IN order for dairy heifer calves to mature with maximum milk production potential, they need to have a strong passive immunity system at birth.

This basically means the calves must receive their mother’s colostrum as soon as possible after birth to kickstart the building of a strong immune system. But new research has shown a path to fine-tuning that advice.

The neonatal immune system at birth is naïve to the wide variety and types of pathogens present in the environment. Consumption of colostrum to provide circulating IgG prior to the cessation of macromolecular transport is essential to ensure healthy calves.

There are a tremendous number of factors that may influence the absorption of IgG by calves, therefore blanket recommendations for feeding one amount of colostrum to all calves may be inappropriate.

There are many colostrum supplement products available on the marketplace, but some of these provide little additional circulating IgG. Therefore, it is essential that producers carefully evaluate claims for improve circulating IgG and animal survival.

During one of the specialist presentations at this year’s digital EuroTier event, Lea Poppe, technical manager with EW Nutrition, in Germany, delved into recent insights and innovative solutions to aid the young calves.

There are a number of problems with low passive immunity in calves but essentially they can all lead to higher rearing costs for farmers. Lea said: “Inadequate serum Ig levels in calves can lead to a negative impact on growth rates of the calves in their first six months, as well as a higher number of antibiotic treatments due to higher morbidity and also higher mortality.

“Together they lead to higher rearing costs and research indicates inadequate serum increased rearing costs for a dairy calf by €60 and €90 for a beef calf,” she said. “Besides this, the milk yield in the animal’s first lactation may be negatively affected by the low levels.”

The team at EW Nutrition wanted to find out what the situations were like on dairy farms across the world and therefore surveyed 55 consultants and veterinarians from five countries including Germany and the UK in December, 2020.

Discussing the outcome, Lea said: “It is worth highlighting that more than 54% thought that the colostrum quality is at a stable level. And 69% answered no to the question ‘do you think calves are sufficiently supplied with immunoglobulins by the colostrum they receive?’

“And 76% of all the experts that we asked saw a direct link between early occurring diarrhoea and a lack of passive immunity,” she added.

Scientific studies conducted in Munich also confirms the results of the survey. Only 41% of the calves in these studies conducted in 2015 were sufficiently supplied with immunoglobulins and nearly a quarter were under-supplied. This situation of being under-supplied is called failure of passive transfer (FPT).

“In practice, this means there is a high number of calves with an immune deficit and they need additional support if the farmer wants to maximise their genetical potential and if he wants to avoid economical losses,” said Lea.

“And also the number of antibiotic treatments will be lowered which is in the general public interest.

“One of the experts actually said he thinks the pathogen load on some farms is so great that no amount of immunity will stop the calf from getting diarrhoea. This means for us the higher the pathogen pressure is, the higher the need for support,” said Lea.

In order to understand the issues surrounding passive immunity Lea said it is important to first understand immunoglobulins which, specifically, are proteins used by the immune system to identify and neutralise foreign substances.

Lea also highlighted details of a trial undertaken in the autumn, 2020, when a dairy farmer in Saudi Arabia tested one of the products from EW Nutrition called Globigen Dia Stop in young dairy heifer calves. This is a dietetic supplementary feed for the stabilisation of water and electrolyte balance to support physiological digestion.

In the trial the farm tested three different dosages in calves with acute diarrhoea and was done to set up a new diarrhoea treatment protocol on the farm.

The trial concluded that between 81% and 100% of the calves recovered within the application period of three and four days, respectively.