Calcium Use after calving

The process of calving is a cause of dehydration. Healthy cows will get up and replenish themselves. The drop in dry matter intake around calving also causes less energy availability for the sodium potassium pump in the rumen further decreasing water intake. Ensuring proper hydration for cows is crucial when administering anti-inflammatory drugs (NSAIDs) during calving or when the cow is unwell. For this reason, it is recommended to provide a drench alongside the medication.

Usually, if a cow is healthy and has a normal calving, giving her Cal Plus drench is not necessary. Most farms have generated a list with cows that are prone to post partum issues. This list includes cows experiencing a difficult calving, delivering a death calf, over and under conditioned cows, cows with a history of milk fever or above average milk production and after delivering twins. These cows do benefit from rehydration and the delivery of calcium, energy, magnesium, and hydrolysed yeast (Cal Plus). Stokes and Goff in 2001 published the benefits of giving calcium propionate with water, where they described a significant reduction in the incidence of metritis.

If the cow has a “normal” calving the need of drenching the cow should be re-evaluated. There are many other options available in the Canadian market to provide oral calcium. Research has examined calcium boluses, but administering fat-soluble vitamins only once does not provide any extra advantages.    Published comparison trials between boluses with or without Vitamin D3 added did not show a difference in milk production.

Numerous calcium boluses are available, and Diamond City Farm Supply has recently launched Calcivit, a liquid calcium product, in Canada. Studies have demonstrated that not all boluses dissolve at the same rate and a Dairy Research Summary in 2020 highlighted that. The bolus containing Calcium carbonate dissolved the slowest and remained after 240 minutes in the rumen with a minimum of 75% of the original bolus weight still intact. The source of calcium was from a calciferous sea algae. A published study by Verhoeff show that low solubility results in low bioavailability and despite giving two boluses containing calcium carbonate at the same time the serum calcium levels were peaking significantly slower and lower than even using a more bio-available bolus just once. (see attached publication). The authors concluded that the lowest concentration of blood calcium usually occurs within 12-24 hours of calving, therefore the faster an impact can be mad on calcium blood levels the better.

Magnesium plays a vital role in the cow’s parathyroid gland as it relates to the natural regulation of blood calcium levels, therefore I certainly recommend the inclusion of a sufficient amount of magnesium into the bolus of the drench. The source of magnesium plays a role in bioavailability as well. Magnesium oxide present in CowStart as an example has a much lower availability that the Magnesium Sulphate in Cal Plus and Calcivit

In conclusion both Calcivit and CalPlus have calcium and magnesium sources selected for bioavailability and are present in sufficient quantities. Scientific data from various sources support the ingredients we have included and the benefits of including propionate. While drenching all cows is not always advisable, research has shown that giving extra fluids to cows experiencing issues after calving can be highly beneficial. I am happy to provide more references upon request.

Sjoert Zuidhof DVM, MBA

Take home messages:

1- Drenching is a better option when the cow has a problemHenrietta Vanden Brink

2- Vitamin D3 in a bolus doesn't result in better performance

3- Calcium carbonate in CowStart is not a great choice and a bolus that also has calcium carbonate from a similar seaweed source didn't perform well in the study cited

4- Our calcium sources are very soluble and available, and we have data to show that.