Developing the Rumen

Developing a healthy rumen in your calves is important to ease the transition from a pre-ruminant to a ruminant animal.


Calves are borne pre – ruminant, and as they develop they become ruminants. In other words, as a milk drinking calf, the rumen is the smallest stomach while the abomasums (where milk is digested) is the largest. As the calf starts to eat grain and meal the abomasums shrinks while the rumen increases in size and develops papillae, preparing to take over as the primary gut. The lining of a healthy rumen is covered with papillae (protrusions that enlarge the surface area for nutrient absorption).

Trials show that a calf’s rumen develops earlier if the calf is fed solid feeds such as grains and meals as early as possible. Grain produces butyrate and propionate when fermented and are essential for the development of rumen papilla. Ensure there is plenty of fresh, clean water available. Water increases the uptake of grains as well as multiplying the growth of micro – organisms, essential to a healthy rumen.

Although calves nibble at grass and hay, these products do little to aid in rumen development. They produce acetate which has no effect on papillae development. Calves fed on milk, grass and hay eventually develop working rumens but it takes much longer and you will have to feed milk for a longer period of time.

Early rumen development leads to less scours, healthier calves and better average daily weights. Calves with good rumen development are less likely to experience a drop in condition when fully weaned off milk.



Milk Only



Milk and Hay


Milk and Grain