1. Introduction
Starch is the main dietary energy source in rabbit feeding and is included, mostly from cereals, at rather high levels (170–200 g/kg) in diets for fattening and reproducing rabbits in order to maximize daily growth, reduce feed intake and optimize feed efficiency (De Blas and Mateos, 2010). On the contrary, low dietary starch levels (80–100 g/kg) are recommended during the post-weaning period (Gidenne and Fortun-Lamothe, 2002) to avoid caecal overload of undigested starch, which has been considered a longstanding major cause of digestive-related diseases (Cheeke and Patton, 1980). More recent studies, however, have shown better performance, lower mortality, and/or optimal gut conditions in young rabbits fed with diets containing a higher starch level and, conversely, less insoluble fibre (NDF) levels (Debray et al., 2002 and Gutiérrez et al., 2002).