Farm Animal Metabolism and Nutrition

percentage carbon fermented yields 38, 17,
17, 17 and 11%. Management practices
such as diet and meal frequency influence
these ratios: grains increase propionate and
decrease methane, forages increase acetate
and methane. The important thing to
remember is that the production of end-
products is linked such that, overall, there
must be a redox balance. Feeding forages

versus concentrates causes divergent

ecological changes in the ruminal eco-

system. Both are stable, although grain

feeding taken to extreme may collapse, but

are not compatible.

To see how the end-products are

linked, we shall examine how each is

produced. They all start from pyruvate and

in the production of pyruvate there is a

Glucose Availability and Associated Metabolism 135

Fig. 6.3.Summary of ruminal fermentation (modified from Czerkawski, 1986).