Calcium deficiency has major impact on herd health

A calcium deficiency among your herd is a common but underestimated health challenge. With calcium deficiency around calving, also known as metabolic challenges, a cow is unable to use calcium from her bones quickly enough to get and maintain blood calcium levels. We would like to tell you more about the occurrence and proactive way of tackling metabolic challenges.

Because of the milk production and milk yield peak expected after calving, the calcium requirement rises sharply. This is not only because of a rise in milk production, but also because of colostrum, which excretes twice as much calcium (2.4 grams per litre) as normal milk (1.2 grams per litre). Cows and heifers that produce a lot of colostrum before calving therefore also lose a lot of calcium. A consequence of this is that appetite drops and, as a result, their already negative energy balance further increases. This is because the cow’s body then has to adapt too quickly to the greatly increased need for calcium.

On average, as much as five to six per cent of the herd on a dairy farm suffers from metabolic challenges. For every case of visible metabolic challenges caused by calcium deficiency, there will be approximately 10 or so non-visible cases. Metabolic challenges not only reduces milk yield, but can have effects on fertility along with, in the worst case, mortality. High-yielding, sick, older, fat and thin  (SOFT) cows are particularly affected by metabolic challenges. To optimise animal health and prevent calcium deficiency in dairy cattle, an adequate dry matter ration and the right supply of calcium, phosphorus, magnesium and vitamin D are crucial.  

When does calcium deficiency occur?

A calcium deficiency usually occurs within 48 hours of calving. However, the calcium deficiency may also have developed just before or during calving. This can often be seen at calving itself, when calving proceeds very slowly or stops. This poses a great risk to both cow and calf. As many as 50% of cows and 25% of heifers and second-year cows show dormant calcium deficiency. In this group, therefore, metabolic challenges and all its consequences lurk.  

A cow that has metabolic challenges can be recognised by low appetite and low activity. Her ears are often cold.  The calcium deficiency in the blood causes the skeletal muscles to stop working properly. As a result, your cow can no longer get up properly. Other muscles are also affected by the calcium deficiency, especially smooth muscles in the teat canal and in the uterine wall. This can have far-reaching consequences during and after calving and when closing the cervix, but also affects other organs such as the heart and rumen. Statistically, more than 5% of cows die from metabolic challenges.

What causes calcium deficiency and metabolic challenges?

Calcium is present in both the blood and bones of a cow. With increasing milk yield, there is an increasing calcium requirement. When a cow suddenly needs more calcium, she starts using the calcium supply from the blood. This calcium supply in the blood is later replenished from the bones, kidneys and intestines. However, this process can take some time. Thus, because of the delay, calcium deficiency can still occur in the body (Bosseart, 2009), especially for high-yielding and sick, older, fat and thin (SOFT) cows.  

What is often forgotten, but should not be underestimated, is that when calcium deficiency starts, cows also often have non-optimal rumen function. The rumen contractions stop, which also stops feed breakdown. In this way, the cow ends up in a vicious circle which has a negative impact on the health of your cows. They then often cannot absorb calcium from the feed and metabolic challenges is the result.

Which hormones play a role in calcium?

Several hormones are associated with the release of calcium. Para-thyroid hormone (PTH) reduces the amount of calcium excreted through a cow’s urine. In addition, PTH causes calcium to be withdrawn from the intestines. It does this by activating vitamin D. However, this process does not start until one to two days after calving. Besides vitamin D, magnesium is also very important because this mineral releases PTH. If a cow is deficient in magnesium, PTH cannot be activated and therefore less calcium can be withdrawn from the body. 

Potassium levels also play an important role. Indeed, if the potassium content in a ration is too high, magnesium can again be poorly absorbed. In addition, 80% of cows that remain flat after calving also have a phosphorus deficiency in their blood (Goff et al, 2014). 

In addition, calcitonin is a hormone that strengthens the bones and regulates the calcium concentration in the blood by locking calcium into the bones when possible.  If a cow gets a lot of calcium directly into her blood stream, calcitonin increases as a result and pushes calcium back into the bones, resulting in more rather than less challenges. This is why the AHV solutions below are advised to be administered orally.

Improve the health of your herd around calving

As is well known by now, there are plenty of challenges around calving. To prevent any calcium deficiency, it is important that your herd gets enough calcium, magnesium and phosphorus. AHV Milk Start Paste is a complementary feed supplement for dairy cows to reduce the risk of metabolic challenges.

It gives your cows a calcium boost and also contains magnesium, phosphorus and active Vitamin D3. Vitamin D3 promotes the absorption of calcium and phosphorus from the bones and intestines, improving your cow’s (energy) metabolism and calcium metabolism. 

Our advice to prevent calcium deficiencies

The advice from AHV Territory Managers is to administer 2 x AHV Milk Start Boluses as soon as possible after calving, if possible even prior to calving. This way you ensure that the cow has the right substances to meet its needs at the time of calving. AHV Milk Start Paste is recommended to be administered immediately after calving, so that your cow is quickly supplied with sufficient magnesium, calcium and phosphorus. In addition, the paste gives the cow an energy boost, making her feel the need to feed faster and restarting the mineral and energy mobilization processes. This way, you optimise health at the start of lactation. 

AHV Transition Program

The AHV Transition Program focuses on the period before and after calving and ensures sufficient energy and minerals and stimulates dry matter intake. This program connects excellently with the AHV Uterine Health Program to fully support the recently calved cow and allow her to restart the reproductive cycle in the best way possible.

Contact our Territory Managers directly? You can! Click here and visit our specialists in the field or fill in the form below. www.ahvint.co.nz; email newzealand@ahvint.com; phone 0800 4 248 69