EFFECT OF DIETARY LIPIDS ON NITROGEN-METABOLISM IN THE RUMEN - A REVIEW

This paper deals with the influence of supplementary lipids in the diet on protein degradation and microbial synthesis in the rumen, through the effect of lipids on the microbial ecosystem. Global effects of lipids can be summarized by a trend to decrease ammonia ruminal concentration but duodenal non-ammonia nitrogen flow is not modified. The two components of this flow, non-microbial and microbial flows, generally are not modified so that it can be deduced that modifications of degradation and microbial synthesis due to lipid addition are of low extent. The efficiency of microbial synthesis depends on the nature of fatty acids and is increased especially when organic matter ruminal digestibility is depressed; this can be related to the decrease in protozoa number in the rumen.