Sodium are required for metabolic(energy) processes such as nerve function, muscle function and electrolyte balance in blood. Clinical deficiency has a severe effect on animal productivity and is a common cause of cow death. Calcium and magnesium deficiency at sub-clinical level (no obvious symptoms) can reduce lactation performance by 10% and conception rates at mating.
Comparison of typical pasture levels with animal requirements
Element Typical lush pasture Animal Optimum High Diet Level.
Antagonistic to:
Potassium 3.0-3.5% 1.0% Ca,Mg,Na
Calcium 0.5-0.6% 0.65% P
Magnesium 0.18-0.20% 0.25% Ca
Sodium 0.05-0.15% 0.15% Ca,Mg,K
The reason why clacium and magnesium deficiencies are problems in dairy cow nutrition is due to the antagonistic effect of high potassium in the diet and marginal levels of these nutrients in winter/spring grown pasture.
Potassium:
Potassium deficiency is not an issue for ruminants fed on a green forage based diet. The issue is that the pasture potassium content must be about 3% during late winter and spring for optimum plant growth. This is about 3 times the animal requiement and this reduces the absorption of dietary calcium and magnesium by ruminant animals.
When a grass plant is defoliated, potassium and nitrogen is mobilized from the crown of the plant and the roots so that replacement growth of new leaf tissue is rapid and the potassium content may be up to 5.5%. As the grass leaf expands to full size, the potassium content reduces as the calcium content increases. The typical apperarance of grass leaves that are expanding is light green compared to a deeper green colour of fully expanded leaves.
A grazing rotation length of less than 3 weeks in spring is likely to be associated with increased metabolic stress to stock.
When fertiliser potassium is applied to the soil, luxury uptake and a rapid increase in pasture potassium content is common. Application of potassium fertilisers should be timed to avoid seasonal times when animals are prone to metabolic stress.
Calcium:
Calcium deficiency is generally referred to as 'milk fever' due to the increased incidence of this metabolic problem the start of lactation. Affected ruminant animals have impaired muscle function, particularly smooth muscles associated with the uteris and gut. Symptoms include difficulty with calving (cows), retained placenta and associated infections. The rate of passage of forage through the gut may be reduced which reduces feed intake and energy supply.
Bone Calcium may be mobilized to maintain blood calcium levels however this process requires up to 3 weeks from the start of calcium stress to become effective.If the dietary calcium content is chronically low,bone strength will reduce and the incidence of bone fractures and arthritis will increase.
Here at Digital Harvest we reccommend a combination of Agriferts custom blended trace elements, applied along with their kelp based liquid fertilisers and lime products to bring balance back to your psature & soil.