When compared with a standard commercial diet for growing rabbits, and independently of milk supply (Martínez-Vallespín et al., 2011a), early introduction of a diet with high NDSF (without varying other fibre fractions) decreased feed intake and nutrient supply, reducing growth performance until weaning. In contrast, animals fed with the high NDSF diet achieved a similar LW at 42 days, showing an improvement in feed conversion ratio. However, these results are mainly due to a greater development of the full gastrointestinal tract, particularly of the caecum, resulting in a lower chilled carcass weight and dressing out percentage at 42 days of age. When growing rabbits were kept on the highly-digestible fibre diet until slaughter, not only chilled carcass weight and dressing out percentage but also LW were impaired. Martínez-Vallespín et al. (2013) reported that diets rich in pectins, usually from sugar beet pulp, led to a higher caecal weight independently of simultaneous wide variations in the level of insoluble fibre and/or starch. These results confirm that raising highly-digestible fibre content of diet might impair both performance and carcass yield of growing rabbits, although negative effects might be overestimated in the current study because of a possible positive effect of zinc-bacitracin on animals fed with the commercial diet.