PS9-19. Evaluating Effect of Probiotic Strains Supplementation in Pre- and Peri-weaned Goats on Immune Health, Growth Rate, Microbial Composition and Abundance Using Shotgun Metagenomics.

Abstract

Probiotics are microbes generally regarded as safe that are given to animals as supplements with the objective of improving health among other beneficial outcomes. The objective of this study was to determine the effect of two American Type Culture Collection (ATCC) probiotic strains reported to have antimicrobial and health promoting effect in experimental animals on the gut microbial dynamics, immune health parameters, and growth rate of pre- and peri-weaned pastured goats. Twenty-four newborn goat kids were divided into a probiotic group (12) and administered daily probiotics from birth until one month of age followed by weekly supplementation thereafter until weaning day at three months of age when probiotics were administered daily for one more week. Control animals (12) received saline in place of probiotics. Fecal samples were collected from first day of experiment and weekly thereafter in all experimental animals. Blood samples were taken at initiation, and thereafter biweekly while weights were taken weekly. DNA was extracted from fecal samples and analyzed using shotgun metagenomics. Blood samples were evaluated for IgA and IgG. The growth rate as measured by proportional weight gain and IgG absorbance values were similar between the two groups throughout the study. The IgA values at two weeks post initiation tended to be higher (p = 0.09) for probiotic supplemented group and remained slightly higher at other sampling points up to eight weeks of age although the differences were not significant. No differences in microbial alpha and beta diversity as measured by Chao-1 and Bray-Curtis respectively between treatment groups were detected. Significant differences in several microbial taxa abundance and prevalence at several taxonomic levels were detected between probiotic supplemented and control animals especially during the peri-weaning period with most differences detected at two days post weaning. Uniquely, genera harboring pathogenic species like Escherichia, Campylobacter and Psychrobacter were significantly higher in control animals than probiotic supplemented animals during the peri-weaning period. On the other hand, genera associated with a healthy gut including Phocaecola, CAG-791, Ruminococcus_E, Negativibacillus, Desulvibrio, Colinsella, Odoribacter, Alistipes, Bifidobacterium, Blautia and Limisolactobacillus were all significantly higher in abundance or prevalence in probiotic supplemented animals. The results indicate the tested probiotic strains may have a beneficial effect on immune markers and gut microbiome in young goat kids including a protective gut health effect during the immediate post weaning period. Further analysis will reveal if the microbial differences detected have effect on the overall long-term health, hematological parameters and performance of the animals.