Bulk and nanoparticles of zinc oxide exerted their beneficial effects by conferring modifications in transcription factors, histone deacetylase, carbon and nitrogen assimilation, antioxidant biomarkers, and secondary metabolism in soybean.

Nanoscience paves the way for producing highly potent fertilizers and pesticides to meet farmer's expectations. This study investigated the physiological and molecular responses of soybean seedlings to the long-time application of zinc oxide nanoparticles (ZnO NPs) and their bulk type (BZnO) at 5 mg L-1 under the two application methods (I- foliar application; II- soil method). The ZnO NPs/BZnO treatments in a substance type- and method-dependent manner improved plant growth performance and yield. ZnO NPs transactionally upregulated the EREB gene. However, the expression of the bHLH gene displayed a contrary downward trend in response to the supplements. ZnO NPs moderately stimulated the transcription of R2R3MYB. The HSF-34 gene was also exhibited a similar upward trend in response to the nano-supplements. Moreover, the ZnONP treatments mediated significant upregulation in the WRKY1 transcription factor. Furthermore, the MAPK1 gene displayed a similar upregulation trend in response to the supplements. The foliar application of ZnONP slightly upregulated transcription of the HDA3 gene, while this gene showed a contrary slight downregulation trend in response to the supplementation of nutrient solution. The upregulation in the CAT gene also resulted from the nano-supplements. The concentrations of photosynthetic pigments exhibited an increasing trend in the ZnONP-treated seedlings. The applied treatments contributed to the upregulation in the activity of nitrate reductase and the increase in the proline concentrations. ZnO NPs induced the activity of antioxidant enzymes, including peroxidase and catalase by averages of 48.3% and 41%, respectively. The utilization of ZnO NPs mediated stimulation in the activity of phenylalanine ammonia-lyase and increase in soluble phenols. The findings further underline this view that the long-time application of ZnO NPs at low concentrations is a safe low-risk approach to meet agricultural requirements.

Biosynthesized ZnO Nanoparticles Using Albizia lebbeck Extract Induced Biochemical and Morphological Alterations in Wistar Rats.

Nano-based particles synthesized via green routes have a particular structure that is useful in biomedical applications as they provide cheap, eco-friendly, and non-toxic nanoparticles. In the present study, we reported the effect of various concentrations of Zinc oxide nanoparticles synthesized using A. lebbeck stem bark extract (ZnO NPsAL) as stabilizing agent on rat biochemical profiles and tissue morphology. Adult Wistar rats weighing 170 ± 5 g were randomly classified into eight groups of five rats each; Group A served as a control fed with normal diet and water. Groups B1, B2, C1, C2, D1, D2, and E were treated with 40 mg/kg and 80 mg/kg of the 0.01, 0.05, and 0.1 M biosynthesized ZnO NPsAL and zinc nitrate daily by the gavage method, respectively. The rats were anesthetized 24 h after the last treatment, blood samples, kidney, heart, and liver tissues were collected for biochemical and histopathological analysis. The rats mean body weight, serum alkaline phosphatase, alanine aminotransferase, creatinine, urea, bilirubin, protein, albumin, globulin, total cholesterol, triacylglycerol, and high-density lipoprotein were significantly altered with an increased concentration of biosynthesized ZnO NPsAL when compared with the control group (p < 0.05; n ≥ 5). Furthermore, histopathological analysis of treated rats' kidney, heart, and liver tissue revealed vascular congestion, tubular necrosis, inflammation, and cytoplasmic vacuolation. Biosynthesized ZnO NPsAL showed significant alteration in biochemical parameters and tissue morphology in rats with increasing concentrations of the nanoparticles.

Anticancer properties of green-synthesised zinc oxide nanoparticles using Hyssopus officinalis extract on prostate carcinoma cells and its effects on testicular damage and spermatogenesis in Balb/C mice.

The unclear bio-safety issue and potential risk of nanoparticles (NPs) on various organelles can be considered as a major challenge. In the present study, we have assessed the green synthesis of ZnO nanoparticles using Hyssop (Hyssopus officinalis) extract and their effects on PC3 cell line and BALB/c mice model. The cytotoxicity of the ZnO-NPs was assessed on PC3 cell line by MTT test after characterisation. Apoptotic effect of ZnO-NPs was determined by in vitro AO/PI staining. The histopathological assessments and determination of LH and FSH levels carried out as in vivo analysis in BALB/c adult male mice. The expression of major genes involved in spermatogenesis and sperm maturation (Adam3, Prm1, Spata19, Tnp2, Gpx5) were also analysed. The obtained result demonstrated that the IC50 for PC3 cell line treated with green-synthesised ZnO-NPs during 24 and 48 hr was reported 8.07 and 5 µg/ml respectively. Meanwhile, the induced apoptosis was recorded 26.6% ± 0.05, 44% ± 0.12 and 80% ± 0.07 of PC3 cells. The results of gene expression analysis revealed that the increase in the concentration of ZnO-NPs significantly (p < .05) down-regulated the Adam3, Prm1, Spata-19, Tnp2 and Gpx5 genes. The overall results of this research elucidated that ZnO-NPs impaired spermatogenesis, sperm maturation process and sperm motility.

Exploration of immunomodulatory and protective effect of Withania somnifera on trace metal oxide (zinc oxide nanoparticles) induced toxicity in Balb/c mice.

The current study was undertaken to investigate the immunomodulatory and protective effects of Withania somnifera (WS) extract and Withaferin A (WA) supplementation on zinc oxide nanoparticles mediated toxicity in Balb/c mice. The animals were exposed to ZnO NPs along with WS and WA for 28 days and various parameters like body weight, organ coefficient, cytotoxicity, nitric oxide (NO), total serum protein, phagocytosis, and the gene expression levels of TLR6 and ARG genes were determined. In vivo study showed that, dose-dependent reduction in phagocytosis, an increase in the levels of NO production along with up-regulation of TLR6, arginase gene was significant (P < 0.05) when ZnO NPs were given. However toxicity of ZnO NP was reduced in presence of WS and WA with decreased TLR6 over expression and restoration of phagocytic activities. Our results provided a valuable insight into the underlying mechanism for the protective effects of WS. Mechanism of toxicity induced by Zinc oxide nanoparticles ZnO NPs and immunomodulatory protective effects of Withania somnifera extract (WS) and Withaferin A (WA), in Balb/c mice modal of peritoneal macrophages. Red arrows: effect of ZnO NPs independently leads to ROS production which attenuated the phagocytosis of yeast by macrophages through, up-regulation of TLR6 and down-regulation of arginase gene expression. Green arrows: co-treatment, Impact of Withania somnifera extract with zinc oxide nanoparticles (WS + ZnO NPs), Withaferin A along with zinc oxide nanoparticles (WA + ZnO NPs)-enhance phagocytic activity by counteracting mechanism of ZnO NPs toxicity. Black arrows: increasing or decreasing effects. Per oral (P.O).

Biogenic Au@ZnO core-shell nanocomposites kill Staphylococcus aureus without provoking nuclear damage and cytotoxicity in mouse fibroblasts cells under hyperglycemic condition with enhanced wound healing proficiency.

The aim of the present study is focused on the synthesis of Au@ZnO core-shell nanocomposites, where zinc oxide is overlaid on biogenic gold nanoparticles obtained from Hibiscus Sabdariffa plant extract. Optical property of nanocomposites is investigated using UV-visible spectroscopy and crystal structure has been determined using X-ray crystallography (XRD) technique. The presence of functional groups on the surface of Au@ZnO core-shell nanocomposites has been observed by Fourier transforms infrared (FTIR) spectroscopy. Electron microscopy studies revealed the morphology of the above core-shell nanocomposites. The synthesized nanocomposite material has shown antimicrobial and anti-biofilm activity against Staphylococcus aureus and Methicillin Resistant Staphylococcus haemolyticus (MRSH). The microbes are notorious cross contaminant and are known to cause infection in open wounds. The possible antimicrobial mechanism of as synthesized nanomaterials has been investigated against Staphylococcus aureus and obtained data suggests that the antimicrobial activity could be due to release of reactive oxygen species (ROS). Present study has revealed that surface varnishing of biosynthesized gold nanoparticles through zinc oxide has improved its antibacterial proficiency against Staphylococcus aureus, whereas reducing its toxic effect towards mouse fibroblast cells under normal and hyperglycaemic condition. Further studies have been performed in mice model to understand the wound healing efficiency of Au@ZnO nanocomposites. The results obtained suggest the possible and effective use of as synthesized core shell nanocomposites in wound healing.

Effects of nanosized zinc oxide and γ-polyglutamic acid on eggshell quality and serum parameters of aged laying hens.

In order to increase zinc (Zn) absorption and improve eggshell quality, diets for aged laying hens were supplemented with different Zn sources and the effects on egg production, eggshell quality and serum parameters were recorded. Seventy-five 64-week old brown layers were individually caged and randomly allotted to five treatment groups: an un-supplemented Control and four groups, where the following Zn sources were added to the diets, ZnO (group ZnO), Zn-methionine (group Zn-Met), nanosized ZnO (group nanoZnO) and γ-PGA-nano ZnO (group γ-PGA-nanoZnO). The Zn level was maintained at 80 mg/kg in the supplemented diet, while the Control group received Zn at 40 mg/kg diet. The results indicated that the average daily feed intake was highest in group nanoZnO (p < 0.05), whereas further performance parameters were not influenced by treatments. Eggshell thickness was increased in group γ-PGA-nanoZnO (p < 0.05). Zn content in eggshells and Zn concentration in serum were increased in groups Zn-Met, nanoZnO and γ-PGA-nanoZnO (p < 0.05). Serum ghrelin concentration was significantly elevated in all Zn-supplemented groups, but further increased in groups nanoZnO and γ-PGA-nanoZnO (p < 0.05). Carbonic anhydrase activity was highest in group γ-PGA-nanoZnO and lowest in group Zn-Met (p < 0.05). Compared to the Control and group ZnO, supplementation of γ-PGA-nanoZnO and nanoZnO increased serum IgG levels (p < 0.001). In conclusion, dietary supplementation of nanoZnO and γ-PGA-nanoZnO increased Zn content in eggshells, serum Zn concentration, ghrelin and IgG levels of aged layers when compared to regular ZnO. Compared to Zn-Met, the serum carbonic anhydrase activity and ghrelin levels were also increased. Thus, nanosized ZnO alone or mixed with γ-PGA has positive effects on the Zn status of aged layers.

Zinc oxide nanoparticles as a substitute for zinc oxide or colistin sulfate: Effects on growth, serum enzymes, zinc deposition, intestinal morphology and epithelial barrier in weaned piglets.

The objective of this study was to evaluate effects of zinc oxide nanoparticles (nano-ZnOs) as a substitute for colistin sulfate (CS) and/or zinc oxide (ZnO) on growth performance, serum enzymes, zinc deposition, intestinal morphology and epithelial barrier in weaned piglets. A total of 216 crossbred Duroc×(Landrace×Yorkshire) piglets weaned at 23 days were randomly assigned into 3 groups, which were fed with basal diets supplemented with 20 mg/kg CS (CS group), 20mg/kg CS+3000 mg/kg ZnO (CS+ZnO group), and 1200 mg/kg nano-ZnOs (nano-ZnO group) for 14 days. Results indicated that compared to CS group, supplementation of 1200 mg/kg nano-ZnOs (about 30 nm) significantly increased final body weight and average daily gain, and 3000 mg/kg ZnO plus colistin sulfate significantly increased average daily gain and decreased diarrhea rate in weaned piglets. There was no significant difference in growth performance and diarrhea rate between nano-ZnO and CS+ZnO groups. Supplementation of nano-ZnOs did not affect serum enzymes (glutamic oxalacetic transaminase, glutamic-pyruvic transaminase, and lactate dehydrogenase), but significantly increased plasma and tissue zinc concentrations (liver, tibia), improved intestinal morphology (increased duodenal and ileal villus length, crypt depth, and villus surface), enhanced mRNA expression of ZO-1 in ileal mucosa, and significantly decreased diamine oxidase activity in plasma, total aerobic bacterial population in MLN as compared to CS group. Effects of nano-ZnOs on serum enzymes, intestinal morphology, and mRNA expressions of tight junction were similar to those of high dietary ZnO plus colistin sulfate, while nano-ZnOs significantly reduced zinc concentrations of liver, tibia, and feces, and decreased total aerobic bacterial population in MLN as compared to CS+ZnO group. These results suggested that nano-ZnOs (1200 mg/kg) might be used as a substitute for colistin sulfate and high dietary ZnO in weaned piglets.

Nasal carriage of mecA-positive methicillin-resistant Staphylococcus aureus in pigs exhibits dose-response to zinc supplementation.

Zinc (Zn) is often supplemented at elevated concentrations in swine diets, particularly in piglets, to prevent enteric infections and promote growth. Previous studies from Denmark have suggested a genetic linkage and a phenotypic association between Zn resistance, encoded by czrC, and methicillin-resistance conferred by mecA in Staphylococcus aureus. Such an association has not been reported in the U.S. swine population. We conducted an analysis of the effects of Zn, supplemented as zinc oxide (ZnO), on the nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA) in nursery (n=40) and finisher pigs (n=40) enrolled in a nutritional study. Nasal swabs, collected from nursery and finisher pigs, were inoculated onto MRSA CHROMagar and presumptive MRSA colonies were tested for the presence of mecA and czrC genes by polymerase chain reaction. Zinc susceptibility was determined by the agar dilution method. The prevalence of mecA-positive MRSA was 10% (4/40) and 20% (8/40) among nursery and finisher pigs, respectively. Of the 12 mecA-positive S. aureus isolates, 7 had the czrC gene (58.3%) compared to none among the 68 mecA-negative isolates. The presence of both mecA (p=0.002) and czrC (p=0.006) genes were positively associated with higher levels of Zn supplementation. The median minimum inhibitory concentrations of Zn for czrC-positive and czrC-negative isolates were 12 and 2 mM, respectively (p<0.0001). The link between czrC and mecA genes suggests the importance of elevated Zn supplementation in the co-selection and propagation of methicillin resistance among S. aureus in pigs.

Effect of the interaction of seaweed extracts containing laminarin and fucoidan with zinc oxide on the growth performance, digestibility and faecal characteristics of growing piglets.

Seaweed extracts (SWE) rich in laminarin and fucoidan have shown promise as a supplement for weaned piglets. However, successful application in pig nutrition depends on their bioactivity in the presence of additives such as ZnO. In the present study, a 2 × 2 factorial experiment was carried out to investigate the effect of the interaction between SWE and ZnO on the growth performance, digestibility and faecal characteristics of 192 weaned piglets (6·5 kg). The piglets were penned in groups of 4 (n 12 pens). The study consisted of two phases after weaning: a starter diet period from the day of weaning (0 d) to 21 d and a transition diet period from 21 to 40 d. The dietary treatments were as follows: (1) control diet; (2) control diet+ZnO; (3) control diet+SWE; (4) control diet+ZnO+SWE. Diets containing ZnO improved the faecal consistency of the piglets throughout the experimental period (0-40 d). An effect of the interaction between ZnO and SWE on several variable was observed. The diet containing only SWE or ZnO improved the feed conversion efficiency of the piglets during the transition diet period; however, this effect was not observed when the diet containing both ZnO and SWE was fed. The diet containing only SWE increased the N and organic matter digestibility of the piglets; however, this effect was not observed in the presence of ZnO. An interaction between ZnO and SWE was observed, whereby the faecal counts of Escherichia coli were decreased when piglets were fed the diet containing only SWE, but not when fed the diet containing both SWE and ZnO. In summary, SWE and ZnO improve growth performance when given alone, but not when given in combination. The biological effect of SWE on selected digestibility and faecal characteristics was markedly different when compared with that of ZnO.

Anti-diabetic activity and safety assessment of Ayurvedic medicine, Jasada bhasma (zinc ash) in rats.

Jasada bhasma (zinc ash) is an extensively used Ayurvedic medicine for treating diabetes mellitus. The present communication presents yet unavailable comprehensive scientific data on its physico-chemical nature vis-a-vis anti-diabetic activity and toxicity profile.Zinc ash prepared by traditional method was found to consist of 200-500 nm sized particles, predominantly zinc oxide with hexagonal wurtzite crystal structure. The effective dose range of zinc ash in oral glucose tolerance tests performed using normoglycemic Wistar rats was found to be 3-30 mg/kg. Subsequently anti-diabetic activity was assessed in streptozotocin induced type 1 and type 2 diabetic rats. Four weeks treatment with zinc ash (1, 3, 10 mg/kg) resulted in improved glucose tolerance (16-19%), lowered blood glucose levels (20-33%) and reduced serum insulin levels (27-32%). Systemic absorption was assessed by single dose pharmacokinetic study where serum zinc levels were found to be elevated (3.5 folds) after oral administration of zinc ash. Acute and sub-acute toxicity tests demonstrated safety of zinc ash up to 300 mg/kg doseie. 100 times the efficacy dose in rats. These findings, the first of their kind, provide concrete scientific evidence that justifies usage of zinc ash in diabetes treatment.

A prospective two-year assessment of miconazole resistance in Candida spp. With repeated treatment with 0.25% miconazole nitrate ointment in neonates and infants with moderate to severe diaper dermatitis complicated by cutaneous candidiasis.

A petrolatum and zinc oxide-based ointment containing 0.25% miconazole nitrate is reported to be effective and well tolerated in the treatment of diaper dermatitis complicated by cutaneous candidiasis (DDCC). This prospective, multicenter, open-label, long-term, phase IV study investigated the potential resistance of Candida spp. to repeated topical use of 0.25% miconazole nitrate in infants age 15 months and younger with moderate to severe DDCC. For initial and recurring episodes of DDCC over the 2-year study period, subjects were treated with a 7-day course of 0.25% miconazole nitrate ointment (active components: miconazole nitrate 0.25%, zinc oxide 15%, and white petrolatum 81.35%) with a 7-day follow-up. Clinical and mycologic evaluations were conducted before treatment (day 0) and 7 days after treatment (day 14). Potential resistance to miconazole was defined using an arbitrary breakpoint of minimum inhibitory concentration of 2 µg/mL. There was no evidence of resistance to miconazole in Candida spp. after single or repeated treatment courses of 0.25% miconazole nitrate ointment. For the initial episode of DDCC, 83 of 168 subjects (49.4%) achieved a clinical cure, 77 (45.8%) achieved a mycologic cure, and 49 (29.2%) achieved an overall cure (clinical and mycologic). The overall cure rate for recurrent episodes of DDCC was similar to or numerically greater than rates observed for the initial episode. Treatment of DDCC with 0.25% miconazole nitrate ointment was effective and generally well tolerated. No evidence of the development of resistance to miconazole in Candida spp. was observed.

Zinc oxide nanoparticles-induced intercellular adhesion molecule 1 expression requires Rac1/Cdc42, mixed lineage kinase 3, and c-Jun N-terminal kinase activation in endothelial cells.

The explosive development of nanotechnology has caused an increase in unintended biohazards in humans and in the ecosystem. Similar to particulate matter, nanoparticles (NPs) are strongly correlated with the increase in incidences of cardiovascular diseases, yet the mechanisms behind this correlation remain unclear. Within the testing concentrations of 0.1-10 µg/ml, which did not cause a marked drop in cell viability, zinc oxide NPs (ZnO-NPs) induced intercellular adhesion molecule-1 (ICAM-1) messenger RNA, and protein expression in both concentration- and time-dependent manner in treated human umbilical vein endothelial cells (HUVECs). ZnO-NPs treatment cause the activation of Ras-related C3 botulinum toxin substrate 1 (Rac1)/cell division control protein 42 homolog (Cdc42) and protein accumulation of mixed lineage kinase 3 (MLK3), followed by c-Jun N-terminal kinase (JNK) and transcription factor c-Jun activation. Induction of ICAM-1 and phosphorylation of JNK and c-Jun could be inhibited by either JNK inhibitor SP600125 or Rac guanosine triphosphatase inhibitor NSC23766 pretreatment. In addition, pretreatment with NSC23766 significantly reduced MLK3 accumulation, suggesting the involvement of Rac1/Cdc42-MLK3-JNK-c-Jun signaling in the regulation of ZnO-NPs-induced ICAM-1 expression, whereas these signaling factors were not activated in zinc oxide microparticles (ZnO-MPs)-treated HUVECs. The increase of ICAM-1 expression on ZnO-NPs-treated HUVECs enables leukocytes to adhere and has been identified as an indicator of vascular inflammation. Our data are essential for safety evaluation of the clinical usage of ZnO-NPs in daily supplements, cosmetics, and biomedicines.

Quantification of fibrosis and mast cells in the tissue response of endodontic sealer irradiated by low-level laser therapy.

Low-level laser therapy (LLLT) accelerates tissue repair. Mast cells induce the proliferation of fibroblasts and the development of local fibrosis. The objective of this study was to quantify fibrosis rate and mast cells in connective tissue after endodontic sealer zinc oxide and eugenol (ZOE) was implanted and submitted to LLLT, immediately after implant and again 24 h later. Sixty mice were distributed into three groups: GI, GII, and GIII (n = 20). In GI, the tubes filled with Endofill were implanted in the animals and were not irradiated with LLLT. In GII, the tubes containing Endofill were implanted in the animals and then irradiated with red LLLT (InGaAIP) 685-nm wavelength, D = 72 J/Cm(2), E = 2 J, T = 58 s, P = 35 mW, and in GIII, the tubes with Endofill were implanted and irradiated with infrared LLLT (AsGaAl) 830-nm wavelength, D = 70 J/Cm(2), E = 2 J, T = 40 s, P = 50 mW. After 7 days and 30 days, the animals were killed. A series of 6-µm-thick sections were obtained and stained with Toluidine Blue and Picrosirius and analyzed under a standard light microscope using a polarized light filter for the quantification of fibrosis. The statistics were qualitative and quantitative with a significance of 5%. The irradiation with LLLT did not offer improvement in the fibrosis rate, however, it provided a significant decrease in the concentration of independent mast cells for the period studied.

Zinc oxide nanoparticles induce photocatalytic cell death in human head and neck squamous cell carcinoma cell lines in vitro.

The aim of this study was to determine the photocatalytic effects of zinc oxide (ZnO) NPs in combination with UVA-1 in human head and neck squamous cell carcinoma (HNSCC) cell lines in vitro. NP characteristics and intracellular distribution were described by transmission electron microscopy (TEM). After pre-incubation with ZnO NPs in concentrations of 0.002-20 µg/ml, the HNSCC cell lines HLaC 78 and UD-SCC 7A as well as primary oral mucosa cells (pOMCs) were treated with UVA-1. Cell survival and vitality was observed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazoliumbromide-(MTT)-assay and fluorescein diacetate test. Apoptosis was assessed by annexin-V propidium iodide flow cytometry. Intranuclear distribution of the rod-shaped particles was observed in 3.5% of HNSCC and in 0.5% of pOMCs. UVA-1 irradiation of 15 min in combination with 0.2 and 2 µg/ml of ZnO NP dispersion was shown to reduce the vitality of cancer cell lines significantly in comparison to cells without NP exposure or UVA-1 treatment only. For HLaC 78, a significant reduction in viable cells was already seen at 10 min of UVA-1 treatment and a ZnO NP concentration of 2 µg/ml. Flow cytometry indicated that cell death occurred primarily through necrosis. In pOMCs, vitality was not influenced either by UVA-1 treatment or ZnO NP exposure up to 2 µg/ml or a combination of both. ZnO NPs showed cytotoxicity at 20 µg/ml without UVA-1. Due to their photocatalytic properties, ZnO NPs may induce cell death in human HNSCC cell lines in vitro. Further studies will evaluate a possible benefit in adjuvant cancer therapy.

Effects of dietary zinc supplementation on broiler performance and nitrogen loss from manure.

An experiment was conducted to evaluate the effects of ZnSO4 or ZnO supplementation of broiler diets on growth performance and loss of uric acid N and total N from manure. A total of 240, 1-d-old broiler males were used for this experiment. Each dietary treatment was replicated 3 times with 10 birds per replicate. Chicks were fed a control diet for the first 6 d and then treatment diets for the next 12 d. There were 8 dietary treatments: the control, CuSO4-20, ZnSO4-500, ZnSO4-1,000, ZnSO4-1,500, ZnO-500, ZnO-1,000, and ZnO-1,500 containing 0, 0, 500, 1,000, 1,500 ppm supplemental Zn as ZnSO4 and 500, 1,000, and 1,500 ppm supplemental Zn as ZnO, respectively. A 300-g sample of the broiler manure from each treatment was incubated in a pan for 3 wk at room temperature. After incubation, samples were collected for the measurement of total N and uric acid N. Weight gain, feed consumption, and feed efficiency of chicks fed the diets supplemented with 1,500 ppm Zn as ZnSO4 were significantly lower than those of the other treatments, whereas the ZnO treatments had no negative effects on growth performance. After the 21-d incubation, the uric acid-N levels of manure from chicks fed the ZnO-1,000 treatment were significantly higher than those of manure from chicks fed the ZnSO4-500. The manure from chicks fed the Zn-supplemented diets had significantly less total N loss compared with that from chicks fed the control. The manure from chicks fed ZnO-1,500 had significantly less total N loss than that from chicks fed the other treatment diets. This study indicated that the Zn treatments significantly reduced nitrogen loss in poultry manure, and ZnO could be a better Zn source to prevent nitrogen loss to the atmosphere without any detrimental effect on growth performance.