Development of prebiotics for livestock use.

Weaning imposes tremendous stress on piglets and the period following is characterized by a high incidence of intestinal disturbances with diarrhea and depression of growth performance in piglets. For the last several decades, antimicrobial compounds have been used to promote piglet growth at weaning through the prevention of subclinical and clinical disease. At the same time in recent years, there is an ongoing interest to minimize the use of antibiotics and to find alternatives for antimicrobial growth promoters and new strategies that have been used to enhance gastrointestinal function. Aim of this study was to develop a prebiotic food for piglets characterized by bifidogenic activity, capable of improving the health gut of the animals. Thirty strains of Propionibacterium freudenreichii subsp. shermanii (Cousin et al. 2011) were isolated from dairy products and were tested for their ability to produce bifidogenic growth stimulator (BGS), a prebiotic preparation that selectively stimulates the growth of Bifidobacteria through the action of its component 1,4-dihydroxy-2- naphthoic acid. The BGS activity was determined by an agar diffusion plate assay as reported by Mori et al. , 1997. Bifidogenic activity has been tested on several species of Bifidobacteria previously isolated from piglets stool samples: Bifidobacterium tsurumiense, B. pseudolongum subsp. pseudolongum, B. choerinum, B. thermophilum B. thermacidophilum, B. indicum, B. boum. The two strains of Propionibacterium freudenreichii subsp. shermanii, which showed greatest BGS activity, were reproduced in a pilot plant. The surnatant was submitted to a spray treatment in order to obtain a powder product mixable with the feed. The results showed that BGS activity was unaffected by spray treatment and remained stable in the 12 months after production. The oral BGS administration with the feed could be a possible way to improve the well-being of the weaned animals by modulating intestinal microflora and reduce the incidence of diarrhea. These encouraging preliminary results lead us to propose a randomized, controlled trial of BGS in piglets to demonstrate its efficacy in vivo.