In vitro Fermentation Method as a Tool to Assess the Effects of Secondary Metabolites on Rumen Fermentation—A Brief Review

In vitro fermentation is a useful method to test the effects of secondary metabolites on the rumen fermentation. It can be a noninvasive method when the rumen fluid is collected from slaughterhouses from dead animals. The experimental design for this type of experiment is normally a factorial design where common factors tested are: incubation time, main energy source incubated, and additive concentrations (secondary metabolites). The data gathered from the incubations can be quite extensive and therefore the statistical power of the in vitro method can be very good. In this paper we will discuss the main characteristics (how the method works and which parameters are measured) of the in vitro fermentation method.