Dietary Copper Levels Research Articles

118 Effects of dietary copper levels on growth performance and response to lipopolysaccharide challenge in nursery pigs from sows fed either high or low copper diets

118 Effects of dietary copper levels on growth performance and response to lipopolysaccharide challenge in nursery pigs from sows fed either high or low copper diets

Effect of feeding different levels of dietary copper on production performance, egg quality traits, serum and egg yolk cholesterol content in laying quails

An experiment was conducted with CARI Uttam laying quails (n=120) during 11 to 24 weeks of age to evaluate optimum dietary copper (Cu) level for egg production, egg quality traits, serum and egg yolk cholesterol content. A basal diet having 20% protein and 2700 kcal ME/kg and 5mg Cu/kg was prepared. Five other experimental diets were formulated by addition of Cu sulphate to achieve 10, 15, 100, 150 and 200 mg Cu/kg diet. Each of such diet was offered as mash ad-libitum to laying quails randomly divided into six treatment groups with 10 replicates of two birds each reared in quail laying cages. Significantly (P<0.05) lower egg production was observed at 200mg Cu/kg diet than those fed other diets. The body weight change, feed conversion ratio, egg weight and egg quality traits did not differ significantly due to different dietary treatments. The cholesterol content in egg yolk was significantly(P<0.05) lower in groups fed diets containing 100, 150 and 200 mg Cu/kg diets than other dietary groups at both 45 and 90 days of feeding period. The serum total cholesterol content was also significantly (P<0.05) lower in 100, 150 and 200 mg Cu/kg dietary groups. Based on the results, it was concluded that for optimum production performance and egg quality traits laying quails required 5 mg Cu/kg diet, but feeding copper at 100 mg/kg diet, decreased the egg yolk and serum cholesterol content by 19% and 27%, respectively without affecting the production performance.

Dose-dependent effects of copper supplementation of nursery diets on growth performance and fecal consistency in weaned pigs1

Pharmacological levels of dietary copper (150–250 mg/kg) improve growth performance in pigs, but the majority of Cu is excreted in the manure and may contribute to accumulation in the soil. This experiment with 4 levels of dietary Cu supplementation (15, 80, 120, and 160 mg/kg) from weaning to d 56 after weaning was conducted to determine the dose-dependent effects of dietary Cu on growth performance and fecal consistency in pigs. From d 56 to slaughter, all pigs received the same grower and finisher diets supplemented with 15 mg/kg Cu. Each treatment comprised 10 pens with 8 pigs each, mixed males and females, as experimental units. The pigs were housed in a nursery unit until d 40 after weaning and in a grow–finish unit thereafter. Growth performance and fecal consistency were determined in 2-wk intervals until d 56; thereafter, growth performance was monitored between d 56 and slaughter. The Cu supplementation linearly increased ADFI and ADG (P Pharmacological levels of dietary copper (150–250 mg/kg) improve growth performance in pigs, but the majority of Cu is excreted in the manure and may contribute to accumulation in the soil. This experiment with 4 levels of dietary Cu supplementation (15, 80, 120, and 160 mg/kg) from weaning to d 56 after weaning was conducted to determine the dose-dependent effects of dietary Cu on growth performance and fecal consistency in pigs. From d 56 to slaughter, all pigs received the same grower and finisher diets supplemented with 15 mg/kg Cu. Each treatment comprised 10 pens with 8 pigs each, mixed males and females, as experimental units. The pigs were housed in a nursery unit until d 40 after weaning and in a grow–finish unit thereafter. Growth performance and fecal consistency were determined in 2-wk intervals until d 56; thereafter, growth performance was monitored between d 56 and slaughter. The Cu supplementation linearly increased ADFI and ADG (P

Effect of different levels of dietary zinc, manganese, and copper from organic or inorganic sources on performance, bacterial chondronecrosis, intramuscular collagen characteristics, and occurrence of meat quality defects of broiler chickens

The aim of the experiment was to assess the effects of 2 dietary levels of trace minerals (TM) zinc, manganese, and copper either from organic (OTM) or inorganic (ITM) sources on broiler performance, carcass traits, intramuscular collagen (IMC) properties, occurrence of hock burns (HB), foot pad dermatitis (FPD), femoral and tibia head necrosis, and breast muscle abnormalities (white striping, WS; wooden breast, WB; poor cohesion, PC). A total of 3,600 one-day-old male chicks were randomly assigned to one of 4 dietary treatments in a 2 × 2 factorial arrangement (9 replicates of 100 birds/dietary treatment). Birds were slaughtered at 31 (thinning) and 51d of age. Body weight, daily weight gain (DWG), feed intake, feed conversion rate (FCR), and mortality were determined. A significant effect of the source of TM supplementation was found only in 51-day-old chickens. Birds of the OTM groups were heavier (P < 0.05), with a higher (P < 0.05) DWG and a better FCR (P < 0.05) compared with those of the ITM groups. OTM significantly reduced the lesion scores of femoral head (P = 0.004) and total leg (femur + tibia, P = 0.02) compared to ITM, which is mainly caused by the reduction of the percentages of femoral head transitional degeneration (FHT, P = 0.04) and femoral head necrosis (FHN, P = 0.07). Carcass traits were similar among the experimental groups. No alleviating effect of TM administration on the incidence of FPD and HB in 31- and 51-day-old chickens was found. Similarly, the occurrence and the degrees of WS and WB in 51-day-old chickens was affected neither by the doses nor by the source of TM supplied. IMC characteristics of broiler pectoral muscle were not affected (P > 0.05) by the different sources and doses of TM administrated.

Dietary copper requirement of fingerlingChanna punctatus(Bloch) based on growth, feed conversion, blood parameters and whole body copper concentration

A 12-week feeding trial was conducted to estimate the dietary copper requirement of fingerling Channa punctatus. Six casein−gelatin-based test diets (450 g kg−1 crude protein; 18.81 kJ g−1 gross energy) with graded levels of copper as copper sulphate (3.7, 4.7, 5.7, 6.7, 7.7 and 8.7 mg copper equivalent kg−1 diet) were formulated and fed to triplicate groups of fish (7.25 ± 0.81 cm; 5.21 ± 0.27 g) near to satiation. Fish fed diet with 6.7 mg kg−1 copper had highest absolute weight gain (AWG; 51.63 g fish−1), protein efficiency ratio (PER; 1.42 g fish−1), protein gain (PG; 8.34 g fish−1), haemoglobin (Hb; 9.68 g dL−1), haematocrit (Hct; 31.18%) and RBCs (3.24 × 106 × mm−3). Feed conversion ratio (FCR) was found to be best (1.57) at above level of dietary copper. Whole body copper concentration was found to increase with the increasing levels of dietary copper. Hepatic thiobarbituric acid-reactive substances concentration was found to decrease with increasing dietary concentrations of copper up to 6.7 mg kg−1 beyond which a reverse trend in this parameter was noted. Broken-line regression analysis of AWG, FCR and PG concentrations against varying levels of dietary copper yielded the requirement in the range of 6.66–6.78 mg kg−1. Data generated during this study would be useful in formulating copper-balanced commercial feeds for the intensive culture of this fish.

Extensive Literature Search on the ‘Effects of Copper intake levels in the gut microbiota profile of target animals, in particular piglets’

Extensive Literature Search on the ‘Effects of Copper intake levels in the gut microbiota profile of target animals, in particular piglets’

In vivo effects of high dietary copper levels on hepatocellular mitochondrial respiration and electron transport chain enzymes in broilers

The diet of broiler chickens supplemented with increasing concentrations of copper (Cu) was assessed for the effect of Cu on liver mitochondrial function.A total of 160, 1-d-old Cobb 500 broilers (Gallus domesticus) were randomly assigned in equal numbers into 4 groups, which differed in the concentration of copper supplements in the diet; 11 (control), 110, 220 and 330 mg of Cu/kg dry matter. Liver mitochondrial function was recorded at 12, 24, 36, 48 and 60 d of age.Supplementation with 110 mg Cu/kg dry matter enhanced mitochondrial function and activities of complexes I–V, and this was significant at 36 d of age compared with the other diets (P < 0.05). Supplementation with 220 mg Cu/kg dry matter and 330 mg Cu/kg dry matter enhanced mitochondrial function and activities of complexes I–V at 12, 24 and 36 d of age, but displayed reduced function (P < 0.05) at 48 and 60 d of age except in complex IV (P > 0.05). Mitochondrial hydrogen peroxide (H2O2) production was also increased (P < 0.05) with an increase of copper supplementation in the diet.The results indicate that appropriate dietary copper supplements are sufficient for improving mitochondrial function and activities of the respiratory complexes. Higher concentrations of copper, on the other hand, lead to copper toxicity by affecting certain respiratory complexes.

Copper, zinc and iron levels in infants and their mothers during the first year of life: a prospective study.

BackgroundEssential micronutrients are important for maintenance of life. Deficiency of micronutrients is more likely to be encountered in children, and women studies are required to investigate the status of micronutrients in children and women. This study aimed to longitudinally evaluate changes in zinc, copper, and iron levels in breastfed infants and their mothers during the first year of life.MethodsSerum and hair samples were obtained from 35 healthy breastfed infants (51 % males, 49 % females) and their mothers 2, 6, and 12 months after delivery. All of the samples were assessed using an atomic absorption spectrophotometer. Serum iron levels were determined by a Roche/Hitachi/Modular analyzer. Statistical analyses were performed using SPSS-PC (Version 21.00) software.ResultsHair zinc (p < 0.05) and serum iron (p < 0.001) levels of infants were significantly decreased towards the end of the first year. Infants’ serum copper levels were increased towards the end of the first year. Maternal serum and hair copper levels and serum iron levels were significantly decreased towards the end of the first year. There were no significant correlations between dietary zinc, copper, iron intake, and trace element levels of infants and their mothers.ConclusionsInfants’ hair zinc levels, maternal and infants’ hair copper levels, and infants’ and maternal serum iron levels declined towards the end of the first year. Infants need more zinc after 6 months of age. Infants’ and mothers’ daily iron intake was less than the recommended intake.

Effects of Dietary Different Doses of Copper and High Fructose Feeding on Rat Fecal Metabolome.

The gut microbiota plays a critical role in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). Increased fructose consumption and inadequate copper intake are two critical risk factors in the development of NAFLD. To gain insight into the role of gut microbiota, fecal metabolites, obtained from rats exposed to different dietary levels of copper with and without high fructose intake for 4 weeks, were analyzed by comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GC × GC-TOF MS). In parallel, liver tissues were assessed by histology and triglyceride assay. Our data showed that high fructose feeding led to obvious hepatic steatosis in both marginal copper deficient rats and copper supplementation rats. Among the 38 metabolites detected with significant abundance alteration between groups, short chain fatty acids were markedly decreased with excessive fructose intake irrespective of copper levels. C15:0 and C17:0 long chain fatty acids, produced only by bacteria, were increased by either high copper level or high fructose intake. In addition, increased fecal urea and malic acid paralleled the increased hepatic fat accumulation. Collectively, GC × GC-TOF MS analysis of rat fecal samples revealed distinct fecal metabolome profiles associated with the dietary high fructose and copper level, with some metabolites possibly serving as potential noninvasive biomarkers of fructose induced-NAFLD.

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.

Effects of dietary copper on elemental balance, plasma minerals and serum biochemical parameters of growing-furring male mink (Mustela vison).

The objectives of this study were to study the effects of different levels of dietary copper on copper and zinc balance, plasma minerals and serum biochemical parameters of mink in the growing-furring periods. One hundred and five standard dark male mink were randomly assigned to seven groups with the following dietary treatments: basal diet with no supplemental Cu (Control); basal diet supplemented with either 6, 12, 24, 48, 96, or 192 mg/kg Cu from copper sulfate, respectively. The average daily gain (ADG) linearly (P = 0.0026, P = 0.0006) responded to increasing levels of Cu; maximal growth was seen in the Cu24 group. Feed efficiency tended to improve with the increase of dietary copper level (linear P = 0.0010, quad, P = 0.0011). Fecal copper, urinary copper, retention copper responded in a linear (P < 0.05) fashion with increasing level of Cu. The effect of level of Cu was linear (P < 0.001) for plasma Cu concentration. The serum glutamic-oxalacetic transaminase (GOT) and glutamic-pyruvic transaminase (GPT) activities were increased linearly (P < 0.05) with dose of Cu, but serum total protein (TP) and albumin (ALB) concentrations decreased linearly (P < 0.05) as dietary copper levels increased. Effect of level of Cu was linear (P < 0.001) for serum ceruloplasmin (CER) concentration or Cu-Zn superoxide dismutase (Cu-Zn SOD) activity. Supplemental dose of Cu linearly decreased serum triglyceride (TG) (P = 0.011) and total cholesterol (TC) (P = 0.007). Our results indicated that the activity of Cu-dependent enzymes was enhanced by increasing dietary Cu concentration and that supplementation of Cu in the diet of mink could alter the plasma lipid profile and copper concentration.

Effects of dietary copper on organ indexes, tissular Cu, Zn and Fe deposition and fur quality of growing-furring male mink (Mustela vison).

The objectives of this study were to study the effects of different levels of dietary copper on organ indexes, tissular Cu, Zn and Fe deposition and fur quality of mink in the growing-furring periods. One hundred and five standard dark male mink were randomly assigned to seven groups with the following dietary treatments: basal diet with no supplemental Cu (Control); basal diet supplemented with either 6, 12, 24, 48, 96 and 192 mg/kg Cu from copper sulphate, respectively. The colour intensity scores displayed a linear trend (P = 0.057). The spleen Cu concentrations responded in a linear (P < 0.05) fashion with increasing level of Cu, but copper supplementation did not affect speen concentrations of Fe or Zn. Supplemental dose of Cu linearly increased (P < 0.05) liver Cu and Fe concentrations but did not alter (P > 0.10) liver Zn. Our results indicate that Cu plays an important role in the pigmentation in growing-furring mink, and supplemental dietary Cu in growing-furring mink improve hair colour, and copper has limited effects on liver mineral deposition.

Effects of dietary copper supplementation on nutrient digestibility, serum biochemical indices, and growth rate of young female mink (Neovison vison)

The objective of this study was to determine whether nutrient digestibility and growth performance of mink were affected by different dietary copper levels. Ninety-six 60-day-old healthy female minks were randomly assigned to 8 treatment groups with 12 animals in each group and fed a diet supplemented with either 0, 4, 8, 16, 32, 64, 128 or 256 mg/kg copper as CuSO&lt;sub&gt;4 &lt;/sub&gt;&amp;times; 5H&lt;sub&gt;2&lt;/sub&gt;O, respectively. Our data showed that body weight and average daily gain increased (linear and quadratic, P &amp;lt; 0.05) as Cu increased in the diet, the highest body weight and average daily gain were seen in the Cu32 group. Feed : gain ratio responded in a linear (P = 0.0025) fashion with increasing level of Cu, the lowest feed : gain ratio was seen in the Cu64 group. Digestibility of ether extract responded in a linear (P = 0.0190) fashion with increasing level of Cu. There were no differences in apparent digestibility of dry matter, CP, and gross energy among groups (P &amp;gt; 0.05). N retention linearly (P = 0.0363) responded to increasing levels of Cu. Glutamic-oxalacetic transaminase and glutamic-pyruvic transaminase increased (linear and quadratic, P &amp;lt; 0.05) as Cu increased in the diet; the highest glutamic-oxalacetic transaminase and glutamic-pyruvic transaminase were seen in the Cu256 group. Total protein of the minks was similar among the treatments, however, albumin in serum responded in a linear (P = 0.0370) and quadratic (P = 0.0049) fashion with increasing level of Cu. The activity of ceruloplasmin responded in a linear (P = 0.0001) and quadratic (P = 0.0203) fashion with increasing level of Cu. The activity of Cu-Zn superoxide dismutase responded in a linear (P = 0.0010) fashion with increasing level of Cu. Our results indicate that supplemental Cu plays an important role in the growth performance of mink, helping young female mink digest and efficiently utilize added dietary fat. &amp;nbsp;

Comparative evaluation of copper sulfate and tribasic copper chloride on growth performance and tissue response in Pacific white shrimp Litopenaeus vannamei fed practical diets

Abstract Two trials were conducted to evaluate the response of Pacific white shrimp Litopenaeus vannamei to dietary copper sulfate containing 25.45% copper (Cu) and tri-basic copper chloride (TBCC) containing 58.81% Cu. The basal diet used in each trial was primarily composed of fishmeal, soybean meal, corn starch, and whole wheat and was formulated to contain approximately 10 mg Cu kg − 1 . In trial 1, two sets of diets, one supplemented with copper sulfate (6, 12, and 24 mg Cu kg − 1 ) and the other with TBCC (6, 12, and 24 mg Cu kg − 1 ) were conducted in a clear water recirculating system (N = 4; 0.31 g initial weight) for 8 weeks. In trial 2, shrimp (N = 4; 0.39 g initial weight) was fed the same six diets as trial 1 for 6 weeks in an outdoor green water recirculating system. At the conclusion of the trials, final mean weight, percent weight gain, final biomass, feed conversion ratio (FCR), and survival were determined. There were no significant effects from dietary copper levels on final mean weight, final biomass, FCR, and survival. There was a significant effect of the source of Cu on tissue levels, with shrimp fed TBCC having lower tissue Cu levels in both trials. Copper analysis of select tissues (carapace, hepatopancreas, and hemolymph) of shrimp from trials 1 and 2 indicated some significant difference among the treatments. In trials 1 and 2, when the tissue concentrations are pooled across dietary levels for each copper source, copper levels of the tissues from shrimp fed TBCC were significantly lower than those of shrimp fed diets supplemented with copper sulfate. Application of a slope ratio approach using linear regression of log 10 transformed tissues copper concentration on analyzed copper level indicated a lower bioavailability from TBCC compared with copper sulfate. The results of the present study demonstrate that TBCC is an effective copper source.

Effects of dietary selenium, sulphur and copper levels on selenium concentration in the serum and liver of lamb.

Thirty-two lambs were distributed in eight treatments under 2×2×2 factorial experiment to compare the effects of two levels of selenium (0.2 to 5 mg/kg dry matter [DM]), sulphur (0.25% and 0.37%) and copper (8 and 25 mg/kg DM) levels on selenium concentration in liver and serum of lambs. A liver biopsy was done on all animals and blood samples were collected from the jugular vein prior to the beginning of the treatments. The blood was sampled every thirty days and the liver was sampled after 90 days, at the slaughter. Increasing differences were noticed during the data collection period for the serum selenium concentration, and it was found to be 0.667 mg/L in animals fed with 5 mg Se/kg DM and normal sulphur and copper concentrations in their diet. However, a three-way interaction and a reduction of selenium concentration to 0.483 mg/L was verified when increasing copper and sulphur concentration levels to 25 ppm and 0.37% respectively. The liver selenium concentration was also high for diets containing higher selenium concentrations, but the antagonist effect with the increased copper and sulphur levels remained, due to interactions between these minerals. Therefore, for regions where selenium is scarce, increasing its concentration in animal diets can be an interesting option. For regions with higher levels of selenium, the antagonistic effect of interaction between these three minerals should be used by increasing copper and sulphur dietary concentrations, thus preventing possible selenium poisoning.

Dietary copper requirements of juvenile large yellow croaker Larimichthys croceus

A 10-week feeding trial was conducted to estimate the requirement of dietary copper for juvenile large yellow croaker Larimichthys croceus (initial body weight, 9.18 ± 0.06 g). Six graded levels of dietary copper were designed as 2.61, 3.25, 4.65, 7.16, 11.38, and 18.45 mg kg− 1, respectively. Results showed that fish fed the basal diet with 2.61 mg kg− 1 of copper had the significantly lowest weight gain rate (WGR), activity of copper-zinc superoxide dismutase (Cu-Zn SOD), the total antioxidant capacity (T-AOC), the whole-body Cu concentration and the vertebrae Cu concentration (P < 0.05). When dietary copper increased from 2.61 to 4.65 mg kg− 1, the WGR significantly increased (P < 0.05). Higher dietary copper contents did not result in further increasing of WGR. Higher (> 7.16 mg kg− 1) dietary copper content significantly decreased the Cu-Zn SOD activity and T-AOC in liver (P < 0.05). No significant differences were found in survival, feed efficiency, body compositions, hepatosomatic index, viscerosomatic index and condition factor among the all treatments (P > 0.05). Based on the WGR, the optimal dietary copper content for large yellow croaker was estimated to be 3.41 mg kg− 1. Based on the whole-body Cu concentration, the vertebrae Cu concentration and the Cu-Zn SOD activity in serum, the minimum dietary copper content was estimated to be 5.30, 5.90 and 7.05 mg kg− 1, respectively.

Effect of various levels of dietary copper on liver transaminases, total immunoglobulin and antioxidant status in hariana heifers.

This study was conducted to see the effect of different levels of copper containing mineral supplements on liver transaminase, total immunoglobulin and antioxidant status in heifers (Hariana; Bos indicus ). Eighteen heifers were randomly allotted to 3 dietary treatments (average body weight 145.0±1.0 kg, age 14-18 months) having 6 animals in each and fed for a period of 60 days. Control group G1 was fed basal ration (9.8 mg Cu/kg) comprising of concentrate mixture, berseem and wheat straw without mineral supplementation, G2 (50.1 mg Cu/kg) and G3 (90.4 mg Cu/kg) were supplemented with mineral supplements containing 2.1 and 4.2% CuSO4, respectively. During 60 days feeding trial, blood samples were collected to analyze for liver enzymes (ALT and AST), total immunoglobulin and total antioxidant activity (FRAP assay). Supplementation of Cu containing mineral mixture above (50 or 90 mg Cu/kg DM) physiological requirement did not adversely affected liver transaminase activity, immune status and antioxidant status. It may be concluded that a Cu level (50 ppm) higher than recommended (10 ppm) may be supplemented in the diet of growing animals without compromising health, improving tissue quality and productivity.

Copper overload and deficiency both adversely affect the central nervous system of Drosophila.

The human copper homeostasis disorders Menkes and Wilson disease both have severe neurological symptoms. Menkes is a copper deficiency disorder whereas Wilson disease patients suffer from copper toxicity, indicating that tight control of neuronal copper levels is essential for proper nervous system development and function. Here we examine the consequences of neuronal copper deficiency and excess in the Drosophila melanogaster nervous system, using targeted manipulation of the copper uptake genes Ctr1A and Ctr1B and efflux gene ATP7 in combination with altered dietary copper levels. We find that pan-neuronal over expression of Ctr1B and ATP7 both result in a reduction in viability. The effects of Ctr1B over expression are exacerbated by dietary copper supplementation and rescued by copper limitation indicating a copper toxicity phenotype. Dietary manipulation has the opposite effect on ATP7 over expression, indicating that this causes neuronal copper deficiency due to excessive copper efflux. Copper deficiency also causes a highly penetrant developmental defect in surviving adult flies which can be replicated by both copper excess and copper deficiency targeted specifically to a small subset of neuropeptidergic cells. We conclude that both copper overload and excess have detrimental effects on Drosophila neuronal function, reducing overall fly viability as well as impacting on a specific neuropeptide pathway.

Effects of dietary copper sources on growth, tissue copper accumulation and physiological responses of Japanese sea bass (Lateolabrax japonicus) (Cuvier, 1828) fed semipurified or practical diets

An 8-week trial was conducted to compare the efficacy of a chelated copper (Cu) with the inorganic Cu (CuSO4), in the diet of Japanese sea bass (Lateolabrax japonicus). Six diets were prepared based on two basal diets (semi-purified or practical) at two Cu inclusion levels (0 and 4 mg kg−1 from or chelated-Cu), accordingly named as S0, SI4, SM4, P0, PI4 and PM4 respectively. Each diet was fed to quadruplicate groups of Japanese sea bass (initial weight: 65.0 ± 0.03 g) during the trial. Fish fed practical diets had higher feed intake, specific growth rate, protein efficiency rate (PER), liver Cu accumulation, liver Na+K+-ATPase and plasma alkaline phosphatase, but lower hepatosomatic index than the groups fed semi-purified diets (P < 0.05). Higher PER was exhibited by fish fed chelated-Cu diets than that of fish fed CuSO4 diets (P < 0.05). Although liver Cu accumulation was significantly higher in fish fed practical diets,, liver Cu content increased significantly with increasing dietary copper levels only in fish fed semipurified diets. Chelated-Cu has higher efficiency than CuSO4 when fed in practical diets. Poor growth performance of fish fed semipurified diets might induce underestimating the nutrient requirement of Japanese sea bass.

Does Dietary Copper Supplementation Enhance or Diminish PCB126 Toxicity in the Rodent Liver?

Copper is essential for the function of the mitochondrial electron transport chain and several antioxidant proteins. However, in its free form copper can participate in Fenton-like reactions that produce reactive hydroxyl radicals. Aryl-hydrocarbon receptor (AhR) agonists, including the most potent polychlorinated biphenyl (PCB) congener, 3,3',4,4',5-pentachlorobiphenyl (PCB126), increase copper levels in rodent livers. This is accompanied by biochemical and toxic changes. To assess the involvement of copper in PCB toxicity, male Sprague-Dawley rats were fed an AIN-93G diet with differing dietary copper levels: low (2 ppm), adequate (6 ppm), and high (10 ppm). After three weeks, rats from each group were given a single ip injection of corn oil (control), 1, or 5 μmol/kg body weight PCB126. Two weeks following injections, biochemical and morphological markers of hepatic toxicity, trace metal status, and hepatic gene expression of metalloproteins were evaluated. Increasing dietary copper was associated with elevated tissue levels of copper and ceruloplasmin. In the livers of PCB126-treated rats, the hallmark signs of AhR activation were present, including increased cytochrome P450 and lipid levels and decreased glutathione. In addition, a doubling of hepatic copper levels was seen, and overall metal homeostasis was disturbed, resulting in decreased hepatic selenium, manganese, zinc, and iron. Expression of key metalloproteins was either decreased (cytochrome c oxidase), unchanged (ceruloplasmin and CuZnSOD), or increased (tyrosinase and metallothioneins 1 and 2) with exposure to PCB126. Increases in metallothionein may contribute/reflect the increased copper seen. Alterations in dietary copper did not amplify or abrogate the hepatic toxicity of PCB126. PCB126 toxicity, i.e., oxidative stress and steatosis, is clearly associated with disturbed metal homeostasis. Understanding the mechanisms of this disturbance may provide tools to prevent liver toxicity by other AhR agonists.