It is impossible to overemphasise the importance of the calf's vital first feed immediately after birth. It is not only important to consider that a calf owes its initial immunity exclusively to colostrum – the first thing a calf does in nature, as soon as it can stand, is to locate the mother's udder to feed on colostrum.

In addition to this natural aspect, you should also bear in mind that in future fewer and fewer medicines (in particular antibiotics) will be available for use in agriculture. The principle that "prevention is better than cure" is therefore not only an ethically correct approach, but also a necessary response to the limited options for treating diseases in calves in the near future. Optimising a calf's immunity promotes its health and makes it resistant to pathogens to which it will inevitably be exposed. Much has been written and spoken about the right way of providing colostrum and the development of a calf's immunity. We don't have much to add to that. Just one example: Godden et al 2019: Colostrum Management for Dairy Calves.

Providing colostrum correctly forms the basis for all other elements in the NativeCalfConcept. We would therefore like to summarise the most important aspects of colostrum management here:

1.1. Best quality: 50 g IgG/litre

1.1.1. Immunoglobulin content

The immunoglobulin content in colostrum needs to be monitored (using a Brix refractometer) and documented. Colostrum with an IgG content of 50 g/l ( corresponding to Brix > 22 %) can be used as a first feed. If the quality is lower, you should switch to better-quality colostrum from a stored supply or ensure that at least 4 litres are actually consumed (see section 1.2.).

Transitional milk, the milk from the second milking to the first delivery of the milk to the dairy factory, still contains valuable ingredients such as antibodies and other important bioactive substances. They have a positive local effect in the intestine and promote the development of the intestinal villi and the microbiome in the gut. It should be fed for as long as possible in order to continue to promote healthy colonisation of the intestinal flora with its valuable nutrients.

After that, whole milk should be fed in preference. Whole milk is perfectly adapted to the digestive enzymes of young calves. This is because young calves can only digest high-quality casein and lactose. The enzyme spectrum in the abomasum does not yet allow digestion of vegetable proteins and carbohydrates until 4 to 5 weeks of age.

As discussed above, calves need casein and lactose for optimum nutrition in their first 4 to 5 weeks of life. If milk replacer is to be fed in the initial phase because whole milk cannot be used, care must be taken to ensure the highest quality and maximum digestibility for young calves. Not all CMRs meet these conditions. The ingredients should therefore be carefully examined when selecting a CMR. You may also need to obtain further information from your CMR supplier, for example on the following subject:

If, as described above, different feeds are used (whole milk and CMR), transitioning from one type of feed to the next must be as smooth as possible.

A calf's digestive system often needs 5 to 10 days to adapt to a new feed. So when switching from whole milk to CMR, this should be done slowly.

This is difficult with the MilkTaxi, where one mixture with the same composition is generally made up for all calves. Slow transitions for the calves are therefore not quite so easy.

However, these transitions can be performed very easily with the CalfExpert feeder, which allows appropriate adjustments to be made to a calf's feeding curve, as the mixing ratio of the two feeds can change daily.

Incidentally, this is also possible when feeding two different milk replacers – a high-quality milk replacer for young calves and a CMR adapted to the needs of calves being weaned.

Milk should be given via a teat feeder without exception in order to satisfy a calf's natural need to suckle. The bucket feeder without a teat is not suited to a calf's physiology and, in the worst case, can lead to milk entering the rumen.

Large amounts of feed, at least 10 to 12 litres of milk per day, promote growth in calves. This has a long-term positive effect on the subsequent development of heifers through to the milk yield of lactating dairy cows. These insights have been proven in many international studies and are often confirmed in practice.

The digestive tract of calves and heifers is not fully mature until they are 4 to 6 months old. It is only at this age that the size ratios of the various bovine stomachs equal those of adult cows. Conversely, this means that calves can only digest roughage and concentrates as well as adult cows when they reach this age. However, this might also mean that calves would need to be supplied with milk up to this age in order to ensure their unrestricted development – at least to a certain degree.

Calves are traditionally weaned off the milk at 8 to 10 weeks of age. Milk withdrawal takes place even earlier in some countries. However, it is important to remember that calves only start to develop enzymes that can break down plant proteins and carbohydrates at 4 to 5 weeks of age. As described above, it then takes many more weeks in nature until a young cattle is completely independent of being fed milk. If a calf is weaned off milk at 8 to 10 weeks, the digestive system is often overwhelmed and this leads to what is known as a weaning kink, where the calf stops growing or even loses weight for 1 to 2 weeks. This shows that at this age a calf is not yet able to fully compensate for the energy loss from milk with plant-based feed. It also becomes dramatic for the calf if weaning occurs very abruptly, for example by simply withdrawing a full feed per day.

Another effect that recent studies have shown is a latent acidosis that calves can experience. Due to the withdrawal of milk, the calf feels hungry and usually quickly consumes higher amounts of concentrate feed (which is certainly the aim of this measure). When starch, sugar and carbohydrates are broken down in the rumen, a large amount of short-chain fatty acids are produced, which the rumen may not be able to buffer. This can lead to rumen acidosis. If these fatty acids also enter the intestine, they can cause colonic acidosis. (Neubauer et al 2020: Starch-Rich Diet Induced Rumen Acidosis and Hindgut Dysbiosis in Dairy Cows of Different Lactations)

In most cases, however, this goes undetected and the calves suffer from subclinical acidosis. This can result in intestinal inflammation and other damage.

Nevertheless, this does not mean that we actually have to feed milk for up to 6 months. In the right circumstances, calves can also be completely weaned off milk at an earlier stage. We therefore recommend starting to slowly reduce the amount of milk at around 5 to 6 weeks. The weaning phase can then last a further 6 to 7 weeks. In this way, calves slowly grow accustomed to eating dry feed while still receiving highly digestible milk for a certain period.

Read this blog article to find out what else you should consider when planning the right feed curve.

8.1. Concentrate feed uptake: We have already discussed the risk of concentrate being consumed too soon and too quickly in the last point. The ultimate goal of every cattle farmer is to raise healthy ruminants. It is therefore important to provide calves with the right dry feed, especially during the weaning phase. It is essential to offer calves easily digestible feed components that do not result in the acidosis described above. For example, energy sources such as maize and oats are much more suitable for feeding to calves than wheat starch, which is quickly digestible.

In our three-article blog series, we focus on the key aspects of feeding concentrates. Click here for the first in the series.

In nature, the mother and her newborn calf separate from the herd for a few days after birth. This protects the young calf and strengthens the bond between it and its mother. Separation can also be observed later in the herd. This time it is the calves that separate from the herd of cows into groups of their own age in order to explore the world together.

Both observations provide a useful indication of how calves can be kept in stress-free groups on modern dairy farms.

1. If the cow and calf are separated after birth, it makes sense to provide the calf with another animal with which it can interact and establish a social bond. In this case, it is often not even possible to detect any pain of separation in the calf after birth. Small groups of 2 to 3 calves are appropriate for this. The pain of separation is greater for the mother. However, if separation does not occur until after a day or two, this pain is much more pronounced because a stronger bond has already developed.
2. Calves in a group must have enough space to run around and must be given stimuli to keep them occupied. It is essential that calves have protected areas where they can lie down, sleep and rest, places where they can eat undisturbed and plenty of space for unhindered movement. The age difference should not be too large – a maximum age difference of 2 weeks is ideal. This means that the groups are not particularly large, reflecting the size of the farm. The space available for each calf should be between 2.5 and 4 m².

However, housing calves in TwinHutches or small groups of up to 5 calves has a number of drawbacks, as it usually relies on bucket feeders. If all of the above points regarding natural feeding with gentle feed transitions and lots of small portions are considered, it is almost impossible to avoid using an automatic calf feeder.

Until now, the practice has been to introduce calves to the feeder only after 2 to 3 weeks. It is at this point that they are transferred from their individual or twin hutch to a larger group. However, this involves a lot of additional work since the calves have to be trained to use two different feeding systems (first a (teat) bucket, then a feeding station).

Focusing on a calf's actual natural needs in terms of nutrition and social interaction with other calves in a species-appropriate group housing system maximises animal welfare on a conventional dairy farm.

The economic benefits for the farm are also evident. After all, it leads to lower costs (due to better health, improved fertility and increased longevity) and better yields (due to higher milk yields up to the 2nd lactation) despite the increased costs due to more extensive and longer calf feeding. ‎

So it's a win-win situation for both the farmer and the animal.

For the sake of completeness, we would like to discuss below the key points prior to birth - because the health of the calf also depends on the health of the mother cow and good birth management.

A) Stress-free dry cow management so that the foetus can develop in the best possible way

The life of a calf does not begin at birth, but from the moment the egg is fertilised. Even if the foetus enjoys optimum protection in the womb, the way the mother cow is kept and fed can have a major influence on how the calf develops before and after birth (pre- and postnatal).

1. Influence of feeding on foetal development: Two-phase feeding of cows in the dry cow phase has proven successful. A low-energy diet is fed 6 to 8 weeks before calving to prevent the mother cow from becoming obese and to avoid associated birth problems for the calf and metabolic problems for the cow. The foetus grows rapidly in the last three weeks, so the mother cow's diet needs to change accordingly. This is where the mother cow should be slowly reintroduced to the lactation diet.
2. Influences of stress on foetal development: Studies by B. Dado-Sehn et al 2022 and Laporta et al 2017 show that calves whose mothers suffered from heat stress during the high gestation period develop worse. Poorer immunity and low growth may result. It is therefore important to protect a dry cow from heat in summer.
3. Influences on colostrum quality: The influence on colostrum quality of feeding dry cows is not clearly documented. What is certain is that a high onset of lactation immediately after birth causes colostrum to dilute. Colostrum quantities of over 10 litres in the first milking often have an IgG concentration that is too low.

A good supply of beta-carotene is said to have a positive effect on quality. Vaccinations of the cow, for example with RotaCorona, do not increase the proportion of antibodies, but do ensure that the globulins are specifically adapted to these pathogens.

Stress during the dry period can also have a negative effect on the quality of the first colostrum.

B) Birth management

The birth of a calf poses major challenges for management on a dairy farm. It cannot be scheduled into the daily work routine. And both the duration and the course of the birth are completely unpredictable.

The cows should actually calve on their own, and in the vast majority of cases this is possible. However, calving assistance is sometimes necessary, and in such cases clearly defined and practised procedures help. There are many very good guides, SOPs and videos on the Internet on how to optimise management during the birth of the calf. One example in German-speaking countries is the very clear brochure published by Dr Katharina Traulsen and Dr Marion Tischer in collaboration with Boehringer Ingelheim. The very detailed video course on calving assistance from the “Initiative Tierwohl” (Animal Welfare Initiative) is also highly recommended.

For English-speaking countries, a good example is Charles T. Estill's “The calving process”, which provides a wealth of detail.

We will therefore not go into this in detail here and instead leave this field to other experts.