Effects of Tannic Acid Supplementation on Growth Performance, Oocyst Shedding, and Gut Health of in Broilers Infected with Eimeria Maxima

Abstract

The purpose of this study was to evaluate effects of tannic acid (TA) on growth performance, fecal moisture content, oocyst shedding, gut permeability, lesion score, intestinal morphology, apparent ileal digestibility, and the antioxidant and immune system of broilers infected with Eimeria maxima. A total of 420 one-day-old broilers were distributed to five treatments with seven replicates of 12 birds. The five treatments were the (1) sham-challenged control (SCC; birds fed a control diet and administrated with PBS); (2) challenged control (CC; birds fed a control diet and inoculated with E. maxima); (3) tannic acid 0.5 (TA0.5; CC + 500 mg/kg TA); (4) tannic acid 2.75 (TA2.75; CC + 2750 mg/kg TA); and (5) tannic acid 5 (TA5; CC + 5000 mg/kg TA). The TA2.75 group had significantly lower gut permeability compared to the CC group at 5 days post-infection (dpi). Supplementation of TA linearly reduced oocyst shedding of E. maxima at 7 to 9 dpi (p < 0.05). At 13 dpi, the TA2.75 group had significantly greater apparent ileal digestibility (AID) of dry matter (DM) and organic matter (OM) compared to the CC group. At 13 dpi, supplementation of TA linearly increased jejunal villus height (VH). Thus, this study showed that supplementation of TA at levels of 500 to 2750 mg/kg has the potential to be an anti-coccidial agent against E. maxima in broilers.

Keywords: Eimeria maxima; broilers; gut health; oocyst shedding; tannic acid; tannins.

Figure 1

Alcian blue/the period acid-Schiff (AB/PAS)-stained jejunal morphology of (A) SCC (sham-challenged control): chickens fed a control diet and challenged with phosphate-buffered saline; (B) CC (challenged control): chickens fed a control diet and challenged with 10⁴ of Eimeria maxima; and (C) TA0.5 (tannic acid 500 mg/kg): CC + 500 mg/kg tannic acid. Small purple dots are goblet cells, and big white and purple dots are E. maxima. The SCC group had no E. maxima cross-contamination, and the TA0.5 group had less E. maxima in the mucus layer compared to the CC group.

Figure 2

Relative mRNA gene expression in the jejunum at 6 days post-infection (dpi) (genes related to immune system, gut barrier integrity, and mucin) and 13 dpi (nutrient transporter and mucin) in the SCC ((sham-challenged control): broilers fed a control diet and administrated with phosphate buffered saline via oral gavage); CC ((challenged control): broilers fed a control diet and administrated with 10⁴ of Eimeria maxima via oral gavage); TA0.5 ((tannic acid 500 mg/kg): CC + 500 mg/kg of tannic acid); TA2.75 ((tannic acid 2750 mg/kg): CC + 2750 mg/kg of tannic acid); TA5 ((tannic acid 5000 mg/kg): CC + 5000 mg/kg of tannic acid) groups. Each value represents the mean ± SEM. SCC was compared with CC (unpaired t-test), and the comparison was presented as * 0.05 < p < 0.10, ** p < 0.05, *** p < 0.01. Bars with different letters are significantly different (p < 0.05) by PROC MIXED followed by the Tukey’s multiple comparison test among E. maxima-infected groups (CC, TA0.5, TA2.75, and TA5). Orthogonal polynomial contrasts analysis was conducted to see linear pattern (L) and quadratic pattern (Q) among Eimeria maxima challenged groups. GAPDH, glyceraldehyde 3-phosphate dehydrogenase; NFκB, nuclear factor kappa-light-chain-enhancer of activated B cells; IL, interleukin; JAM2, junctional adhesion molecule 2; ZO2, zonula occludens 2; CLDN4, claudin 4; SGLT1, sodium glucose transporter 1; PepT1, peptide transporter 1; B0AT1, sodium-dependent neutral amino acid transporter 1; EAAT3, excitatory amino acid transporter 3; GLUT2, glucose transporter 2; and MUC2, mucin 2.