Combined Supplementation of Nano-Zinc Oxide and Thyme Oil Improves the Nutrient Digestibility and Reproductive Fertility in the Male Californian Rabbits

Toxicological inhalation studies in rats to substantiate grouping of zinc oxide nanoforms

BACKGROUND

Significant variations exist in the forms of ZnO, making it impossible to test all forms in in vivo inhalation studies. Hence, grouping and read-across is a common approach under REACH to evaluate the toxicological profile of familiar substances. The objective of this paper is to investigate the potential role of dissolution, size, or coating in grouping ZnO (nano)forms for the purpose of hazard assessment. We performed a 90-day inhalation study (OECD test guideline no. (TG) 413) in rats combined with a reproduction/developmental (neuro)toxicity screening test (TG 421/424/426) with coated and uncoated ZnO nanoforms in comparison with microscale ZnO particles and soluble zinc sulfate. In addition, genotoxicity in the nasal cavity, lungs, liver, and bone marrow was examined via comet assay (TG 489) after 14-day inhalation exposure.

RESULTS

ZnO nanoparticles caused local toxicity in the respiratory tract. Systemic effects that were not related to the local irritation were not observed. There was no indication of impaired fertility, developmental toxicity, or developmental neurotoxicity. No indication for genotoxicity of any of the test substances was observed. Local effects were similar across the different ZnO test substances and were reversible after the end of the exposure.

CONCLUSION

With exception of local toxicity, this study could not confirm the occasional findings in some of the previous studies regarding the above-mentioned toxicological endpoints. The two representative ZnO nanoforms and the microscale particles showed similar local effects. The ZnO nanoforms most likely exhibit their effects by zinc ions as no particles could be detected after the end of the exposure, and exposure to rapidly soluble zinc sulfate had similar effects. Obviously, material differences between the ZnO particles do not substantially alter their toxicokinetics and toxicodynamics. The grouping of ZnO nanoforms into a set of similar nanoforms is justified by these observations.

The effect of combining green iron nanoparticles and algae on the sustainability of broiler production under heat stress conditions

Background

Natural feed additives in broiler feed contribute to the overall health, productivity, and economic viability of broiler chickens while meeting consumer demands and preferences for natural products. The purpose of this research was to determine the effect of green iron nanoparticles (Nano-Fe) and Halimeda opuntia supplementation in broiler diets on performance, ammonia excretion in excreta, Fe retention in tissues and serum, carcass criteria, and meat quality under hot environmental conditions.

Methods

A total of 256 one-day-old male Ross 308 broiler chicks were randomly assigned to one of four feeding treatments for 42 days. Each treatment had eight replications, with eight chicks per replicate. The treatments were Negative control (CON), positive control (POS) supplemented with 1 g/kg Halimeda opuntia as a carrier, POS + 20 mg/kg Nano-Fe (NFH1), POS + 40 mg/kg Nano-Fe (NFH2).

Results

When compared to CON and POS, dietary Nano-Fe up to 40 mg/kg enhanced (p < 0.001) growth performance in terms of body weight (BW), body weight gain (BWG), and feed conversion ratio (FCR). Nano-Fe had the highest BWG and the most efficient FCR (linear, p < 0.01, and quadratic, p < 0.01) compared to POS. Without affecting internal organs, the addition of Nano-Fe and POS enhanced dressing and reduced (p < 0.001) abdominal fat compared to control (CON). Notably, the water-holding capacity of breast and leg meat was higher (p < 0.001), and cooking loss was lower in broilers given Nano-Fe and POS diets against CON. In comparison to POS, the ammonia content in excreta dropped linearly as green Nano-Fe levels increased. When compared to CON, increasing levels of Nano-Fe levels boosted Fe content in the breast, leg, liver, and serum. The birds fed on POS showed better performance than the birds fed on CON.

Conclusion

Green Nano-Fe up to 40 mg/kg fed to broiler diets using 1 g/kg Halimeda opuntia as a carrier or in single can be utilized as an efficient feed supplement for increasing broiler performance, Fe retentions, carcass characteristics, meat quality, and reducing ammonia excretions, under hot conditions.

Dietary zinc-chitosan nanoparticles addition influences on growth performance, apparent total tract digestibility, carcass indices, and immune function in weaned rabbits

The aim of this study was to study the effect of zinc oxide-chitosan nanoparticles (Zn-CNPs) on growth performance, plasma constituents, carcass indices, and immune function in rabbit diets. Eighty weaned V-line males rabbits at 5 weeks of age were divided into four dietary groups of control diet; 50 Zn-CNPs; 75 Zn-CNPs;100 Zn-CNPs. Supplementation of Zn-CNPs did not affect final live body weight and average daily weight gain. 100 ppm Zn-CNPs recorded (p < 0.05) higher digestibility of DM, OM, CP, EE, and NFE. Dietary groups of 75 and 100 ppm were higher (p < 0.05) in DCP, TDN (%), and DE (kcal/kg). Zn-CNPs supplementation was higher (p < 0.05) in hot carcass and spleen weights %. The addition of Zn-CNPs in diets promoted dressing%. Significant increases (p < 0.05) in plasma total protein and albumin levels for 75 and 100 Zn-CNPs. Zn-CNPs decreased (p < 0.05) glucose, total cholesterol, LDL concentrations and increased (p < 0.05) plasma zinc levels, IgG, IgM. Plasma HDL level increased (p < 0.05) with 75 and 100 ppm Zn-CNPs. In conclusion, Zn-CNPs supplementations can use safely as a zinc source in rabbits diets without any detrimental effects on growth performance, plasma constituents, and carcass indices. Moreover, 50, 75, and 100 ppm Zn-CNPs enhanced the immune functions.

Effects of Dietary Acacia nilotica Fruit, Zinc Oxide Nanoparticles and Their Combination on Productive Performance, Zinc Retention, and Blood Biochemistry of Rabbits

This study aims to examine the effects of supplementing male rabbit diets with nanoparticles of zinc oxide (Nano-ZnO) and Acacia nilotica fruit powder (ANFP) on production sustainability under hot climatic conditions. Eighty Californian male rabbits aged 40 days old (average body weight 738.5 ± 11 g) were divided into four treatment groups and administered one of the following diets: control diet, Nano-ZnO (50 mg/kg), ANFP (5 g/kg), or a combination of Nano-ZnO (50 mg/kg) and ANFP (5 g/kg) for a period of 60 days. Each of the 20 rabbits used in a treatment was regarded as a replicate. The results showed that adding Nano-ZnO and ANFP individually or in combination to rabbits' diets improved (p < 0.05) growth performance in comparison to control. In addition, zinc contents in serum or the testis tissues in the Nano-ZnO- and ANFP-treated rabbits were significantly greater (p < 0.05) than those in the control group. In addition, serum levels of creatinine, alanine aminotransferase, and aspartate aminotransferase were decreased (p < 0.05) by supplementation of Nano-ZnO, ANFP, or their combination. Carcass criteria did not differ among the treatments. Overall, the findings of the present study indicate that rabbits fed diets containing Nano-ZnO and ANFP, as well as their combination, showed improvements in growth performance, kidney and liver functions, as well as zinc retention in tissues under hot climatic conditions. The combination of Nano-ZnO and ANFP exhibited the best performance in the rabbits. More research on the synergistic effects of Nano-ZnO and ANFP in the sustainable production of rabbit meat is required.

Ramifications of Heat Stress on Rabbit Production and Role of Nutraceuticals in Alleviating Its Negative Impacts: An Updated Review

Heat stress has become a widespread concern worldwide, which is a major environmental stress that causes substantial economic loss in the rabbit industry. Compared to other agricultural animals, rabbits are more sensitive to heat stress as they have fewer sweat glands and a thicker coat of fur, increasing the heat dissipation complexity. Thus, heat stress hurts rabbits' productivity, meat quality, reproductive performance, antioxidative properties, immune responsiveness, intestinal histomorphology, and microbiome. Nutraceuticals include vitamins, minerals, antioxidants, organic acids, fatty acids, probiotics, prebiotics, synbiotics, enzymes, and medicinal plants due to the possible impacts on maintaining common biological situations, strengthening immune response, and preventing illness, which ultimately led to an increase in productivity. Nutraceuticals have recently attracted a lot of attention to alleviate the adverse impacts of heat stress in rabbit farms. The objective of the current review is to provide acquaintance with the recent findings about the impact of heat stress on rabbit productivity and the advantages of dietary supplementation of nutraceuticals in mitigating it.

Impact of Alpinia galanga and zinc on semen quality and some reproductive hormone constituents in California rabbit bucks

The objective of the current study was to investigate the influence of synergism of the dry powder of Alpinia galanga rhizomes (AGR) and/or zinc sulfate in the diet on semen quality and reproductive traits of California rabbit bucks. The study was conducted in two stages. First stage: appreciation of semen characteristics, 36 California rabbit bucks (aged 5 months) with average body weights of 2980 g were divided randomly into six treatments (six individuals each). The treatment groups were: first group, control fed basal diet (C); second group, fed basal diet plus 1 g AGR/kg dry matter (DM) (AGR1); third group, fed basal diet plus 2 g AGR/kg DM (AGR2); fourth group, fed basal diet plus 200 mg Zn/litre drinking water (Zn); fifth group, fed basal diet plus 1 g AGR/kg DM and 200 mg Zn/litre drinking water (AGR1 + Zn); sixth group, fed basal diet plus 2 g AGR/kg DM and 200 mg Zn/litre drinking water (AGR2 + Zn). Second stage: the previous bucks were used to determine the efficiency of semen on reproductive fertility traits, 48 mature does (aged 6 months, nulliparous) with an average body weight of 3050 ± 20.7 g were divided randomly into six treatments and inseminated with previous groups of treated bucks. The results of the first stage, recorded high activity on gonadotropins hormones: follicle-stimulating hormone (FSH) and luteinizing hormone (LH), free testosterone (FT), progesterone (P₄) and oestrogen (E₂17β) concentrations for AGR1 + Zn and AGR2 + Zn compared with the control group. Groups AGR1, AGR2, AGR1 + Zn and AGR2 + Zn had significantly lowered concentrations of triglycerides, total cholesterol, low-density lipoprotein, and malondialdehyde (MDA), whereas high-density lipoprotein and total antioxidant capacity (TAC) were increased significantly compared with the control group. The group supplemented with AGR with or without Zn had significantly improved ejaculate volume, advanced motility, sperm concentration, and cell integrity. Fertility rate and litter size were improved in all groups compared with the control. It was concluded that supplementing diets with Alpinia galanga and Zn significantly increased sperm percentage, motility and reproductive hormones (testosterone, FSH, LH, E₂17β, P₄). This suggested that this plant when used may be favourable for improved sperm quality and fertility parameters.

Implication of apoptosis and oxidative stress in mitigation of ivermectin long-term hazards by zinc nanoparticles in male rabbits

Ivermectin is the medication of choice for treating human onchocerciasis and is used in veterinary medicine to treat a variety of ectoparasites and endoparasites. This study was designed to investigate the effects of zinc nanoparticles (ZnNPs) on the fertility of male rabbits exposed to experimental ivermectin (IVM) intoxication. A total of 72 mature male rabbits were equally divided into 4 groups (n = 18). The first group (CTR) served as control; the second group (IVM) received subcutaneous injection of IVM (0.2 mg/kg body weight); the third group (ZnNPs) fed on zinc nanoparticles (60 mg/kg diet); and the fourth group (ZnNPs + IVM) were administered IVM and zinc nanoparticles at the same doses. The experiment lasted for 9 weeks. Results revealed that IVM-intoxicated rabbits showed impaired growth performance parameters, including body weight, total body weight gain (TBWG), total feed intake (TFI), and feed conversion ratio (FCR). Moreover, carcass characteristic and fertility parameters (including semen quality parameters and testosterone levels) were also impaired after IVM administration. Additionally, testicular malondialdehyde (MDA) and antioxidant (reduced glutathione, superoxide dismutase, catalase) levels as well as the histopathology and immunohistochemical expression of caspase 3 and PCNA in the testes and epididymis were detrimentally affected. On the contrary, ZnNP administration efficiently improved most of these parameters in IVM-intoxicated rabbits. In conclusion, ZnNPs exhibited promising ability for improving the growth and fertility status of rabbits and reducing the deleterious effects of IVM possibly through the suppression of apoptotic and oxidative pathways.

Effects of Zinc Oxide Nanoparticle Supplementation on Performance, Digestibility, and Blood Biochemistry of Californian Male Rabbits Under Hot Climatic Conditions

This study aims to investigate the effects of nanoparticles of zinc oxide (Nano-ZnO) supplementation on productive performance, nutrient digestibility, mineral retention, and blood biochemistry of Californian male rabbits under hot climatic conditions. A total of 100 Californian male rabbits 90 days of age (BW: 1790 ± 13 g) were randomly assigned to one of five treatment diets: Nano-ZnO at 0, 25, 50, 75, or 100 mg/kg, respectively, for 90 days. The rabbits were raised in an open house system (average ambient temperature of 39 °C, relative humidity of 30-35%, and temperature-humidity index of 33.6-34.0). Each treatment had 20 rabbits, and each rabbit was considered as a replicate. During the entire study period, there were no significant differences (P > 0.05) in BW, BW gain, feed intake, or feed conversion ratio between the treatment groups. Nano-ZnO supplementation at 25, 50, 75, and 100 mg/kg enhanced the digestibility coefficient of crude protein (CP) and ether extract (EE) considerably (quadratically, P < 0.05) when compared to the control group. In addition, when Nano-ZnO was supplemented at 25, 50, 75, and 100 mg/kg, serum levels of creatinine, alanine aminotransferase (ALT), and aspartate aminotransferase (AST) were considerably lower than the non-supplemented control group. Furthermore, when comparing the control and Nano-ZnO-fed rabbits, serum testosterone concentrations increased significantly (P < 0.05) in the treated groups. In addition, compared to the other groups, the 50 mg/kg Nano-ZnO group had the highest cecal Lactobacilli spp. count. These findings suggest that supplementing Californian male rabbits with 50 mg/kg dietary Nano-ZnO enhanced CP and EE digestibility, cecal Lactobacilli spp., as well as serum testosterone levels, and decreased serum ALT and AST levels under hot climatic conditions.

Different Strategies to Attenuate the Toxic Effects of Zinc Oxide Nanoparticles on Spermatogonia Cells

Zinc oxide nanoparticles (ZnO NPs) are one of the most used nanoparticles due to their unique physicochemical and biological properties. There is, however, a growing concern about their negative impact on male reproductive health. Therefore, in the present study, two different strategies were used to evaluate the recovery ability of spermatogonia cells from the first stage of spermatogenesis (GC-1 spg cell line) after being exposed to a cytotoxic concentration of ZnO NPs (20 µg/mL) for two different short time periods, 6 and 12 h. The first strategy was to let the GC-1 cells recover after ZnO NPs exposure in a ZnO NPs-free medium for 4 days. At this phase, cell viability assays were performed to evaluate whether this period was long enough to allow for cell recovery. Exposure to ZnO NPs for 6 h and 12 h induced a decrease in viability of 25% and 41%, respectively. However, the recovery period allowed for an increase in cell viability from 16% to 25% to values as high as 91% and 84%. These results strongly suggest that GC-1 cells recover, but not completely, given that the cell viability does not reach 100%. Additionally, the impact of a synthetic chalcone (E)-3-(2,6-dichlorophenyl)-1-(2-hydroxyphenyl)prop-2-en-1-one (1) to counteract the reproductive toxicity of ZnO NPs was investigated. Different concentrations of chalcone 1 (0-12.5 µM) were used before and during exposure of GC-1 cells to ZnO NPs to mitigate the damage induced by NPs. The protective ability of this compound was evaluated through viability assays, levels of DNA damage, and cytoskeleton dynamics (evaluating the acetylated α-tubulin and β-actin protein levels). The results indicated that the tested concentrations of chalcone 1 can attenuate the genotoxicity induced by ZnO NPs for shorter exposure periods (6 h). Chalcone 1 supplementation also increased cell viability and stabilized the microtubules. However, the antioxidant potential of this compound remains to be elucidated. In conclusion, this work addressed the main cytotoxic effects of ZnO NPs on a spermatogonia cell line and analyzed two different strategies to mitigate this damage, which represent a significant contribution to the field of male fertility.

Liquid-Phase Synthesis of Nano-Zinc Oxide and Its Photocatalytic Property

To solve the problem of liquid-phase synthesis of nano-ZnO, a photocatalytic performance study was proposed. In this study, the microwave homogeneous precipitation method was used to add different types and amounts of surfactants. The synthesis of nano-zinc oxide was controlled by changing the reaction system conditions. The photocatalytic properties of nano-zinc oxide for degrading three water-soluble dyes were preliminarily studied and discussed. The results show that the photocatalytic performance of nano-ZnO is closely related to its size, morphology, specific surface area, and even crystallographic direction.

Beneficial and toxicological aspects of zinc oxide nanoparticles in animals

Nanotechnology is a far‐reaching technology with tremendous applications in various aspects, including general medicine, veterinary medicine, agriculture, aquaculture, and food production. Nanomaterials have exceptional physicochemical characteristics, including increased intestinal absorption, biodistribution, bioavailability, and improved antimicrobial and catalytic properties. Although nanotechnology is gaining ground in animal management, husbandry, and production, its wide use is still hampered by occasional toxicity and side effects. Zinc oxide nanoparticles (ZnO‐NPs) have long been utilized in animal production, aquaculture, and pet animal medicine. However, the use ZnO‐NPs in animals has been associated with reports of toxicity and side effects. ZnO‐NPs may have shown numerous beneficial effects in animals; its use must be regulated with care to avoid unwanted consequences. Thus, this review emphasizes the usage of ZnO‐NPs in animal production and laboratory animals and the potential side effects associated with the use of nanoparticles as a feed supplement and therapeutic compound.

Synergistic effect of ZnO NPs and imidacloprid on liver injury in male ICR mice: Increase the bioavailability of IMI by targeting the gut microbiota

Although many toxicological studies on pesticides and nanoparticles have been conducted, it is not clear whether nanoparticles will increase the toxicity of pesticides. In this study, we chose imidacloprid (IMI) as a representative pesticide, and explored the influence of ZnO NPs on the toxic effect of IMI. In addition, we studied the bioaccumulation of IMI in mice. Using biochemical index analysis, liver histopathological analysis, non-targeted metabolomics, and LC/MS analysis, we found that ZnO NPs increased the toxicity of IMI, which may be related to the increase in IMI bioaccumulation in mice. In addition, we used intestinal histopathological analysis, RT-qPCR, and 16sRNA sequencing to find that the disturbance of the gut microbiota and the impaired intestinal barrier caused by ZnO NPs may be the reason for the increase in IMI bioaccumulation. In summary, our results indicate that ZnO NPs disrupted the intestinal barrier and enhanced the bioaccumulation of IMI, and therefore increased the toxicity of IMI in mice. Our research has deepened the toxicological insights between nanomaterials and pesticides.