Dietary Copper Supplementation Research Articles

Effect of Dietary Inorganic Copper on Growth Performance and Some Hematological Indices of Siberian Sturgeon Acipenser baerii Juveniles

AbstractThis research work was conducted to evaluate the effect of dietary copper (Cu) levels on growth performance, feed utilization, and some hematological parameters of juvenile Siberian Sturgeon Acipenser baerii. Five semipurified diets containing 0, 3, 6, 12, and 24 mg Cu/kg in the form of copper sulfate pentahydrate (CuSO4·5H2O) were formulated to provide the actual dietary copper values of 1.8, 5.7, 10.1, 15.9, and 28.3 mg Cu/kg diet, respectively. The obtained results exhibited a significant improvement in the final weight, protein efficiency ratio, daily growth coefficient, and hepatosomatic index with increasing dietary copper levels up to 10.1 mg/kg diet, while the feed conversion ratio significantly decreased. Also, erythrocyte count, hemoglobin, and hematocrit values increased with increasing levels of dietary copper, but no steady trend was observed in mean corpuscular hemoglobin changes. Furthermore, the neutrophils were significantly increased with enhancing the copper level in the fish diet, while the lymphocytes declined. Findings of the current research illustrate that an appropriate dietary copper level is required for improvement of growth performance, oxygen transfer capability, and white blood cell proliferation. Based on the broken‐line regression analysis of leukocyte count and monocyte percentage, the optimum dietary copper supplementation was estimated to be 10.63 and 10.36 mg Cu/kg diet, respectively.

Effects of dietary copper on growth, antioxidant capacity and immune responses of juvenile blunt snout bream (Megalobrama amblycephala) as evidenced by pathological examination

The goal of this study was to investigate the effects of dietary Cu on growth, antioxidant capacity and immune responses in juvenile blunt snout bream with histological examination. Fish were fed three practical diets containing graded copper levels ranging from 1.43 mg/kg-9.13 mg/kg for 10 weeks. The control diet (1.43 mg/kg) significantly improved the growth performance of blunt snout bream (P < 0.05). The 5.21 mg/kg dietary copper significantly increased immunoglobin M (IgM) and complement 3 (C3) content and significantly decreased the activity of alanine transaminase (ALT) in plasma (P < 0.05). The diets containing 5.21 and 9.13 mg/kg copper significantly increased albumin (ALB) content and significantly decreased triglyceride (TG) content (P < 0.05). Dietary copper supplementation improved antioxidant capacity and decrease the content of malondialdehyde (MDA) by regulating the activities of catalase (CAT), total superoxide dismutase (T-SOD) and copper zinc superoxide dismutase (Cu/Zn-SOD) (P < 0.05). With respect to the mRNA levels, the 5.21 mg/kg dietary copper significantly lowered the Kelch-like ECH associated protein 1 (Keap1) mRNA levels and significantly increased the nuclear factor erythroid 2-related factor 2 (Nrf2) mRNA levels (P < 0.05). Furthermore, significant improvements in Cu/Zn-SOD, CAT and heat stress protein 70 (HSP70) mRNA levels were observed in fish fed the 5.21 and 9.13 mg/kg dietary coppers. The relative expression of HO-1 was significantly enhanced in fish fed the 5.21 mg/kg dietary copper (P < 0.05). Dietary copper supplementation affected nuclear factor-kappa B (NF-κB) expression, which further decreased the mRNA levels of pro-inflammatory cytokines, including tumour necrosis factor-alpha (TNF-α), interleukin 8 (IL-8) and interleukin 1β (IL-1β), and increased the mRNA levels of anti-inflammatory cytokines, including interleukin 10 (IL-10). With respect to histological examination, there were no obvious pathological differences among the three groups. Overall, our study indicated that suitable dietary copper supplementation could improve growth performance and antioxidant capacity and weaken the inflammatory response in blunt snout bream.

Effects of inorganic and organic dietary copper supplementation on growth performance and tissue composition for juvenile red drum ( Sciaenops ocellatus L.)

A feeding trial was conducted to evaluate the dietary copper requirement of red drum (Sciaenops ocellatus) and compare the bioavailability of copper sulphate (CuSO₄) and copper‐ethanolamine. A basal diet was formulated using semi‐purified ingredients and analysed to contain 3 mg Cu/kg. Both copper sources were supplemented to the basal diet at either 5, 10 or 20 mg Cu/kg of dry diet. No significant differences were observed in growth performance of fish fed the various diets. However, red drum fed all copper‐supplemented diets retained more copper in liver and whole‐body tissues compared to fish fed the basal diet. Within both inorganic and organic copper treatments, the highest tissue copper concentrations were observed in fish fed diets supplemented with 10 mg Cu/kg. No significant differences were detected in net copper retention regardless of the nature of the copper source; hence, the bioavailability of copper sulphate and copper‐ethanolamine complex was not different in the diets for juvenile red drum. Furthermore, the minimum copper requirement for growth performance of juvenile red drum appeared to be satisfied when fish were fed the basal diet containing 3 mg Cu/kg diet, and no detrimental effects were observed in red drum fed diets supplemented with 20 mg Cu/kg.

Effect of Dietary Copper and Zinc Supplementation on Semen Quality of Murrah Bulls

The effect of dietary supplementation of Cu and Zn on semen quality parameters and certain bio-chemicals parameters were evaluated in Murrah bulls. Twelve mature Murrah bulls (4-6 years of age) were divided into three groups (n=4) T1, T2, and T3 based on semen volume and concentration and were fed as per ICAR standard (2013). However, the animals were supplemented with 0%, 25%, and 50% Cu and Zn above the basal diet in T1, T2 and T3 groups, respectively for 180 days. Quantitative and qualitative characteristics of semen, blood and seminal plasma antioxidant status, blood and semen minerals (Cu, Zn, Ca and Mn) were determined in experimental Murrah bulls. Semen ejaculate volume (mL) increased in T2 and T3 while sperm concentration (million/mL), intact acrosome (%), HOST reacted spermatozoa (%) increased in T3 group compared to T1 and T2 groups. No difference was observed in mass motility, pH, live spermatozoa (%) in semen sexual behaviour except dismounting time which was decreased in T3 than T1 and T2 (plessthan0.05). SOD activity in blood plasma and LPO activity decreased in seminal plasma in both T2 and T3 groups than T1, whereas catalase activity did not show any significant difference. Cu and Zn supplementation in T2 group improved plessthan0.05) Zn level in blood and seminal plasma and Cu level in blood plasma only, but not in seminal plasma. Therefore, it can be concluded that supplementation of Zn and Cu at 50% above the recommended levels of ICAR (2013) improved the qualitative and quantitative attributes of semen in Murrah bulls.

Effects of Copper Sources and Levels on Lipid Profiles, Immune Parameters, Antioxidant Defenses, and Trace Element Residues in Broilers.

The study was conducted to investigate the effects of copper sources and levels on lipid profiles, immune parameters, antioxidant defenses, and trace element contents of meat and liver in Arbor Acres broilers. A total of 504 male broilers were randomly divided into 7 groups with 6 replicates per group and 12 broilers per replicate. The experiment was used in a 3 × 2 + 1 factorial experiment design; broilers in the control group were fed a basal diet, and broilers in the other six groups were fed basal diets supplemented with 3 sources (copper sulfate, tribasic copper chloride, and copper methionate) and 2 levels (10 and 20mg/kg). The results showed that the levels of cholesterol and low-density lipoprotein cholesterol in broilers were significantly decreased with the increase of dietary copper level (P <0.05). Serum IL-6 and IgA contents, ceruloplasmin and GSH-Px activities, and liver copper contents of broilers increased significantly with dietary copper levels (P <0.05). Compared with the control group, dietary copper supplementation significantly decreased serum cholesterol (P <0.05) and significantly increased serum IL-6, ceruloplasmin, SOD, GSH-Px, and liver copper (P <0.05). Dietary supplementation of basic copper chloride and copper methionate significantly decreased low-density lipoprotein cholesterol content and liver iron content (P < 0.05). In conclusion, dietary copper supplementation can effectively reduce serum cholesterol content and improve immune and antioxidant functions in broilers. Adding 20mg/kg copper to broiler diet can increase the copper content in the liver, but it will not affect the copper content in the chicken.

Trientine selectively delivers copper to the heart and suppresses pressure overload-induced cardiac hypertrophy in rats.

Our study reveals that TETA, traditionally regarded as a copper chelator, in lower doses delivers copper selectively to the heart through a mechanism independent of copper transporter-1 or -2. Copper supplementation by a lower dose of TETA suppresses pressure overload-induced cardiac hypertrophy. Since ischemic heart disease and hypertrophic cardiomyopathy are accompanied by myocardial copper loss, this approach of using a lower dose of TETA to supplement copper to the heart would help treat the disease condition of patients with such cardiac events.

Effect of dietary copper levels on the growth performance and nutrient utilization in fattening pigs

The present study was conducted to investigate the effect of dietary copper supplementation on the growth performance, nutrient digestibility and copper metabolism in fattening pigs. A total of 24 pigs (Landrace X Large White X Duroc) with an average initial BW of 30±1.05 kg, the pigs were divided into four treatment groups, with three replicates per treatment and two pigs per replicate, in accordance with a completely randomized design based on the BW. The results indicated that dietary copper supplementation increased the growth performance, CP and EE digestibility. However, there was no significant increase in the DM and OM digestibility. In addition, copper deposition increased with the increase in dietary copper supplementation, while copper absorption, increased with the decrease in dietary copper levels. In conclusion, fattening pigs with 30-60 kg BW can utilize 45-135 mg/kg Cu and porkers at BW of 60-120 kg can also utilize 10-45 mg/kg Cu as CuSO4 for an increased copper utilization and a decreased in copper deposition.

Effect of different sources of copper supplementation on performance, nutrient utilization, blood-biochemicals and plasma mineral status of growing Hariana heifers

Twenty-four, 12-18 months old Hariana heifers were used to determine the effects of organic and inorganic dietary copper (Cu) supplementation on performance, nutrient utilization, blood biochemicals and plasma mineral status. Cu was supplemented (8 mg/kg diet DM) as copper proteinate, copper propionate and copper sulfate (CuSO4. Animals were divided into four treatment groups with 6 animals in each group and were fed basal diet as per NRC (2001) for a period of 120 days. The basal diet contained 8.0 mg of Cu/kg DM. T1 (control) was fed only basal diet with no added copper while in T2: 8 mg/kg DM of copper proteinate; T3: 8 mg/kg DM of copper propionate; T4: 8mg/kg diet CuSO4 was added respectively.The intake, daily gain, feed:gain ratio, BCS and FCR were not affected by Cu supplementation. The TDN intake and ADF digestibility were significantly higher in both the organic Cu supplemented groups. The intake of Cu was significantly higher in Cu supplemented groups. The concentration of plasma ALT, AST enzymes, total cholesterol and total immunoglobulins were not affected by sources of Cu in diet. The antioxidant activity and plasma Cu concentration were significantly higher in Cu supplemented groups, irrespective of sources. Thus, supplementation of 8 mg/kg DM Cu had no beneficial effect on growth performance and blood biochemicals. In conclusion, chelating agents have no effect on bioavailability of copper. Also, the organic copper can be a preferred form to be supplemented for better digestibility in heifers.

Regression of pressure overload‐induced cardiac hypertrophy by TETA‐mediated myocardial copper supplementation in rats

Sustained pressure overload leads to cardiac hypertrophy and copper efflux from the heart. Dietary copper supplementation replenishes copper in the heart and reverses cardiac hypertrophy. On the contrary, a copper selective chelator, trientine (TETA), reverses left ventricular hypertrophy associated with diabetes. The present study was undertaken to test the hypothesis that TETA functions as a copper chaperone delivering copper to the heart leading to regression of cardiac hypertrophy. Adult male Sprague‐Dawley rats were subjected to transverse aortic constriction (TAC) to induce cardiac hypertrophy. Eight weeks after the surgery cardiac hypertrophy was developed and myocardial copper was reduced. TETA was then administrated by gavage at two different doses (21.9 mg/kg·day and 87.6 mg/kg·day) for six weeks. The results showed that at lower dose, TETA replenished copper contents in the heart, accompanied by a decrease in blood plasma and an increase in urine of copper concentrations. At higher dose, TETA did not replenish copper contents in the heart, but markedly increased copper concentrations in the urine, along with a decrease in serum copper concentrations. Corresponding to myocardial copper repletion, lower dose TETA reversed cardiac hypertrophy, as judged by a reduction in the left ventricle wall thickness (LVAWd and LVPWd) and a decrease in the heart size (heart weight/tibia length), and diminished cardiac fibrosis, as reflected by a decrease in collagen I content. TETA at higher dose not only did not regressed cardiac hypertrophy, but caused cardiac hypertrophy in sham‐operated rats. This study demonstrates that TETA, at lower dose, functioned as a copper chaperone delivering copper to the heart of copper deprivation and, at higher dose, simply remained its chelator function removing copper from the body by urinary excretion.Support or Funding InformationSupported by National Science Foundation of China (81230004 and 81300109).This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Copper supplementation in drinking water reverses dietary iron overload‐induced anemia and cardiac hypertrophy in mice

Our previous studies showed that high‐iron (0.88% carbonyl iron) diet feeding of mice and rats lead to impaired growth, severe anemia, tissue copper depletion and cardiac hypertrophy.1,2 Interestingly, these pathophysiological perturbations were prevented by addition of extra copper to the high Fe diet, indicating the role of copper deficiency in the pathogenesis. The current study was undertaken to test the hypothesis that dietary copper supplementation to Fe overload mice could restore systemic copper status, and reverse the anemia and cardiac hypertrophy. Weanling, male C57BL/6 mice were fed AIN‐93G‐based diets containing adequate (~8 ppm) Cu in combination with adequate (~80 ppm) or high (~8000 ppm) Fe for 4 weeks. Then, the mice were given 20 mg/L Cu (as Cu sulfate) in drinking water for another 3 weeks. Subsequently, the iron and copper‐related phenotype of the mice was assessed. High‐Fe diet fed mice showed a significant growth impairment and systemic Cu deficiency, accompanied by severe anemia, decreased serum ceruloplamine (Cp) activity and cardiac hypertrophy. Cu replenishment via drinking water corrected the deficits in hemoglobin (Hb), hematocrit (HCT) and serum Cp levels, restored tissue Cu status, and reversed cardiac hypertrophy. It was further found that high‐Fe feeding significantly impaired intestinal Cu absorption, and disturbed Cu tissue distribution. This study demonstrates that high Fe consumption blocks intestinal Cu absorption, leading to a systemic Cu deficiency which resulted in a severe anemia and cardiac hypertrophy in mice. Cu supplementation corrects these physiologic perturbations. These observations provided further evidence of physiologically‐relevant iron‐copper interactions in mammals.Support or Funding InformationSupported by NIH grant 1R01 DK074867 (to J.F.C.).This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Effects of dietary copper supplementation on performance, egg quality parameters, yolk cholesterol and fatty acid profiles in laying hens

The present study envisaged the effects of different levels of dietary copper supplementation on performance, egg quality parameters, serum and yolk cholesterol and triglyceride levels, and yolk fatty acid profile in laying hens. Total 96 Lohman laying hens (38 weeks old) were randomly divided into four groups (n=24 each). Experimental diets were prepared by adding copper (0, 200, 250 or 300 mg/kg) to basal diet and feeding was lasted 12 weeks. Dietary copper supplementation decreased egg weight and feed intake but did not affect other performance parameters compared to the control diet. Shape index, shell weight, shell thickness, yolk color, yolk index, albumen index, and haugh unit were not influenced by dietary copper supplementation, whereas shell strength increased due to the inclusion of copper in the basal diet. Copper supplementation did not affect the fatty acid profile of the egg yolk. The yolk cholesterol ratio decreased by 7.22% in the presence of 250 mg/kg copper supplementation compared to control diet. Therefore, high levels of dietary copper supplementation in the diet of laying hens can be beneficial for improving shell strength and reducing the cholesterol content of the yolk.

Effects of various levels of dietary copper supplementation with copper sulfate and copper hydroxychloride on Pacific white shrimp Litopenaeus vannamei performance and microbial communities

A 42–day trial was conducted to evaluate the performance of juvenile (0.30g initial weight) Pacific white shrimp Litopenaeus vannamei offered diets containing various levels of copper hydroxychloride (Cu2(OH)3Cl) containing 58.8% copper (Cu) or Cu sulfate (CuSO4) containing 25.5% Cu. The basal diet (360g/kg protein, 80g/kg lipid) was primarily composed of soybean meal, fish meal, corn protein isolate and whole wheat and was formulated to be deficient in Cu (approximately 10mgCu/kg). The basal diet (B10) was supplemented with 30, 90, 150, and 210mgCu/kg from each Cu source. With the exception of 1 treatment (H220, Cu supplemented diet with dietary copper 210mg/kg from Cu hydroxychloride, n=4), five replicate groups of 15 shrimp per tank (initial weight 0.30g) were offered the test diets in slight excess. At the end of the trial, no significant differences were observed in final biomass (53.20–64.40g), final mean weight (4.34–4.87g), weight gain (1349–1544%), feed conversion ratio (FCR, 1.61–1.82), survival (81.3–96.0%), and thermal growth coefficient (0.082–0.087). The carapace, hepatopancreas, and whole shrimp Cu were significantly increased with dietary Cu levels from either source. No significant differences in hemolymph Cu contents were observed between the two sources. The Cu concentrations of hepatopancreas and whole shrimp were significantly lower in shrimp fed diets with Cu hydroxychloride than those in shrimp fed diets with Cu sulfate. The Cu contents of final whole body significantly increased with dietary Cu levels from either source and corresponded to a decreased trend in whole body Cu retention as dietary Cu increased regardless of source. Sequencing of intestinal and fecal microbiomes (16S V1–V3) captured distinct microbial communities based on source but not copper treatment group. However, the abundance of several specific family and genera of bacteria did appear to respond to different types and doses of dietary copper. Among these we observed a trend of decreased abundance of particular species of Vibrios, including V. harveyi, V. sinaloensis and V. orientalis. Results of this study confirm that both copper sources are utilized efficaciously by Pacific white shrimp, however, differential deposition patterns indicated the two sources of Cu are metabolized differently. Hence, additional studies to assess the specific metabolic pathways of various Cu sources as well as possible effects of high copper levels on resistance to infection should be undertaken in the future. Statement of relevanceIn this study, we assessed the efficacy of various levels of dietary copper supplementation with copper sulfate and copper hydroxychloride in Pacific white shrimp. Our finding shows that both copper sources are utilized efficaciously but metabolized differently by shrimp. This manuscript provides valuable information about effects of high copper levels from two copper sources in shrimp.

Source of supplemental dietary copper, zinc, and manganese affects fecal microbial relative abundance in lactating dairy cows

Appropriate trace mineral supplementation can improve immune response and hoof health in cattle and at much higher rates of supplementation to swine and poultry can alter microbial colonization of the gut, resulting in improved gut health. Diet can influence fecal microbial excretion in cattle, and the fecal microbiome may serve as a means for assessing gastrointestinal microbial changes. We hypothesized that feeding diets that differed in source of supplemental Cu, Zn, or Mn would alter the relative abundance of fecal microbes in lactating dairy cattle and that organic Zn would have the greatest effect. Twenty-four cows were fed diets devoid of supplemental Cu, Zn, and Mn for a 16-d preliminary phase (basal diet provided 9, 29, and 32 mg/kg of Cu, Zn, and Mn, respectively), and then were randomly assigned to 1 of 3 treatment diets (n = 8 cows/treatment): one group of cows was fed supplemental Cu, Zn, and Mn from sulfate minerals; the second group was fed glycinate minerals; and the third group was fed Cu and Mn sulfate with glycinate Zn. Assayed total dietary concentrations were approximately 21, 73, and 72 mg/kg for Cu, Zn, and Mn, respectively. Milk production (averaged 38.8 kg/d), DMI (averaged 25.8 kg/d), and milk components were not affected by treatment. Fecal DNA was extracted, amplified using a universal primer targeting the V4-V5 hypervariable region of the 16S rRNA gene, and sequenced to compare microbial community composition between treatments. Relative abundances of Treponema species-level operational taxonomic units (OTU) were less for animals fed Cu and Mn sulfate with glycinate Zn compared with sulfates alone, but were similar to animals fed glycinate mineral sources. Relative abundances for exclusive glycinate mineral and sulfate mineral treatments were similar. Treponema OTU and cultured representatives are often associated with bovine digital dermatitis. These data may provide an additional link between organic Zn supplementation and improved hoof health. To our knowledge this is the first report of a dietary treatment decreasing the relative abundance of Treponema OTU in cattle feces; however, the potential benefits of this response on overall animal health and the mechanism for the observed responses are unknown and warrant further investigation.

Effects of Dietary Copper Supplementation on Laying Performance, Egg Quality and Plasma Cholesterol Fractions in Laying Ducks

Effects of Dietary Copper Supplementation on Laying Performance, Egg Quality and Plasma Cholesterol Fractions in Laying Ducks

Regression of pressure overload‐induced cardiac hypertrophy by trientine‐induced copper redistribution to the heart in rats

Sustained pressure overload leads to pathological cardiac hypertrophy, and copper efflux from the heart with an increase in plasma copper concentrations. Dietary copper supplementation replenishes copper content and reverses the pathogenesis in mice with cardiac hypertrophy. We recently observed that copper‐trientine complex increased copper uptake by primary cultures of neonatal rat cardiomyocytes. The present study was undertaken to test the hypothesis that trientine can redistribute copper from plasma to the copper‐depleted heart tissue. Adult male Sprague‐Dawley rats were subjected to ascending aortic constriction (AAC). Sixteen weeks after the operation, cardiac hypertrophy was observed by echocardiography and trientine at a dose of 8 mg/kg, twice a day, was administered orally for 6 weeks. At the end of the treatment, copper concentrations were significantly increased in the heart and significantly reduced in the plasma. Along with copper redistribution, cardiac hypertrophy was reversed almost back to the normal as judged by IVSD and LVPWD, and cardiac function was improved as indicated by EF and FS. In addition, the level of cardiac fibrosis was reduced as reflected by the decrease in the content of collagens type I and III and the reduced cross linking of the collagens. This study demonstrates that trientine, although traditionally considered as a copper chelator, is capable of redistributing copper from plasma to the heart leading to regression of pathological cardiac hypertrophy and improved cardiac function.Support or Funding InformationNational Science Foundation of China (81230004 and 81300109).

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.

Effect of dietary inorganic copper on growth performance and hematological profile of Nile tilapia subjected to heat-induced stress

The effects of graded levels of dietary copper supplementation on the growth, hematological profile, ceruloplasmin activity, and resistance to high temperature stress of Nile tilapia (Oreochromis niloticus) were analyzed. A total of 240 fish (8.05±0.45g) were randomly distributed in 30 tanks (250L) and fed six diets containing graded levels of Cu2SO4·5H2O (0.0, 4.0, 6.0, 8.0, 1000 and 1500mgCu·kg−1 diet) for 120days. Growth performance as well as hematological, biochemical and histopathological parameters in the liver were analyzed. After the feeding period, the fish were subjected to heat/dissolved oxygen-induced stress (32°C/2.3mg·L−1) for three days, when the same hematological and biochemical parameters were evaluated. The toxicity of dietary copper supplementation impaired the growth performance (P<0.05) of fish fed 1000mgCu·kg−1 and 1500mgCu·kg−1 and influenced the hematological profile after the feeding period (P<0.05). The ceruloplasmin enzyme exhibited higher activity after heat stress. Histopathological changes in the fish liver were observed in all of the treatments, regardless of the dietary copper supplementation. Fish fed diets without copper supplementation showed the lowest value of iron in the liver, which differed significantly (P<0.05) from the levels in fish fed the highest copper supplementations. The highest levels of copper supplementation resulted in the highest values of copper concentration in the liver, whereas supplementation with 0–8mgcopper/kg diet did not change the copper concentrations in the liver. Therefore, considering the fish growth, health, ceruloplasmin activity and liver histopathology, it can be concluded that levels of available copper close to the required amount were sufficient to ensure the growth and health of Nile tilapia, even under the stress condition, whereas an excess of this mineral in the diet impaired the growth and health of this species. Statement of relevanceCopper is an essential micro mineral, and its requirement has been established for some fish species. However, there is a lack of information on the effects of dietary copper supplementation on fish subjected to stress. Therefore, it is important to understand how fish fed graded levels of copper respond under stress that is usual in fish farms. Thus, economic losses can be avoided.

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 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;

Dietary copper supplementation improves pelt characteristics of female silver fox (Vulpes fulva) during the winter fur-growing season.

Copper has an essential role in normal fur pigmentation and fur quality. This study evaluated the effects of cupric citrate (CuCit) supplementation on growth, nutrients metabolism and pelt characteristics of the female silver fox (Vulpes fulva). Fifty age-matched female silver foxes with similar body weights were randomly divided into five dietary groups for 58 days during the winter fur-growing season. The basal diet contained 4.92 mg/kg copper. Groups I-V were supplemented with 6, 30, 60, 90 or 150 mg Cu from CuCit per 1 kg dry matter basal diet. Serum alkaline phosphatase activity was significantly higher (P<0.05) in those fed 90 mg/kg Cu than those fed 150 mg/kg Cu. Pelt total thickness was significantly higher (P<0.05) in those fed 30 mg/kg Cu than foxes fed 6 mg/kg Cu supplemented diet, but were similar to the other groups. Length of guard hair was significantly lower (P<0.05) in those fed 90 mg/kg Cu than fed 6 mg/kg Cu and 30 mg/kg Cu, but were similar to the other groups. Length of underhair was significantly higher (P<0.05) in those fed 6 mg/kg Cu than those fed 90 mg/kg Cu, but was similar to the other groups. Considering decreasing environmental contamination and improving pelt performance, supplementing 30 mg/kg Cu from CuCit (actual copper 35 mg/kg dry matter) is appropriate for female silver fox.