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Colostrum, transition milk and maternal impact: There’s still a lot to learn

Amanda Fischer and Michael Steele for Progressive Dairyman Published on 12 March 2018
New born calf

Recently, there has been a resurgence in calf research, with producers, academics and industry professionals developing an interest in techniques to improve the health and welfare of newborn and pre-weaning dairy calves.

Some may think there is little left to learn about young dairy calves; however, this could not be further from the truth.



Over the past decade, there has been increasing consumer interest in food safety and animal welfare. Yet the rate of morbidity and mortality in pre-weaning calves is the highest amongst all animals in the dairy herd, with morbidity reaching up to 46 percent and mortality up to 5 percent.

The way we raise dairy calves is a stark contrast to how a calf would be raised in nature or in a beef production setting, in which calves have a much lower rate of illness and death compared to their dairy counterparts.

When describing our traditional management strategies to other livestock producers and the general public, it becomes clear we still have major knowledge gaps to fill about how to properly manage pre-weaning dairy calves in order to ensure their health and success as future production animals.

1. Colostrum: More than IgG

As there is no transfer of immune factors from the dam to the calf in utero, newborn calves rely on the feeding of good-quality colostrum to provide them with passive immunity. For this reason, immunoglobulin G (IgG) in bovine colostrum has been the primary focus of research over the last few decades.


However, IgG is only one of the estimated hundreds of bioactive compounds present in colostrum, and it has recently been shown there are 50 immune proteins, aside from IgG, found exclusively in colostrum.

In addition to immune factors, colostrum also contains higher amounts of growth factors, hormones, fatty acids and nucleotides when compared to mature milk. Similarly, colostrum also contains high amounts of simple sugars, known as oligosaccharides, which can aid in the development of beneficial gut bacteria as well as eradicating gastrointestinal pathogens.

If the dam is producing all of these compounds, it is safe to say there is an evolutionary reason behind it, one vital to the development of the newborn calf. Unfortunately, research on how these compounds may affect the calf is lacking and could provide us with a missing link between good colostrum management and calf health.

2. Transition from colostrum to a milk diet

As mentioned previously, the way we raise dairy calves is in opposition to how they would be raised in nature. In a natural setting, a calf would consume “transition milk,” which is defined as milkings two to six, directly from the dam. However, transition milk is commonly discarded on-farm, resulting in the calf being transitioned from colostrum directly onto whole milk or milk replacer.

Similar to colostrum, transition milk contains an abundance of bioactive compounds not present in whole milk. Moreover, a study from Europe showed calves fed subsequent meals of transition milk after the initial colostrum meal had a decreased risk of eye, ear and nasal discharge.


The authors suggested this phenomenon might have been due to the growth factors and cytokines in transition milk having an “immune-enhancing” effect on the calf, thus resulting in better health. However, research characterizing the bioactive compounds in bovine transition milk is only just beginning to come to light.

Moreover, if feeding transition milk can indeed improve the health of calves, research at the calf level should be conducted to determine the specific compounds that may cause this effect. This could contribute to better transition milk management, as well as highlight specific compounds that may be used as a supplement in whole milk or milk replacer to improve the health of dairy calves.

3. Impact of the dam on calf health and well-being

The calf is commonly separated from the dam immediately after birth to decrease the risk of exposure to harmful pathogens as well as ensure the calf receives an adequate amount of good-quality colostrum. A study conducted in Quebec in 2010 showed 32.5 percent of herds separate the calf from the dam within two hours after birth, and 73.2 percent do so within 12 hours.

Yet it has been demonstrated calves kept with the dam for 14 days after birth gained more than three times the weight and displayed better health than those who were separated at one day.

Although more research in this field is needed due to the contrast in this approach with respect to disease transmission, keeping the dam with the calf for extended periods of time may have benefits from a production standpoint.

In addition, consumer interest may play a role in our decision to separate the calf from the dam. A survey conducted by the University of British Columbia in 2013 demonstrated 48 percent of participants were opposed to separation immediately after birth. The major reasons behind this opposition were: It compromises the calf and cow emotionally, and the industry should make more of an effort to follow natural processes by keeping the dam and calf together.

With the recent implementation of ProAction, welfare standards and their effect on consumer interest will likely play a major role in the future of our production systems and should be considered further.

Take-home messages

The high rates of morbidity and mortality in the dairy calf sector are concerning. Moreover, the way in which we manage calves is in opposition to natural behaviours and other production systems, such as beef. There is still an overwhelming amount of information to be uncovered in regards to neonatal calf management, specifically concerning bioactives in colostrum, the transition from colostrum to a milk diet and the impact of the dam on the calf.

By uncovering fundamental information in these areas of research, we can improve animal welfare standards as well as lower the rates of morbidity and mortality to ensure a healthy calf.  end mark

PHOTO: New born calf. Staff photo.

Michael Steele is an assistant professor of ruminant nutrition for the University of Alberta Department of Agricultural, Food and Nutritional Science. Email Michael Steele

Amanda Fischer is a research assistant with the Department of Agricultural, Food and Nutritional Science at the University of Alberta

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