Effects of Hydrolysable Tannins as Zinc Oxide Substitutes on Antioxidant Status, Immune Function, Intestinal Morphology, and Digestive Enzyme Activities in Weaned Piglets

Abstract

Zinc oxide (ZnO) has negative environmental effects and bioavailability in weaned piglets. Thus, finding safe and effective ZnO substitutes to improve intestinal health and to prevent diarrhea of weaned piglets is urgently required. Therefore, this experiment was conducted to evaluate the effects of hydrolysable tannins (HT), ZnO and HT versus ZnO on growth performance, antioxidant status, serum immunity, intestinal morphology, and digestive enzyme activities in weaned pigs. A total of 144 piglets (28 d-old, initial body weight 7.81 ± 0.99 kg) were assigned to 4 treatments with 6 replicates of 6 piglets each. The experiment lasted 28 d (d 1 to 14 as for phase 1 and d 15 to 28 as for phase 2). The dietary treatments include a corn-soybean meal basal diet (CON); ZnO diet (CON + 2000 mg/kg ZnO in phase 1 and 137.5 mg/kg ZnO in phase 2); HT diet (CON + 1000 mg/kg HT in the overall period (d 1 to 28); HT + ZnO diet (CON + 2000 mg/kg ZnO + 1000 mg/kg HT in phase 1, and 137.5 mg/kg ZnO + 1000 mg/kg HT in phase 2). In phase 1, the incidence of diarrhea was lower (p < 0.05) in the HT + ZnO group than CON. Serum catalase (CAT) and glutathione peroxidase (GSH-Px) were increased (p < 0.01) and malondialdehyde (MDA) was decreased (p < 0.01) in the HT + ZnO group than CON. Compared with CON, immunoglobulin M (IgM), immunoglobulin A (IgA) were increased (p < 0.05) in the HT + ZnO group. In phase 2, both HT and HT + ZnO had a trend to improve (p < 0.10) daily gain. The concentration of total antioxidant capacity (T-AOC) and IgM in serum was higher (p < 0.01) in HT compared with CON. Supplementation of HT improved (p < 0.01) GSH-Px activities in ileum mucosa than the ZnO group. Compared with CON, trypsin, lipase activities, and villus height of jejunum were improved (p < 0.05) in HT and HT + ZnO. The ratio of villus height to crypt depth in the jejunum was improved (p < 0.05) in the HT + ZnO group and which also was increased (p < 0.05) in ileum in the HT group compared with CON. Propionic acid, butyric acid, and acetic acid concentrations in the colon were increased (p < 0.05) in the HT group than CON. Overall, HT + ZnO treatments could be used to replace ZnO for reducing diarrhea and improving antioxidant capacity, immunity, and digestive enzyme activities in weaned piglets.

Phenolic compounds as natural feed additives in poultry and swine diets: a review

“…With the exception of some members of the phenolics family (tannins, saponons, toxic alkaloids) the most of the plant extract did not show anti-nutritive in animal diets [ 4 ]. For example, high concentration of condensed tannins from certain plant extract in animal feed can precipitate protein digestion showed lower performance with nutrient retention in monogastric animals [ 5 , 6 ]; whereas higher body weight with improve health status in chickens offered hydrolysable tannins was recorded [ 7 ]. This is because hydrolysable tannic acid extracted from wood was enrich with polyphenolic compounds [ 8 , 9 ].…”

“…The perception of applying natural polyphenols in poultry and swine diets has been tested since 1989 [ 27 ] and later on it was considered for further research during the last two decades due to their potential biological roles [ 6 , 28 ]. The biological role of phenolic compounds with their mode of action in farm animals were described in details below.…”

Effect of chestnut wood extract on performance, meat quality, antioxidant status, immune function, and cholesterol metabolism in broilers

“…Tannins are secondary plant metabolites that are commonly classified under 2 groups, condensed tannins and hydrolysable tannins. Condensed tannins hold the antinutritional factors and could decrease protein digestibility because of its protein precipitation nature, and thus, the long-term uses of condensed tannins could decrease the growth performance and nutrient digestibility in monogastric animals ( Smulikowska et al., 2001 ; Liu et al., 2020 ). On the other hand, it is believed that hydrolysable tannins have a positive role in growth performance and health status in chickens ( Schiavone et al., 2008 ).…”

Effects of Zinc Oxide and Arginine on the Intestinal Microbiota and Immune Status of Weaned Pigs Subjected to High Ambient Temperature

“…colonization. Hosseindoust et al [24] and Liu et al [7] reported that the antimicrobial activity of ZnO against coliforms makes it an ideal candidate to control the microbiota, however, they did not report any change in the number of Clostridium spp. In another study, the population of coliforms and Clostridium spp.…”

“…There is evidence that high doses of dietary ZnO controlled pathogen growth in the intestine [6]. Besides, dietary supplementation with high doses of ZnO increases the absorption rate that can enhance the antioxidant status [7]. However, feeding high doses of ZnO results in substantial quantities of Zn excretion, and causes environmental concerns [6].…”