Published online by Cambridge University Press: 20 November 2017
The in vitro gas production (GP) technique was developed using strained rumen fluid (SRF) as an inoculum. This requires the use of surgically modified animals and it is questionable whether maintaining cannulated animals for this purpose can be justified. Faeces (FAE) have been used as an alternative inoculum, but while total gas volume tends to be the same, the rate of gas production is usually slower. This is probably because of a lower microbial activity in FAE. If the initial activities of the two inoculum sources were controlled, the differences between them may be reduced. The objective of this experiment, therefore, was to compare the GP profiles obtained when different concentrations of SRF and FAE were used, and the initial activity of the inocula equalised.