In vitro parameters as predictors of metabolizable energy values of roughages

To predict the metabolizable energy (ME) values of roughages based on in vitro 24h gas production (GP) with cell wall contents and/or chemical components, data of Sayan et al. (2004) for 40 roughages were used in the study. Based on R² (determination coefficient) values, best predictions were made when GP and ADF values were used with crude protein, ash and ether extract separately or together.