The ideal rumen pH for ruminant animals is between 6 and 7, as levels outside this range can hinder microbial health and feed utilization. A pH below 6 results in acidosis, which prevents the growth of cellulose-digesting microorganisms. Additionally, the large intestine's caecal-colonic fermentation contributes 10-15% of gross energy but leads to loss of microbial protein through manure.

1. digestive system of
ruminant animals
By Dr Iqra Bano chandio

8. Rumen pH
• The ideal rumen pH value is between 6 and 7.
• The ruminal microorganisms are healthiest within
this range. If the pH value varies too much, some
types of micro-organisms are eliminated, and there is
reduced utilization of the feed.
• Micro-organisms that digest cellulose (hay, silage,
etc.) are unable to grow or ferment cellulose with a
pH value below 6.0. When ruminal pH drops below
6, the rumen is considered to be acidotic.

26. The Large intestine

27. The Large intestine
•The large intestine, especially the caecum and
colon, supports an active fermentation that is
quite similar to that in the reticulo-rumen.
•The caecal-colonic fermentation may supply 10-
15% of the gross energy available to a dairy
cow. However, most microbial protein
generated by this fermentation is lost via the
manure.