Evaluation of the energy value of rabbit feeds: a critical review

An analysis is given of the methods actually used for the determination and calculation of the energy value of rabbit feeds and feedstuffs. The apparent digestible energy (DE) system is recommended. Standardization of the applied methodology for in vivo determination is emphasized. Four to six ad libitum fed growing rabbits are necessary to obtain sufficiently accurate results. The reliability of the estimation of the feeds' energy content, based on the table values of the ingredients, is discussed. The importance of using recently and properly determined data is stressed. Multiple regression equations, based on the results of the chemical analysis of feeds, explain 85-90% of the variability of DE content. The first attempts with in vitro techniques are encouraging.