Effect of copper on antioxidant ability and nutrient metabolism in broiler chickens stimulated by lipopolysaccharides

The aim of the experiment was to investigate the interaction between Cu intake, inflammatory challenge and oxidative stress in broiler chickens. Furthermore, it was tested whether plasma ceruloplasmin (Cp) could be a sensible parameter for dietary Cu. One hundred forty-four day old chickens were raised on a basal control diet without added copper (Group Cu-6.5, basal Cu content 6.5 mg/kg diet) or a diet supplemented with Cu at 8 or 50 mg/kg (Groups Cu-14.5 and Cu-56.5, respectively) with four replicates of 12 animals for each treatment. Starting on day 21, chickens were injected intraperitoneally with lipopolysaccharides (LPS) once a day for 3 days. Before this challenge, Group Cu-14.5 had the lowest gain and the feed to gain ratio was the highest. After injection of LPS, however, chickens of Group Cu-14.5 had the best zoo-technical performance. For chickens of Group Cu-6.5, LPS injection resulted in elevated rectal temperature, and lower erythrocyte superoxide dismutase (CuZn-SOD) activity, compared with the other groups. LPS injection increased plasma uric acid in Group Cu-6.5 significantly, but was without influence in Group Cu-56.5. At all Cu-levels, LPS injection increased erythrocyte CuZn-SOD activity and decreased thiobarbituric acid reacting substances. No significant difference in plasma Cp was found in chickens fed different dietary Cu. LPS injection significantly increased plasma Cp in Group Cu-56.5. The results suggest that varying dietary Cu levels seem to modulate the parameters involved in immunological responses and oxidant stress and that plasma Cp is not a reliable parameter for dietary Cu.     

Effect of dietary caffeine and zinc on the activity of antioxidant enzymes,zinc, and copper concentration of the heart and liver in fast-growing rats

The purpose of this study was to determine the relationship between concentrations of Zn and Cu and the activities of superoxide dismutase and glutathione peroxidase in the heart and liver of young rat pups whose dams were fed a diet supplemented with caffeine and/or Zn. Four groups of dams with their newborn pups were fed one of the following diets for 22 d: 20% protein basal diet; the basal diet supplemented with caffeine (2 mg/100 body wt); the basal diet supplemented with Zn (300 mg/kg diet); or the basal diet supplemented with caffeine plus Zn. The Cu levels in the livers of the pups were decreased by maternal intake of the caffeine and Zn diet. The maternal intake of the caffeine diet increased Mn-superoxide dismutase (MnSOD) activity and Cu, Zn-superoxide dismutase (CUZnSOD) in the heart of the pups. On the other hand, the activity of Cu,ZnSOD was significantly reduced in the liver of pups whose dams consumed a caffeine, Zn, or caffeine plus Zn diet. Cu, ZnSOD activity in the liver of the pups seems to be correlated with Cu levels in the tissue. Selenium-dependent glutathione peroxidase (GSH-Px) activities in the heart and liver showed no difference among the groups. The effect of dietary caffeine and/or Zn on the activity of antioxidant enzymes in the heart and liver were different in young rats. The activities of these enzymes in the heart were lower than in the liver of 22-d-old rats. Our experiments indicate that the heart has limited defenses against the toxic effects of peroxides when compared to the liver.     

Effects of low copper and high zinc intakes and related changes in Cu,Zn-superoxide dismutase activity on DMBA-induced mammary tumorigenesis

The effect of low copper and high zinc intakes on Cu,Zn-superoxide dismutase (Cu,Zn-SOD) activity and mammary tumorigenesis induced by 9,10-dimethyl-1,2-benzanthracene (DMBA) was investigated. Groups of 40 weanling female Sprague-Dawley rats were fed a modified AIN-76 diet containing the following (/kg diet): 1 mg Cu (0.016 mmol) and 30 mg Zn (0.459 mmol); 6 mg Cu (0.094 mmol) and 30 mg Zn (0.459 mmol) (control); or 6 mg Cu (0.094 mmol) and 150 mg Zn (2.295 mmol) for 21 wk. At 5 wk, 30 rats/group were given 4 mg (15.6 mumol) DMBA in corn oil intragastrically, and controls (10/group) received corn oil alone. Erythrocyte Cu,Zn-SOD activity was measured at 3, 5 (just before DMBA), 9, 13, 17, and 21 wk. The group fed the high-Zn diet had a slightly lower weight gain and food consumption. DMBA treatment had no effect on these parameters. Plasma and liver Cu concentration decreased in the low-Cu group. Femur zinc was significantly elevated in the high-Zn group. Erythrocyte Cu,Zn-SOD activity was decreased in the low-Cu group from 3 to 21 wk and was significantly elevated in the high-Zn group at 3 and 5 wk. In the low-Cu group, there were 5 nonmalignant adenomas and 3 malignant adenocarcinomas; in the control group, there were 4 adenomas and 3 adenocarcinomas; in the high-Zn group, there were 5 adenomas and 3 adenocarcinomas. No relationship between Cu,Zn-SOD activity and the presence of tumors could be found.     

Organic Zn and Cu supplementation imprints on seminal plasma mineral,biochemical/ antioxidant activities and its relationship to spermatozoal characteristics in bucks

This experiment was conducted to study the effect of mineral supplementation on seminal plasma minerals level, biochemical constituents and total antioxidant capacity of Osmanabadi bucks. The study comprised of forty healthy bucks, aged five months were randomly assigned to ten groups (n = 4 per group). The control group was fed with a basal diet without any additional mineral supplementation. In addition to basal diet, treatment bucks were supplemented with three graded doses of organic Zinc (Zn) as 20, 40 and 60 mg/kg dry matter (DM); organic Copper (Cu) as 12.5, 25, 37.5 mg/ kg DM and combination of Zn + Cu as Zn20+Cu12.5, Zn40+Cu25, Zn60+Cu37.5 mg /kg DM basis respectively. Minerals were supplemented for 8 months and the separated seminal plasma used for analysis of minerals, biochemical profile, total antioxidant capacity (TAC), lipid peroxidation (LPO), and protein carbonylation (PC). In treatment groups, significantly lower LPO and PC were observed, except Zn60 and Zn60+Cu37.5, where higher malondialdehyde (MDA) (P < 0.05) formed. The TAC was relatively higher (P < 0.05) in Zn20, Zn40, Cu12.5 and Zn60+Cu37.5 than control. The minerals and biochemical parameters were significantly altered and positive relationship was observed among them. From this study, it was concluded that supplemented minerals changed the seminal plasma minerals profile (Zn- 7–13; Cu- 0.5–1.9 mg/L), reduced the stress (LPO and PC of control Vs treatment as 0.3 Vs 0.1 nmol/ml and 25.7 Vs 4.3 nmol protein carbonyl/mg protein), which improved the sperm quality in Zn40, all Cu treatments and Zn60+Cu37.5 groups respectively.     

Zinc dyshomeostasis in rats with aldosteronism. Response to spironolactone

Zinc is a structural constituent of many proteins, including Cu/Zn superoxide dismutase (SOD), an endogenous antioxidant enzyme. Hypozincemia has been found in patients hospitalized with congestive heart failure, where neurohormonal activation, including the renin-angiotensin-aldosterone system (RAAS), is expected and oxidative stress is present. This study was undertaken to elucidate potential pathophysiological mechanisms involved in Zn dyshomeostasis in aldosteronism. In rats receiving aldosterone/salt treatment (ALDOST) alone for 1 and 4 wk or in combination with spironolactone (Spiro), an ALDO receptor antagonist, we monitored 24-h urinary and fecal Zn excretion and tissue Zn levels in heart, liver, and skeletal muscle, together with tissue metallothionein (MT)-I, a Zn(2+)-binding protein, and Cu/Zn-SOD activities in plasma and tissues. When compared with unoperated, untreated, age-/sex-matched controls, urinary and, in particular, fecal Zn losses were markedly increased (P < 0.05) at days 7 and 28 of ALDOST, leading to hypozincemia and a fall (P < 0.05) in plasma Cu/Zn-SOD activity. Microscopic scars and perivascular fibrosis of intramural coronary arteries first appeared in the right and left ventricles at week 4 of ALDOST and were accompanied by increased (P < 0.05) tissue Zn, MT-I, and Cu/Zn-SOD activity, which were not found in uninjured liver or skeletal muscle. Spiro cotreatment prevented cardiac injury and Zn redistribution to the heart. Thus increased urinary and fecal Zn losses, together with their preferential translocation to sites of cardiac injury, where MT-I overexpression and increased Cu/Zn-SOD activity appeared, contribute to Zn dyshomeostasis in rats with aldosteronism, which were each prevented by Spiro. These findings may shed light on Zn dyshomeostasis found in patients with decompensated heart failure.     

Copper in organic proteinate or inorganic sulfate form is equally bioavailable for broiler chicks fed a conventional corn-soybean meal diet

An experiment was conducted to investigate the bioavailability of organic copper (Cu) proteinate relative to inorganic Cu sulfate for broiler chicks fed a conventional corn-soybean meal basal diet. A total of 320 day-old Arbor Acres commercial male chicks were assigned to one of five treatments in a completely randomized design involving a 2 × 2 factorial arrangement with two levels of added Cu (125 or 250 mg Cu/kg) and two Cu sources (Cu proteinate and Cu sulfate) plus a control with no added Cu for an experimental phase of 42 days. Plasma and liver tissue samples were collected at both 21 and 42 days of age, and bile samples were also obtained at 42 days of age for Cu analyses. The Cu concentrations in liver and bile increased linearly (P < 0.001) on both days 21 and 42 as dietary Cu levels increased. No significant (P > 0.17) linear regression relationships were observed between plasma Cu concentrations on days 21 and 42 or log10 liver Cu concentration on day 21 and daily analyzed Cu intake. Therefore, based on the slope ratios from multiple linear regressions of log10 liver and bile Cu concentrations with daily analyzed Cu intake on day 42, when Cu sulfate was set as 100%, the estimated relative bioavailability values of Cu proteinate were 78.8% for log10 liver Cu concentration and 79.3% for log10 bile Cu concentration, respectively. There was no significant (P > 0.08) difference in bioavailability between Cu proteinate and Cu sulfate for broilers chicks in this experiment.     

Intracellular Cu/Zn superoxide dismutase (Cu/Zn-SOD) from hard clam Meretrix meretrix: its cDNA cloning, mRNA expression and enzyme activity

Hard clam (Meretrix meretrix) is an economically important bivalve in China. In the present study, a gene coding for an intracellular Cu/Zn-SOD was cloned and characterized from hard clam. The full-length cDNA of this Cu/Zn-SOD (designated as Mm-icCuZn-SOD) consisted of 1,383?bp, with a 462-bp of open reading frame (ORF) encoding 153 amino acids. Several highly conserved motifs, including the Cu/Zn binding sites [H(46), H(48), H(63), and H(119) for Cu binding; H(63), H(71), H(80), and D(83) for Zn binding], an intracellular disulfide bond and two Cu/Zn-SOD signatures were identified in Mm-icCu/Zn-SOD. The deduced amino acid sequence of Mm-icCu/Zn-SOD has a high degree of homology with the Cu/Zn-dependent SODs from other species, indicating that Mm-icCu/Zn-SOD should be a member of the intracellular Cu/Zn-dependent SOD family. Real-time PCR analysis showed that the highest level of Mm-icCu/Zn-SOD expression was in the hepatopancreas, while the lowest level occurred in the hemocytes. Hard clam challenged with Vibrio anguillarum showed a time-dependent increase in Mm-icCu/Zn-SOD expression that reached a maximum level after 6?h. Mm-icCu/Zn-SOD purified as a recombinant protein expressed in E. coli retained a high level of biological activity, 83?% after 10?min incubation at 10–50?°C, and more than 87?% after incubation in buffers with pH values between 2.2 and 10.2. These results indicated that Mm-icCu/Zn-SOD may play an important role in the innate immune system of hard clam.     

Relative bioavailability of copper in a copper-lysine complex or copper sulfate for ruminants as affected by feeding regimen

An experiment was conducted with 40 crossbred wether lambs to compare the relative bioavailability of Cu from a Cu-lysine complex with that from Cu sulfate under two feeding regimens. Liver biopsy samples were collected by a laparotomy technique and lambs were given 12 days to recover and adapt to individual pens. Lambs were fed either a control basal diet (9.8 mg kg⁻¹ Cu dry matter (DM) basis) or basal supplemented with 180 mg kg⁻¹ Cu as either reagent grade CuSO₄ · 5H₂O or a feed-grade Cu-lysine complex. There were 12 lambs fed control diet and 14 lambs fed each Cu-supplemented diet. Half of the lambs given each diet were fed 1.0 kg of their respective diet once daily at 08:00 h. The remaining half were fed 1.0 kg in equal portions (166 g) six times during a 24 h period at 04:00 h, 08:00 h, 12:00 h, 16:00 h, 20:00 h and 24:00 h. Lambs were fed experimental diets for 10 days, then killed and livers removed for Cu analysis. Lambs fed once daily accumulated more (P < 0.05) Cu in liver than those fed every 4 h. There was no Cu source × feeding regimen interaction (P > 0.10). Based on multiple linear regression slope ratio of log₁₀ transformed final liver Cu concentration on total intake of Cu (mg day⁻¹) with the initial liver biopsy Cu concentration as a covariate, bioavailability of Cu from Cu-lysine relative to Cu sulfate was 93.4% (P > 0.05) for combined feeding regimens.     

Cadmium accumulation, zinc status, and mineral bioavailability of growing rats fed diets high in zinc with increasing amounts of phytic acid

Five groups of individually housed albino rats (n=7, initial average weight=48 g) were fed diets based on egg albumen and cornstarch (basal diet 8.2 g Ca, 6.0 g P, 0.7 g Mg, 225 mg Zn, 150 mg Fe, 60 mg Mn, 8 mg Cu, and 5 mg Cd) over a 4-wk period. Group I (control) was fed the basal diet free of phytic acid (PA). In groups II, III, IV, and V, cornstarch was replaced by 3.5, 7.0, 10.5, and 14.0 g sodium phytate/kg diet, respectively. Daily gain, feed efficiency, Zn status (Zn in plasma, femur, testes, liver and kidneys, activity of the plasma alkaline phosphatase) and apparent absorption of Zn, Fe, Cu, and Mn remained unchanged by the different dietary treatments. PA decreased apparent Mg absorption significantly and apparent absorption of Ca in tendency. Increasing the amount of phytate caused a corresponding enhancement of amount of the digestible P. Cd accumulation in the liver was not significantly altered, and kidney Cd accumulation slightly increased owing to PA. In conclusion, it was shown that under conditions of high dietary Zn, PA had only little effect on the carryover of Cd in growing rats.     

Relationship between dietary copper concentration and acetylcholine-induced vasodilation in the microcirculation of rats

Dietary copper deficiency has been shown to significantly reduce acetylcholine (Ach)-induced vascular smooth muscle relaxation. The current study was designed to examine the relative relationship between dietary copper and the vasodilator response to Ach in the microcirculation of the rat. Male weanling rats were fed a purified basal diet supplemented with 6.0, 3.0, 1.5 or 0.0 microg Cu/g diet for 4 weeks to provide an adequate, two marginal, and deficient intakes of dietary copper. Arteriole dilation in response to increasing concentrations of acetylcholine (10(-7) to 10(-4) M) was measured in the in vivo cremaster muscle microcirculation for each dietary group. Liver copper and both aortic and erythrocyte Cu,Zn-SOD activity were used as indices of systemic copper status. Dilation to the increasing concentrations of Ach was only different in the 0 microg Cu supplemented group compared to the copper-adequate control values. However, the combined results showed an exponential increase in 10(-5) M Ach-induced vasodilation as liver copper concentration increases from 0 microg Cu/g dry wt. This relationship suggests that dilation is attenuated at liver Cu concentrations below 5 microg/g dry wt. The results indicate that Ach-induced vasodilation is copper-dependent but that the pathway is not very sensitive to short-term marginal restriction of copper intake.     

Combined Effects of Muscular Dystrophy,Ecological Stress,and Selenium on Blood Antioxidant Status in Broiler Chickens

The results obtained in this study demonstrated that experimentally induced alimentary muscular dystrophy (MD) in Cobb 500 broiler chickens resulted in increased plasma concentrations of malondialdehyde (MDA), deviations in activities of erythrocyte antioxidant enzymes Cu,Zn-SOD (decrease), and CAT (increase) as well as reduction in plasma concentrations of trace elements Cu, Zn, and Se in affected birds. These data evidenced the presence of oxidative stress in birds with MD, reared both under conditions of ecological comfort and ecological stress. The increased MDA and САТ levels and the reduced Cu,Zn-SOD, Cu, Zn, and Se concentrations in healthy chickens reared under unfavorable microclimatic conditions such as higher air temperature and humidity, higher ammonia concentrations, and lower light intensity were indicative about an induced ecological stress. After the 10-day oral treatment with a selenium-containing preparation, the levels of MDA, Cu,Zn-SOD, CAT, Cu, Zn, and Se attained their normal values in chickens with MD, reared under ecologically comfortable conditions. According to our results, ecological stress was shown to exert independently a significant adverse effect upon the levels of the studied parameters and possibly to be a cause for their slower and not complete normalization despite the selenium therapy in experimental broiler chickens.     

Copper deficient rats and mice both develop anemia but only rats have lower plasma and brain iron levels

Iron homeostasis depends on adequate dietary copper but the mechanisms are unknown. Mice (Mus musculus) and rat (Rattus norvegicus) offspring were compared to determine the effect of dietary copper deficiency (Cu-) on iron status of plasma, liver, brain and intestine. Holtzman rat and Hsd:ICR (CD-1) outbred albino mouse dams were fed a Cu- diet and drank deionized water or Cu supplemented water. Offspring were sampled at time points between postnatal ages 13 and 32. Cu- rat and mouse pups were both anemic, but only rat pups had lower plasma and brain iron levels. Plasma iron was lower throughout the suckling period in Cu- rats but not Cu- mice. Cu- mice derived from dams restricted of Cu only during lactation were also severely anemic without hypoferremia. Intestinal metal analysis confirmed that Cu- pups had major reductions in intestinal concentration of Cu, increased Fe, and normal Zn. However, whole mouse (less the intestine) analysis demonstrated normal content of Fe indicating that the limitation in iron transport by intestinal hephaestin had no consequence to total iron reserves of the mouse. Further research will be needed to determine the reason Cu- mice were anemic since the "ferroxidase" hypothesis does not explain this phenotype.     

Effect of dietary amounts of inorganic and organic zinc on productive and physiological traits of White Pekin ducks

The effects of different dietary amounts of organic and inorganic Zn were studied in male White Pekin ducks (WPD) from 1 to 56 days of age. The control diet (26 ppm of Zn from raw ingredients) was supplemented with 30, 60 and 120 ppm of Zn from both inorganic and organic sources, for a total of seven treatment groups, each containing five replicates of nine 1-day-old ducklings each. BW, feed intake and feed conversion ratio (FCR) were recorded at 1, 28 and 56 days of age. At 56 days of age, five birds per group were used in a digestibility trial to measure Zn retention and excretion. At the end of the trial, five birds per treatment were slaughtered and carcass traits as well as Zn content in tibia and liver were measured. Samples of blood from five birds per treatment were used to measure plasma concentration of Zn and Cu. BW gain during the entire period of the trial increased (P < 0.001) by 30 and 60 ppm of Zn. Increasing Zn contents progressively increased (P < 0.001) the tibia and the liver Zn contents as well as the plasma Zn and Cu contents. The concentration of 120 ppm of Zn increased (P < 0.001) tibia ash and decreased (P < 0.001) abdominal fat in the carcasses. In the period 1 to 56 days, Zn oxide increased (P < 0.001) growth rate and improved (P < 0.03) FCR compared with organic Zn, whereas organic Zn increased (P < 0.003) the dressed carcass percentage. Organic Zinc increased (P < 0.001) Zn and Cu concentration in the plasma. A level of 30 ppm of Zn from an inorganic source was adequate for male WPD during 1 to 56 days of age, based on positive effects of growth rate and Zn excretion.     

The influence of dietary sulphur loading on metabolism and health in young sheep fed low fibre and high starch diet

The purpose of the experiment was to evaluate the long-term effect of a low roughage diet (7-8% CF) with or without sulphur (S) supplementation (elemental and sodium sulphate 1:1) on basal dietary components, Zn, Cu and S availability, rumen metabolism and health in growing sheep. The control diet contained 0.2% and the supplemented diet 0.8% of S on a DM basis. The experiment lasted 12 weeks. The intake of the diet with 0.8% of S resulted in an increase in rumen acetic acid concentration. Rumen lactic acid concentrations in S-supplemented versus control sheep were higher in the first and lower in the third month, and decreased at the end of the third month of the experiment in both groups. Blood plasma pyruvate was lower at the end of the experiment in S-supplemented sheep than in control sheep. In the 5th week of the experiment, the high S diet depressed basal nutritional components as well as Zn and Cu availability. After 12 weeks of feeding of this diet, polioencephalomalacia had developed in all sheep.     

Analysis of the value of copper erythrocyte concentration measurement in the diagnosis of copper deficiency in bovines

BackgroundA reliable and practical method for assessing Cu status in live animals is not available. Blood Cu levels may not accurately reflect the true Cu status of the herd, and can over-predict Cu status during stress and inflammation. On the other hand, assessment of liver Cu is the most reliable indicator of Cu stores, but it is an invasive procedure that requires specialized training. The aim of this study was to evaluate the usefulness of Cu levels in red blood cells to determine the Cu status, with special emphasis in their correlation with erythrocyte Cu, Zn superoxide dismutase enzyme activity (ESOD), in bovines with Cu deficiency induced by high molybdenum and sulfur levels in the diet.MethodsThree similar assays were performed, with a total of twenty eight calves. The Cu-deficient group (n = 15) received a basal diet supplemented with 11 mg of Mo/kg DM as sodium molybdate, and S as sodium sulfate. The control group (n = 13) received a basal diet supplemented with 9 mg of Cu/kg DM as copper sulfate.Samples of blood and liver were taken every 28–35 days. Cu levels were measured in liver (expressed as µg/g DM), plasma (expressed as µg/dl), and erythrocytes (expressed as µg/g Hb) by flame atomic absorption spectroscopy. Superoxide dismutase (SOD1) activity was determined in red blood cells and was expressed as IU/mg hemoglobin.InfoStat Statistical Software 2020 was used for the statistical analysis. Cu levels in plasma, red blood cells and liver, and ESOD activity were analyzed by ANOVA. The correlation between erythrocyte Cu levels and the rest of the parameters were analyzed by Pearson Correlation test. Unweighted Least Squares Linear Regression of SOD1 was developed. The autocorrelation between the monthly measurements was also determined by Durbin-Watson test and autocorrelation function.ResultsThe assays lasted 314–341 days, approximately. Levels indicative of Cu deficiency for bovines were detected at 224 days (23 ± 11.6 µg/g DM) for liver Cu concentration; and at 198 days (55 ± 10.4 µg/dl) for plasma Cu concentration, in Cu-deficient animals. Liver and plasma Cu values indicative of Cu deficiency were not observed in the control group.Pearson Correlation test indicated that all indices of Cu status used in this study were significantly correlated. The highest value was obtained between ESOD and red blood Cu (0.74). There was a significant correlation between red blood Cu and plasma Cu (0.65), and with hepatic Cu (0.57). ESOD activity showed a similar significant positive correlation with liver Cu concentrations and with plasma Cu (0.59 and 0.58, respectively).ConclusionThe extremely low levels of liver and plasma Cu, the ESOD activity, erythrocyte Cu levels, and the periocular achromotrichia observed in the Cu-deficient animals showed that the clinic phase of Cu deficiency was reached in this group. The ESOD activity and erythrocyte Cu levels showed a strong association, indicating that the values of erythrocyte Cu may serve as an effective tool in assessing Cu status and diagnose a long-term Cu deficiency in cattle.     

Dietary pharmacological or excess zinc and phytase effects on tissue mineral concentrations, metallothionein, and apparent mineral retention in the newly weaned pig

Feeding pharmacological zinc (Zn) to weaned pigs improves growth, and dietary phytase improves P and Zn availability. Metallothionein (MT) increases in the duodenum, kidney, and liver of pigs fed 1000 mg Zn/kg with phytase or 2000 mg Zn/kg with or without phytase when fed for 14 d postweaning. The goal of this study was to determine the effects of feeding pharmacological Zn and phytase on tissue minerals, MT, mineral excretion, and apparent retention. Twenty-four newly weaned pigs (20 d; 7.2 kg) were individually fed twice daily, a basal diet supplemented with 0, 1000, or 4000 mg Zn/kg as Zn oxide, without or with phytase (500 phytase units [FTU]/kg) for 14 d, followed by a basal diet (100 mg Zn/kg) without phytase for 7 d. Pigs fed 4000 mg Zn/kg without phytase had higher (p=0.01) plasma, hepatic, renal Zn, renal Cu, and hepatic, renal, and jejunal MT than pigs fed the basal diet or 1000 mg Zn/kg. Duodenal MT was higher (p=0.0001) in pigs fed 1000 and 4000 mg Zn/kg than in pigs fed the basal diet. In pigs fed 1000 and 4000 mg Zn/kg, Zn loading occurred during the first 11 d of supplementation; by d 14, excess Zn was being excreted in the feces.     

Assessment of the Zinc and Copper Status in Alpaca

This study was performed with the aim of investigating the concentration of zinc and copper in the blood of healthy alpacas (Vicugna pacos) kept in central Europe and to compare the concentration of Zn and Cu in plasma and in whole blood. A further objective was to evaluate blood Zn and Cu in relation to different micromineral supplementation, age and sex groups of alpacas. A total of 299 alpacas (224 adults and 75 crias) from 18 farms were included in this study. The concentrations of copper and zinc in plasma/whole blood were measured by flame atomic absorption spectrometry. The results of this study show high individual variability in plasma Zn (median 3.54, range 1.56–8.01 μmol/l), whole blood Zn (median 10.01, range 6.23–75.0 μmol/l), plasma Cu (median 7.53, range 2.93–16.41 μmol/l) and whole blood Cu (median 6.33, range 3.02–13.95 μmol/l). Plasma Zn was not significantly influenced by sex, age or feeding group. Whole blood Zn was only significantly higher in females than in males. The intake of Zn in all groups was equal to or higher than the nutritional recommendation. During excessive supplementation, Zn absorption decreased and thus blood Zn did not reflect the higher intake. Only a weak correlation was found (Spearman correlation coefficient r = 0.384; p > 0.01; n = 204) between plasma and whole blood Zn concentrations. Plasma copper concentration was significantly influenced by age, sex and feeding; whole blood Cu by age and feeding. However, neither plasma Cu nor whole blood Cu reflected the intake of the element. We found a close correlation between plasma and blood copper concentrations (Spearman correlation coefficient r = 0.9043; p ≤ 0.01; n = 99). According to our results, copper in plasma or blood is not a good indicator of copper intake.     

Effects of Zinc Glycinate on Productive and Reproductive Performance,Zinc Concentration and Antioxidant Status in Broiler Breeders

An experiment was conducted to investigate the effects of zinc glycinate (Zn-Gly) supplementation as an alternative for zinc sulphate (ZnSO₄) on productive and reproductive performance, zinc (Zn) concentration and antioxidant status in broiler breeders. Six hundred 39-week-old Lingnan Yellow broiler breeders were randomly assigned to 6 groups consisting of 4 replicates with 25 birds each. Breeders were fed a basal diet (control group, 24 mg Zn/kg diet), basal diet supplemented with 80 mg Zn/kg diet from ZnSO₄ or basal diet supplemented with 20, 40, 60 and 80 mg Zn/kg diet from Zn-Gly. The experiment lasted for 8 weeks after a 4-week pre-test with the basal diet, respectively. Results showed that Zn supplementation, regardless of sources, improved (P?<?0.05) the feed conversion ratio (kilogram of feed/kilogram of egg) and decreased broken egg rate, and elevated (P?<?0.05) the qualified chick rate. Compared with the ZnSO₄ group, the 80 mg Zn/kg Zn-Gly group significantly increased (P?<?0.05) average egg weight, fertility, hatchability and qualified chick rate, whereas it decreased (P?<?0.05) broken egg rate. The Zn concentrations in liver and muscle were significantly higher (P?<?0.05) in 80 mg Zn/kg Zn-Gly group than that in ZnSO₄ group. Compared with ZnSO₄ group, 80 mg Zn/kg Zn-Gly group significantly elevated (P?<?0.05) the mRNA abundances of metallothionein (MT) and copper-zinc superoxide (Cu-Zn SOD), as well as the Cu-Zn SOD activity and MT concentration in liver. Moreover, the 80 mg Zn/kg Zn-Gly group had higher (P?<?0.05) serum T-SOD and Cu-Zn SOD activities than that in the ZnSO₄ group. This study indicated that supplementation of Zn in basal diet improved productive and reproductive performance, Zn concentration and antioxidant status in broiler breeders, and the 80 mg Zn/kg from Zn-Gly was the optimum choice for broiler breeders compared with other levels of Zn from Zn-Gly and 80 mg/kg Zn from ZnSO₄.     

Limited effects of combined dietary copper deficiency/iron overload on oxidative stress parameters in rat liver and plasma

Copper (Cu) deficiency decreases the activity of Cu-dependent antioxidant enzymes such as Cu,zinc-superoxide dismutase (Cu,Zn-SOD) and may be associated with increased susceptibility to oxidative stress. Iron (Fe) overload represents a dietary oxidative stress relevant to overuse of Fe-containing supplements and to hereditary hemochromatosis. In a study to investigate oxidative stress interactions of dietary Cu deficiency with Fe overload, weanling male Long–Evans rats were fed one of four sucrose-based modified AIN-93G diets formulated to differ in Cu (adequate 6 mg/kg diet vs. deficient 0.5 mg/kg) and Fe (adequate 35 mg/kg vs. overloaded 1500 mg/kg) in a 2×2 factorial design for 4 weeks prior to necropsy. Care was taken to minimize oxidation of the diets prior to feeding to the rats. Liver and plasma Cu content and liver Cu,Zn-SOD activity declined with Cu deficiency and liver Fe increased with Fe overload, confirming the experimental dietary model. Liver thiobarbituric acid reactive substances were significantly elevated with Fe overload (pooled across Cu treatments, 0.80±0.14 vs. 0.54±0.08 nmol/mg protein; P<.0001) and not affected by Cu deficiency. Liver cytosolic protein carbonyl content and the concentrations of several oxidized cholesterol species in liver tissue did not change with these dietary treatments. Plasma protein carbonyl content decreased in Cu-deficient rats and was not influenced by dietary Fe overload. The various substrates (lipid, protein and cholesterol) appeared to differ in their susceptibility to the in vivo oxidative stress induced by dietary Fe overload, but these differences were not exacerbated by Cu deficiency.