Abstract:
The 28 Lactic Acid Bacterial strains were isolated from 54 samples of healthy chicken intestinal tracts collected from markets in Bangkok. The bacteria were then tested for antibiotic test with Bordetella avium, Listeria monocytogenes, Pasteurella multocida, Proteus vugalis, Pseudomonas aeruginosa, Salmonella enteritidis, Salmonella typhimurium and Staphylococcus aureus. The results showed that supernatant of 6 Lactic Acid Bacterial strains produced zones of inhibition on solid media. All 6 strains were taxonomically classified as 2 Lactobacillus acidophilus strains, 1 Lactobacillus bulgaricus strain, 1 Lactobacillus fermentum strain, 1 Lactobacillus casei Subsp. Tolerans strain, and 1 Lactobacillus jensenii strain. When mixed culture of these Lactobacillus spp. Were supplemented to chickens as probiotic, Lactobacillus fermentum was the only strain that could not survive in chicken's intestine. In addition, the efficiency test of probiotic was conducted and showed that tested chickens, in which mixed probiotics were supplemented, had larger body weights than the control with statistical singnificance (P<0.05) and Feed Conversion Ratio was not significantly different. When conducting a challenging test with Salmonella typhimurium, it revealed that mix culture Lactobacillus spp. Could decrease the infection of certain Salmonella spp. The results from this work could be concluded that using mixed culture of Lactobacillus spp. As probiotics in increasing chicken production was benefitial as the same as the use of other growth promotants and could be used as alternatives for antibiotics