Dietary Manganese Levels Research Articles

Dietary Intake Levels of Iron, Copper, Zinc, and Manganese in Relation to Cognitive Function: A Cross-Sectional Study.

Background: Previous studies have related circulating levels of trace metal elements, of which dietary intake is the major source, to cognitive outcomes. However, there are still relatively few studies evaluating the associations of dietary intake levels of iron, copper, zinc, and manganese with cognitive function (CF). Methods: We leveraged the data of 6863 participants (mean [standard deviation] age = 66.7 [10.5] years) in the Health and Retirement Study (2013/2014). Dietary intake levels of iron, copper, zinc, and manganese were calculated from a semi-quantitative food frequency questionnaire. CF was assessed using the 27-point modified Telephone Interview for Cognitive Status (TICS). We used linear regression models to calculate the mean differences in global CF scores by quintiles of dietary intake levels of trace metal elements. Results: Among the study participants, the mean (SD) values of daily dietary intake were 13.3 (6.3) mg for iron, 1.4 (0.7) mg for copper, 10.7 (4.6) mg for zinc, and 3.3 (1.6) mg for manganese. Compared with the lowest quintile of dietary iron intake (<8.1 mg), the highest quintile (≥17.7 mg) was associated with a lower cognitive score (-0.50, -0.94 to -0.06, P-trend = 0.007). Higher dietary copper was significantly associated with poorer CF (P-trend = 0.002), and the mean difference in cognitive score between extreme quintiles (≥1.8 vs. <0.8 mg) was -0.52 (95% confidence interval: -0.94 to -0.10) points. We did not observe significant associations for dietary intake of zinc (P-trend = 0.785) and manganese (P-trend = 0.368). Conclusion: In this cross-sectional study, higher dietary intake of iron and copper was related to worse CF, but zinc and manganese intake levels were not significantly associated with CF.

The effect of varying dietary manganese and selenium levels on the growth performance and manganese-superoxide dismutase activity in nursery pigs

Antioxidant activity in the weaned piglet is important for the developing animal at a cellular level. This study examined the impact of varying dietary levels of manganese and selenium on piglet growth performance and plasma manganese superoxide-dismutase (MnSOD) specific activity. Weaned piglets were blocked by weight (N = 216; 5.21 ± 1.17 kg; 21 ± 3 d) and sex (2 barrows and 2 gilts/pen). Pens (n = 9 pens/treatment) within a block were randomly assigned to dietary treatments in a 2 × 3 factorial design to examine the effect of adding different levels of Mn (0, 12, and 24 mg/kg added Mn from MnSO4 when pigs were fed diets containing 2 levels of Se (0.1 and 0.3 mg/kg added Se from Na2SeO3). Diets were fed in three phases (P1 = d 1–7, P2 = d 8–21, P3 = d 22–35). Pigs and orts were weighed weekly and blood collected on d 0, 7, 21, and 35 for analysis of red blood cell MnSOD. Data were analyzed via the GLM procedure of SAS. No Mn x Se interactions were observed. There was a linear response (P < 0.05) in overall average daily gain across dietary Mn levels. There was a linear trend (P < 0.10) in overall average daily feed intake across Mn levels. Gain to feed ratio (d 0–35) was not impacted by Mn or Se (P > 0.10). MnSOD activity in RBC increased from d 0–7, peaked at d 7, and decreased until d 35. On d 7, diets with 12 mg/kg Mn significantly increased (P < 0.05) MnSOD specific activity (0.91 IU/mg) compared to diets with 24 mg/kg Mn (0.67 IU/mg) but did not differ from diets with 0 mg/kg Mn (0.87 IU/mg). The dietary treatment that maintained specific MnSOD activity was 12 mg/kg Mn and 0.1 mg/kg Se supplemented, while ADG was maximized in diets with 24 mg/kg Mn supplemented.

Dietary manganese levels influence growth, manganese bioaccumulation and expression of genes involved in antioxidant response of swimming crab ( Portunus trituberculatus )

An 8-week feeding trial was conducted to investigate the effects of dietary manganese (Mn) levels on growth performance, Mn bioaccumulation in tissues and antioxidant capacity in juvenile swimming crab (Portunus trituberculatus). Six semipurified experimental diets were formulated to contain graded levels of Mn (manganese sulphate monohydrate as Mn source); the analysed Mn concentrations were 9.8, 20.2, 29.7, 38.2, 65.6 and 123.6 mg/kg. The percent weight gain (PWG) and specific growth rate (SGR) were significantly affected by dietary Mn levels; the highest PWG and SGR were found in crabs fed with the diet containing 38.2 mg/kg Mn. Crabs fed with the diet containing 123.6 mg/kg Mn had higher Mn concentration in muscle and carapace than those fed with the other diets. However, the highest Mn concentration in hepatopancreas was recorded in crabs fed with the diet containing 65.6 mg/kg Mn. Moreover, the lowest activities of manganese superoxide dismutase (Mn-SOD), catalase (CAT) and total antioxidant capacity (T-AOC) occurred at crabs fed with the dietary 9.8 mg/kg Mn. Crabs fed with the 9.8 mg/kg Mn diet exhibited lower relative expression of genes involved into antioxidant ability such as cytosolic manganese superoxide dismutase (cMnsod), glutathione peroxidase (gpx), peroxiredoxin (prx) and catalase (cat) in hepatopancreas than those fed with the other diets, and the highest expression were recorded in crabs fed with the diet containing 38.2 mg/kg Mn. Based on two slope broken-line and quadratic regression analysis of PWG against dietary Mn levels, the optimum dietary Mn requirement was estimated to be 48.02 and 53.30 mg/kg for juvenile Portunus trituberculatus. The present study provided further insight into the function of dietary Mn in crustacean.

58 The Effect of Altering Dietary Manganese and Selenium Levels on the Growth Performance and Blood Manganese-superoxide Dismutase Activity in Nursery Pigs

Abstract The objective of this study was to determine the effect of altering dietary levels of manganese and selenium on growth performance and MnSOD specific activity. Weaned piglets were blocked by weight (n = 216; 5.21 ± 1.17 kg; 21 ± 3 d) and sex (2 barrows and 2 gilts/pen). Pens within a block were randomly assigned to dietary treatments in a factorial design with main effects of Se (0.1 and 0.3 ppm) and Mn (0, 12, and 24 ppm). Diets (n = 9 pens/treatment) were fed in three phases (P1 = d 1–7, P2 = d 7–21, P3 = d 21–35). Pigs and orts were weighed weekly and pigs were bled on d 0, 7, 21, and 35 for analysis of specific activity of red blood cell MnSOD. Data were analyzed as 2x3 factorial design via SAS PROC GLM. There were no Se effects or Mn x Se interactions observed. There was a linear increase (P &amp;lt; 0.05) in overall ADG (397, 424, and 438 g day-1pig-1 for 0, 12, 24 ppm Mn, respectively). There was a linear trend (P &amp;lt; 0.1) in overall ADFI (557, 560, 592 g day-1pig-1 for 0, 12, 24 ppm Mn, respectively). Feed efficiency (d 0–35) across increasing Mn levels were 0.71, 0.76, 0.74 (P &amp;gt; 0.1). MnSOD activity in RBC increased from d 0–7, peaked on d 7 and decreased to d 35. On d 7, diets with 12 and 0 ppm Mn had significantly increased (P &amp;lt; 0.05) MnSOD activity (0.91 and 0.87 IU mg-1 protein, respectively) compared to diets with 24 ppm Mn (0.67 IU mg-1 protein). The dietary treatment that best maintained MnSOD activity was 0.3 ppm Se and 12 ppm Mn supplemented, while ADG was maximized in the diet with 0.3 ppm Se and 24 ppm Mn supplementation.

Dietary manganese requirement of fingerling Indian major carp, Labeo rohita (Hamilton) estimated by growth, tissue manganese concentration and hepatic manganese-superoxide dismutase activity

Dietary manganese requirement of Labeo rohita fingerlings (6.4 ± 0.12 cm; 2.3 ± 0.07 g) was estimated by feeding seven isonitrogenous and isoenergetic (350 g kg−1 crude protein; 16.7 kJ g−1 gross energy) test diets with different manganese concentrations (1.6, 2.6, 5.1, 11.1, 20.3, 40.2 and 80.1 mg kg−1 diet). The test diets were hand-fed to triplicate groups of fish at 08:00, 12:00 and 16:00 h to apparent satiation for 8-week. Live weight gain (LWG), protein efficiency ratio, specific growth rate, feed conversion ratio, protein gain, manganese concentration in the scales, vertebrae and whole body, and hepatic manganese-superoxide dismutase (Mn-SOD), total superoxide dismutase, catalase, glutathione peroxidise and lipase activities improved significantly (P < .05) in fish fed diets containing increasing manganese concentrations up to 11.1 mg kg−1 and then stabilized. Maximum apparent manganese retention (P < .05) was recorded in groups fed with 1.6 and 2.6 mg kg−1 dietary manganese levels followed by a significant decrease in fish fed higher levels of dietary manganese. Dietary manganese supplementation exerted no significant effects (P > .05) on the body moisture and ash contents, but showed a significant influence (P < .05) on the protein and fat contents, viscerosomatic index, hepatosomatic index, and condition factor. Increase in dietary manganese levels significantly affected (P < .05) whole body, vertebrae, scales and liver mineralization, except copper concentration. Hepatic malondialdehyde (MDA) concentration and lactate dehydrogenase (LDH) activity significantly decreased with increment in manganese levels up to 11.1 mg kg−1 diet. Broken-line regression analysis of LWG, scales, whole body and vertebrae manganese concentration, and hepatic Mn-SOD activity against dietary manganese concentrations, indicated the manganese requirement of L. rohita fingerlings in the range of 9.4–10.9 mg kg−1 of diet.

Effect of Dietary Manganese and Zinc Levels on Growth and Bone Status of Senegalese Sole (Solea senegalensis) Post-Larvae.

Essential dietary trace elements, such as zinc (Zn) and manganese (Mn), critically influence a wide range of physiological, metabolic, and hormonal processes in fish larvae and post-larvae. Despite their importance for normal fish growth and skeletal development, trace mineral nutrition has not been extensively studied in the early stages of development of fish. Post-larvae of an emergent aquaculture species, Senegalese sole (Solea senegalensis), were the subject of this study in order to better understand the effects of diet supplementation of trace minerals upon fish larval development and performance. Sole post-larvae were fed a combination of organic Mn (45 and 90mgkg-1 feed) and organic Zn (100 and 130mgkg-1 feed) and survival, growth, mineral deposition rates, and vertebral bone status were assessed. Our results showed that although no significant effect was found on the growth performance of Senegalese sole post-larvae, Mn and Zn supplementation to a commercial microdiet for marine fish larvae at higher dietary levels (Mn at 90mgkg-1 and Zn at 130mgkg-1) improved larval survival, decreased the severity of vertebral malformations, and increased the deposition of Mn in bone.

Effects of manganese-supplemented diets on growth performance, blood biochemistry, nitrogen metabolism and skeletal development of rex rabbits

(Background) Manganese (Mn) is an essential mineral, although its effects on rabbits is not clear. (Research Purpose) This study was conducted to investigate the effects of the level of supplementation of dietary manganese on growth performance, blood biochemistry, nitrogen metabolism and skeletal development of growing Rex rabbits. (Methods) Two hundred 3-month-old healthy Rex rabbits with similar body weights were randomly divided into 5 groups (A, B, C, D, E), with 40 replicates in each group. The rabbits in the 5 groups were fed a basal diet containing 0, 5, 10, 20 and 40 mg/kg manganese (in the form of manganese sulfate), respectively. The trial included 7 days for adaptation and 29 days of testing. Seven days before the end of feeding, eight rabbits from each group were transferred into a metabolic cage for metabolic testing. (Results) The results showed that supplemental dietary manganese levels did not significantly influence final body weight (FBW) or average daily feed intake (ADFI) (P＞0.05). Average daily gains (ADG) were significantly higher in the 20 mg/kg manganese group than in the other groups, and the ratio of feed to body weight gain (F/G) was significantly affected by manganese level (P < 0.05). No significant differences were found in the digestion coefficients among the groups (P > 0.05). Regarding carcass traits, the thymus index and total fat were significantly different (P < 0.05) among the groups, but there were no other significant differences (P > 0.05). The addition of manganese had no significant effect on the intake of nitrogen (IN), fecal nitrogen (FN), digestible nitrogen (DN) or the apparent digestibility of nitrogen (NAD). Compared to the other groups, urinary nitrogen (UN) was lower in the 20 mg/kg group, although nitrogen deposition (RN), nitrogen utilization (NUR) and the biological potency of nitrogen (NBV) were higher in this group (P < 0.05). As the amount of manganese added to the diet increased, serum triglycerides decreased (P < 0.05). Serum Mn-SOD was significantly lower in the 5 mg/kg manganese group than in the other groups (P < 0.05). The results of this study demonstrate that a diet with supplemented manganese can improve Rex rabbit growth performance and increase RN, NUR and NBV. There were no significant effects of different dietary levels of Mn on the ratio of bone to meat (P > 0.05) or bone strength (P < 0.05). (Conclusion) In conclusion, we determined that the optimal level of manganese supplementation in the diet of growing Rex rabbits was 20 mg/kg, which was also found to reduce nitrogen emissions into the environment.

Effect of levels and sources of dietary manganese on growth and mineral composition of post-smolt Atlantic salmon fed low fish meal, plant-based ingredient diets

The impact of dietary manganese (Mn) levels and sources on the growth and mineral composition of post-smolt Atlantic salmon (Salmo salar) fed practical diets was studied. Seven experimental diets were prepared with graded supplementation level of Mn; basal diet had a Mn concentration of 15 mg kg−1, four diets with 5, 15, 35 and 65 mg kg−1 supplementation of Mn as MnSO4 and two diets with at 5 and 15 mg kg−1 supplementation of Mn as Mn-glycine (Mn-gly). Atlantic salmon (initial weight, 307 ± 25 g) were distributed to 21 tanks (35 fish/tank). These fish were randomly fed with one of the experimental diets, in triplicate groups to apparent satiation for 8 weeks. At week 4 and 8, samples of whole body, plasma, bile, liver and vertebrae were collected, and their mineral concentration determined. At week 8, feaces were collected by stripping for measuring apparent availability coefficient (AAC). Neither the Mn inclusion level, nor the source had a significant impact on growth and other performance indicators. Plasma and bile Mn concentrations were significantly affected by dietary treatments at both sampling points, at week 4 and 8; whereas, whole body, liver and vertebrae responded significantly only at the end of 8 weeks. Dietary Mn level needed to meet the requirement of post-smolt Atlantic salmon was estimated by non-linear regression models using saturation of whole body or tissue Mn status as response criteria. The estimates based on Mn concentration in whole body, vertebrae, plasma and apparent availability were 29.5 ± 5.3, 26.2 ± 2.7, 26.3 ± 4.9 and 34 ± 3.4 mg Mn kg−1 diet, respectively. Analysis of relative bioavailability index showed that low inclusion of Mn-gly (5 mg kg−1 supplementation) was 2.6 to 4.5-fold more efficient than MnSO4 to attain whole body or tissue Mn saturation levels. On the contrary, high inclusion of Mn-gly (15 mg kg−1 supplementation) reduced the AAC of Mn, zinc (Zn) and copper (Cu), along with lower Mn and Zn status in tissues. The mean estimate of dietary Mn required to maintain tissue Mn saturation ranged between 26 and 34 mg Mn kg−1 diet; the corresponding Mn supplementation (as MnSO4) ranged from 14 to 22 mg Mn kg−1 diet. The supplementation level can be reduced to 4.9 to 5.7 mg Mn kg−1 diet by using Mn-gly as Mn source without compromising growth or Mn status of Atlantic salmon. High inclusion levels of Mn-gly (15 mg kg−1 diet) was found to be not beneficial.

Preanalytical interventions when using automated biochemistry tracks

(Background) Manganese (Mn) is an essential mineral, although its effects on rabbits is not clear. (Research Purpose) This study was conducted to investigate the effects of the level of supplementation of dietary manganese on growth performance, blood biochemistry, nitrogen metabolism and skeletal development of growing Rex rabbits. (Methods) Two hundred 3-month-old healthy Rex rabbits with similar body weights were randomly divided into 5 groups (A, B, C, D, E), with 40 replicates in each group. The rabbits in the 5 groups were fed a basal diet containing 0, 5, 10, 20 and 40 mg/kg manganese (in the form of manganese sulfate), respectively. The trial included 7 days for adaptation and 29 days of testing. Seven days before the end of feeding, eight rabbits from each group were transferred into a metabolic cage for metabolic testing. (Results) The results showed that supplemental dietary manganese levels did not significantly influence final body weight (FBW) or average daily feed intake (ADFI) (P＞0.05). Average daily gains (ADG) were significantly higher in the 20 mg/kg manganese group than in the other groups, and the ratio of feed to body weight gain (F/G) was significantly affected by manganese level (P < 0.05). No significant differences were found in the digestion coefficients among the groups (P > 0.05). Regarding carcass traits, the thymus index and total fat were significantly different (P < 0.05) among the groups, but there were no other significant differences (P > 0.05). The addition of manganese had no significant effect on the intake of nitrogen (IN), fecal nitrogen (FN), digestible nitrogen (DN) or the apparent digestibility of nitrogen (NAD). Compared to the other groups, urinary nitrogen (UN) was lower in the 20 mg/kg group, although nitrogen deposition (RN), nitrogen utilization (NUR) and the biological potency of nitrogen (NBV) were higher in this group (P < 0.05). As the amount of manganese added to the diet increased, serum triglycerides decreased (P < 0.05). Serum Mn-SOD was significantly lower in the 5 mg/kg manganese group than in the other groups (P < 0.05). The results of this study demonstrate that a diet with supplemented manganese can improve Rex rabbit growth performance and increase RN, NUR and NBV. There were no significant effects of different dietary levels of Mn on the ratio of bone to meat (P > 0.05) or bone strength (P < 0.05). (Conclusion) In conclusion, we determined that the optimal level of manganese supplementation in the diet of growing Rex rabbits was 20 mg/kg, which was also found to reduce nitrogen emissions into the environment.

Growth, feed utilization, mineralization and antioxidant response of stinging catfish Heteropneustes fossilis fed diets with different levels of manganese

The present research was organized to assess the effects of varying dietary levels of manganese on growth, feed efficiency, mineralization and antioxidant response of fingerling stinging catfish Heteropneustes fossilis (7.84 ± 0.08 g). Isonitrogenous (400 g kg−1 crude protein) and isocaloric (17.89 kJ g−1 gross energy) casein-gelatin based purified diets containing varying levels of manganese (1.85, 3.79, 5.92, 7.68, 9.82, 12.09 and 13.96 mg kg−1) were formulated and fed to triplicate groups of fish for a period of 12 week. MnSO4.H2O was used as the dietary manganese source. Absolute weight gain, protein gain, protein efficiency ratio and feed conversion ratio were found to improve with increasing dietary manganese level from 1.85 to7.68 mg kg−1 diet and then stabilized. Whole body protein and moisture content were found to improve with increasing dietary manganese level up to 7.68 mg kg−1 followed by no change on further increase in dietary manganese. On the other hand, whole body fat reduced with increasing dietary manganese level up to 7.68 mg kg−1 and then stabilized. However, body ash was not significantly (P > .05) affected by graded levels of dietary manganese. Whole body and vertebrae mineralization was also affected by dietary manganese levels. Except whole body copper, zinc and vertebrae zinc concentration all other minerals such as manganese, iron, calcium and phosphorus were significantly (P < .05) affected with increasing dietary manganese levels. Hepatic antioxidant enzymes activity, total superoxide dismutase, manganese superoxide dismutase and catalase activity were found to improve with increasing dietary manganese levels from 1.85 to 7.68 mg kg−1. Malondialdehyde concentration exhibited decreasing tendency (P < .05) with incremental manganese levels in the diets from 1.85 to 7.68 mg kg−1 and then stabilized. Condition factor and hepatosomatic index were also found to decrease with increase in dietary manganese levels while viscerosomatic index did not show any change in response to variable levels of dietary manganese. Broken-line regression analysis of absolute weight gain, protein gain, vertebrae manganese and hepatic Mn-SOD activity against variable levels of dietary manganese depicted the optimal dietary manganese requirement for fingerling H. fossilis ranging between 7.81 and 8.16 mg kg−1 diet.

Dietary Levels of Zinc and Manganese on the Performance of Broilers Between 1 to 42 Days of Age

The objective of this study was to determine the optimal dietary concentration of zinc and manganese on the performance characteristic and the requirement of these trace minerals derived from organic sources for broilers from 1 to 42 days of age. In experiment 1, zinc was evaluated, whereas manganese was evaluated in experiment 2. In each experiment, 320 males chicks were distributed in iron mesh metabolic cages (0.9m x 0.7m x 0.5m), according to a completely randomized experimental design in eight treatments with five replicates of eight birds each. In experiment 1, zinc sulfate was included at 0,60 and 100mg/kg and zinc methionine at 20, 40, 60, 80 and 100mg/kg. In experiment 2, manganese sulfate was added at 0, 65 and 105mg/kg and manganese methionine at 25, 45, 65, 85 and 105 mg/kg. Trace mineral requirements were determined comparing only organic trace mineral levels. The evaluated trace minerals (zinc and manganese) did not influence broiler performance, independently of source or level. It was concluded that the requirements of broilers from 1 to 42 days of age were supplied with no addition of zinc or manganese, under the conditions of the present experiments. However, under commercial rearing conditions, which are more challenging, the use of levels higher than 33.00 mg/kg and37.80 mg/kg of zinc and manganese, respectively, may be justified.

Effect of Dietary Organic Selenium and Manganese Supplementation on Productive Performance of Local Laying Hens Fed Diet Contained Soybean Oil as a Source of Essential Fatty Acids.

A total number of 300 Sinai laying hens and 30 cocks, 27 wks- old were used. The laying hens and cocks were weighed, and randomly divided into ten experimental groups with three replicates for each to investigate effects of layer dietary supplementation different levels of organic manganese (Mn-Met), selenium (Se-Met) and their mixture on productive and reproductive performance, internal egg quality, Mn and Se retention during the laying period from 27 – 43 weeks of age. The layer diets contained 1.5% soybean oil as a source of essential fatty acids and it contained gradually levels of organic Mn (20, 40, and 60 mg organic Mn /kg diet), organic Se (0.1, 0.2 and 0.3 mg organic Se /kg diet) and their mixture (20+0.1, 40+0.2 and 60+0.3 mg /kg diet (organic Mn + organic Se), where the diets premix of treatments 2,3 and 4 without Mn, 5,6 and 7 without Se and 8, 9 and 10 without Mn and Se compared to the control diet which contained mineral Mn and Se. Results showed that hens fed diets supplemented with 40mg organic Mn + 0.2 mg organic Se/ Kg diet, 60 mg organic Mn and 0.2 mg organic Se / Kg diet returned to occupy the first position in egg number as compared to the control diet by about 5.88, 5.49 and 4.66% respectively. The superiority of egg mass produced from hens fed diets supplemented with 0.2mg organic Se, 40mg organic Mn + 0.2mg organic Se and 40mg organic Mn/Kg diet. The best feed conversion resulted from the diet supplemented 0.2 mg organic Se, 40 mg organic Mn+ 0.2mg organic Se /kg diet and 60 mg organic Mn / kg diet. All dietary treatments recorded the lowest values in terms of content fresh yolk of total cholesterol. The diet contained 0.1mg organic Se and 40mg organic Mn /kg diet produced eggs with higher total antioxidant as compared with the control diet. In stored yolks, hens fed diets supplemented with 0.1, 0.2 mg organic selenium and 20mg organic Mn + 0.1mg organic Se / kg diet produced eggs with lower cholesterol concentration content. The fertility % of eggs from hens fed diets supplemented with 0.2 mg organic Se and 40 mg organic Mn / Kg diet increased compared to the control died. The higher value of scientific hatchability % occurred as a result of the diets supplemented with40 mg organic Mn and 40 mg organic Mn+0.2 organic Se /Kg diet / Kg diet than the control diet. All dietary treatments had significant higher selenium retention than control diet. The diet supplemented with 0.2 mg organic Se diet and 60 mg organic Mn /Kg diet resulted in decrease in total serum cholesterol compared to the control diet. The diet with organic Mn and Se together at the medium dose (40+ 0.2 mg / Kg diet) leads to higher value of serum antioxidant activity by about 33 % of control diet. The results indicated that the diet contained 0.2mg organic Se, 60 mg organic Mn and the mixture between 40 mg organic Mn+0.2mg organic Se /kg diet improved egg production performance, profile lipids, antioxidant activity in eggs and blood serum as well as economic efficiency of egg production.

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.

Growth, digestive and absorptive abilities and antioxidative capacity in the hepatopancreas and intestine of young grass carp (Ctenopharyngodon idellusVal.) fed graded levels of dietary manganese

To study the effects of manganese on growth performance, digestive and absorptive abilities, as well as the antioxidative capacity in the hepatopancreas and intestine, young grass carp (Ctenopharyngodon idellus Val.) (264 ± 1 g) were fed diets containing graded levels of manganese at 3.65 (control), 8.62, 13.48, 18.24, 22.97 and 27.86 mg kg−1 diet for 8 weeks. Per cent weight gain (PWG) and feed intake were the poorest in fish fed the basal diet (P < 0.05). The activities of trypsin, lipase and alkaline phosphatase in the intestine were significantly enhanced with dietary manganese level at 13.48 mg kg−1 diet (P < 0.05). Additionally, in the hepatopancreas and intestine, the protein carbonyl and malondialdehyde contents were the lowest in fish fed the diet with dietary manganese level at 13.48 mg kg−1 diet (P < 0.05), while the anti-hydroxyl radical capacities, manganese superoxide dismutase (MnSOD), glutathione peroxidase and glutathione-S-transferase activities were significantly enhanced with dietary manganese level at 13.48 mg kg−1 diet (P < 0.05). Moreover, the catalase activity and glutathione content in the intestine were the highest in fish fed the diet with dietary manganese level at 18.24 mg kg−1 diet (P < 0.05). These results indicated that optimum dietary manganese promoted growth, enhanced the digestive and absorptive abilities, and improved the antioxidative capacity in young grass carp. Based on the quadratic regression analysis for PWG and intestinal MnSOD activity, the manganese requirements for young grass carp with the initial body weight of 264 g were 16.91 and 18.21 mg kg−1 diet respectively.

Effects of dietary manganese sources and levels on growth performance, relative manganese bioavailability, antioxidant activities and tissue mineral content of juvenile cobia (Rachycentron canadumL)

This study was conducted to compare the effects of manganese sulphate (Mn-S), glycine manganese(Mn-Gly) and manganese 2-hydroxy-4-(methylthio)butyrate (Mn-HMB) on juvenile cobia, Rachycentron canadum L. Treatments consisted of 0, 2, 4, 8, 16 or 32 mg supplemental Mn kg−1 from Mn-S, Mn-Gly or Mn-MHB. Growth performance, manganese status, antioxidant activities and tissue mineral content were analysed after a 70-day feeding period. Specific growth rate (SGR) increased with feeding 6.29 to 12.65 mg Mn kg−1 diet from the Mn-S or 6.86 to 12.39 mg Mn kg−1 from the Mn-Gly or 6.50 to 8.33 mg Mn kg−1 from the Mn-HMB and then plateaued above these levels. Feed conversion ratio (FCR) show decreasing first and then increased trend. Survival rate (SR) were not affected by the dietary treatments (P > 0.05). Fish fed diets supplemented with manganese at levels of 4–32 mg Mn kg−1 had obviously higher hepatic Mn-SOD activity (P < 0.05); on the contrary, hepatic has lower malondialdehyde (MDA) content (P < 0.05) than fish fed the basal diet. The manganese concentrations of whole body and vertebrae increased with increasing dietary Mn levels from 2–32 mg Mn kg−1 (independent on manganese sources). Dietary Mn supplementation did not significantly influence the copper concentrations of whole body and vertebrae, the zinc concentrations of whole body and liver. Analysis by the broken-line regression of SGR indicated that the optimal dietary Mn requirements in juvenile cobia were 15.42, 11.22 and 10.50 mg Mn kg−1 diet from Mn-S, Mn-Gly or Mn-HMB respectively.

Effects of different dietary manganese levels on growth performance and N balance of growing mink (Neovision vision).

Two experiments were conducted to study the effects of dietary manganese levels on growth performance, nutrients digestibility, and N balance of minks during growing period. In experiment 1, 75 healthy male minks (60 days old) were selected and randomly divided into five groups with different types of diet. The diet was supplemented with 0 (control), 50, 100, 300, and 600 ppm of manganese as MnSO4 of dry matter (DM) in basic diet, respectively. From early July to middle September, the results showed that the final body weights of minks were significantly affected by diets (P < 0.05). Average daily gains (ADG) were significantly higher in the 300-ppm manganese group than those in other groups. The ratio of feed to body weight gain (F/G) was significantly affected by manganese level (P < 0.05). In experiment 2, 45 male minks (75 days old) with the same body weight were selected from each group of experiment 1 to carry out the nutrient digestion and N-balance tests which lasted for 4 days for the collection of the feces and urine, and the diets and treatment codes were same as in experiment 1. The results showed that no significant differences were found in DM, crude protein (CP), and crude carbohydrate (CC) digestibility among all groups (P > 0.05), but ether extract (EE) and gross energy (GE) digestibility were all the highest in the 300-ppm group. N intake and fecal N were similar among all groups (P > 0.05). Urinary N was lower in the 300-ppm group; in contrast, N retention was higher in this group (P < 0.05). In conclusion of experiment 1 and experiment 2, the diet supplemented with 300 ppm of manganese (as manganese sulfate) could improve the growth performance and increase the EE and GE digestibility of mink during the growing period and moreover reduce the nitrogen emissions to the environment, and the optimal total manganese level in mink's diet was 409.16 in DM during the growing period.

Effects of dietary manganese levels on growth, antioxidant defense and immune responses of the juvenile white shrimp, Litopenaeus vannamei, reared in low salinity water

Effects of dietary manganese levels on growth, antioxidant defense and immune responses of the juvenile white shrimp, Litopenaeus vannamei, reared in low salinity water

Dietary Manganese Modulates Expression of the Manganese-Containing Superoxide Dismutase Gene in Chickens1–3

To investigate the possible mechanism(s) by which dietary manganese (Mn) levels and sources modulate the expression of the manganese-containing superoxide dismutase (MnSOD) gene at both the transcriptional and translational levels, we used 432 8-d-old male broiler chicks in a 1 plus 4 × 2 design. Chickens were given either a diet without Mn supplementation [control (C)] or diets supplemented with 100 (optimal) or 200 (high) mg Mn/kg diet from inorganic Mn sulfate (I) or 3 organic complexes of Mn and amino acids with weak (W), moderate (M), or strong (S) chelation strength up to 21 d of age. Compared with C chicks, chicks fed Mn-supplemented diets had higher (P < 0.01) Mn concentrations, specificity protein 1 (Sp1) DNA-binding activities, MnSOD mRNA levels, MnSOD mRNA-binding protein (MnSOD-BP) RNA-binding activities, MnSOD protein concentrations, and MnSOD activities within heart tissue, but lower (P < 0.01) heart activating protein-2 (AP-2) DNA-binding activities. Chicks fed M diets had higher (P < 0.05) heart Mn concentrations, MnSOD mRNA levels, and MnSOD-BP RNA-binding activities compared with those fed the I and W diets and lower (P < 0.01) AP-2 DNA-binding activities than those fed other treatment diets. These results suggest that dietary Mn could modulate the expression of the MnSOD gene in broilers by altering Sp1 and AP-2 DNA-binding activities at the transcriptional level and enhancing MnSOD-BP RNA-binding activity at the translational level. Additionally, an organic Mn source with moderate chelation strength could be more effective than other Mn sources in activating MnSOD gene expression at both the transcriptional and translational levels.

Effects of dietary manganese on growth and tissue manganese concentrations of juvenile gibel carp,Carassius auratus gibelio

A 68-day growth trial was conducted in a flow-through system to determine the effect of dietary manganese levels on growth and tissue manganese concentration of juvenile gibel carp (Carassius auratus gibelio). Seven purified diets containing 7.21, 8.46, 9.50, 10.50, 13.03, 19.72 and 22.17 mg manganese (as manganic sulfate) per kilogram diet were fed to triplicate groups of fish (initial weight 3.21 +/- 0.01 g). The results showed that dietary manganese levels did not significantly affect feed intake of the fish. Specific growth rate, feed efficiency, total hepatic superoxide dismutase activity, carcass and skeletal manganese concentration increased significantly with increased dietary manganese(P < 0.05) while condition factor decreased significantly(P < 0.05). It was concluded that dietary requirement of manganese was 13.77 mg Mn per kilogram diet. Carcass and skeletal manganese concentration could also be used to evaluate the manganese requirement. Total hepatic superoxide dismulase activity was not a sensitive indicator for dietary requirement.

Influence of Supplemental Manganese and Zinc on Live Performance and Carcass Quality of Broilers

An experiment was conducted to evaluate the influence of varying levels of dietary manganese (Mn) and zinc (Zn) on broiler production. Corn-soybean meal type feeds were supplemented with either 0:0, 60:50, 120:100, or 180:150 ppm inorganic Mn:Zn and fed throughout 49 days of production. At 49 days of age, all birds wee subjected to pre-slaughter handling typical of industry practice, processed on automated equipment, and manually deboned on stationary cones. Measurements assessed live performance, carcass quality, and skeletal integrity. Supplemental levels of Mn:Zn did not influence either broiler performance or carcass quality. Skeletal integrity was similarly unaffected.