All dry-cow strategies need follow-up
7. October 2019

All dry-cow strategies need follow-up

Bovine veterinarian Susanne Sommerlund, LVK, is convinced: X-Zelit works, but needs follow-up like any other dry-cow strategy. Otherwise you risk not getting the full effect of the product.

Bovine veterinarian Susanne Sommerlund, LVK, urges farmers to follow up on their dry-cow strategy, no matter if they acidify, calcify or use X-Zelit. Photo: Klaus Eriksen

Susanne Sommerlund is a bovine veterinarian for LVK and visits many dairy cattle herds. She experiences close up how different dry-cow strategies work in practice.

She has herds that run X-Zelit feeding, herds that run acidification using the Low CAB model and herds that ‘calcify’ the cows.

“I actually see an effect from all three models. The most important thing is to stick to one strategy and go all in for it. I once experienced a farmer who ran Low CAB together with half a portion of X-Zelit, which are two vastly different strategies. He ended up falling between two stools.”

Each strategy has a different follow-up

One of the bovine veterinarian’s golden rules is that no matter which dry-cow strategy you choose, you have to follow it up.

“Some farmers are content to see things improve, but I really like working according to what we actually know: results and counts from urine or blood samples, depending on the strategy you’ve chosen,” she says. If a farmer chooses X-Zelit or to ‘calcify’ the cows, he has to follow up these approaches with blood samples, while the Low CAB strategy can also be followed up by measuring pH in the urine.

“It’s essential that a farmer’s advisors know which follow-up belongs to which strategy,” she explains.

Results can change

Susanne-SommerlundIf you ask the LVK veterinarian, quarterly blood samples are a minimum requirement when calcifying or acidifying the dry cows, because the results can change significantly, such as when a farmer starts using a new harvest of grass which changes the CAB value.

“Small adjustments of the volume used to acidify or calcify are often needed to maximise the effect. On the other hand, I’ve experienced that the amount of X-Zelit (500 grams per cow per day in the last two weeks before calving) is the same all year round and from one herd to another,” Susanne Sommerlund explains.

She emphasises that even if the amount of X-Zelit is the same across herds, follow-up is still necessary.

“It’s often the case that evaluating blood-sample results in new herds that start using X-Zelit reveal management adjustments that can make good results even better; many are content with less,” Susanne Sommerlund points out.

Other farmers fail to succeed with X-Zelit, for instance and change strategies without ever having tested to see whether the cows were actually absorbing 500 grams of X-Zelit.

“It usually takes small adjustments to get real success,” she says.

X-Zelit requires blood samples

The X-Zelit strategy is followed up by taking blood samples and, in this context, the vet recommends taking three to five blood samples from older newly-calved cows, as the risk of hypocalcaemia increases with age. Blood samples should be taken about 17 hours after calving as this is when blood calcium levels are lowest.

As far as X-Zelit is concerned, the blood levels of both calcium and phosphorous are checked because the level of phosphorous can reveal whether a cow has absorbed the 500 grams a day required by the strategy.

“If she hasn’t, we have to find out why. Did we give her 500 grams? I experience that particularly in large herds that don’t manage to count their dry cows, the number can vary by perhaps 10 to 15 cows a week, and a cow may only have been fed 400 grams of X-Zelit. Or a cow might also have been fed 500 grams, but the feed wasn’t mixed properly, and the cow sorted out the X-Zelit product,” Susanne Sommerlund explains.

“Cows that have been correctly fed X-Zelit in the last ten days before calving will have a maximum phosphorous level of 0.8 millimole per litre, and the calcium level will be at least 2.15 millimoles per litre,” Susanne Sommerlund explains.

Know your strategy

The vet emphasises the importance of being thoroughly familiar with the chosen strategy, knowing how it works and how to implement it.

Among other X-Zelit details worth remembering is that the farmer must remember to take away the X-Zelit ration from the cow after calving.

“This is simply crucial, because if he doesn’t, the cow will get milk fever – and a severe case at that – and this will require repeated treatments,” says Susanne Sommerlund, who also points out that X-Zelit should not just be poured out over the blades in the feed mixer, because it easily gets stuck to the blades and never makes it to the feed ration. The best method is to pour it in along the sides.

It works

The experienced veterinarian is convinced that X-Zelit works but emphasises that the product’s full effect can only be achieved if all the surrounding external factors are in order, too.

“For instance, if the energy distribution is lopsided during the dry period, you will never maximise the effect of X-Zelit,” she explains.

Subclinical milk fever and complications

No one knows the extent of subclinical milk fever in the herd until the calcium level of newly calved cows has been checked.

Subclinical milk fever has many complications, such as retained placenta and displaced abomasum.

“The complications are preventable by focusing on follow-up and evaluating your dry-cow strategy. Besides the significant animal-welfare effect of preventing these diseases, it really makes good economic sense to get the cows off to the best possible start after calving,” Susanne Sommerlund says.


For more information on X-Zelit, visit


X-Zelit's pitfalls

X-Zelit works, but there are a number of pitfalls, according to bovine veterinarian Susanne Sommerlund, LVK

  • It mustn’t be possible for cows to sort out X-Zelit. Its slightly bitter taste will make cows want to avoid eating it if they can. Therefore, the best solution is to add it in the mixer cart. If it is sprinkled over the dry-cow ration, the compound must be adequately stirred to avoid being sorting out.
  • Do not add X-Zelit to the mixer feed cart by pouring it over the blades, as X-Zelit can get stuck to them, and the full amount will never reach the dry-cow ration. Therefore, add X-Zelit to the mixer by pouring it in along the sides.
  • Make sure to correctly and precisely dose it – count the number of dry cows receiving the ration – to ensure that each dry cow gets 500 grams a day for at least two weeks before calving. This also requires adjusting the ration to ensure that no large residual quantifies are left.
  • Make sure that once the cows have calved, they do not under any circumstances receive feed with X-Zelit, as this could cause even worse cases of milk fever which must be repeatedly treated with calcium.