Rumen development in dairy calves

Rumen development is stimulated by concentrates and water, so it’s important to get the calf eating calf starter and drinking water from day one.

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At birth, the rumen is small, undeveloped and does not contribute to digestion. It must develop before it can digest forages. Concentrates and water intake are the most important factors for rumen development.

If stimulated early on, a calf’s rumen can start to function from as early as five days of age. Most calves are actively ruminating by 28 days. Eating concentrates and drinking water provide rumen microbes with the nutrients they need to grow and multiply. After three weeks of eating starter concentrate, there will be enough rumen microbes to ferment feed and supply the calf with energy.

Starter concentrate

Calf starter should be offered from day one, as shown in this photo.

Calf eating starter concentrate
  • Starter can be provided as a pellet or coarse feed and should be highly palatable to encourage early intake
  • Make sure starter has sufficient particle size for proper rumen development
  • Don’t feed powdery or dusty concentrate as it reduces intakes

Initially, calves only eat small amounts, but intake begins to increase around 14 days of age. Buckets that are too full, as shown in the photo below, have a high chance of feed spoilage. To avoid wastage, provide small amounts of fresh starter daily and watch calves to see when they need more concentrates.

Bucket full of calf concentrate.


Forages are a good source of fibre, which promotes growth of the rumen’s muscular layer and helps maintain the health of the rumen lining. As well as a starter, good-quality forage should be offered as early as day three on a ‘little and often’ basis to ensure freshness and encourage intake.

Place feed racks and buckets at a suitable height for calves to reach and reduce the possibility of soiling.

Useful links

Calf management guide

If you would like to order a hard copy of the Calf management guide, please contact or call 0247 799 0069.