Influence of propolis residue on the bacterial flora in the cecum of Nanbu Kashiwa

Abstract

Since the growth promoter effect of antibiotics was found, manykinds of antibiotics have been used as feed additives for the improvement of growth performance. Since January1, 2006, however, European Parliament prohibited the use of antibiotics as feed additives for promoting animal growth because of biosecuritythreats arising from the increasing resistance of pathogens to antibiotics. Thereafter, various natural substrates having the growth promoter effect have been attempted to use as feed additives instead of antibiotics. Honeybees collect propolis from the cracks in the bark of trees, and it has the versatile pharmacological activities including antibacterial effect. Therefore, the present studyaimed to examine the influence of propolis residue, which was the residue after ethanol extraction, on the cecal bacterial flora in the meat-type chicken, Nanbu Kashiwa. Twenty-eight-d-old female Nanbu Kashiwa were given an ordinary diet for 90 days. During last 10 days, an experimental diet including 2% of propolis residue was provided. At the end of experimental period, ceca were removed and DNA was isolated from cecal content. The V3 region of the bacterial 16S rRNA gene was amplified byPCR using the 357F-GC and 518R primers. To indentifythe bacterial diversity, denaturing gradient gel electrophoresis (DGGE) was applied, and the optical intensityof DGGE bands was determined. The major bands were excised, and DNA was reamplified byPCR. The sequencing data were analyzed by the Basic Local Alignment Search Tool (BLAST) of DNA Data Bank of Japan. The bacteria identified byPCR-DGGE and BLAST were Lactobacillus aviaries, Lactobacillus, Olsenella, Coriobacterium, Paraprevotella, Prevotellaceae, Clostridiaceae and Bacteroidaceae. The DGGE band of which the optical intensityof the propolis residue group was lower than the control group was the family Prevotellaceae.The successful use of propolis residue to reduce the familyPrevotellaceaeshowed the possibility to use propolis residue as alternative feed additives. © 2014, Japan Poultry Science Association.