Performance and intestinal health of piglets in the nursery phase subjected to diets with condensed black wattle ( Acacia mearnsii) tannin

Objective: The objective of this study was to evaluate the use of condensed tannin from black acacia ( Acacia mearnsii) as a substitute additive for zinc oxide and growth-promoting antibiotics on the performance, digestibility, and intestinal health of piglets in the nursery phase. Methods: A total of 200 PIC piglets that were 22 days old and weighed 6.0 +/- 0.9 kg were subjected to four treatments in the nursery phase (22 to 64 days of age): CONTR (control diet); ENR+ZnO (control diet + 10 mg/kg of enramycin + 2,500 mg/kg of zinc oxide during the first 21 days); BUT (control diet + 900 mg/kg of sodium butyrate) and TAN (control diet + 2,000 mg/kg of condensed tannin). The experimental design was a randomized block with 4 treatments and 10 replicates, with a pen of five animals each as the experimental unit. The zootechnical performance, diarrhea index score, dietary digestibility and metagenomics of the deep rectum microbiota were evaluated. Results: The TAN had greater weight gain in the nursery phase and final weight (p<0.05) than the CONTR (394 vs 360 g/d, and 22.6 vs 21.1 kg, respectively), with these values being intermediate for the ENR+ZnO and BUT (365 and 382 g/d, and 21.3 and 22.1 kg, respectively). There was no difference between treatments for semi-liquid diarrhea (score 2), but CONTR had more cases of severe diarrhea (score 3; p<0.05) than ENR+ZnO, BUT and TAN, with 42, 18, 29, and 21 cases, respectively. The treatments had no impact on rare taxa or the relative abundances of taxonomic groups (uniformity), but the use of TAN promoted an increase in the abundances of Brevibacillus spp. and Enterococcus spp. compared to the other treatments (p<0.05). Conclusion: The use of condensed tannin from black wattle as a performance-enhancing additive was effective, with effects on performance and intestinal health, demonstrating its potential as a substitute for zinc oxide and enramycin in the diets of piglets in nursery phase.