The objective of this study was to evaluate the caecal microbial activity and caecotrophy nutritional contribution in rabbits fed diets with differents starch levels (22 or 32% on average) from a high or low inclusion of corn grain and differents fiber sources (alfalfa hay or soybean hulls), in a 2x2 factorial design. In the first experiment, 40 rabbits were individually housed in fattening cages within entirely randomized design, and fed ad libitum from 45 to 85 days of age, when they were slaughtered for collection of the ileal and caecal contents. The VFA total concentration was influenced by the interaction among treatments, being 93.82 mmol/l for the diets with high starch level and soybean hulls and 80.03 mmol/l for the diets with low starch level and alfalfa hay. In the second experiment, 40 rabbits aged 65 days were housed individually in fattening cages, in a completly randomized design, fed ad libitum for 10 days, and then received a wood necklace to allow caecotrophes collection. There was influence of the interaction between treatments on the caecotrophes protein and energy levels, being 29.66% and 4204.87 kcal/kg for the diets with high starch level and soybean hulls, and 27.98% and 4080.46 kcal/kg for the diets with low starch level and alfalfa hay. The diets with high starch level and those with soybean hulls showed higher enrichment of caecal contents and the best nutritional support for the rabbits.
alfalfa hay; caecal microorganisms; caecotrophagy; corn; rabbits; soybean hulls
