Live yeast stability in rabbit digestive tract: Consequences on the caecal ecosystem, digestion, growth and digestive health

Abstract Live yeast Saccharomyces cerevisiae NCYC Sc 47 was added to the diet of weaning rabbits (35d old) to analyse the effects on the caecal ecosystem (biotope and bacterial community), digestion and health status. Two levels of yeast (1 and 10 g/kg feed, group C1 and C10 corresponding to 10 6 and 10 7  CFU/g DM) were compared to a control group (C0) without live yeast addition. Three groups of 10 young rabbits were used in a first experiment to measure digestibility and caecal parameters and to calculate the yeast survival rate in the digestive tract. Growth performance and health status were studied on 3 further groups of 40 rabbits (Experiment 2). The live yeast concentration fell slightly after diet pelleting (0.1–0.5 log CFU/g DM), at 70–80°C. The survival rate of yeast in digestive tract was high and increased from 90 to 97% (P