Phytogenics and encapsulated sodium butyrate can replace antibiotics as growth promoters for lightly weaned piglets.

The objective of this study was to evaluate the effect of essential oils plus dry herbs (PHYTO) and encapsulated sodium butyrate (BUT) supplementation compared with enramycin (ENR), as a growth promoter, on the performance, diarrhoea control and intestinal microbiota in lightly weaned piglets. Two hundred weaned piglets, 20 days old, 4.69 ± 0.56 kg, were submitted during the nursery phase (20 to 69 days of age) to four treatments: control (CTR)-without any additive supplementation; ENR (with 8 ppm of enramycin throughout), BUT (with 2000 ppm between 20 to 34 d, 1500 ppm between 34 to 48 d and 1000 ppm between 48 to 69 d), and PHYTO (150 ppm between 20 to 48 d). At 62 days old, forty piglets (10 replicates per treatment) were slaughtered to perform bacterial identification through 16S rRNA (V3-V4) sequencing of the caecal content. During the second phase of the trial (34 to 48 days), the BUT group showed higher DWG (P = 0.023) and BW (P = 0.039) than the CTR group, and all groups that received additives had better FCR than the CTR group (P = 0.001). In the last phase of the trial (48 to 69 days), the ENR group presented a better FCR (P = 0.054) than the CRT and other groups. In the total period (20 to 69 days), ENR and BUT showed better FCR (P = 0.006) than CRT. Diarrhoea incident data showed differences (P<0.05), favouring the BUT treatment compared to the CTR. Only the Megasphaeraceae and Streptococcaceae families showed differences (p<0.05) in relative abundance between CTR and PHYTO and between CTR and BUT, respectively. Differential abundances of the Megasphaera and Streptococcus genera were observed between CTR and PHYTO and CTR and BUT. Phytogenics and encapsulated sodium butyrate are able and effective for modulating the specific caecal microbiota, improving performance and controlling diarrhoea occurrence.