The fattening performances, nitrogen excretion and health status of growing rabbits were studied in response to a linear reduction of the digestible fibre (DgF = water-insoluble pectins + hemicelluloses) to crude protein ratio (DFP) in four diets (from 1.01 to 1.55). As the crude protein level was reduced from 17.7% to 13.9% (in diets DFP1 DFP4), the DgF level was increased from 18.5% to 22.1%, without changes to poorly-digestible fibre levels (ADF = 19%). A total of 644 rabbits per diet were used in a multi-site study (n = 6). Between weaning (28d-37d according to sites) and 49d of age, reduction of the DFP ratio led to a linear decrease in weight gain (-4 g/d between DFP1 and DFP4, P<0.001), associated with a reduced feed intake (-5.7% between DFP1 and DFP4). However, for the whole fattening period, growth and intake did not differ significantly among the diets. Over the whole fattening period (35d-70d old), the mean faecal nitrogen output was of 1 g/N per day and per rabbit, and remained similar for the four diets, while the urinary N output was reduced by 55% between DFPI and DFP4 (P<0.001). Accordingly, the total N output per rabbit was of 82.4g. 75.5 g, 63.2 g and 57.4g (P<0.001) in animals fed with DFP1-DFP4 diets, respectively. The nitrogen output per kg of live weight of rabbit produced was 52.0 g. 47.9 g, 40.7 g and 36.9 g for DFP1 DFP4, respectively. At the same time, an increase of the DFP ratio of over 1.3 (CP20%) reduced the mortality by diarrhoea for the two highest DFP ratios when compared to the two lowest ratios (5.2% vs. 7.8%, P<0.05), and led to a 40% reduction of the health risk index between weaning and slaughtering (20.0% vs. 12.6% for DFPI and DFP4, respectively, P<0.01). A significant reduction of mortality from rabbit epizootic enteropathy (3 sites) was also observed when the DFP ratio was increased to over 1.3. A reduction of the protein level in favour of a higher digestible-fibre level is therefore a useful feeding strategy which improves the resistance of the growing rabbit to enteropathy, without major impairment of performances, and with a reduced nitrogen output. (C) 2013 Elsevier B.V. All rights reserved.