Net mineral requirements for the growth and maintenance of Somali lambs

Minerals are limiting factors in animal production, and the knowledge of mineral requirements for livestock is crucial to the success of a commercial enterprise. Hair sheep may have different mineral requirements than those presents by the international committees. A study was carried to evaluate the net calcium (Ca), phosphorus (P), magnesium (Mg), sodium (Na), potassium (K), zinc (Zn), iron (Fe), manganese (Mn) and copper (Cu) requirements for the growth and maintenance of Brazilian Somali lambs. A total of 48 hair lambs (13.5±1.8 kg) aged 60±15 days were allocated to individual pens. Eight animals were slaughtered at the beginning of the experiment to serve as a reference group to estimate initial empty BW (EBW) and initial body composition. The remaining lambs (n=40) were assigned to a completely randomized design with eight replications in five levels of metabolizable energy (ME; 4.93, 8.65, 9.41, 10.12 and 11.24 MJ/kg DM). When the lambs of a given treatment reached an average BW of 28 kg, they were slaughtered. Initial body composition was used to calculate the retention of minerals. Mineral body composition was fit using a logarithmic equation in the form of a nonlinear model. The maintenance requirements were estimated from regressions of mineral retention in the empty body on mineral intake. The body mineral concentration decreased in lambs with a BW ranging from 15 to 30 kg. The net mineral requirements (100 g/day of average daily gain (ADG)) decreased from 0.52 to 0.51 g for Ca, 0.28 to 0.23 g for P, 0.02 to 0.02 g for Mg, 0.09 to 0.08 g for Na, 0.11 to 0.09 g for K, 1.30 to 1.08 mg for Zn, 3.77 to 3.22 mg for Fe, 0.08 to 0.06 mg for Mn and 0.09 to 0.08 mg for Cu when BW increased from 15 to 30 kg. The daily net requirements for maintenance per kilogram of BW were 30.13 mg of Ca, 27.58 mg of P, 1.26 mg of Mg, 4.12 mg of Na, 8.11 mg of K, 0.133 mg of Zn, 0.271 mg of Fe, 0.002 mg of Mn and 0.014 mg of Cu. The results of this study indicate that the net mineral requirements for weight gain and maintenance in Brazilian Somali lambs are different than the values that are commonly recommended by the main evaluation systems for feed and nutritional requirements for sheep. These results for the nutritional requirements of minerals may help to optimize mineral supply for hair sheep.     

Seven Dietary Minerals (Ca, P, Mg, Fe, Zn, Cu, and Mn) and Their Relationship with Blood Pressure and Blood Lipids in Healthy Adults with Self-Selected Diet

The purpose of this study is to evaluate the dietary intakes of calcium (Ca), phosphorus (P), magnesium (Mg), iron (Fe), zinc (Zn), copper (Cu), and manganese (Mn) and investigate their correlation with blood pressure and blood lipids. Targeting 258 healthy men and women, blood pressure was measured, and blood samples were collected to analyze serum lipids, and then the intakes of seven minerals were assessed through a food intake survey for 3 days using a 24-h recall method. The average age of the men and women was 49.55 and 49.19, respectively. The daily energy intake of the men was 1,830.57 kcal, which was significantly higher than that of women, 1,476.23 kcal (p?<?0.001). The mineral intake of the subjects was as follows: 450.95 mg/day for Ca, 915.24 mg/day for P, 279.23 mg/day for Mg, 12.60 mg/day for Fe, 8.25 mg/day for Zn, 1.23 mg/day for Cu, and 4.22 mg/day for Mn. These accounted for 63.83, 130.76, 90.74, 129.75, 97.50, 154.49, and 113.50 % of adequate intake or the recommended intake of each mineral, respectively. Subjects who did not satisfy the estimated average requirement were 74.00 % for Ca, 63.18 % for Mg, and 41.86 % for Zn. After adjusting for age, sex, BMI, and energy intake, Mg intake had a negative correlation with systolic blood pressure (SBP), and Cu intake had a significant negative correlation with SBP and diastolic blood pressure (DBP). Also, Mn intake was negatively correlated with DBP, serum total cholesterol, and triglycerides. Thus, it is concluded that the dietary intakes of Mg, Cu, and Mn may play an important role in controlling blood pressure and lipids in Korean adults.     

Effect of zinc supplementation from two sources on growth,nutrient utilization and immune response in male crossbred cattle (Bos indicus×Bos taurus) bulls

To investigate effects of Zn supplementation on performance, mineral balance and immune response, 15 male crossbred cattle (Bos indicus×Bos taurus) bulls of about 14 ± 0.4 months of age and weighing 226.0 ± 9.1 kg were divided in to three groups of five. Bulls in the control group were fed wheat straw and a concentrate mixture (basal diet with 32.5 mg Zn/kg dry matter (DM)), and in ZnSO₄ and ZnProp groups 35 mg Zn/kg DM was added through Zn sulphate and Zn propionate, respectively. All bulls were fed their respective treatment diets for 180 days. Daily feed intake was recorded and bulls were weighed at every 15 days to determine change in body weight (BW). After 120 days of feeding, bulls were vaccinated with Brucella abortus strain 19, and cell mediated and humoral immune responses were assessed between 120 and 148 days of experimental feeding. After 150 days of feeding, a metabolism study of 6 days duration was completed to determine nutrient digestibility and mineral balances (i.e., Ca, P, Zn, Cu, Fe and Mn). Intake of total DM, digestibility of DM, crude protein, ether extract, neutral detergent fibre and acid detergent fibre, N balance, average daily gain, feed: gain did not differ between the groups. Intake, excretion and balance of Ca, P, Zn, Cu, Fe and Mn also did not differ between the groups. However, retention of Zn was higher (P<0.001) in the ZnProp group. Bulls supplemented with Zn propionate had higher cell mediated (P<0.01) and humoral (P<0.05) immune response, while there was no alteration in immune response due to Zn sulphate supplementation. Results indicate that a diet containing about 32.5 mg Zn/kg DM was adequate to support normal growth and digestibility, but a better immune response occurred when Zn propionate was added to the diet at 35 mg/kg DM versus Zn sulphate.     

南四湖区农田土壤有机质和微量元素空间分布特征及影响因素

基于地统计学和GIS技术相结合的方法,研究了南四湖区农田土壤有机质和微量元素的空间分布特征及其影响因素。结果表明,土壤有机质和微量元素均属中等变异程度,除硼符合正态分布外,其余土壤属性均符合对数正态分布。结构分析表明,除硼为纯块金效应外,土壤有机质和其它微量元素空间自相关性较强,其中结构性因素起主导作用。克里格插值结果表明,土壤有机质分布总体趋势为由北向南逐渐降低,锰、铜、锌分布总体趋势为中部高,南北两端低。影响因素分析表明,土壤类型、耕层质地、坡度、土地利用类型和地貌类型对土壤有机质均有显著影响。土壤类型主要是由于成土母质的差异影响土壤有机质的高低与分布,随质地由砂变粘、坡度由低变高,土壤有机质含量逐步升高,田间管理水平的差异是造成不同土地利用类型下土壤有机质含量差异的主要原因。微量元素中,除硼不受影响外,铁、锰、铜和锌与土壤类型、耕层质地、坡度、土地利用类型和地貌类型密切相关。     

Selected trace elements and esterase activity of carbonic anhydrase levels in lambs with pneumonia

The levels of, zinc, copper, Fe, Zn, Cu, Mn, Mg, K, Na, and Cl and the activity of carbonic anhydrase were determined in lambs with pneumonia. A significant decrease of p<0.01 level in Zn concentration, in Cu level (p<0.001) and significant increases in K and Na levels (p<0.05) and of the Cu/Zn ratio (p<0.001) were observed in the study group. The carbonic anhydrase activity was decreased in the study group, but the decrease was not statistically significant (p>0.05). Also, nonsignificant decreases of Fe, Mg, and Cl and increase of the Mn concentration were also observed in the lambs with pneumonia (p>0.05). Our results suggest that the significant element changes reported here and the Cu/Zn ratio, but not the activity of carbonic anhydrase, can be used as indicators of pneumococcal infection.     

Levels of copper and zinc in diets for growing and finishing pigs can be reduced without detrimental effects on production and mineral status

One hundred and sixty pigs were used to evaluate dietary copper (Cu) and zinc (Zn) supplementation on performance, fecal mineral levels, body mineral status and carcass and meat quality. Diets differed in mineral form (MF) (Cu and Zn in the form of proteinate amino acid chelate (organic) or sulfate (inorganic)) and inclusion level (IL) (27 mg/kg of total Cu and 65 mg/kg of total Zn ('low') or 156 mg/kg of total Cu and 170 mg/kg of total Zn ('high')) according to a 2 × 2 factorial arrangement of treatments. Pigs were used from 25 to 107 kg body weight (BW) and fed their respective diets ad libitum. Blood and fecal samples were collected on days 14 and 77 of the experiment. Blood was analyzed for concentration of Cu and Zn, hemoglobin (Hb), Cu content of red blood cells (RBC Cu) and alkaline phosphatase (ALP) and feces for Cu and Zn concentration. Hot carcass weight (HCW) and backfat depth were measured at slaughter and indices of meat quality were assessed on a section of longissimus thoracis. Liver, kidney and bone samples were collected immediately after slaughter and liver and kidney were tested for Cu and Zn content, while bone was only tested for Zn. Over the entire experimental period (25 to 107 kg BW) no significant treatment differences in average daily gain (ADG) or average daily feed intake (ADFI) occurred; however, feed conversion ratio (FCR) was improved by the inclusion of proteinate amino acid chelate (P = 0.012). Copper and Zn concentrations in feces were in direct proportion to the IL in the diet. Blood mineral levels were within normal physiological ranges in all treatments and tissue Cu and Zn concentrations increased with dietary IL (P < 0.05). Results indicate that Cu and Zn fecal concentrations were reduced by approximately 6-fold for Cu and by 2.5-fold for Zn by feeding 27 mg/kg Cu and 65 mg/kg Zn, in either the proteinate amino acid chelate or the sulfate form, compared with a diet containing 156 mg/kg Cu and 170 mg/kg Zn. This decrease in total dietary Cu and Zn did not reduce performance or mineral status of pigs.     

Effects of organic complexed or inorganic Co,Cu, Mn and Zn supplementation during a 45-day preconditioning period on productive and health responses of feeder cattle

This experiment evaluated production and health parameters among cattle offered concentrates containing inorganic or organic complexed sources of supplemental Cu, Co, Mn and Zn during a 45-day preconditioning period. In total, 90 Angus×Hereford calves were weaned at 7 months (day −1), sorted by sex, weaning BW and age (261±2 kg; 224±2 days), and allocated to 18 drylot pens (one heifer and four steers per pen) on day 0; thus, all pens had equivalent initial BW and age. Pens were randomly assigned to receive a corn-based preconditioning concentrate containing: (1) Cu, Co, Mn and Zn sulfate sources (INR), (2) Cu, Mn, Co and Zn complexed organic source (AAC) or (3) no Cu, Co, Mn and Zn supplementation (CON). From day 0 to 45, cattle received concentrate treatments (2.7 kg/animal daily, as-fed basis) and had free-choice access to orchardgrass (Dactylis glomerata L.), long-stem hay and water. The INR and AAC treatments were formulated to provide the same daily amount of Co, Cu, Mn and Zn at a 50-, 16-, 8- and ninefold increase, respectively, compared with the CON treatment. On day 46, cattle were transported to a commercial feedlot, maintained as a single pen, and offered a free-choice receiving diet until day 103. Calf full BW was recorded on days −1 and 0, 45 and 46, and 102 and 103 for average daily gain (ADG) calculation. Liver biopsy was performed on days 0 (used as covariate), 22 and 45. Cattle were vaccinated against respiratory pathogens on days 15, 29 and 46. Blood samples were collected on days 15, 29, 45, 47, 49, 53 and 60. During preconditioning, mean liver concentrations of Co, Zn and Cu were greater (P⩽0.03) in AAC and INR compared with CON. No treatment effects were detected (P⩾0.17) for preconditioning feed intake, ADG or feed efficiency. No treatment effects were detected (P⩾0.48) for plasma concentrations of antibodies against Mannheimia haemolytica, bovine viral diarrhea types 1 and 2 viruses. Plasma haptoglobin concentrations were similar among treatments (P=0.98). Mean plasma cortisol concentration was greater (P⩽0.04) in CON compared with INR and AAC. No treatment effects were detected (P⩾0.37) for cattle ADG during feedlot receiving. Hence, INR and AAC increased liver concentrations of Co, Zn and Cu through preconditioning, but did not impact cattle performance and immunity responses during preconditioning and feedlot receiving.     

The exposure level of heavy metals at four different locations near Gan-Ning-Meng reaches of the Yellow River,China

Hair, water, and sediment samples (n = 69, 27, and 24, respectively) were collected at four locations (P1–P4) along the Yellow River Gan-Ning-Meng (GNM) reaches, China. Total elemental contents of Cd, Cr, Cu, Fe, Mn, Pb, and Zn were determined using inductively coupled plasma mass spectroscopy (ICP-MS) to investigate their distribution and exposure levels in the different media. Results showed that trace metals had widely spatial variability in water and hair samples. There were the highest levels of mean concentrations of Cd, Cu, Fe, Mn, Pb, and Zn (geometric mean, GM = 0.22, 17, 65, 3.0, 4.9, and 170 μg/g, respectively) in residents' hairs living at P2. Most of the hair donors in this study showed high concentrations of Cr when compared with the literature. Differences could be distinguished for Mn (p = 0.001) and Fe (p = 0.001) with gender, and for Cr (p = 0.021), Zn (p = 0.003), and Pb (p = 0.035) with age, respectively. The pollution assessments revealed an unpolluted degree in filtered water and a moderately polluted degree for Cd in sediments at P1–P4. Correlation analysis showed significant correlations between hair and sediment samples for Cr and Mn. This paper provides basic and useful information in facing public and environmental health challenges in the GNM sections of the Yellow River.     

Effects of different proteins on the metabolism of Zn, Cu, Fe, and Mn in rats

Many factors are known to influence trace element metabolism and one of them is dietary protein. The present study examines the effects of casein, soybean protein, and peanut protein on the metabolism of the Zn, Cu, Fe, and Mn in growing rats. The results showed that Zn, Fe, and Mn excretions in the feces of peanut protein-fed rats (PPERs) were similar to that of casein-fed rats (CPFRs) (p>0.05), whereas all of the Zn, Cu, Fe, and Mn excretions in the urine of PPFRs were significantly higher than that of CPFRs (p<0.05), but its apparent absorption rate (AAR) of Cu, Fe and its apparent retention rate (ARR) of Cu were all higher than that of CPFRs (p<0.05). Hepatic Zn content of soybean protein-fed rats (SPFRs) was higher than that of CPFRs and PPFRs (p<0.05 respectively) and serum, renal, and femoral Cu contents of SPFRs were significantly lower; however, hepatic Cu, and renal Mn contents were significantly higher than that of CPFRs (p<0.05, respectively); The hepatic Fe content of SPFRs was significantly higher than that of CPFRs and PPFRs (p<0.01, respectively). To sum up, compared to casein, soybean protein might be a good dietary source to make up for Zn and Fe deficiency, and also peanut protein to make up for Cu and Fe deficiency.     

Essential trace elements in milk and blood serum of lactating donkeys as affected by lactation stage and dietary supplementation with trace elements

The aim of this trial was to study the concentration of zinc (Zn), iron (Fe), copper (Cu), manganese (Mn), selenium (Se), cobalt (Co) and iodine (I) in milk and blood serum of lactating donkeys, taking into account the effects of lactation stage and dietary supplementation with trace elements. During a 3-month period, 16 clinically healthy lactating donkeys (Martina-Franca-derived population), randomly divided into two homogeneous groups (control (CTL) and trace elements (TE)), were used to provide milk and blood samples at 2-week intervals. Donkeys in both groups had continuous access to meadow hay and were fed 2.5 kg of mixed feed daily, divided into two meals. The mixed feed for the TE group had the same ingredients as the CTL, but was supplemented with a commercial premix providing 163 mg Zn, 185 mg Fe, 36 mg Cu, 216 mg Mn, 0.67 mg Se, 2.78 mg Co and 3.20 mg I/kg mixed feed. The concentrations of Zn, Fe, Cu, Mn, Se, Co and I were measured in feeds, milk and blood serum by inductively coupled plasma-MS. Data were processed by ANOVA for repeated measures. The milk concentrations of all the investigated elements were not significantly affected by the dietary supplementation with TE. Serum concentrations of Zn, Fe, Cu Mn and Se were not affected by dietary treatment, but TE-supplemented donkeys showed significantly higher concentrations of serum Co (1.34 v. 0.69 μg/l) and I (24.42 v. 21.43 μg/l) than unsupplemented donkeys. The effect of lactation stage was significant for all the investigated elements in milk and blood serum, except for serum manganese. A clear negative trend during lactation was observed for milk Cu and Se concentrations (−38%), whereas that of Mn tended to increase. The serum Cu concentration was generally constant and that of Co tended to increase. If compared with data reported in the literature for human milk, donkey milk showed similarities for Zn, Mn, Co and I. Furthermore, this study indicated that, in the current experimental conditions, the mineral profile of donkey milk was not dependent on dietary TE supply.     

Wachstumsuntersuchungen an Bullen des Schwarzbunten Milchrindes (SMR) bei niedrigem Fütterungsniveau

Artificially dried ryegrass, untreated and ammonia‐treated wheat straw were ground and incubated in nylon bags in the rumen of three sheep each fed with diets based on roughage or concentrate. Dry matter degradability, the concentration and the release of the trace elements Cu, Fe, Mn and Zn from the incubated feeds were measured after 0 (washing loss), 6, 12, 24, 48 and 72 h rumen incubation time.

Dry matter degradability, trace element concentration and their release were significantly influenced by the kind of incubated feeds, incubation time and feeding of sheep.

Cu‐ (1.8–6.9 mg kg^?1 DM) and Zn concentrations (36–103 mg kg^?1 DM) of straw residues in the bags were much higher than those of original straw (1.2–1.6 and 8.1–9.9 mg kg^?1 DM resp.).

The inflow of Cu and Zn in the bags containing straw residues was higher than their release. The Cu‐, Fe‐ and Mn‐release from ryegrass was similar to the dry matter degradability, but the Zn‐release was much lower.     

Source of Copper May Have Regressive Effects on Serum Cholesterol and Urea Nitrogen Among Male Fattening Lambs

An experiment was conducted to determine the effect of dietary copper (Cu) on mineral profile, hematological parameters, and lipid metabolism in lambs. Eighteen Zandi male lambs (approximately 3 months of age; 17.53?±?1.6 kg of body weight) were housed in individual pens and were assigned randomly to one of three treatments. Treatments consisted of (1) control (no supplemental Cu), (2) 10 mg Cu/kg dry matter (DM) from copper sulfate (CuS), and (3) 10 mg Cu/kg DM from Cu proteinate (CuP). The Cu concentration was 8.2 mg/kg DM in the basal diet. Blood was sampled from the jugular vein at the beginning of the study (enrollment, before feeding Cu supplement) and at days 25, 50, and 70 of experiment. The amounts of total serum glucose, urea nitrogen, calcium, phosphorus, iron, copper, zinc, and lipids and hematological parameters were measured. Average daily gain and feed efficiency were improved (P?<?0.05) with Cu supplementation and were better for the lambs fed diet supplemented with CuP. The concentrations of serum Ca, P, and Zn were not affected by source of Cu in the diet. However, Fe concentration was lower (P?<?0.01) in the Cu-supplemented groups. Experimental treatment had no significant effects on the hematological parameters. The serum glucose concentration was not affected by treatments. However, the urea nitrogen concentrations were significantly affected (P?<?0.05) by added Cu and was lower for CuP group as compared to the lambs in the CuS and control groups. Addition of Cu had no influence (P?>?0.05) on the serum triglyceride concentration, but lambs fed with CuP supplement had lower (P?<?0.05) serum cholesterol than the CuS and control animals. These results indicated that CuP supplemented at 10 mg/kg DM improved gain and enhanced the efficiency of nitrogen in male lambs.     

Comparative study on the effects of salinomycin,monensin and meso-2,3-dimercaptosuccinic acid on the concentrations of lead,calcium, copper,iron and zinc in lungs and heart in lead-exposed mice

Background and aimEnvironmental lead (Pb) exposure damages the lungs and is a risk factor for death from cardiovascular disease. Pb induces toxicity by a mechanism, which involves alteration of the essential elements homeostasis. In this study we compare the effects of salinomycin (Sal), monensin (Mon) and meso-2,3-dimercaptosuccinic acid (DMSA) on the concentrations of lead (Pb), calcium (Ca), copper (Cu), iron (Fe) and zinc (Zn) in the lungs and heart of lead-exposed mice.MethodsSixty days old male ICR mice were divided into five groups: control (Ctrl) – untreated mice obtained distilled water for 28 days; Pb-intoxicated group (Pb) – exposed to 80 mg/kg body weight (BW) Pb(NO₃)₂ during the first 14 days of the experimental protocol; DMSA-treated (Pb + DMSA) – Pb-exposed mice, subjected to treatment with an average daily dose of 20 mg/kg BW DMSA for two weeks; Monensin-treated (Pb + Mon) – Pb-exposed mice, obtained an average daily dose of 20 mg/kg BW tetraethylammonium salt of monensic acid for 14 days; Pb + Sal - Pb-exposed mice, treated with an average daily dose of 20 mg/kg BW tetraethylammonium salt of salinomycinic acid for two weeks. On the 29^th day of the experiment the samples (lungs and heart) were taken for atomic absorption analysis.ResultsThe results revealed that exposure of mice to Pb for 14 days significantly increased the concentration of the toxic metal in both organs and elevated the cardiac concentrations of Ca, Cu and Fe compared to untreated mice. Pb exposure diminished the lung concentrations of Ca and Zn compared to that of untreated controls. DMSA, monensin and salinomycin decreased the concentration of Pb in the lungs and heart. Among the tested chelating agents, only salinomycin restored the cardiac Fe concentration to normal control values.ConclusionThe results demonstrated the potential application of polyether ionophorous antibiotic salinomycin as antidote for treatment of Pb-induced toxicity in the lungs and heart. The possible complexation of the polyether ionophorous antibiotics with Ca(II) and Zn(II), which can diminish the endogenous concentrations of both ions in the lungs should be taken into account.     

Serum Levels of Trace Elements and Heavy Metals in Patients with Acute Hemorrhagic Stroke

Trace elements are essential components of biological structures, but alternatively, they can be toxic at concentrations beyond those necessary for their biological functions. Changes in the concentration of essential trace elements and heavy metals may affect acute hemorrhagic stroke. The aim of this study was to measure serum levels of essential trace elements [iron (Fe), zinc (Zn), manganese (Mn), copper (Cu), and magnesium (Mg)] and heavy metals [cobalt (Co), cadmium (Cd), and lead (Pb)] in patients with acute hemorrhagic stroke. Twenty-six patients with acute hemorrhagic stroke and 29 healthy controls were enrolled. Atomic absorption spectrophotometry (UNICAM-929) was used to measure serum Fe, Cu, Pb, Cd, Zn, Co, Mn and Mg concentrations. Serum Cd, Pb and Fe levels were significantly higher in patients with acute hemorrhagic stroke than controls (p < 0.001), while serum Cu, Zn, Mg and Mn levels were significantly lower (all p < 0.001). However, there was no significant difference between the groups with respect to serum Co levels (p > 0.05). We first demonstrate increased Cd, Pb, and Fe levels; and decreased Cu, Zn, Mg, and Mn levels in patients with acute hemorrhagic stroke. These findings may have diagnostic and prognostic value for acute hemorrhagic stroke. Further studies are required to elucidate the roles of trace elements and heavy metals in patients with acute hemorrhagic stroke.     

Bioaccumulation of trace metals in Mediterranean mussels (Mytilus galloprovincialis) from a fish farm with copper-alloy mesh pens and potential risk assessment

Concentrations of trace metals were determined in the muscle tissue, digestive gland and gills of Mediterranean mussels (Mytilus galloprovincialis) collected from different locations around an offshore copper alloy fish farm. Levels of copper (Cu), zinc (Zn), manganese (Mn) and iron (Fe) as mg/kg wet weight in the edible part of the mussels collected from distant zone (upstream Zn7.33 > Fe2.8 > Cu0.13 > Mn0.07 and downstream Zn9.9 > Fe5.67 > Cu0.18 > Mn0.17) were significantly lower (p < 0.05) than those sampled from the cage zone (bottom panel Zn22.25 > Fe13.75 > Cu2.39 > Mn0.85 and cage frame Zn17.1 > Fe8.74 > Cu1.39 > Mn0.26). Trace metal concentrations in mussels were significantly higher (p < 0.05) in the samples from the frame and bottom panel of the copper alloy mesh pen, compared to those from distant areas, namely the farm affected downstream -and non-affected upstream locations. However, the rates of target hazard quotients (THQ) for all tested trace metals from all locations in the present study were smaller than “one” (THQ < 1), indicating that the consumption of mussels grown around a cage farm with copper alloy mesh pens were within safe limits and did not exceed maximum levels suggested by the US Food and Drug Administration (USFDA) and European Union (EU) regulations for seafood consumption.     

Prüfung einer quantitativen Futterrestriktion ab 3. Lebenswoche bei der Aufzucht von Junghennen der Mastrichtung im Käfig

The concentrations of Fe, Zn, Cu and Mn were determined in meat, inner organs, blood and residual carcass in a total of 24 barrows and gilts of 60 kg and 100 kg of live weight, respectively. The finisher diet contained 192 ppm Fe, 113 ppm Zn, 18 ppm Cu and 65 ppm Mn with, as calculated, a great proportion originating from the mineral supplement. During growth, the contents of Fe, Cu and Mn were significantly reduced. No sex differences occurred. In the lean meat of the 100 kg pigs, common values accounting for 1.1 mg Fe, 2.8 mg Zn and 0.05 mg Cu per 100 g were analyzed. The manganese concentration of 0.01 mg per 100 g, however, was considerably lower as the corresponding figure from nutrient tables. In the finishing period, the animals retained per animal and day about 18 mg Fe, 15 mg Zn and 0.2 mg Cu. Mn retention was not significantly different from zero. The low utilization rates calculated from these data can be partly explained by the moderately excessive supply in this fattening period. In order to reduce the trace element load of the soils, a considerably lower tolerance of excessive trace element contents in finisher diets has to be developed.     

Trace mineral source influences digestion,ruminal fermentation,and ruminal copper,zinc, and manganese distribution in steers fed a diet suitable for lactating dairy cows

High solubility of certain trace minerals (TM) in the rumen can alter nutrient digestibility and fermentation. The objectives of the present studies were to determine the effects of TM source on 1) nutrient digestibility and ruminal fermentation, 2) concentrations of soluble Cu, Zn, and Mn in the rumen following a pulse dose of TM, and 3) Cu, Zn, and Mn binding strength on ruminal digesta using dialysis against a chelating agent in steers fed a diet formulated to meet the requirements of a high producing dairy cow. Twelve Angus steers fitted with ruminal cannulae were adapted to a diet balanced with nutrient concentrations similar to a diet for a high producing lactating dairy cow for 21 d. Steers were then randomly assigned to dietary treatments consisting of 10 mg Cu, 40 mg Mn, and 60 mg Zn/kg DM from either sulfate (STM), hydroxychloride (HTM) or complexed trace minerals (CTM). The experimental design did not include a negative control (no supplemental Cu, Mn, or Zn) because the basal diet did not meet the National Research Council requirement for Cu and Zn. Copper, Mn, and Zn are also generally supplemented to lactating dairy cow diets at concentrations approximating those supplied in the present study. Following a 14-d adaptation period, total fecal output was collected for 5-d. Following the fecal collection period, rumen fluid was collected for Volatile fatty acid (VFA) parameters. On the following day, the same diet was provided for 14 d, without supplemental Cu, Zn, and Mn. This period served as a wash-out period. A pulse dose of 100, 400, and 600 mg of Cu, Zn, Mn, respectively, from either STM, HTM, or CTM, was administered via ruminal cannulae to the steers on day 15. Over a 24-h period ruminal samples were obtained every 2-h. Following centrifugation, the supernatant was analyzed for Cu, Mn, and Zn. Ruminal solid digesta samples from times 0, 12, and 24 h after bolus dosing were exposed to dialysis against Tris-EDTA. Digestibility of NDF and ADF were lesser in STM vs. HTM and vs. CTM supplemented steers. Steers receiving HTM and CTM had greater total VFA concentrations than STM, and molar proportions of individual VFA were not affected by treatment. Ruminal soluble Cu and Zn concentrations were greater post dosing in STM and CTM supplemented steers at 2, 4, and 6 h for Cu and 4, 6, 8, 10 and 12 h for Zn when compared to HTM supplemented steers. The release of Cu and Zn from ruminal solid digesta following dialysis against Tris-EDTA at 12 and 24 h postdosing was greater for steers receiving HTM compared to those receiving STM or CTM. Results indicate trace mineral source impacts: 1) how tightly bound Cu and Zn are to ruminal solid digesta; 2) fiber digestion; 3) and ruminal total VFA concentrations.     

Alterations in plasma essential trace elements selenium, manganese, zinc, copper, and iron concentrations and the possible role of these elements on oxidative status in patients with childhood asthma

The aim of the present study is to evaluate the status of plasma essential trace element selenium (Se), manganese (Mn), copper (Cu), zinc (Zn), and iron (Fe) concentrations and the effect of these elements on oxidative status in patients with childhood asthma. Plasma Se, Mn, Cu, and Zn concentrations were determined by atomic absorption spectrophotometry (AAS) and Fe concentrations, malondialdehyde (MDA), and total antioxidant capacity (TAC) were determined by the colorimetric method. The plasma MDA/TAC ratio was calculated as an index of oxidative status. Plasma albumin levels were measured to determine nutritional status. Plasma Fe concentrations, MDA levels and the MDA/TAC ratio were significantly higher (p<0.001, p<0.001, and p<0.01, respectively) and Se and Mn concentrations and TAC were lower (p<0.01, p<0.05, and p<0.01, respectively) in patients when compared to the healthy subjects. Plasma Zn, Cu, and albumin levels were not found to be significantly different in patients and controls (p>0.05). There were positive relationships between plasma MDA and Fe (r=0.545, p<0.001) and TAC and Se (r=0.485, p<0.021), and a negative correlation between TAC and MDA values (r= −0.337, p<0.031) in patients with childhood asthma. However, there was no correlation between these trace elements and albumin content in patient groups. These observations suggest that increased Fe and decreased Se concentrations in patients with childhood asthma may be responsible for the oxidant/antioxidant imbalance.     

The effects of di(2-ethylhexyl) phthalate and/or selenium on trace element levels in different organs of rats

Di(2-ethylhexyl)phthalate (DEHP), a widely used plasticizer for synthetic polymers, is known to have endocrine disruptive potential, reproductive toxicity, and induces hepatic carcinogenesis in rodents. Selenium (Se) is a component of several selenoenzymes which are essential for cellular antioxidant defense and for the functions of mammalian reproductive system. The present study was designed to investigate the effects of DEHP exposure on trace element distribution in liver, testis, and kidney tissues and plasma of Se-deficient and Se-supplemented rats. Se deficiency was produced by feeding 3-week old Sprague-Dawley rats with ≤0.05 mg Se/kg diet for 5 weeks, and supplementation group were on 1 mg Se/kg diet. DEHP treated groups received 1000 mg/kg dose by gavage during the last 10 days of feeding period. Se, zinc (Zn), copper (Cu), iron (Fe) and manganese (Mn) levels were measured by inductively coupled plasma mass spectrometry (ICP-MS). Se supplementation caused significant increases in hepatic, renal, and testicular Se levels. With DEHP exposure, plasma Se and Zn, kidney Se, Cu and Mn levels were significantly decreased. Besides, liver Fe decreased markedly in all the DEHP-treated groups. Liver and kidney Mn levels decreased significantly in DEHP/SeD group compared to both DEHP and SeD groups. These results showed the potential of DEHP exposure and/or different Se status to modify the distribution pattern of essential trace elements in various tissues, the importance of which needs to be further evaluated.     

Reducing effect of ingesting tannic acid on the absorption of iron, but not of zinc, copper and manganese by rats

Interest in the beneficial effects of polyphenols, including tannic acid (TA), is increasing, although, these compounds also have adverse effects; for example, on the absorption of iron (Fe), and possibly other trace minerals. We examined the effect of a graded dose of TA on the absorption of Fe and compared with that of zinc (Zn), copper (Cu) and manganese (Mn) in rats. We also investigated the effect of TA on cecal fermentation which plays a role in absorption. In Experiment 1, to set the optimum dose of Fe, male Sprague-Dawley rats (weighing 70-90 g) after acclimatization were fed with different levels of dietary Fe (5, 10, 20, 30 and 35 mg/kg). We observed that the hematocrit (Ht), serum Fe concentration and transferrin saturation (%) were each reduced in those rats fed less than 20 mg/kg Fe in a dose-dependent manner. In Experiment 2, the rats were fed with test diets containing the minimum required level of Fe, 30 mg/kg diet, with (5, 10, 15 and 20 g/kg diet) or without TA for a period of three weeks. Feeding a diet containing more than 10 g TA/kg diet, but not 5 g TA/kg diet, reduced the hemoglobin concentration (Hb), Ht and serum Fe concentration due to decreased Fe absorption. In contrast, the Zn, Cu and Mn absorption was not affected by TA feeding. It is also demonstrated that liver Fe, but not the Zn, Cu and Mn contents, were lower in the TA groups than in the TA-free control group. Feeding TA slightly decreased the pH value of the cecal contents with an increase in the major short-chain fatty acid pool. About 15% of the ingested TA were recovered in the feces of each TA-fed group. Our results demonstrate that more than 10 g TA/kg diet induced anemia by reducing the Fe absorption, although there was no effect on the absorption of other important trace minerals. Our findings suggest that the usual intake of polyphenols is relatively safe, but that a high intake by supplementation or by dietary habit of tannin affects only the Fe level.