Can calves get subacute rumen acidosis?  Dr. Jim Quigley, Technical and Research Manager for Provimi North America, examines this question in the latest issue of his Calf Notes newsletter.

Quigley defines the criteria for SARA as rumen pH below 5.8. He cites two research studies that indicate SARA may not only be possible in calves, but a fairly common condition. He says reasons for this may include:

  • Rapid fermentation of carbohydrate by rumen bacteria.  urther, formulation of diets to include rapidly fermentable sources of starch and sugar may exacerbate this effect.
  • Limited volatile fatty acid (VFA) absorption, especially in the first few weeks of life.
  • Once pH falls below 6.0, protozoa in the rumen (if established in the young calf) die off, which results in less sequestration of starch granules and increased rate of fermentation.
  • Young calves often have limited saliva production, plus their saliva does not contain as much bicarbonate as that of older calves.
  • Lack of effective fiber resulting in the development of keratinization of the rumen may slow absorption of VFAs, thereby increasing rumen acids and reducing pH.
  • Lack of rumen mat and regurgitation in young calves limits additional saliva production.

Quigley says calves with SARA are likely to exhibit dark, thin stools that are so common on dairies and calf ranches that they may be perceived to be “normal.” However, they are not. Quigley will explore the implications of SARA in calves in the next issue of Calf Notes.