Quantitative review of in situ starch degradation in the rumen

The partition of starch digestion in the digestive tract of ruminants has a great influence on various animal responses. There is a need to more accurately estimate and control the amount of starch degraded in the rumen. A quantitative review on starch degradability in situ was conducted from a database built from 48 references corresponding to 302 observations. Appropriate statistical analyses have been performed, particularly to correct for the variations among laboratories. The estimated values for the in situ starch parameters and for the effective degradability were calculated for 22 ingredients. The effect of some chemical or physical treatments was also investigated and quantified. The data confirmed that large differences occurred due to intrinsic properties of the feed. Furthermore, there was a strong influence of processing, especially on feedstuffs containing slowly degrading starch. This study updated the data on starch degradability in situ. The values presented have an interest for feedstuffs evaluation, for diet formulation and also for modeling ruminal digestion.