Rumen Development in Calves Stimulated by Calf Starter Intake

Dr. Ronald L. Boman
USU Extension Dairy Specialist

Recent articles in the scientific and popular press have stressed the importance of proper feeding and management techniques for dairy replacement heifers. One area that we too often overlook is the early feeding of a high quality calf starter. As I was browsing the �web� the other day I came across an item on the Pennsylvania State University web site ( that caused me to reflect on something I was taught in the mid 1970's concerning rumen development in young dairy calves. It was that the volatile fatty acids from the fermentation of calf starter (grains) in the developing rumen are a principal factor causing early rumen mucosa and papilli development. At the above mentioned Penn State web site, one can see photographs of the interior of the rumens of 4, 6, 8 and 12 week old calves that were fed milk only, or milk and hay, or milk, hay and grain, or just milk and grain.

As would be expected, there was hardly any rumen papilli development at six weeks of age when only milk was fed. Startlingly enough, even when hay was included with the milk, there was very little rumen papilli development even up to 12 weeks of age. In those calves fed milk, hay and grain from birth and then slaughtered at 8 weeks of age, there was some papilli development. However, calves that were fed milk and grain (calf starter) from birth to just 6 weeks of age had good papilli development and dark coloration associated with larger, more developed blood vessels.

  1. Feed a palatable grain-based calf starter with milk or with a really good milk replacer and encourage starter consumption as early as possible after the calf has received at least two (2) good feedings of colostrum (put starter in its mouth after feeding milk to acquaint it with the starter).
  2. Keep calf starter fresh and clean and always in front of the calves to encourage consumption.
  3. Research has demonstrated that calves that have access to water (in addition to milk) will consume more starter.
  4. Usually, when the calf is consuming an average of three (3) lbs of starter/day for a week, it can be weaned.
  5. Feeding milk for longer than 6 to 8 weeks may favor 'Mother Nature,' but it is expensive, labor intensive and may interfere with the calf's rumen development.
  6. Once the calf is weaned, good quality hay should be gradually introduced into the ration, but continue to feed at least five to eight (5 to 8) lbs of starter/grower and make sure that clean water is always available.