REVIEW OF THE MAIN METHODS OF CELL-WALL ESTIMATION - INTEREST AND LIMITS FOR RUMINANTS

This review describes methods for cell wall measurement which have been or are the most useful for ruminant feeding. The methods have been classified into three main categories: direct or gravimetric methods, fractionation methods into separate constituents and physico-chemical methods. The chemical basis and the nutritive information are presented for these three groups of methods. This review emphasizes the relative advantages of the different methods and the factors to be kept in mind when choosing the most appropriate method for a definite goal. Indeed, it seems that when feeds are from varied or unknown origins, analytical schemes including lignin determinations are the most suitable for a routine analysis in order to determine their nutritive value. When analysing feeds from the same botanical family, a physico-chemical method like the near infrared spectroscopy is probably the best method, especially when there is a large number of samples.