Effect of D-mannitol on feed digestion and cecotrophic system in rabbits

This study aimed to evaluate the effect of sugar alcohol as an energy source for cecal microbes on digestibility, cecotrophy (i.e. reingestion of microbial products of cecum, cecotrophs) and performance in rabbits. Thus, we fed rabbits an experimental diet that included 5% of D-mannitol, and collected hard feces and cecotrophs to be analyzed for crude protein (CP), acid detergent fiber (ADF), ether extract (EE), crude ash (CA) and dry matter (DM). Cecotrophic behavior of the rabbits was also observed. Feeding D-mannitol increased (P < 0.01) digestibility of ADF, resulting in a decrease (P < 0.05) in the concentration in hard feces. The increase (P < 0.05) in CP concentration was attributed to lower (P < 0.05) digestibility. D-mannitol had a similar modulatory effect on CP and ADF concentrations in hard feces and cecotrophs. Accordingly, estimations of the proportion of nutrients recycled by cecotrophy to dietary intake (PR), obtained by the two calculation methods, showed an increase (P < 0.01) in PR of CP and a decrease (P < 0.05) in that of ADF. Daily weight gain and feed efficiency increased (P < 0.05) for D-mannitol-fed rabbits, while daily feed intake decreased (P < 0.05). These results suggest the possibility of using D-mannitol as a stimulator of cecal microbial growth and cellulolytic activity, and therefore, improved rabbits performance.