The high intestinal digestibilities of total
long-chain fatty acids and C18 fatty acids in
both diets attested that the high fat ration
(milk diet) with 1% calcium did not limit fatty
acid intestinal absorption in dairy cows. However,
the results noted on microbial or partially
microbial fatty acids, because of higher intestinal
digestibilities (+10 to +15 points) with the milk
diet [control values were similar to previous
results with conventional diets (25, 27, 28,
30)], suggested that a high fat ration probably
limited microbial fatty acid synthesis intensity
in the large intestine as well as in the rumen.
However, a terminal ileum cannula should be
used to confirm this hypothesis.