Effect of zinc oxide nanoparticles on broilers' performance and health status

Enhancing broiler growth and carcass quality: impact of diets enriched with Moringa oleifera leaf powder conjugated with zinc nanoparticles

This study evaluated the effects of Moringa oleifera leaf powder extract stabilized with zinc nanoparticles (ZnNPs-MLPE) as a natural growth promoter in broiler diets. Randomly assigned 264 one-day-old Ross 308 chicks to four different feeding treatments, with each group being subdivided into six replicates, each comprising 11 unsexed chicks. The control group was fed a basic diet without additives, while the experimental groups were supplemented with 1.0, 2.0, or 3.0 cm³ of ZnNPs-MLPE/L of diet. The findings demonstrated that 2.0 and 3.0 cm³/L ZnNPs-MLPE supplementation significantly enhanced live body weight (LBW) and weight gain (BWG). Feed intake (FI) and feed conversion ratio (FCR) did not show significant differences between the treated groups and the control, indicating that the additive did not negatively affect feed efficiency. However, an increase in abdominal fat was noted in the ZnNPs-MLPE treatments relative to the control. Blood analysis revealed that the ZnNPs-MLPE groups had significantly lower levels of "total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL), very low-density lipoprotein (VLDL), and alanine transaminase (ALT) compared to the control group. In contrast, total protein (TP), albumin, and the albumin/globulin (A/G) ratio" were higher in the ZnNPs-MLPE groups. Immunoglobulins IgY and IgM, as well as superoxide dismutase (SOD) levels, were elevated. Malondialdehyde (MDA) levels were reduced, indicating improved antioxidant capacity and immune function in the ZnNPs-MLPE-treated groups. In conclusion, supplementation with ZnNPs-MLPE at 2.0 and 3.0 cm³/L positively impacted broiler growth efficiency, antioxidant capacity, and immunological functionality. These findings support the potential of ZnNPs-MLPE as an effective natural growth enhancer for producing healthier poultry products.

Comparative effects of dietary zinc nanoparticle and conventional zinc supplementation on broiler chickens: A meta-analysis

Background and Aim

Zinc (Zn) is important for various physiological processes in broiler chickens, including protein and carbohydrate metabolism, growth, and reproduction. The gastrointestinal absorption of Zn in broiler chickens was notably low. One approach that has been explored for enhancing the bioavailability of Zn is the development of Zn nanoparticles (NPs). Zn is required for various physiological processes in broiler chickens, including protein and carbohydrate metabolism, growth, and reproduction. Therefore, this study aimed to assess the impact of conventional Zn and Zn NPs on broiler chickens using a meta-analysis methodology.

Materials and Methods

A database was built from published literature to evaluate the effects of the addition of Zn NPs and conventional Zn on broiler chicken responses, including the following parameters: production performance; carcass cuts; visceral organ weight; lymphoid organ weight; nutrient digestibility; intestinal villi; mineral Zn, calcium, and phosphorus concentrations; hematology; blood parameters; immunoglobulin; and intestinal bacterial population. Various scientific platforms, including Scopus, Web of Science, PubMed Central, and Google Scholar, were used to search for peer-reviewed articles. A database was created from 25 studies that met the inclusion criteria. The data were then processed for a meta-analysis using a mixed-model methodology. Different types of Zn (NPs versus conventional) were considered fixed effects, different studies were treated as random effects, and p-values were used as model statistics.

Results

Across the parameters observed in this study, the use of Zn NPs was more efficient in Zn utilization than conventional Zn, as evidenced by the average dose of Zn NPs being much lower than that of conventional Zn (79.44 vs. 242.76 mg/kg) yet providing similar (p > 0.05) or even significantly better effects (p < 0.05) compared to conventional Zn usage.

Conclusion

This investigation revealed the beneficial influence of Zn NPs in broiler chickens compared to the conventional utilization of Zn through an all-encompassing meta-analysis. Moreover, Zn NPs have proven to be more effective in Zn utilization when juxtaposed with conventional Zn, as demonstrated by the significantly lower quantity of Zn NPs administered compared to conventional Zn, while yielding comparable or even superior outcomes compared to the traditional utilization of Zn. A limitation of this study is that the Zn NPs used were sourced from inorganic Zn NPs. Therefore, future research should focus on evaluating the efficiency of organic Zn NPs in broiler chicken feed.

Does the dietary supplementation of organic nano-zinc as a growth promoter impact broiler's growth, carcass and meat quality traits, blood metabolites and cecal microbiota?

The present investigation aimed to examine the impact of different dietary organic zinc nanoparticle (ZnNP) levels on gut bacteria, meat quality, growth performance, carcass traits, and blood indicators of broilers. A total of 180 unsexed one-wk broiler chicks (Cobb) were allotted to 3 experimental groups and received a basal diet supplemented with 0, 0.2, and 0.4 mg ZnNPs/Kg diet, respectively. The results showed that, after 38 d of age, the supplementary ZnNPs at a level of 0.4 mg/kg raised body weight and weight gain compared to the control and 0.2 mg ZnNPs/kg diet. The addition of ZnNPs improved the daily feed intake. Some of the carcass characteristics in ZnNPs groups excelled that of the control. ZnNPs treatments gave higher dressing % and decreased (P < 0.05) the cholesterol rates, LDL, and uric acid in the blood. In addition, it gave the best concentrations of ALT and AST. The ZnNPs groups exhibited substantially (P < 0.05) improved moisture and fat values in meat samples. The group given ZnNPs at a concentration of 0.4 mg/kg had a substantially (P < 0.05) lower count of TYMC and E. coli. In conclusion, the high level of ZnNPs (0.4 mg/kg) improved the broilers' performance and some of their carcass traits, enhancing their health and meat quality.

Zinc Oxide Nanoparticles Significant Role in Poultry and Novel Toxicological Mechanisms

Zinc oxide nanoparticles (ZnO NPs) have involved a lot of consideration owing to their distinctive features. The ZnO NPs can be described as particularly synthesized mineral salts via nanotechnology, varying in size from 1 to 100 nm, while zinc oxide (ZnO), it is an inorganic substrate of zinc (Zn). The Zn is a critical trace element necessary for various biological and physiological processes in the body. Studies have revealed ZnO NPs' efficient immuno-modulatory, growth-promoting, and antimicrobial properties in poultry birds. They offer increased bioavailability as compared to their traditional sources, producing better results in terms of productivity and welfare and consequently reducing ecological harm in the poultry sector. However, they have also been reported for their toxicological effects, which are size, shape, concentration, and exposure route dependent. The investigations done so far have yielded inconsistent results, therefore, a lot of additional studies and research are required to clarify the harmful consequences of ZnO NPs and to bring them to a logical end. This review explores an overview of efficient possible role of ZnO NPs, while comparing them with other nutritional Zn sources, in the poultry industry, primarily as dietary supplements that effect the growth, health, and performance of the birds. In addition to the anti-bacterial mechanisms of ZnO NPs and their promising role as antifungal, and anti-colloidal agent, this paper also covers the toxicological mechanisms of ZnO NPs and their consequent toxicological hazards to vital organs and the reproductive system of poultry birds.

Plant-ZnO nanoparticles interaction: An approach to improve guinea grass (Panicum maximum) productivity and evaluation of the impacts of its ingestion by freshwater teleost fish

We aimed to evaluate the possible effects of the application of zinc oxide nanoparticles [ZnO NPs; 68.96 ± 33.71 nm; at 100 and 500 mg/kg in a soil mixture of the Typic Dystrophic Red Latosol type and sand (2:1 ratio)] in the cultivation of Panicum maximum (until 125 days), using different biomarkers in addition to evaluating the uptake of Zn by the plants. Furthermore, we assessed the possible transfer of ZnO NPs from P. maximum leaves to zebrafish and their potential. Plants cultivated in substrates with ZnO NPs at 500 mg/kg showed reduced germination rate and growth. However, at 100 mg/kg, plants showed higher biomass and productivity, associated with higher Zn uptake, without inducing oxidative and nitrosative stress. Zinc content in zebrafish was not associated with ingesting leaves of P. maximum cultivated in substrate containing ZnCl₂ or ZnO NPs or with genotoxic, mutagenic, and biochemical effects. In conclusion, ZnO NPs (at 100 mg/kg) are promising in the cultivation of P. maximum, and their ingestion by zebrafish did not cause changes in the evaluated biomarkers. However, we recommend that studies with other animal models be conducted to comprehensively assess the ecotoxicological hazard associated with applying ZnO NPs in soil.

Toxic effects of zinc oxide nanoparticles as a food additive in goat mammary epithelial cells

Zinc oxide nanoparticles (ZnO NPs) have recently been used as food preservatives and additives because of their good antibacterial and nutritional functions. This study performed RNA-seq analyses to evaluate the potential toxicity of ZnO NPs on goat mammary epithelial cells (GMECs) in vitro. Our results suggested that the ZnO NP treatment significantly reduced GMEC viability in a time- and dose-dependent manner. Transcriptomic analysis showed that ZnO NP exposure changed the expression levels of more than 500 genes in GMECs, including various biological pathways. We observed that decreased mitochondrial membrane potential caused mitochondrial dysfunction. Further study indicated that the treatment of cells with ZnO NPs resulted in the accumulation of reactive oxygen species (ROS), which led to oxidative stress. Meanwhile, the expression of genes (TNFα, TNFR1, FADD, Caspase 8 and Caspase 6) associated with the death receptor pathway was upregulated, which indicated the death receptor-mediated extrinsic apoptosis pathway was activated. Moreover, the expression levels of Bax, Cytc, Caspase 3 and Caspase 9 were upregulated, while the expression levels of Bcl2 were downregulated, which indicated mitochondria-mediated intrinsic apoptosis pathway was activated. More notably, ZnO NP exposure increased the expression levels of ER stress-related genes (PERK, ATF4, eIF2α and CHOP) and proteins (p-PERK, p-eIF2α, PERK and CHOP). Furthermore, gene ontology (GO) terms and genes related to autophagy were altered, suggesting that exposure to ZnO NPs might activate autophagy in GMECs. In summary, our findings showed that ZnO NPs could exert significant toxic effects on GMECs through multiple mechanisms. These pathways are related to each other and influence each other to participate in ZnO NPs-induced the damage of GMECs. Thus, their safe use in the feed and food industry should be considered. Meanwhile, RNA-seq might represent a new method of assessing the toxicity mechanisms of nanomaterials.

Influence of Dietary Biosynthesized Zinc Oxide Nanoparticles on Broiler Zinc Uptake, Bone Quality, and Antioxidative Status

A total of 180 broiler chickens (Cobb500) were randomly allotted to five experimental groups consisting of six replicates and six birds in each pen. Each group was fed a basal diet supplemented with 100 mg/kg ZnO (control) and 10, 40, 70, and 100 mg/kg ZnO NPs for 35 days. Resultantly, Zn uptake and accumulation in serum, breast muscle, tibia bone, and liver were linearly and significantly (p < 0.05) increased with increasing dietary ZnO NPs supplementation at 100 mg/kg compared to the control group (dietary 100 mg/kg ZnO), implying effective absorption capacity of ZnO NPs. This was followed by lower Zn excretion in feces in broilers fed ZnO NPs compared to controls (p < 0.05). Furthermore, dietary ZnO NPs at 40, 70, and 100 mg/kg levels improved broiler tibia bone morphological traits, such as weight, length, and thickness. Similarly, tibia bone mineralization increased in broilers fed ZnO NPs at 100 mg/kg compared to the control (p < 0.05), as demonstrated by tibia ash, Zn, Ca, and P retention. Antioxidative status in serum and liver tissue was also increased in broilers fed dietary ZnO NPs at 70 and 100 mg/kg compared to the control (p < 0.05). In conclusion, dietary ZnO NPs increased Zn absorption in broiler chickens and had a positive influence on tibia bone development and antioxidative status in serum and liver tissue, with dietary ZnO NPs supplementation at 70 and 100 mg/kg showing the optimum effects.

Nano Zinc Oxide Improves Performance, IGF-I mRNA Expression, Meat Quality, and Humeral Immune Response and Alleviates Oxidative Stress and NF-κB Immunohistochemistry of Broiler Chickens

A 35-day trial was set to explore the effects of different dietary zinc sources on growth, insulin-like growth factor I (IGF-I) mRNA expression, meat quality, immune response, antioxidant activity, and immunohistochemistry of nuclear factor kappa B (NF-κ7B) of broiler chickens. Ross 308 broiler chicks (n = 156) were randomly assigned into four experimental groups. The G1 received the basal control diet without zinc supplementation; the G2, G3, and G4 were supplemented with zinc oxide, zinc lysine, and nano zinc oxide, respectively, at a level of 40 mg Zn/kg diet. The data revealed that nano zinc oxide linearly improved the overall growth performance parameters. Nano zinc oxide linearly elevated (P < 0.001) mRNA expression of IGF-I followed by G3. The pH value of breast muscle in G4 shows a linearly decreasing value (P < 0.001). Also, the linearly highest expressible release volume percentage and lightness (L*) value with the lowest redness (a*) value (P < 0.05) were recorded in G4 and G3. A numerical increase in the total antibody titer was recorded on the 35^th day in the G3 and G4. A numerical elevation in the superoxide dismutase (SOD) and a numerical reduction in the serum malondialdehyde (MDA) were recorded in the G4. The section of the liver from G4 revealed significantly very low expression of NF-κB staining. It is concluded that nano zinc oxide is considered the more trending zinc source. It had no negative effects on the health status and can be used in broiler diet premix.

Effects of dietary supplementation of myco-fabricated zinc oxide nanoparticles on performance, histological changes, and tissues Zn concentration in broiler chicks

A five weeks biological experiment was planned to investigate the impacts of dietary supplementation with zinc oxide nanoparticles (ZnONPs) synthesized by the endophytic fungus Alternaria tenuissima on productive performance, carcass traits, organ relative weights, serum biochemical parameters, histological alteration in some internal organs and concentration of this element in the serum, liver, thigh and breast muscle in broiler chicks. A total of 108 3-day-old commercial broiler chicks (Cobb 500) were individually weighed and equally distributed in a completely randomized design arrangement according to the dose of ZnONPs supplementation into 3 dietary experimental groups. There were 6 replications having 6 birds per replicate (n = 36/ treatment) for each treatment. The three experiential dietary treatments received corn-soybean meal-based diets enhanced with 0 (control), 40 and 60 mg/kg diet of ZnONPs respectively with feed and water were provided ad libitum consumption through 5 weeks life span. Present results indicated that after 5 weeks of feeding trial and as compared to control, the ZnONPs supplementation groups recorded higher body weight, improved feed consumption, feed conversion ratio and performance index. Serum biochemical analyses revealed that serum cholesterol, triglyceride, low density lipoprotein and uric acid decreased significantly, while high density lipoprotein and liver enzyme concentrations were increased significantly. Meanwhile, zinc accumulation in serum, liver and breast and thigh muscle were linearly increased with increasing zinc supplementation. It could be concluded that supplementation of ZnONPs to broiler diet at 40 or 60 mg/kg improved productive performance, birds' physiological status and the lower levels Zn (40 mg/kg diet) revealed promising results and can be used as an effective feed additive in broilers.

WGCNA Analysis of Important Modules and Hub Genes of Compound Probiotics Regulating Lipid Metabolism in Heat-Stressed Broilers

This study aimed to study compound probiotics’ (Lactobacillus casei, Lactobacillus acidophilus and Bifidobacterium) effects on production performance, lipid metabolism and meat quality in heat-stressed broilers. A total of 400 one-day-old AA broilers were randomly divided into four groups, each containing the same five replicates, with 20 broilers in each replicate. The control (21 °C) and experiment 2 were fed a basic corn−soybean meal diet. Experiment 1 (21 °C) and experiment 3 were fed a basic corn−soybean meal diet with 10 g/kg compound probiotics on days 7 and 28, respectively. The ambient temperature of experiment 2 and experiment 3 was increased to 30−32 °C (9:00−17:00) for 28−42 days, while the temperature for the other time was kept at 21 °C. The results showed that, compared with the control, the production performance and the content of high-density lipoprotein cholesterol in experiment 1 and triglyceride (TG) in experiment 2 increased (p < 0.05). Compared with experiment 2, TG decreased and the production performance increased in experiment 3 (p < 0.05). However, there was no significant change in meat quality indicators. Weighted gene co-expression network analysis (WGCNA) was used to analyze the intramuscular fat, abdominal fat and five blood lipid indicators. We found five related modules. Fatty acid biosynthesis, glycerolipid metabolism, and fat digestion and absorption were the pathways for KEGG enrichment. Additionally, NKX2-1, TAS2R40, PTH, CPB1, SLCO1B3, GNB3 and AQP7 may be the hub genes of compound probiotics regulating lipid metabolism in heat-stressed broilers. In conclusion, this study identified the key genes of compound probiotics regulating lipid metabolism and provided a theoretical basis for the poultry breeding industry to alleviate heat stress.

The efficacy of metal nanocomposite (Fe3O4/CuO/ZnO) to ameliorate the toxic effects of ochratoxin in broilers

BACKGROUND

The study aimed to investigate the effectiveness of different doses of metal nanocomposite (MNc) (Fe3O4/CuO/ZnO) lower than its cytotoxic level in order to overcome or minimize the ochratoxin (OTA) adverse effects in broilers fed on contaminated ration. The study conducted on 120 one-day old chicks which were divided into equal 6 groups; G1: negative control, G2: positive control (fed on OTA 17 ppb), G3& G4 (fed MNc only with low and high doses respectively). The rest two groups G5 & G6 (treatment groups) were fed on OTA, post induced ochratoxification, treated with low and high doses respectively.

RESULTS

Body weight gain and heamatocellular elements in both treated groups increased significantly than control. Serum phagocytic nitric oxide levels were increased significantly in both treated groups than control groups. Prothrombin time (PT), Alanine aminotransferase (ALT) and gamma-glutamyltransferase (GGT) activities decreased significantly (P < 0.05) in both treated groups than intoxicated control group (G2) but still higher than non-intoxicated control group (G1). Total protein, albumin, globulin, calcium and phosphorus increased significantly in both treated groups than intoxicated control group. Kidney function tests showed significant improvement in both treated groups than intoxicated control group. Antioxidant study revealed that malondialdehyde (MDA) decreased significantly in treated groups than intoxicated control group. Ochratoxin residue decreased significantly in treated groups. Metal residues in tested liver and muscle of treated groups showed no-significant difference with non-intoxicated control group (G1) at the experiment's end. In conclusion, feeding either low or high doses of MNc to broilers were significantly counteracting the negative impacts of OTA or its residue and increase their body weight.

A perspective review on the effect of different forms of zinc on poultry production of poultry with special reference to the hazardous effects of misuse

Zinc (Zn) is a unique micro-mineral because it is an essential component in many enzymes such as superoxide dismutase, carbonic anhydrase, and alkaline phosphatase, as well as being important for regulation of proteins and lipids metabolism, and sex hormones. This mineral is applied in poultry production in three forms; inorganic, organic, and nanoparticle form. The nano-form of Zn is preferable in application to other conventional forms with regard to absorption, bioavailability, and efficacy. Broilers fed on diets supplemented with Zn showed improvement of growth performance, carcass meat yield, and meat quality. In addition, Zn plays an important role in enhancing of both cellular and humeral immune responses, beside its antimicrobial and antioxidant activities. In laying hens, dietary addition of Zn improves the eggshell quality and the quantity of eggs. Moreover, Zn has a vital role in breeders in terms of improving the egg production, fertility, hatchability, embryonic development, and availability of the hatched chicks. Therefore, this review article is focused on the effects of using Zn on the performance and immunity of poultry, as well as its antimicrobial and antioxidant properties with special reference to the hazardous effects of the misusing of this mineral.

Maximum levels of cross-contamination for 24 antimicrobial active substances in non-target feed. Part 12: Tetracyclines: tetracycline, chlortetracycline, oxytetracycline, and doxycycline

The specific concentrations of tetracycline, chlortetracycline, oxytetracycline and doxycycline in non-target feed for food-producing animals, below which there would not be an effect on the emergence of, and/or selection for, resistance in bacteria relevant for human and animal health, as well as the specific antimicrobial concentrations in feed which have an effect in terms of growth promotion/increased yield were assessed by EFSA in collaboration with EMA. Details of the methodology used for this assessment, associated data gaps and uncertainties are presented in a separate document. To address antimicrobial resistance, the Feed Antimicrobial Resistance Selection Concentration (FARSC) model developed specifically for the assessment was applied. The FARSC for these four tetracyclines was estimated. To address growth promotion, data from scientific publications obtained from an extensive literature review were used. Levels in feed that showed to have an effect on growth promotion/increased yield were reported for tetracycline, chlortetracycline, oxytetracycline, whilst for doxycycline no suitable data for the assessment were available. Uncertainties and data gaps associated with the levels reported were addressed. It was recommended to perform further studies to supply more diverse and complete data related to the requirements for calculation of the FARSC for these antimicrobials.

Impacts of Supplementing Broiler Diets with Biological Curcumin, Zinc Nanoparticles and Bacillus licheniformis on Growth, Carcass Traits, Blood Indices, Meat Quality and Cecal Microbial Load

The current study aimed to investigate the influence of dietary zinc nanoparticles (ZnNPs), curcumin nanoparticles (CurNPs), and Bacillus licheniformis (Bl) on the growth, carcass, blood metabolites, and the count of some cecal microorganisms of Indian River (IR) broilers. Chicks were allotted into seven experimental groups: control group, 1st, 2nd and 3rd groups were given diets enriched with ZnNPs, CurNPs and Bl (3.0, 5.0 and 2.0 cm3/kg diet, respectively). The 4th, 5th and 6th groups were given diets supplemented with ZnNPs (3.0) + Bl (2.0) (ZP); ZnNPs (3.0) + CurNPs (5.0) (ZC) and ZnNPs (3.0) + CurNPs (5.0) + Bl (2.0) (ZCP) cm3/kg diet, respectively. The results revealed that ZnNPs and CurNPs exhibited a considerable antimicrobial activity against pathogenic bacteria and fungi. They also inhibited the growth of microbes in a range of 50-95 µg/mL. The diet supplemented with ZnNPs, CurNPs, and Bl increased the body weight compared to the control after five weeks of age. Additionally, values of daily feed intake increased in these groups; however, the feed conversion ratio decreased. All values of carcass traits were better than that of the control. The treatments led to decreased abdominal lipids compared to the control. The activity of liver enzymes and malondialdehyde (MDA) activity decreased in the treated groups. In a converse trend, the levels of oxidative enzymes, amylase, protease, lipase and immunoglobulin were higher than that of the control. Meat quality properties were improved and cecal microbial counts were decreased. In conclusion, the ZnNPs, CurNPs, and Bl improved the broiler's weights, carcass traits, meat quality traits, as well as some blood indices and cecal microbial load. Therefore, the inclusion of ZnNPs, CurNPs, or Bl is recommended for broiler feeding regimens to improve the performance and health status.

Broiler welfare is preserved by long-term low-dose oral exposure to zinc oxide nanoparticles: preliminary study

The potential public health risk through utilizing of zinc oxide nanoparticles (ZnO NPs) in food constitutes the major obstacle to the expansion of nanoparticle (NP) in food industry. Liver histology, bone marrow and liver genotoxicity, immunity, and oxidant status were investigated upon long-term ZnO NPs feed supplementation. One hundred and sixty male IR (Indian River) chicks were randomly allocated to one of the four dietary treatments: control, ZnO NPs at 10, 20, or 40 mg/kg for 42 days. This study revealed non-significant hepatic histopathological alterations and DNA damage and the treatment had no influence on body and organ weights, liver enzymes, lipid peroxidation (MDA), IgG, IgM, and interferon gamma (IFN-γ). This study suggests that low-dose (< 40 mg/kg diet) long-term ZnO NPs supplementation to broiler chicks has no observed potential adverse effects on normal histology of the liver, blood physiology, immune system, and DNA damage of liver and bone marrows, which are critical features for validating ZnO NPs for use in food. Further studies are required to evaluate the probable withdrawal period of ZnO NPs before approval as a dietary supplement in broiler or livestock diets.

Zinc oxide nanoparticles prevent multidrug resistant Staphylococcus-induced footpad dermatitis in broilers

The current experiment was designed to evaluate the effects of dietary supplementations of zinc oxide nanoparticles (ZONPs) on some behavioural, performance, welfare and histopathological changes in broilers exposed to multidrug resistant Staphylococcus aureus (MRSA)-induced footpad dermatitis (FPD). Eighty-four male Indian River (IR) broilers were randomly allotted to six different dietary treatments as follows: C-ve, C+ve, 10, 20, 30 and 40 ppm ZONPs from 7 to 49d of age. At day 28, broilers (n = 70) were sub-cutaneously injected with 0.5 ml of saline containing 5.3 × 107 CFU/ml of S. aureus (MRSA) in each metatarsal foot pad. Control (non-infected) broilers were given 0.5 ml of saline (n = 14). Results clarified that non-infected birds and ZONPs-fed birds had significantly higher standing and feeding activities and lower resting activities in comparison with the infected group. Also, the S. aureus infected group had significantly lower body weight gain (BWG) and higher feed conversion ratio (FCR) than the non-infected group. In addition, the non-infected birds and ZONPs groups had significantly lower object crossing and tonic immobility times (TI) and gait scores (GS) in comparison with the S. aureus group. Only ZONPs 30, 40 ppm and non-infected groups had a significantly higher latency to lie time (LLT) and lower serum cortisol level in comparison with the S. aureus group. Moreover, there were significant changes in the gross lesion score and histopathological lesions between the different groups. In conclusion, the dietary supplementation of ZONPs can reduce S. aureus-induced negative effects of FPD in broilers.

Comparative effects of zinc oxide and zinc oxide nanoparticle as feed additives on growth, feed choice test, tissue residues, and histopathological changes in broiler chickens

Zinc is an essential nutritional trace mineral required for growth and health. The aim of the current work is to compare the effects of bulk zinc oxide and zinc oxide nanoparticles (ZnO-NPs) on the growth performance, feeding behavior, and zinc residues in tissues with the associated histopathological alterations in chicken. Meanwhile, the antibacterial activity against the isolated E. coli O78 strain was evaluated. Ninety Hubbard one-day-aged broiler chicks were divided into 3 groups, 30 each: birds of the 1st group fed a basal ration, those of the 2nd group fed a ration containing zinc oxide at a dose of 3000 mg/kg diet, and chicks of the 3rd group are given a ration containing ZnO-NPs at a dose of 90 mg/kg diet from 2 to 20 days age. The experiment lasted for 35 days. Feed choice test was done at the 3rd week of age on another 12 birds. Results revealed that birds fed with ZnO-NPs showed an improvement in body weight compared with the zinc oxide-administered group. There was no reluctance from birds to both diets supplemented with either zinc oxide or ZnO-NPs, with a constant preference to ZnO-NPs diet throughout the 5-min test. The highest levels of zinc were detected in the livers, kidneys, lungs, and muscles in the 1st day following cessation of drug administration. There was no significant effect on the levels of creatinine, uric acid, AST, and ALT. Mild to moderate degenerative changes as well as necrosis could be detected in the livers and hearts following both treatments. In conclusion, nano-zinc oxide could be practically used in broiler feed at a dose of 90 mg/kg diet instead of bulk zinc oxide, at a dose of 3000 mg/kg diet, with an improved body weight. Both supplements caused no significant effects on serum parameters and had the same antibacterial activity against E. coli O78.