Effects of Tannic Acid Added to Diets Containing Low Level of Iron on Performance, Blood Hematology, Iron Status and Fecal Microflora in Weanling Pigs

Abstract

This study investigated the effects of tannic acid (TA) in the diets for weanling pigs prepared with/without supplemental Fe on performance, hematology, fecal microflora and diarrhea incidence. Limestone and calcium phosphate used in Experiment 1 and 2 were of semi-synthetic and feed-grade quality, respectively; while the trace-mineral premix used in both the experiments was prepared without any added Fe source. In Experiment 1, 108 weaned pigs (Landrace × Yorkshire × Duroc, initially 6.46 ± 1.04 kg BW) were allotted to 3 treatments including control (diet added with FeSO4 and antibiotic), T1 (diet devoid of FeSO4 and antibiotic) and T2 (T1 diet added with 125 mg/kg TA). Each treatment had 4 replicates with 9 pigs in each pen. Feeding of T1 diet had a negative effect on the performance and plasma Fe status of pigs, while addition of TA to T1 diet resulted in performance of pigs comparable to pigs fed the control diet, reduced diarrhea incidence but had a negative influence on the hematological and plasma Fe indices. Additionally, pigs fed T2 diet had fewer (p<0.05) total anaerobic bacteria, Clostridium spp. and coliforms than pigs fed T1 diet, and greater number of Bifidobacterium spp. and Lactobacillus spp. in feces when compared with pigs fed control and T1 diets. In Experiment 2, 144 weaned pigs (Landrace × Yorkshire × Duroc, initially 6.00 ± 1.07 kg BW) were allotted to 4 dietary treatments including control (diet added with FeSO4 and antibiotic) and diets devoid of supplemental Fe added with antibiotic (An), TA and both (AnTA). Each treatment had 4 replicates with 9 pigs in each pen. Addition of An, TA or both to diets devoid of supplemental Fe did not have any effect on performance, blood hematology and plasma Fe but resulted in reduced (p<0.05) diarrhea incidence and lower (p<0.05) fecal coliform population than pigs fed the control diet. These results suggest that TA has a negative influence on blood hematology and plasma Fe status when diets are inadequate in Fe; however, TA reduced diarrhea incidence and might have antimicrobial activity.

Potential and challenges of tannins as an alternative to in-feed antibiotics for farm animal production

“…In addition, adding chestnut tannin at the concentration of 15 g/kg DM decreased fecal shedding of E. coli for cattle fed hay diets ( Min et al., 2007 ). However, other tannins such as that from sainfoin and S. lespedeza at lower concentration (<13.5 g CT/kg DM) had no effect on fecal E. coli shedding ( Lee et al., 2009a , Lee et al., 2009b , Berard et al., 2009 ). Supplementation of A. nodosum meal at the dietary concentrations of 10 to 20 g/kg DM significantly decreased E. coli O157:H7 fecal shedding in cattle ( Table 1 ).…”

“…(2008) Purple prairie clover Condensed tannins (CT) E. coli O157:H7 challenged lamb Fresh forage 36 g/kg DM ECT Reduced E. coli O157:H7 fecal shedding Huang et al. (2015) Sericea lespedeza CT Goat Hay 13.5 g/kg DM ECT No effect on fecal E. coli Lee et al., 2009a , Lee et al., 2009b Chestnut Hydrolyzable tannins (HT) Cattle Hay 15 g/day Reduced fecal E. coli Min et al. (2007) Sainfoin CT Cattle Hay/silage 1.1 to 12 g/kg DM No effect on fecal shedding Berard et al.…”

“…and Lactobacillus spp. Lee et al., 2009a , Lee et al., 2009b Tannic acid HT Broiler chicken (1 to 35 day) 0.50% Increased growth performance; reduced blood glucose level; increased fat content in breast and thigh meat; reduced cholesterol content in liver Starčević et al. (2015) Tannic acid HT Broiler chicken (1 to 12 day) 0, 0.75%, or 1.5% No effect on Salmonella cecal culture-positive chicks or in the numbers of Salmonella typhimurium in the cecal contents Kubena et al.…”

“…and Lactobacillu s spp. were increased by 0.0125% tannin acid ( Lee et al., 2009a , Lee et al., 2009b ). Tannic acid at the concentration of 0.5% increased growth performance and fat content in breast and thigh meat, but reduced blood glucose concentration and cholesterol content in the liver of broiler chicken ( Starčević et al., 2015 ).…”

Effects of dietary Glycyrrhiza polysaccharide on growth performance, blood parameters and immunity in weaned piglets

“…Most plant extracts with antibiotic properties have the advantage of low cost, low toxicity, and good effectiveness (Rocha et al, 2005), and have been proven useful as feed additives for piglets to relieve weaning stress (Lee et al, 2009). Polysaccharides extracted from plants are a kind of biopolymer synthesised from monosaccharide subunits (Yin et al, 2019).…”