Comparison of porous and nano zinc oxide for replacing high-dose dietary regular zinc oxide in weaning piglets

Piglet growth performance improved by dietary supplementation of porous or nano particles of zinc oxide may be related to the gut microbiota

Previous studies on porous or nano particles zinc oxide (ZnO) in the piglets have mainly focused on growth performance and intestinal inflammation, but have scarcely explored the efficacy on gut microbiota. In addition, the efficacy of nano particles ZnO, which is related to its product quality, remains undefined. This study aimed to determine the efficacy of dietary 500 mg/kg porous or nano particles ZnO on the growth performance and gut microbiota of the weaned piglets. A total of 128 weaned piglets were randomly assigned to the dietary groups: NC (basal diet), PC (basal diet + 3,000 mg/kg conventional ZnO), 500HiZ (basal diet + 500 mg/kg porous particles ZnO), and 500ZNP (basal diet + 500 mg/kg nano particles ZnO). Compared with the NC diet group, both 500HiZ and 500ZNP increased (P < 0.05) average daily feed intake (1 to 28 d) and average daily gain (1 to 28 d), and the 500ZNP tended to decrease feed to gain ratio (F:G ratio, 1 to 28 d) (P = 0.09). Both 500HiZ and 500ZNP decreased crypt depth of the ileum and increased claudin-2 in the duodenum and zonula occludens-1 in the ileum (P < 0.05). Moreover, both 500HiZ and 500ZNP decreased IL-1β and tumor necrosis factor-α (TNF-α) in the jejunum and decreased TNF-α and IL-6 in the ileum (P < 0.05). Both 500HiZ and 500ZNP increased microbial β-diversity index in the ileum and microbial α-diversity indices in the colon of piglets (P < 0.05). The probiotic genera Coprococcus (500ZNP) and Blautia (500HiZ) were positively correlated with the F:G ratio (1 to 28 d) in colon of piglets (P < 0.05). In addition, 500HiZ promoted mitochondrial fusion protein 1 (MFN1) and zinc transporter-1 (ZnT-1) in the jejunum (P < 0.05), whilst 500ZNP decreased MFN1 in the jejunum and ZnT-1 in the ileum (P < 0.05). In summary, both 500HiZ and 500ZNP improved the growth performance of piglets, which is likely via the genera Blautia and Coprococcus, respectively. Both 500HiZ and 500ZNP improved barrier function and inflammation of the intestine, and 500HiZ achieved better efficacy than 500ZNP on intestine mitochondrial functions.

Dietary Palygorskite Clay-Adsorbed Nano-ZnO Supplementation Improves the Intestinal Barrier Function of Weanling Pigs

This study aimed to investigate the effects of PNZ on intestinal mucosal barrier function in weaning piglets. A total of 210, 21-day-old piglets with similar body weights (6.30 ± 0.51 kg) were randomly allocated into seven groups: control group (CON), antibiotic group (ANT), ZnO group (ZO), nano-ZnO group (NZO) and low, middle, and high PNZ groups (LPNZ, MPNZ, and HPNZ). The seven groups were, respectively, fed control diets or control diets supplemented with antibiotics; 3,000 mg/kg ZnO; 800 mg/kg nano-ZnO; 700, 1,000, or 1,300 mg/kg PNZ. More integrated intestinal villi were observed in the LPNZ group. In the jejunum of LPNZ group, the crypt depth significantly decreased (P &lt; 0.05), and the ratio of villus height to crypt depth (V/C) significantly increased (P &lt; 0.05). In addition, the villus width and surface area of the ileum were significantly increased in the LPNZ group (P &lt; 0.05). Dietary supplementation with PNZ can significantly increase the number of goblet cells in the mucosa of the jejunum and ileum (P &lt; 0.05), decrease the contents of TNF-α and IL-1β (P &lt; 0.05), and increase the contents of sIgA and IL-4 in the jejunal and ileal mucosa (P &lt; 0.05). Meanwhile, the mRNA expression of MCU2 and ZO1 in PNZ group were significantly increased (P &lt; 0.05), the mRNA expression of TLR4 and MyD88 was downregulated (P &lt; 0.05). With increasing levels of PNZ, decreased proinflammatory cytokines and increased intestinal mucosal barrier function in weaned pigs was observed. In conclusion, supplementation with PNZ could effectively improve the intestinal barrier function of weanling piglets and potentially could replace the use of high doses of ZnO and antibiotics. The appropriate dose of PNZ for supplementation was 700 mg/kg.

Growth, physiological performance, and pork quality of weaner large white piglets to different inclusion levels of nano zinc oxide

Thirty intensively reared piglets averaged 7.6 ± 0.32 kg were used for the experiment. The piglets were randomly allotted to 5 different treatments: 200 mg/kg, 400 mg/kg, 600 mg/kg nano zinc oxide (nZnO; 50 nm), positive control (tylosin 10%), and the negative control (no additive) in a completely randomized design. Data were collected for weight changes, blood parameters, and carcass and meat quality characteristics. Piglets supplemented with 200 mg/kg had elevated (P < 0.05) weight gain, while those supplemented with 400 and 600 mg/kg nZnO had higher comparable weight gains, while the control groups had the least comparable weight gain values. Pigs fed 600 mg/kg of nano zinc had the highest albumin concentrations with the least values observed in 200 and 400 mg/kg groups. Pigs offered tylosin 10% and 600 mg/kg had higher comparable total protein, while those fed control diet had the lowest total protein concentration. Pigs supplemented with nZnO had highest comparable values for slaughter weights. The supplementation of 600 mg/kg had elevated values of villi height, while the groups supplemented with 200 and 400 mg/kg had a similar trend, and the control had the least comparable values of villi height. It could be concluded that the supplementation of nZnO at a dietary dose of 600 mg/kg gave the best performance in terms of intestinal morphology (villus height), growth performance, meat quality, and immune response.

Impact of zinc oxide, benzoic acid and probiotics on the performance and cecal microbiota of piglets

Background

Intestinal health remains a key factor in animal production because it is essential for digestion, absorption and bacterial fermentation. Feed additives have been used to attenuate the weaning stress such as Zinc Oxide (ZnO) and benzoic acid (C₇H₆O₂). The objective of this study was to evaluate the impact of of benzoic acid and probiotics (BA + P) on performance, diarrhea and cecal microbiota of piglets in the nursery phase (23 to 65 days).

Results

One hundred and sixty weaned piglets with an initial weight of 6.335 ± 0.698 kg and 23 days of age were submitted to four treatments: supplementation with 2500 ppm of Zinc oxide (ZnO), supplementation with a commercial blend of benzoic acid and probiotics (Bacillus licheniformis, Bacillus subtilis and Enterococcus faecium NCIMB 10415; Vevogut P®) (BA + P), supplementation with Zinc oxide plus benzoic acid and probiotics (ZnO + BA + P), and controls receiving only the basal diet without any supplementation. At 65 days of age, 32 piglets (n = 8 per treatment) were slaughtered for the evaluation of the cecal microbiota. Supplementation with ZnO and BA + P were associated with better feed conversion (P < 0.05) in the early stage (23 to 49 days) and with an improvement in all performance parameters over the entire experimental period. The occurrence of diarrhea was lower (P < 0.05) in the BA + P group. The 4 most abundant phyla along with unclassified bacteria represented 93% of all sequences. Firmicutes dominated the cecal microbiota of all groups, followed by Bacteroidetes. Richness represented by the observed number of genera and by the Chao index were statistically lower in ZnO and ZnO + BA + P supplemented animals compared to controls. The beta diversity analysis that compares similarities between bacterial communities demonstrated formation of two distinct clusters containing samples with and without supplementation with ZnO, confirming a strong influence of ZnO on the intestinal microbiota.

Conclusion

The use of Benzoic acid with probiotics yields similar performance results with lower impact on the gut microbiota compared to ZnO, and it should be considered as a potential alternative in swine production.

Supplementary Information

The online version contains supplementary material available at 10.1186/s42523-021-00151-y.

In-Feed Supplementation of Resin Acid-Enriched Composition Modulates Gut Microbiota, Improves Growth Performance, and Reduces Post-Weaning Diarrhea and Gut Inflammation in Piglets

The weaning process represents a delicate phase for piglets, and is often characterized by lower feed intake, lower weight gain, diarrhea, and ultimately increased mortality. We aimed to determine the effects of RAC supplementation in diets on improving piglet growth and vitality, reducing post-weaning diarrhea, and enhancing gut health. In a 2 × 2 × 2 factorial experiment, we selected forty sows and their piglets. Piglets were followed until seven weeks of age. There were no significant differences found between RAC treated and control piglets until weaning (p = 0.26). However, three weeks after weaning, RAC treated piglets had higher body weight and average daily growth (ADG) than the control piglets (p = 0.003). In addition, the piglets that received RAC after weaning, irrespective of mother or prior creep feed treatment, had lower post-weaning diarrhea (PWD) and fecal myeloperoxidase (MPO) level than control piglets. Gut microbiota analysis in post-weaning piglets revealed that RAC supplementation significantly increased Lachnospiraceae_unclassified, Blautia, Butyricicoccus, Gemmiger and Holdemanella, and decreased Bacteroidales_unclassified. Overall, RAC supplementation to piglets modulated post-weaning gut microbiota, improved growth performance after weaning, reduced post-weaning diarrhea and reduced fecal myeloperoxidase levels. We therefore consider RAC to be a potential natural feed supplement to prevent enteric infections and improve growth performance in weaning piglets.

Using Zinc Oxide Nanoparticles to Improve the Color and Berry Quality of Table Grapes Cv. Crimson Seedless

Producing high-quality table grapes is becoming a challenge in the warmer area of the world due to the global increase in temperature, which negatively affects anthocyanin biosynthesis and other fruit quality attributes. Nanotechnology is a growing field that can be a very useful tool to improve crop productivity and sustainability. The red color is one of the major fruit quality parameters that determine table grape marketability. This study aimed to investigate the role of the zinc element in improving the marketable characteristics of Crimson seedless (Vitis vinifera L.) table grape berries i.e., color, firmness, total soluble solids and sugars; besides its role in activating PAL and SOD enzymatic systems. Additionally, this paper investigated the additive advantages of zinc when applied in nanometric form. Five concentrations of zinc oxide nanoparticles, ZnO NPs (0, 25, 50, 100 and 250 ppm), were compared to zinc oxide in mineral form at a concentration of 250 ppm to investigate their effects on the marketable characteristics of Crimson seedless grape cultivar. The treatments were applied as foliar spray on three-year-old Crimson seedless vines grafted on Richter 110 rootstock grown in one of the major table grape production area in Egypt. The experiment was arranged in completely randomized block design and each vine was sprayed with five letters of the solution. The use of the lowest concentration (25 ppm) of ZnO NPs achieved the highest significant enzyme activity (PAL and SOD). Moreover, the T.S.S, sugars and anthocyanin content in berries increased significantly in association of decreasing acidity. On the other hand, the use of a 50 ppm concentration led to an increase in fruit firmness. Collectively, our data showed that 25 ppm of zinc nanoparticles improved PAL and SOD enzymes activity, improved red coloration in table grape and was more effective than the 250 ppm zinc oxide mineral form.

Changes in Diarrhea Score, Nutrient Digestibility, Zinc Utilization, Intestinal Immune Profiles, and Fecal Microbiome in Weaned Piglets by Different Forms of Zinc

Simple Summary

Piglets, especially at the weaning stage, are highly susceptible to various diseases due to an incomplete immune system development and stress responses. Post-weaning diarrhea has a significant impact on piglet growth rate and mortality, resulting in economic losses to the swine industry. Zinc oxide (ZnO) is widely used as a weaning diet supplement in the swine industry to prevent diarrheal diseases and promote immune system development. Despite the recently demonstrated beneficial effects of ZnO, many efforts have been made to reduce its excessive use in piglets owing to environmental pollution and toxic effects on tissues; thus, the need for an effective alternative ZnO form, which promotes zinc utilization, has been gaining attention. However, we do not completely understand the mode of action of ZnO alternatives or the amount required to exert positive effects on weaned piglets. Therefore, we conducted this study to evaluate the effects of different forms of ZnO alternatives (ZnO chelate with glycine (chelate-ZnO) and nanoparticle-sized ZnO (nano-ZnO)) on diarrhea score, nutrient digestibility, zinc utilization, intestinal immune profiles, and fecal microflora on piglets, together with a comparison of the standard ZnO treatment. We found that 200 ppm Nano-ZnO had similar positive effects on weaned piglets compared with 2500 ppm ZnO and therefore is a promising alternative to ZnO.

Abstract

Twenty weaned piglets with initial body weight of 6.83 ± 0.33 kg (21 day of age, LYD) were randomly assigned to four treatments for a two-week feeding trial to determine the effects of different dietary zinc on nutrient digestibility, intestinal health, and microbiome of weaned piglets. The dietary treatments included a negative control (CON), standard ZnO (ZnO, 2500 ppm), zinc chelate with glycine (Chelate-ZnO, 200 ppm), and nanoparticle-sized ZnO (Nano-ZnO, 200 ppm). At 0 to 1 week, the diarrhea score was decreased in the CON group compared with the ZnO, Chelate-ZnO, and Nano-ZnO group. In overall period, the ZnO and Nano-ZnO groups exhibited improved diarrhea scores compared to the CON group. The apparent total tract digestibility of dry matter and gross energy was the lowest in the CON group after one week. Compared to the ZnO group, the chelate-ZnO group exhibited higher proportion of T-bet+ and FoxP3+ T cells and the nano-ZnO group had higher numbers of RORgt+ and GATA3+ T cells in the mesenteric lymph nodes. ZnO group increased IL-6 and IL-8 levels in the colon tissues and these positive effects were observed in both chelate ZnO and nano-ZnO groups with lower level. The 16S rRNA gene analysis showed that the relative abundance of Prevotella was higher in the ZnO-treated groups than in the CON group and that of Succinivibrio was the highest in the nano-ZnO group. The relative abundance of Lactobacillus increased in the ZnO group. In conclusion, low nano-ZnO levels have similar effects on nutrient digestibility, fecal microflora, and intestinal immune profiles in weaning pigs; thus, nano-ZnO could be used as a ZnO alternative for promoting ZnO utilization and intestinal immunity.

The Effects of Dietary Porous Zinc Oxide Supplementation on Growth Performance, Inflammatory Cytokines and Tight Junction's Gene Expression in Early-Weaned Piglets

This study was conducted to investigate the effect of dietary porous ZnO supplementation on the growth performance, inflammatory cytokines and tight junction's gene expression in weaned piglets. A total of 192 weaned piglets were randomly allocated to 4 experimental groups (n=48/group) and fed, during 14 d, with one of the following dietary treatments: 1) basal diet (NC); 2) basal diet with 3,000 mg/kg of conventional ZnO (PC); 3) basal diet with 750 mg/kg of porous ZnO (low inclusion porous ZnO, LP-ZnO); 4) basal diet with 1,500 mg/kg porous ZnO (high inclusion porous ZnO, HP-ZnO). Results showed that dietary supplementation with regular ZnO or porous ZnO (750 and 1,500 mg/kg) improved average daily gain (ADG), feed to gain ratio (F/G) and jejunum morphology, while decreasing diarrhea incidence. Compared with the NC group, porous ZnO at both doses (750 or 1,500 mg/kg) increased serum alkaline phosphatase (ALP), immunoglobulin G (IgG) and insulin-like growth factor 1 (IGF-1) concentrations, but decreased serum glucose (GLU). Moreover, the mRNA expression of anti-inflammation cytokine (TGF-β), tight junction (Occludin, ZO-1) in the jejunum by different ZnO administration were significantly increased compared with the NC group, while mRNA expression of pro-inflammatory (IL-8), membrane channels that transport water (AQP3) and miR-122a were significantly decreased. It can be concluded that porous ZnO even at low dose (750 mg/kg) can be an effective alternative to pharmacological (3,000 mg/kg) conventional ZnO in reducing diarrhea, promoting the growth performance, increasing anti-inflammatory cytokines and tight junctions, reducing pro-inflammatory cytokines of weaned piglets.

Towards Zero Zinc Oxide: Feeding Strategies to Manage Post-Weaning Diarrhea in Piglets

Simple Summary

Zinc oxide (ZnO) supplementation at pharmacological doses in post-weaning piglets is a consolidated practice that allows efficient control of post-weaning diarrhea (PWD), a condition exacerbated by Escherichia coli F4 (K88) infections. Far from being completely elucidated, the multifactorial ZnO mechanism of action is in all likelihood exerted at the gastrointestinal level. However, increasing environmental concerns are arising from prolonged ZnO use. This article reviews the utilization of ZnO in piglets, the biological rationale behind its powerful activity, and the emerging threats that are leading towards a significant reduction in its use. Finally, a wide analysis of the strengths and weaknesses of innovative alternative strategies to manage PWD at the nutritional level is given.

Abstract

Zinc oxide (ZnO) at pharmacological doses is extensively employed in the pig industry as an effective tool to manage post-weaning diarrhea (PWD), a condition that causes huge economic losses because of its impact on the most pivotal phase of a piglet’s production cycle. In a multifactorial way, ZnO exerts a variety of positive effects along the entire gastrointestinal tract by targeting intestinal architecture, digestive secretions, antioxidant systems, and immune cells. ZnO also has a moderate antibacterial effect against Escherichia coli F4 (K88), the main causative agent of PWD. However, the environmental impact of ZnO and new emerging threats are posing serious questions to the sustainability of its extensive utilization. To work towards a future free from pharmacological ZnO, novel nutritional approaches are necessary, and many strategies have been investigated. This review article provides a comprehensive framework for ZnO utilization and its broad mode of action. Moreover, all the risks related to pharmacological ZnO levels are presented; we focus on European institutions’ decisions subsequently. The identification of a novel, complete solution against PWD should be accompanied by the adoption of holistic strategies, thereby combining good management practices to feeding approaches capable of mitigating Escherichia coli F4 (K88) infections and/or lowering ZnO utilization. Promising results can be obtained by adjusting diet composition or employing organic acids, natural identical compounds, polyphenol-rich extracts, prebiotics, and probiotics.

A Review of Microwave Synthesis of Zinc Oxide Nanomaterials: Reactants, Process Parameters and Morphoslogies

Zinc oxide (ZnO) is a multifunctional material due to its exceptional physicochemical properties and broad usefulness. The special properties resulting from the reduction of the material size from the macro scale to the nano scale has made the application of ZnO nanomaterials (ZnO NMs) more popular in numerous consumer products. In recent years, particular attention has been drawn to the development of various methods of ZnO NMs synthesis, which above all meet the requirements of the green chemistry approach. The application of the microwave heating technology when obtaining ZnO NMs enables the development of new methods of syntheses, which are characterised by, among others, the possibility to control the properties, repeatability, reproducibility, short synthesis duration, low price, purity, and fulfilment of the eco-friendly approach criterion. The dynamic development of materials engineering is the reason why it is necessary to obtain ZnO NMs with strictly defined properties. The present review aims to discuss the state of the art regarding the microwave synthesis of undoped and doped ZnO NMs. The first part of the review presents the properties of ZnO and new applications of ZnO NMs. Subsequently, the properties of microwave heating are discussed and compared with conventional heating and areas of application are presented. The final part of the paper presents reactants, parameters of processes, and the morphology of products, with a division of the microwave synthesis of ZnO NMs into three primary groups, namely hydrothermal, solvothermal, and hybrid methods.

Effect of Fluoride on Small Intestine Morphology and Serum Cytokine Contents in Rats

This study aimed to determine the effect of excessive fluoride (F) on the morphological characteristics of the small intestine and the contents of serum cytokines in rats. A total of 48 3-week-old healthy female Sprague-Dawley rats were randomly divided into four groups (n = 12). The control group was given deionized distilled water, while the F treatment groups were treated with water containing 25, 50, and 100 mg F^-/L. After 70 days of treatment, the duodenum, the jejunum, and the ileum were collected to measure the developmental parameters and the distribution of intestinal glycoproteins, goblet cells, and mast cells through Pannoramic Viewer, Periodic Acid-Schiff (PAS) staining, Alcian blue and periodic acid-Schiff (AB-PAS) staining, and toluidine blue staining, respectively. The contents of cytokines, namely, interleukin (IL)-1β, IL-2, IL-6, and tumor necrosis factor (TNF)-α, in serum were detected via enzyme-linked immunosorbent assay (ELISA). Results showed that the villus height, crypt depth, villus height to crypt depth ratio, goblet cells, glycoproteins, and mast cells of the small intestine significantly decreased (P < 0.05 or P < 0.01) in the F treatment group. The contents of IL-1β, IL-2, IL-6, and TNF-α were significantly lower in the F treatment group than in the control group (P < 0.05 or P < 0.01). In summary, excessive F intake impaired intestinal development and immune function by decreasing the developmental parameters and the distribution of immune cells, glycoproteins, and cytokines.