Prediction of fatty acid content and composition of forages in the new INRA feed tables

摘要

Forages may contribute to the nutritional value of milk and meat through their content and composition in fatty acids (FA). To optimise a ruminant diet for a target milk or meat FA composition, we need to know the FA content and composition of feedstuffs. However, no detailed FA composition of forages is available in feed tables. The objective of this study was to develop predictive models of FA content and composition of forages, from a database of published studies post-dated 1970. Models were developed for fresh forages, for estimating total FA content and FA composition from crude protein (CP) content and from total FA content, respectively. For conserved forages, total FA content and composition were estimated from the corresponding fresh forage using models integrating the effects of conservation and harvest conditions. Models were also established to estimate their FA content and profile from their CP content when the laboratory analysis is performed on conserved forages. Overall, these models enable the estimation of FA content and composition for different types of forages and were applied to complete the characterisation of forages in the new INRA feed tables.