Isoacids In Ruminant Nutrition: Their Role In Ruminal And Intermediary Metabolism And Possible Influences On Performances — A Review
Published 1987 · Biology
Abstract Isoacids is the collective term for the branched-chain fatty acids: isobutyric, 2-methylbutyric and isovaleric acid and the straight-chain valeric acid, which are naturally produced in ruminant's digestive tracts. They are mainly built up from the degradation products of the amino acids valine, isoleucine, leucine and proline and should in turn be used for the biosynthesis of those amino acids and higher branched chain volatile fatty acids. Besides their role as specific nutrients for the ruminal cellulolytic bacteria, isoacids seem to have a general positive influence on microbial fermentation. Only limited information is available on the influence of isoacids on the intermediary metabolism. Alteration of the growth hormone and indirect effects (via amino acids) on mammary gland and skeletal muscles are suggested. In a conventional ruminant diet, a supplement of isoacids does not seem to have a positive effect on feed intake. From a review of cattle experiments, it appeared that, in lactating cows, a nutritional supplement of isoacids may have a positive influence on milk production, but, for optimal performances of growing cattle, ruminal deficiency of isoacids does not seem to be a limiting factor.