Dietary Zinc Supplementation Research Articles

Assessment of the Mitigative Capacity of Dietary Zinc on PCB126 Hepatotoxicity and the Contribution of Zinc to Toxicity.

Hepatic levels of the essential micronutrient, zinc, are diminished by several hepatotoxicants, and the dietary supplementation of zinc has proven protective in those cases. 3,3',4,4',5-Pentachlorobiphenyl (PCB126), a liver toxicant, alters hepatic nutrient homeostasis and lowers hepatic zinc levels. The current study was designed to determine the mitigative potential of dietary zinc in the toxicity associated with PCB126 and the role of zinc in that toxicity. Male Sprague-Dawley rats were divided into three dietary groups and fed diets deficient in zinc (7 ppm Zn), adequate in zinc (30 ppm Zn), and supplemented in zinc (300 ppm). The animals were maintained for 3 weeks on these diets, then given a single IP injection of vehicle or 1 or 5 μmol/kg PCB126. After 2 weeks, the animals were euthanized. Dietary zinc increased the level of ROS, the activity of CuZnSOD, and the expression of metallothionein but decreased the levels of hepatic manganese. PCB126 exposed rats exhibited classic signs of exposure, including hepatomegaly, increased hepatic lipids, increased ROS and CYP induction. Liver histology suggests some mild ameliorative properties of both zinc deficiency and zinc supplementation. Other metrics of toxicity (relative liver and thymus weights, hepatic lipids, and hepatic ROS) did not support this trend. Interestingly, the zinc supplemented high dose PCB126 group had mildly improved histology and less efficacious induction of investigated genes than did the low dose PCB126 group. Overall, decreases in zinc caused by PCB126 likely contribute little to the ongoing toxicity, and the mitigative/preventive capacity of zinc against PCB126 exposure seems limited.

Reproductive and productive performances of crossbred Andaman local pigs under small holder production system at Bay Islands, India

The present study appraises different traditional feeding practices followed by farmers and effect of dietary zinc supplementation on the reproductive and productive performances of crossbred Andaman local pigs. In the 1st experiment the effect of three feeding practices were evaluated and in the 2nd experiment the effect of supplementation of 80 ppm Zn on growth of weanling piglets were evaluated. The locally available feed ingredients like rice bran, taro (Colocasia esculenta) leaves, broken rice, broken wheat, maize, and coconut cake were used in different proportion for feeding. The different reproductive parameters like the mean age at puberty, age at first conception and first farrowing and various litter traits varied significantly (<0.01) among the three treatment groups. In the next experiment the effect of Zn supplementation on post weaning growth performances of piglets were studied. In treatment group (n=5) 80 ppm Zn was supplemented along with normal farm diet where as in control group (n=5) normal diet was given. The experiment continued for three months. The results showed that the sow receiving the ration made up of coconut cake, broken rice or maize performed better than the sow receiving ration made up of colocasia leaves and rice bran in respect of reproductive performances. Similarly, inclusion of 80 ppm Zn in stater ration enhanced the daily body weight.

Nanosize of zinc oxide and the effects on zinc digestibility, growth performances, immune response and serum parameters of weanling piglets

The aim of this study was to investigate the effect of dietary supplementation of nanosize zinc on zinc digestibility, growth performances, immune response and serum parameters of weanling piglets. Ninety-six LYD weanling piglets were assigned to control, zinc oxide (ZnO), organic-Zn (Zn-methionine) and nanosize ZnO (nano-Zn) groups with four replicates. The zinc was at the 120 mg/kg level in the treatment group's diet, while the control group's was 80 mg/kg Zn. The experiment results indicated that the nano-Zn and organic-Zn groups had significantly higher Zn digestibility compared to the ZnO and control groups. For the immune response traits, the IgG level and goat red blood cells (GRBC) antibody titer were nano-Zn and organic-Zn>ZnO>control; in the phytohemagglutinin (PHA) challenge test result, nano-Zn>organic-Zn>ZnO>control; in regard to the γ-globulin level, nano-Zn and organic-Zn>ZnO and control, with significant difference between groups. In the serum parameters aspect, serum Zn concentration in nano-Zn and organic-Zn groups were higher than in the ZnO and control groups, serum growth hormone concentration was increased in the nano-Zn group than in the other groups. In conclusion, nanosize zinc oxide for dietary supplementation can increase zinc digestibility, serum growth hormone levels and carbonic anhydrase activity and enhance the immune response of weanling piglets.

Microcirculatory effects of zinc on fructose-fed hamsters

Background and aimsFructose is a major dietary component directly related to vascular dysfunction and diseases such as obesity, diabetes, and hypertension. Zinc is considered a non-pharmacological alternative for treating diabetes due to its antioxidant and hyperglycemia-lowering effects in diabetic animals. Therefore, the aim of this study was to evaluate the effects of dietary zinc supplementation on the microcirculatory parameters of fructose-fed hamsters. Methods and ResultsMale hamsters (Mesocricetus auratus) were fed drinking water substituted by 10% fructose solution for 60 days, whereas control animals were fed drinking water alone. Their microcirculatory function was evaluated using cheek pouch preparation, as well as their blood glucose and serum insulin levels. Their microcirculatory responses to acetylcholine (ACh, an endothelium-dependent vasodilator) and to sodium nitroprusside (SNP, an endothelium-independent vasodilator) as well as the increase in macromolecular permeability induced by 30 min of ischemia/reperfusion (I/R) were noted. Endothelium-dependent vasodilation was significantly increased in control animals with high zinc supplementation compared to the groups without zinc supplementation. Zinc was able to protect against plasma leakage induced by I/R in all control and fructose-fed groups, although the microvascular permeability was higher in animals fed drinking water substituted by 10% fructose solution compared to those fed filtered drinking water alone. ConclusionOur results indicate that dietary zinc supplementation can improve microvascular dysfunction by increasing endothelial-dependent dilatation and reducing the increase in macromolecular permeability induced by I/R in fructose-fed animals.

Effect of Zinc on Appetite Regulatory Peptides in the Hypothalamus of Salmonella-Challenged Broiler Chickens.

The effects of dietary Zinc (Zn) supplementation on the gene expression of appetite regulatory peptides were investigated in Salmonella-infected broiler chickens. Broiler chickens (Arbor Acres, 1day old) were allocated randomly into 24 pens of 10 birds. The chickens from 12 pens were fed with basal diet and the other with basal diet supplemented with Zn (ZnSO4·H2O, 120mg/kg). At 5days of age, the chickens were divided into 4 treatments with 6 pens: basal diet; basal diet and Salmonella challenge; Zn-supplemented diet; Zn-supplemented diet and Salmonella challenge. At 42days of age, the hypothalamus from 6 chickens per treatment (1 chicken per pen) was individually collected for gene expression determination. Results showed that dietary supplementation of Zn reduced the gene expression of hypothalamic ghrelin and tumor necrosis factor alpha (TNF-α) (P < 0.05). Salmonella infection upregulated the messenger RNA (mRNA) levels of hypothalamic neuropeptide Y (NPY) and TNF-α. Zn supplementation and Salmonella inoculation were significantly correlated with the mRNA levels of toll-like receptor 2-1 (P < 0.05). However, neither dietary Zn supplementation nor Salmonella inoculation had significant effect on hypothalamic agouti-related protein, cocaine- and amphetamine-regulated transcript, and pro-opiomelanocortin. This study shows that dietary Zn supplementation promoted orexigenic appetite regulatory peptides and reduced the expression of the inflammatory cytokine TNF-α in the hypothalamus of Salmonella-challenged broilers.

Preventing Gut Leakiness and Endotoxemia Contributes to the Protective Effect of Zinc on Alcohol-Induced Steatohepatitis in Rats1–3

Background: Zinc deficiency has been well documented in alcoholic liver disease.Objective: This study was undertaken to determine whether dietary zinc supplementation provides beneficial effects in treating alcohol-induced gut leakiness and endotoxemia.Methods: Male Sprague Dawley rats were divided into 3 groups and pair-fed (PF) Lieber-DeCarli liquid diet for 8 wk: 1) control (PF); 2) alcohol-fed (AF; 5.00–5.42% wt:vol ethanol); and 3) AF with zinc supplementation (AF/Zn) at 220 ppm zinc sulfate heptahydrate. The PF and AF/Zn groups were pair-fed with the AF group. Hepatic inflammation and endotoxin signaling were determined by immunofluorescence and quantitative polymerase chain reaction (qPCR). Alterations in intestinal tight junctions and aldehyde dehydrogenases were assessed by qPCR and Western blot analysis.Results: The AF rats had greater macrophage activation and cytokine production (P < 0.05) in the liver compared with the PF rats, whereas the AF/Zn rats showed no significant differences (P > 0.05). Plasma endotoxin concentrations of the AF rats were 136% greater than those of the PF rats, whereas the AF/Zn rats did not differ from the PF rats. Ileal permeability was 255% greater in the AF rats and 19% greater in the AF/Zn rats than in the PF rats. The AF group had reduced intestinal claudin-1, occludin, and zona occludens-1 (ZO-1) expression, and the AF/Zn group had upregulated claudin-1 and ZO-1 expression (P < 0.05) compared with the PF group. The intestinal epithelial expression and activity of aldehyde dehydrogenases were elevated (P < 0.05) in the AF/Zn rats compared with those of the AF rats. Furthermore, the ileal expression and function of hepatocyte nuclear factor 4α, which was impaired in the AF group, was significantly elevated in the AF/Zn group compared with the PF group.Conclusions: The results demonstrate that attenuating hepatic endotoxin signaling by preserving the intestinal barrier contributes to the protective effect of zinc on alcohol-induced steatohepatitis in rats.

Dietary zinc supplementation increased TNFα and IL1β-induced RANKL expression, resulting in a decrease in bone mineral density in rats.

We investigated the effect of dietary zinc supplementation on bone metabolism in rats. Four-week-old male Wistar rats were fed a 30.0 mg zinc/kg diet (C), a 300.0 mg zinc/kg diet (HZ) or a 3,000.0 mg zinc/kg diet (EZ) for 4 weeks. The zinc content of the femur gradually increased in accordance with the gradual increase in the dietary zinc level. Although the mRNA expression of zinc transporters in bone did not differ between the groups, the mRNA expression of metallothioneins was increased in the HZ and EZ groups compared to the C group. Moreover, the bone mineral density was significantly decreased in the HZ and EZ groups compared to the C group. Furthermore, the mRNA expression of tumor necrosis factor α, Interleukin-1β and osteoclastogenesis-related genes such as receptor for activator of nuclear factor-κB (NF-κB) ligand, tumor necrosis factor receptor-associated factor 6, and nuclear factor of activated T cells cytoplasmic 1 was significantly increased in the HZ and EZ groups compared to the C group. These findings suggested that dietary zinc supplementation reduced bone mineral density through the promotion of bone resorption via an increase in the expression of receptor for activator of NF-κB ligand induced by tumor necrosis factor α and Interleukin-1β.

EFFECT OF DIETARY SUPPLEMENTAL ZINC SOURCE AND LEVEL ON GROWTH PERFORMANCE, DIGESTIBILITY COEFFICIENTS AND IMMUNE RESPONSE OF NEW ZEALAND WHITE RABBITS

This study was carried out to investigate the effect of dietary zinc (Zn) supplementation in inorganic (zinc sulfate, ZnSO4) and organic (zinc methionine, Zn-Met) forms at two levels (100 or 200 mg/kg diet) on growth performance, digestibility coefficients and immune response of New Zealand White (NZW) male rabbits. One hundred male NZW rabbit (at 6 weeks of age, 808 ± 11g average body weight) were divided into five homogenous groups. The 1st group was fed basal diet including vitamins & minerals premix which contained 58 mg Zn as a control, the 2nd and the 3rd groups were fed on the same diet supplemented with 100 or 200 mg Zn/kg diet as zinc sulfate (ZnSO4, inorganic form) and the 4th and the 5th groups were fed on the same diet supplemented with 100 or 200 mg Zn/kg diet as zinc methionine (Zn-Met, organic form). Results showed that live body weight at 22 wks of age and total body weight gain of rabbits fed diets supplemented with Zn was significantly (P<0.01) higher than those fed diet without supplementation. Rabbits fed diet supplemented with 200 mg Zn-Met/kg diet had significantly heaviest body weight, followed by rabbits fed diet supplemented with 100 mg Zn-Meth/kg diet than groups fed diet supplemented with 200 and 100 mg ZnSO4. Rabbits fed diets supplemented with Zn-Met or ZnSO4 converted feed better than those fed diets without supplementation. Rabbits fed diets supplemented of Zn-Meth at 200 or 100 mg/Kg diets improved nutrients digestibility and nutritive values expressed as TDN and DCP of diets. Zn supplementation (Zn-Meth or ZnSO4) to rabbit diets significantly (P<0.01) affected cell-mediated immune response at different hours post injection of phytohemoagglutinins (PHA). Zn from Zn-Meth (200 or 100 mg/kg diets) significantly increased heighten cellular immunity than zinc from ZnSO4. Rabbits fed diets supplemented with Zn (Zn-Meth or ZnSO4) with any levels had significantly (P<0.01) higher antibody titer against sheep red blood cell (SRBC) at different weeks post immunization than those fed control diets. Zn-Meth improved significantly antibody titer against SRBC than zinc from ZnSO4. Inclusion 200 mg Zn-Met/kg diet significantly improved antibody titer post three weeks of SRBC injection than 100 mg Zn-Met. It can be concluded that dietary Zn methionine (organic form( at level of 200 mg/kg of rabbit diet improved nutrients digestibility and nutritive values of diets, which could be associated with better growth performance and immune efficiency.

Effects of dietary zinc supplementation on nutrient digestibility, haematological biochemical parameters and production performance in male sika deer (Cervus nippon)

The purpose of the present study was to investigate the effects of dietary zinc (Zn) supplementation on antler growth, haematological biochemical parameters and nutrient digestibility in farmed male sika deer. Twenty-five 2-year-old growing male sika deer were randomly divided into five Groups (A, B, C, D and E; 5/group). Animals in Groups A, B, C, Dand E received 0, 5, 15, 40, 100 mg Zn/kg, respectively. Group A, without supplementation acted as a control. The treatment diets were the same basal diet supplemented with 5, 15, 40 and 100 mg Zn/kg (provided as Zn methionine), respectively. The results showed that the digestibility of dry matter (DM) and crude protein in Groups D and E were greater than that in Groups A, B and C (P &lt; 0.05). Digestibility of neutral detergent fibre in Group E was higher than in the control group (P &lt; 0.05). Plasma Zn concentrations were increased by Zn supplementation and were higher (P &lt; 0.01) for the treatment groups supplemented with 15, 40 and 100 mg Zn/kg DM than for the control and 5 mg/kg Zn groups (P &lt; 0.01). Faecal Zn content in Groups D and E was higher than that in Group A (P &lt; 0.01). The content of albumin in plasma from Group E was greater than in the control and Groups B, C and D (P &lt; 0.05). The concentrations of testosterone in plasma from Groups C, D and E were decreased (P &lt; 0.05) compared with the control. The days between antler initiation and harvesting of deer in Groups D and E were decreased (P &lt; 0.05). Average daily gain of fresh antler and dry antler of deer in Groups D and E was significantly higher than that in the control group (P &lt; 0.05). In conclusion, a control diet containing 58.6 mg Zn/kg was inadequate for achieving optimal productivity for sika deer. The recommended Zn supplementation is from 76.7 to 99.0 mg/kg for 2-year-old male sika deer.

GW26-e4478 Effects of zinc status on high-fat diet-induced cardiac hypertrophy

We investigated the effect of dietary zinc supplementation and deficiency in mice consuming a high-fat on cardiac inflammation, cardiac fibrosis, and left ventricular function and structure using an animal model of adolescent obesity. Male C57BL/6J mice (3 weeks of age) were fed either high fat

High dietary zinc supplementation increases the occurrence of tetracycline and sulfonamide resistance genes in the intestine of weaned pigs

BackgroundDietary zinc oxide is used in pig nutrition to combat post weaning diarrhoea. Recent data suggests that high doses (2.5 g/kg feed) increase the bacterial antibiotic resistance development in weaned pigs. Therefore, the aim of this study was to investigate the development of enterobacterial antibiotic resistance genes in the intestinal tract of weaned pigs.FindingsWeaned pigs were fed diets for 4 weeks containing 57 (low), 164 (intermediate) or 2425 (high) mg kg−1 analytical grade ZnO. DNA extracts from stomach, mid-jejunum, terminal ileum and colon ascendens were amplified by qPCR assays to quantify copy numbers for the tetracycline (tetA) and sulfonamide (sul1) resistance genes in Gram-negative bacteria. Overall, the combined data (n = 336) showed that copy numbers for tetracycline and sulfonamide resistance genes were significantly increased in the high zinc treatment compared to the low (tetA: p value < 10−6; sul1: p value = 1 × 10−5) or intermediate (tetA: P < 1.6 × 10−4; sul1: P = 3.2 × 10−4) zinc treatment. Regarding the time dependent development, no treatment effects were seen 1 week after weaning, but significant differences between high and low/intermediate zinc treatments evolved 2 weeks after weaning. The increased number of tetA and sul1 copies was not confined to the hind gut, but was already present in stomach contents.ConclusionsThe results of this study suggest that the use of high doses of dietary zinc beyond 2 weeks after weaning should be avoided in pigs due to the possible increase of antibiotic resistance in Gram-negative bacteria.Electronic supplementary materialThe online version of this article (doi:10.1186/s13099-015-0071-3) contains supplementary material, which is available to authorized users.

Zinc dyshomeostasis during polymicrobial sepsis in mice involves zinc transporter Zip14 and can be overcome by zinc supplementation.

Integrity of the immune system is particularly dependent on the availability of zinc. Recent data suggest that zinc is involved in the development of sepsis, a life-threatening systemic inflammation with high death rates, but with limited therapeutic options. Altered cell zinc transport mechanisms could contribute to the inflammatory effects of sepsis. Zip14, a zinc importer induced by proinflammatory stimuli, could influence zinc metabolism during sepsis and serve as a target for therapy. Using cecal ligation-and-puncture (CLP) to model polymicrobial sepsis, we narrowed the function of ZIP14 to regulation of zinc homeostasis in hepatocytes, while hepatic leukocytes were mostly responsible for driving inflammation, as shown by higher expression of IL-1β, TNFα, S100A8, and matrix metalloproteinase-8. Using Zip14 knockout (KO) mice as a novel approach, we found that ablation of Zip14 produced a delay in development of leukocytosis, prevented zinc accumulation in the liver, altered the kinetics of hypozincemia, and drastically increased serum IL-6, TNFα, and IL-10 concentrations following CLP. Hence, this model revealed that the zinc transporter ZIP14 is a component of the pathway for zinc redistribution that contributes to zinc dyshomeostasis during polymicrobial sepsis. In contrast, using the identical CLP model, we found that supplemental dietary zinc reduced the severity of sepsis, as shown by amelioration of cytokines, calprotectins, and blood bacterial loads. We conclude that the zinc transporter ZIP14 influences aspects of the pathophysiology of nonlethal polymicrobial murine sepsis induced by CLP through zinc delivery. The results are promising for the use of zinc and its transporters as targets for future sepsis therapy.

Abstract 4576: Early-in-life dietary zinc supplementation or deficiency and susceptibility to mammary carcinogenesis in female Sprague-Dawley rat

Abstract Zinc deficiency during pregnancy and early postnatal life can adversely affect the health and predispose to an increased risk of developing chronic diseases at adulthood. The present study was designed to evaluate whether exposure to the dietary zinc supplementation or deficiency during the pregnancy, lactation and juvenile stages interferes with the development of mammary gland and susceptibility to the mammary carcinogenesis induced by 7,12-dimethylbenzanthracene (DMBA) in female Sprague-Dawley (SD) rats. Pregnant females were allocated into three groups (n = 15 each): dams received diets containing normal levels (35mg/Kg), deficient (3mg/Kg) or with supplementation (180mg/Kg) of zinc during gestational day 10 (GD 10) until the weaning of litters. After weaning, the females offspring were allocated into three groups and received the same diets as their dams until postnatal day PND 51 or 53. On PND 51, females SD (n = 10, 1 pulp/litter) were euthanized for removal of the abdominal mammary tissue for whole mount analysis or received a single dose of DMBA (50mg/kg, ig) for initiation of mammary carcinogenesis and euthanized on PND 53 (n = 10, 1 pulp/litter) or PND 180 (n = 16, 1 pulp/litter). On PND 53, mammary glands were collected for cell proliferation, apoptosis and estrogen receptor alpha (ER-α) immunohistochemistry analyzes, as well as evaluation the expression of genes related to DNA damage and repair, apoptosis, cell cycle and signaling related to estrogen receptor and p53 by TaqMan Low-density Array (TLDA).Tumors collected at PND 180 were processed for histological evaluation. Male and female offspring from dams receiving dietary zinc deficiency presented a significant reduction in body weight on PND 0, 10, 21 e 51. The mean number of the terminal buds (TEBs), ducts terminal (TEDs) and alveolar buds (ABs) in mammary gland did not differ among the groups. Dietary zinc supplementation significantly increased the indexes of cell proliferation in the mammary glands in relation to the control group while the indexes of apoptosis and ER-α did not differ among the groups. Also, dietary zinc supplementation significantly led downstream of Api5 and Ercc1 target genes related to apoptosis inhibitor and DNA repair, respectively. Also, dietary zinc supplementation or deficiency did not significantly change the histological pattern, volume, latency, incidence or multiplicity of mammary tumors in relation to the control group. However, dietary zinc supplementation increased the tumors number in 72%. The present findings suggest that the treatment with zinc suplementation during the stages of pregnancy, lactation and juvenile could have increased the susceptibility to development of mammary tumors induced by DMBA. Citation Format: Flávia Regina Moraes Silva, Lucas Tadeu Bidinotto, Robson Francisco Carvalho, Luis Fernando Barbisan. Early-in-life dietary zinc supplementation or deficiency and susceptibility to mammary carcinogenesis in female Sprague-Dawley rat. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4576. doi:10.1158/1538-7445.AM2015-4576

Effects of dietary zinc supplementation during a forced molt on subsequent hen performance and egg quality.

A total of 200 Hy- Line Brown commercial layer hens (64) weeks of age, were used in&#x0D; this study to investigate the impacts of different dietary zinc supplementation during a&#x0D; forced molt on subsequent hen performance and egg quality. The hens were randomly&#x0D; divided into (5) treatment groups of 40 hens each treatment. There were four replicate&#x0D; cages per treatment. The hens in the treatment 1 (control) were fed a layer ration&#x0D; containing 0 ppm ZnO, water and feed were provided ad libitum and received 16 hours&#x0D; of light/day, treatment (2) were fed a layer ration containing 28000 ppm Zn as zinc oxide&#x0D; for 11 days, treatment (3) 37000 ppm ZnO for 9 days, treatment (4) 46000 ppm ZnO for&#x0D; 7 days, and treatment (5)on-again, off-again program (ON-OFF).The experimental&#x0D; period was divided into seven periods (1) 64-66, (2) 67-69, (3) 70-72, (4) 73-75, (5) 76-&#x0D; 78, (6) 79-81, (7) 82-84 weeks. The results indicated that different levels of dietary zinc&#x0D; were improved Hen Day (H.D) egg production and egg weight at periods 70-72, 73-75,&#x0D; 76-78, 79-81, 82-84 weeks, except treatment 37000 ppm ZnO in period 70-72 was&#x0D; reduced in both egg production and egg weight, yolk and white weight improved also in&#x0D; these five periods above, feed intake was improved in two periods 70-72 and 73-75&#x0D; weeks, feed conversion ratio was decreased in two periods 73-75 and 76-78 weeks,&#x0D; compared to both control and ON-OFF program. Haugh unit was improved in dietary&#x0D; zinc treatments and ON-OFF program in all periods except period 64-66 weeks&#x0D; compared to control. The percentage of weight loss was increased in the period 64-67&#x0D; weeks for all treatments except control. Different dietary zinc supplementation was&#x0D; increased the concentration of zinc in yolk from 10.20 ppm (control) to 32.84, 29.61 and&#x0D; 51.08 and, white from 3.50 ppm (control) to 5.96, 5.90 and 6.37 ppm for 28000, 37000&#x0D; and 46000 ppm during fed them with Zn for 11, 9 and 7 days, respectively, but the&#x0D; concentration of zinc in yolk and white was reduced week by week after following the&#x0D; refeeding of a control diet and was normally by week 6.

Effects of Dietary Copper and Zinc Supplementation on Growth Performance, Tissue Mineral Retention, Antioxidant Status, and Fur Quality in Growing-Furring Blue Foxes (Alopex lagopus).

A 4×2 factorial experiment with four supplemental levels of copper (0, 20, 40, or 60 mg copper per kg dry matter) from copper sulfate and two supplemental levels of zinc (40 or 200 mg zinc per kg dry matter) from zinc sulfate was conducted to investigate the effects of dietary copper and zinc supplementation on growth performance, tissue mineral retention, antioxidant status, and fur quality in growing-furring blue foxes. One hundred and twenty healthy 15-week-old male blue foxes were randomly allocated to eight dietary treatments with 15 replicates per treatment for a 70-day trial from mid-September to pelting in December. The average daily gain and feed conversion ratio were increased with copper supplementation in the first 35 days as well as the overall period (P<0.05). In addition, copper supplementation tended to increase feed intake during the first 35 days (P<0.10). Diets supplemented with 200 mg/kg zinc did not affect body gain (P>0.10) and feed intake (P>0.10) but improved feed conversion (P<0.05) compared with those supplemented 40 mg/kg zinc throughout the experiment. No copper×zinc interaction was observed for growth performance except that a tendency (P=0.09) was found for feed intake in the first 35 days. Supplementation of copper or zinc improved crude fat digestibility (P<0.01) but had no effects on the digestibility of other nutrients. Fecal copper was increased with both copper (P<0.01) and zinc addition (P<0.05). However, fecal zinc was affected only by dietary zinc addition (P<0.01). Mineral contents in serum and kidney were not affected by dietary treatments (P>0.05). However, the level of copper in the liver was increased with copper supplementation (P<0.05) and tended to decrease with zinc supplementation (P=0.08). Dietary zinc addition tended to increase the activity of alkaline phosphatase (P=0.07). The activities of copper-zinc superoxide dismutase and catalase tended to increase by copper (P=0.08) and zinc addition (P=0.05). Moreover, a copper×zinc interaction was observed for catalase in the experiment (P<0.05). Serum malondialdehyde concentration decreased with the increasing of dietary copper and zinc levels (P<0.05). The activity of glutathione peroxidase tended to increase by copper addition (P=0.09). For fur quality, foxes fed diets supplemented with high copper had larger skin length and darker pelts than those fed the basal diet without copper addition (P<0.05). In conclusion, this study demonstrated that dietary copper and zinc supplementation can improve growth by increasing feed intake and improving fat digestibility. Additionally, copper and zinc can enhance the antioxidant capacity of blue foxes. This study also indicates that additional zinc up to 200 mg/kg did not exert significant adverse effects on the copper metabolism of growing-furring blue foxes.

Effect of Frusemide on Serum and Urinary Zinc levels in Rabbits

Introduction: Zinc is an essential trace element playing a vital role in the maintenance of health. Frusemide, a loop diuretic, is known to deplete sodium, potassium, magnesium and calcium levels. But, very few reports exist on its effect on Zinc levels. Hence, this study was performed on rabbits to investigate the same in detail. Material & Methods: Healthy adult New Zealand White rabbits (n=6 per group) were treated with Normal saline (2 ml kg-1) and Frusemide (5, 10 or 15 mg kg-1 each) intraperitoneally. Their serum and urinary zinc levels were studied by Atomic Absorption Spectrophotometry. Analysis of serum Zinc levels was also done after dietary Zinc supplementation for 20 days. Results: A dose-dependent decrease in serum Zinc levels owing to increased urinary Zinc excretion was observed. Both the urinary volume and urinary Zinc concentration increased dose-dependently. The percent fall in serum Zinc occurred in proportion to the pre-treatment serum values. Administration of Zinc in the diet restored the serum Zinc levels to normal. Conclusion: Frusemide may be responsible for Zinc depletion. Supplementation of Zinc may help to prevent the same in patients on prolonged Frusemide therapy. Key words: Dose-dependent, Frusemide, Frusemide-induced complications, Hypozincaemia, Hyperzincuria, Rabbits.

The beneficial effect of dietary zinc supplementation on anaemia and immunosuppression in Trypanosoma brucei infected rats

Zinc is an essential trace element crucial for normal development and function of cells mediating nonspecific immunity and protects bio-molecules from oxidative damage. This study was designed to assess the effects of dietary zinc supplementation on anaemia and immunity of trypanosome-infected rats. Thirty rats, divided into five groups (A–E) of 6 each, were used for the study. Parameters used to assess the effect of the supplementation are antibody response to Sheep RBC using direct haemagglutination test, parasitaemia using the rapid matching method, WBC count using the improved Neubauer haemocytometer method, haemoglobin concentration using the cynomethaemoglobin technique while PCV was determined using the microhaematocrit method. The pre-infection supplementation did not prolong the pre-patent period significantly (p > 0.05). However, it significantly (p < 0.05) increased the packed cell volume (PCV), haemoglobin (Hb) concentration, leucocyte count, and antibody titre by day 7 on the supplementation (OTS). Following infection on day 7 OTS, the PCV and Hb decreased but remained significantly (p < 0.05) higher than the infected not supplemented (INS) group, while on day 14 OTS, they maintained a significantly (p < 0.05) higher antibody titre as compared to other groups. On day 21 OTS, theweight of 8 ppm and not infected not supplemented (NINS) groups was significantly (p < 0.05) higher but the relative organ weight of their liver and spleen was significantly (p < 0.05) lower than 2 ppm, 4 ppm and INS groups. On day 21 OTS, the parasitaemia levels of INS group was significantly (p < 0.05) higher than the supplemented groups. From the results, dietary zinc supplementation can be useful in the management of anaemia and immunosupression caused by trypanosomes in rats.

Effect of zinc and phytase supplementation on performance, serum biochemical profiles and carcass quality of crossbred (Hampshire × Assam local) pigs

Twenty-four castrated weaned (42 days, 11.39 kg) pigs were used in a 2 × 2 factorial experiment to determine the influence of dietary zinc (0 upto 100 ppm/kg) and phytase (0 or 200 FTU phytase units/kg) supplementation on the performance, serum biochemical profiles and carcass quality. Growth rate and feed efficiency were significantly higher (P < 0.05) for pigs supplemented with phytase and zinc. Total serum protein, glucose, cholesterol, Ca, P and Zn concentrations were significantly higher (P < 0.05) in phytase supplemented group, whereas serum alkaline phosphatase estimates were lower (P < 0.05). No significant differences in carcass characteristics and proximate composition of meat were observed which indicated no adverse effect of zinc and enzyme supplementation. These results indicated that the growth-promoting effect of phytase may be due to increased zinc and other serum mineral concentrations and zinc dependent blood biochemical functions.

The RpoE Stress Response Pathway Mediates Reduction of the Virulence of Enteropathogenic Escherichia coli by Zinc.

Zinc supplements are an effective clinical treatment for infantile diarrheal disease caused by enteric pathogens. Previous studies demonstrated that zinc acts on enteropathogenic Escherichia coli (EPEC) bacteria directly to suppress several virulence-related genes at a concentration that can be achieved by oral delivery of dietary zinc supplements. Our in vitro studies showed that a micromolar concentration of zinc induced the envelope stress response and suppressed virulence in EPEC, providing a possible mechanistic explanation for zinc's therapeutic action. In this report, we investigated the molecular and physiological changes in EPEC induced by zinc. We found that micromolar concentrations of zinc reduced the bacterial growth rate without affecting viability. We observed increased membrane permeability caused by zinc. Zinc upregulated the RpoE-dependent envelope stress response pathway and suppressed EPEC virulence gene expression. RpoE alone was sufficient to inhibit virulence factor expression and to attenuate attaching and effacing lesion formation on human host cells. By mutational analysis we demonstrate that the DNA-binding motif of RpoE is necessary for suppression of the LEE1, but not the LEE4, operon. Predictably, inhibition of the RpoE-mediated envelope stress response in combination with micromolar concentrations of zinc reduced EPEC viability. In conclusion, zinc induces the RpoE and stress response pathways in EPEC, and the alternate sigma factor RpoE downregulates EPEC LEE and non-LEE virulence genes by multiple mechanisms.

Dietary organic zinc and selenium supplementation improves semen quality and fertility in layer breeders

Dietary organic zinc and selenium supplementation improves semen quality and fertility in layer breeders