The role of NFC in weaning calves

Next to growth, rumen development should be the main focus of early calf feeding. During the milk feeding period, the first stomach has to develop into a fully functional rumen to sustain calf growth after weaning. In situations where this is not the case, a clear drop in daily growth is seen after the calves are weaned. In these cases, calves can easily lose the head start achieved during the milk feeding period.

Early feed intake and rumen development

Unlocking the genetic potential of calves in the first months of life is crucial. When we stop feeding milk, the rumen has to handle and provide most of the nutrients the calves were receiving via the milk. To build a fully functional rumen, there are three major issues we need to address:

  • First is the ability of the rumen microbiota to efficiently ferment feed. Increasing the microbial activity will produce volatile fatty acids (VFAs) and microbial proteins. Boosting the production of VFAs will contribute to the development of rumen papillae, which will then support the absorption of the consecutive VFAs.
  • Second is ensuring the rumen wall is formed. The rumen wall is the organ responsible for the absorption of the nutrients available from rumen fermentation. Roughage will support rumen development and contribute to building rumen wall muscles.
  • Third is the muscle activity of the rumen wall, this is crucial for proper rumen fermentation and absorption of nutrients. Continuously mixing the rumen contents ensures contact of the microbiota with the available feed and the transport of nutrients to the rumen wall for absorption.

Rumen development

Rumen development is crucial and largely accomplished with the intake of solid feed, especially non-fiber carbohydrates (NFC).
Research shows the total amount of NFC consumed is the most decisive factor for rumen development. Based on NFC digestibility, a total intake of 15 kg of NFC is needed for full rumen development (Graph 1). Once the rumen is fully developed, calves can rely on rumen fermentation to drive further growth and the weaning process can start. Therefore, supplying your calves with high-quality starter supports both a smooth transition and faster rumen development. Something to consider, based on the data in Graph 1, is that there is no difference in NFC digestibility between a pelleted starter or a textured starter; both will support a smooth transition equally.

Calf starter NPC digestibility

Graph 1: Effect of cumulative NFC intake on development of NFC digestibility (Quigley et al., 2018)
Pel = Pelleted starter | Tex = Textured starter-Muesli | TMR = Starter mixed with 5 % grass hay

Does the physical shape matter?

Feed intake is especially important for young calves. The more feed calves are eating the higher the growth and the smaller the weaning dip. In fact, in optimal conditions there will not be a weaning dip. Of course, the utilization of nutrients highly depends on the digestibility of the feedstuffs provided to the calves. As mentioned, the NFC content of the starter feed is crucial for rumen development. The questions remain, does the physical shape of the starter matter? Should we prefer a pellet or a textured starter (muesli)?

Eventually, there is no real preference between pellets or textured starters. In general, we see a bit faster acceptance of textured starters at the onset of feeding due to the physical attractiveness of the textured starter triggering the calves to eat. After that, pellets have an advantage as intake will increase faster due to the density of the pelleted feeds.

In most cases, the textured starter is a combination of flaked grains and a pellet. Flaking the grains contributes to the digestibility and physical attractiveness of the starter. The included pellet typically contains more NDF rich feedstuffs as well as minerals and vitamins. However, the NDF content of the calf starter should be limited and the majority of the NDF source should come from a limited amount of chopped straw or hay.

When feeding either a muesli or pellet, chopped straw is a preferred source of NDF as, in general, it has a higher level of effective fiber and is less variable than hay. The nutritional value of hay is typically higher than straw however, at this time in the calf’s life, the intake of roughage and the physical properties of the roughage are more important for rumen development.


Earlyfeed has a long history in young animal nutrition for all animal species. This young animal program is characterized by exceptional feed with palatable raw materials, intake stimulating ingredients, and highly digestible nutrients to support extended health and to encourage growth. Rumipellet is an excellent well-balanced calf starter which has all the nutrients calves needs during both the milk period and during/after the weaning period. Next to this, Rumipellet has an extensive functional feed ingredient program to support the health, growth, and development of young calves. This health concept contains well know and trusted products like Aromabiotic® Cattle, Vitanox, and other state of the art additives.

With Rumipellet, the complete genetic potential of calves becomes unlocked!

Your Earlyfeed expert
Harrie van der Vliet
Product Manager Ruminants

This contact was suggested based on the location you are browsing from. You can of course also consult our other contacts and locations here.

Do you want to get things right from the start?

Getting your rearing strategies right early in the production cycle, pays off in the long run.
Together, let’s give the youngest animals everything they need to perform well later in life.

Stay up-to-date

Would you like to be kept informed of our latest developments? Register here and stay up to date.