Volume 22 • Issue 02 • 2018 incidence of post-calving mastitis cases and even vaginal and uterine prolapses can all be linked to low blood calcium levels , namely subclinical hypocalcaemia . And because of this effect on the digestive tract , DMI ( Dry Matter Intake ) drops , and ketosis and fatty liver syndrome are all possible consequences of a high producing dairy cow that is not eating enough ( low DMI ) in the first few days after calving .
Treatments for Hypocalcaemia
For cows whose blood calcium levels are low , but are still standing and able to swallow , oral calcium supplementation is often the best approach . Intravenous ( I / V ) calcium in cows still standing , walking and swallowing is not recommended because I / V calcium causes a rapid increase in blood calcium levels , often to potentially dangerous levels . Often , for cows that have gone down and cannot stand up due to milk fever , only very careful I / V calcium treatment will actually save her life . After the necessary and successful treatment with I / V calcium , the cow is normocalcaemic ( i . e . normal blood calcium levels ) but for 4-6 hours only , as a result , these animals can experience relapses . These relapses can either be seen as her going down again , or more commonly , the blood calcium levels drop to above the level where she would have gone down again , but still well below the level of where the knock-on problems occur again ( rumen and intestines not working , as well as uterus and teat sphincter muscles not working too ) – again , all without being visible to the farmer or vet !
Subcutaneous Calcium Treatment
In cows that are not already already down ( severely hypocalcaemic ) and dehydrated , subcutaneous calcium is well absorbed initially - however blood concentrations of calcium are increased , but again only for 4 to 7 hours ! And whether it ’ s clinical milk fever or subclinical hypocalcaemia , one would ideally aim to supplement these cows with a calcium source that would raise blood calcium levels for as long as practically possible within the first 24 hours after calving .
Types of Oral Calcium Supplementation
Supplementing calcium either : routinely postcalving ( in cows 2nd lactation / calf and older ); or as a follow-up after life-saving I / V calcium , certain oral formulations serve this purpose well . One should familiarise yourself with the type of calcium supplemented : some are poorly absorbed ( e . g . calcium carbonate ); some are relatively well absorbed but take a longer time to do so without being longer acting ( e . g . calcium propionate ). Others are very effective at being absorbed quickly , the only downside being that they do not last very long ( e . g . calcium chloride ); while others take slightly longer to make a contribution to blood calcium levels , but then go on to do so for many hours ( e . g . calcium sulphate ).
Beyond the Calcium Type and Quantity
No matter how good all the various supplements on the market are , nutrition , both pre- and post-calving , remains the most important – no question . And dietary acidification creates an ideal pH in the cow ’ s body in which the hormone responsible for efficient calcium usage and absorption ( PTH ) can function optimally . The cow will now be able to : a ) draw on calcium reserves from her own bones ; b ) she will be efficiently absorbing the calcium in her ration or grazing and , c ) her kidneys will be reabsorbing any calcium ‘ attempting ’ to leave her body via her urine .
Calcium Bolusses
Bovikalc is a combination of calcium chloride and calcium sulphate , combining the fast , high availability of calcium chloride , with the longer acting , sustained release contribution of calcium sulphate . Once the bolus is in the rumen the blood calcium levels show an increase within 30-40 minutes , and continues to positively raise blood calcium levels for 12 hours or more thereafter . A combination of quick-acting combined with sustained release .
In addition to providing the cow with a longeracting calcium contribution , the bolus is also acidogenic which has been proven to cause the cow to further draw on her own calcium reserves .
The bolus is coated in a thin layer of wax to aid in the swallowing process , and also as a result does not have an unpleasant taste . Administering a bolus is faster and more convenient than most other calcium supplementation administration methods , it is also efficient resulting in almost no wastage at all of the product .
References available from author
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