Decision Making Simplified.

Decision Making Simplified.

14th January 2011
Peter Burton

The rule is simple, feed magnesium to cows prior to calving and calcium after, or is it?  We grew up with the knowledge that feeding magnesium prior to calving helped with the release of calcium from the animals own reserves.
 
As cows got older and bones hardened calcium availability declined and the likelihood of metabolic disorders increased.
 
With the advent of maize silage and the increase in fertiliser nitrogen usage the need to increase calcium supplementation became greater.  Nitrogen fertiliser reduces clover growth and increases the rate of grass growth, thereby reducing the intake of calcium.  Maize contains relatively low levels of calcium so for best effect calcium needs to be added.
 
To actually digest the mix of feeds extra energy should be added, however the amount required will depend on sunshine hours at the time, the frequency and rate of nitrogen fertiliser applications, and climatic stress at the time.
 
So what is the best formula?  The most important concept to retain is that everything; feed, fertiliser, animal breed and age, weather conditions, management practises are all inter-related; alter one thing and everything else changes.
 
The second most important concept is that everything starts with the soil.  If there are ill health issues of any sort go back to the soil, ensure initially that physical soil structures are as close to ideal as possible before analysing soil or tissue tests.
 
A well-structured soil is capable of providing a mineral rich pasture of sufficiently high energy for near maximum animal production.  The key is well-structured, and there are some easy checks with a spade that can be made.
 
All soils compress under the weight of heavy animals and in certain conditions this leads to compaction.  The application of DoloZest, containing Golden Bay Dolomite, once a year helps overcome compaction problems.
 
Dolomite is a proven soil conditioner that contains magnesium, calcium, and a wide range of essential minerals.  Applied to the soil at 220kg/ha dolomite provides 25kg/ha of magnesium, sufficient to replace losses on a high performing dairy unit, and 53kg/ha of calcium.
 
Provided DoloZest is applied annually, autumn being an ideal time, calcium/magnesium related metabolic disorders are minimised.