Abstract
Benzoic acid (BA) and essential oils (EO) have antimicrobial properties and can be used in antibiotic restriction situations. The objective of this study was to evaluate the effects of BA and EO on cecal content microbiota in weaned piglets and growth performance from the nursery to finishing phase. One hundred and twenty barrows were weaned at 23 days (6.40 ± 0.53 kg) and assigned into 3 treatments (10 replicates) in randomized block design: basal diet without additives (NC), basal diet with antibiotics (PC), and association of 0,3% benzoic acid and essential oil (BA+EO). Colistin sulphate (200 ppm) in the nursery diets and enramycin (10 and 5 ppm) in the growing and finishing diets were used in the PC treatment. The pigs were weighed 0, 42 and 132 days into the experiment. On day 9, one animal per pen (7 replicates) was euthanized and the cecal content was collected for microbiome analyses. Growth performance was analyzed by MIXED procedure (SAS, 2009) and the Tukey test was used to compare the means (P < 0.050). The averages for biodiversity between treatments were compared using the number of OTUs and the Kruskal Wallis test (P < 0.050), and the statistical program STAMP was used. In the microbiome analyses, the results of the taxonomic classification, by principal components analysis (PCA), showed a marked difference in bacterial communities per treatment and a significant increase in the number of operational taxonomic units (OTUs) was observed in the BA+EO group (P < 0.05). At 132 days, the final weight (P = 0.006) and total average daily gain (P = 0.028) of BA+EO and PC were higher than NC. In conclusion, supplementation with BA+EO increases biodiversity in cecal content in the post-weaning period, resulting in an improvement in the growth performance of finishing pigs.
Keywords: additives, pigs, microbiome