Selection of prebiotic oligosaccharides suitable for synbiotic use in calves

The aims of this experiment were to identify suitable commercial prebiotic substrates for bifidobacteria of calf origin and to verify in vivo the effects of the selected prebiotics on survival of applied and naturally occurring bifidobacteria in calf intestines. First, in vitro utilization of selected fructooligosaccharides, galactooligosaccharides, and inulin by Bifidobacterium animalis ssp. animalis (two strains), B. choerinum, B. thermophilum, and B. longum ssp. suis was investigated. The highest specific growth rates were observed with Vivinal® (galactooligosaccharides) and Raftilose P85 (fructooligosaccharides); therefore, these prebiotics were used for in vivo tests. Three groups of calves were investigated. A single dose of a probiotic mixture of five strains of rifampicin-resistant variants of bifidobacteria (RRBs) in form of fermented milk was fed to 2-days-old calves in the first experimental group (PROB). In the second group (SYNB), a single dose of probiotics was administered to calves at the same age, but a prebiotic mixture containing selected substrates was fed to the calves every day until 7 weeks of age (the end of the study). The third group, which did not receive any treatment, was used as a control. The survival of applied and naturally-occurring bifidobacteria and the numbers of selected faecal bacterial groups were determined by cultivation. Our results showed that the fed RRBs were able to survive passage through the gastrointestinal tract, with counts of more than 107 CFU/g in the PROB group. Significantly higher numbers of RRBs (more than 108 CFU/g) were found in the SYNB group at age 4 days. RRBs persisted in intestines for at least 49 days in both experimental groups without further significant differences. Counts of other determined bacteria were not significantly affected by the treatments. Our results showed that the selected prebiotics improve the survival of bifidobacteria passing through the digestive tract. Selected combination of pro- and prebiotics seems to be promising synbiotic in term of promoting survival of administered bacteria in intestine. However its effect on animal performance must be verified in other experiment with larger groups of animals.