Source Of Mn Research Articles

Effects of sources and levels of dietary supplementary manganese on growing yak's in vitro rumen fermentation.

Manganese (Mn) is an essential trace element for livestock, but little is known about the optimal Mn source and level for yak. To improve yak's feeding standards, a 48-h in vitro study was designed to examine the effect of supplementary Mn sources including Mn sulfate (MnSO4), Mn chloride (MnCl2), and Mn methionine (Met-Mn) at five Mn levels, namely 35 mg/kg, 40 mg/kg, 50 mg/kg, 60 mg/kg, and 70 mg/kg dry matter (includes Mn in substrates), on yak's rumen fermentation. Results showed that Met-Mn groups showed higher acetate (p < 0.05), propionate, total volatile fatty acids (p < 0.05) levels, ammonia nitrogen concentration (p < 0.05), dry matter digestibility (DMD), and amylase activities (p < 0.05) compared to MnSO4 and MnCl2 groups. DMD (p < 0.05), amylase activities, and trypsin activities (p < 0.05) all increased firstly and then decreased with the increase of Mn level and reached high values at 40-50 mg/kg Mn levels. Cellulase activities showed high values (p < 0.05) at 50-70 mg/kg Mn levels. Microbial protein contents (p < 0.05) and lipase activities of Mn-Met groups were higher than those of MnSO4 and MnCl2 groups at 40-50 mg/kg Mn levels. Therefore, Mn-met was the best Mn source, and 40 to 50 mg/kg was the best Mn level for rumen fermentation of yaks.

Cobalt and Manganese Extraction from Ocean Nodules by Co-Processing with Steel Metallurgical Slag

Polymetallic nodules, also called manganese nodules (due to their high content of this element), contain various valuable metals such as Cu, Ni and Co. These seabed minerals are a good alternative source of Co and Mn due to the decrease in the grade of mineral deposits on the earth’s surface. For the treatment of manganese nodules, acid-reducing leaching is apparently the most attractive, due to its low cost compared to other processes, short operational times, and it is more friendly to the environment. In this investigation, the extraction of Mn and Co from manganese nodules from two different locations was studied in acid media and by reusing a steel slag obtained from a steel smelting process. An ANOVA analysis was performed to determine the most appropriate Manganese Nodule/Fe(res) ratio and time to dissolve Co and Mn from the nodules. Effect of temperature on the process was evaluated, and then a residue analysis was carried out. Finally, it was discovered that the best results were obtained when working at 60 °C in a time of 15 min, obtaining extractions of approximately 98% Mn and 55% Co. Additionally, the formation of polluting elements was not observed, nor the precipitation of Mn and Co species in the studied residues.

Effects of different manganese sources on nutrient digestibility, fecal bacterial community, and mineral excretion of weaning dairy calves.

Mn, which is an essential trace mineral for all animals, has functions in skeletal system development, carbohydrate and lipid metabolism. The aim of this study was to clarify the effects of different manganese (Mn) sources in basal diets on nutrient apparent digestibility, fecal microbes, and mineral elements excretion before and after weaning. A total of 15 Holstein heifer calves (6-week-old, 82.71 ± 1.35, mean ± standard error) were randomly designed into three groups (five each): no extra Mn supplemented (CON), 20 mg Mn/kg (dry matter basis) in the form of chelates of lysine and glutamic acid in a mixture of 1:1 (LGM), and 20 mg Mn/kg (dry matter basis) in the form of MnSO4. All calves were weaned at 8 weeks of age. The experiment lasted for 28 days (14 days before weaning and 14 days after weaning). Dry matter intake (DMI) was recorded daily. The animals were weighed by electronic walk-over, and body size indices were collected using tape on days -14, -1, and 14 of weaning. The feces of calves was collected to measure the apparent digestibility of nutrients (acid insoluble ash was an internal marker) and bacterial community on days -1, 1, 3, 7, and 14 of weaning. Fecal mineral concentration was determined by inductively coupled plasma emission spectroscopy on days -1, 1, 7, and 14 of weaning. The results showed that, compared with the CON group, adding LGM to diets containing 158.82 mg/kg Mn increased the apparent digestibility (P < 0.05). The Chao 1 and Shannon index of fecal bacteria decreased at day 1 in the LGM and MnSO4 groups and increased after weaning. The PCoA results indicated that the LGM group was distinctly separate from the CON and MnSO4 groups during the whole experimental period. Significant differences (P < 0.05) were observed in the relative abundance of two phyla (Proteobacteria and Spirochaetota) and eight genera (Alloprevotella, Prevotellaceae_UCG-001, Clostridia UCG 014, RF39, UCG-010, Pseudomonas, Ralstonia, and Treponema) in three groups. Moreover, the LGM group showed less excretion of Fe, P, and Mn than the MnSO4 group. In summary, 20 mg Mn/kg diet supplementation improved nutrient digestibility, changed the fecal microbial community, and reduced mineral excretion. Organic Mn supplementation in the diet had more advantages over the sulfate forms in weaning calves.

Elemental content in under-utilized green leafy vegetables of urban waterbodies in Kolkata, India and their associated health risk

The study reports the micronutrient content of some underutilized and lesser-known aquatic plants from urban water bodies that have enormous potential for contributing to improving food security and diversifying diets. Naturally growing plants were sampled from 21 small waterbodies in Kolkata, India. Based on traditional knowledge about their uses and their yield estimates from these water bodies Alternanthera philoxeroides, Ipomoea aquatica, Commelina benghalensis, Enhydra fluctuans & Ludwigia adscendens, were selected for elemental analysis. The two commonly occurring plants, A. philoxeroides and I. aquatica, were a good source of Mn, Fe and Se contributing > 25% of the recommended intake for Mn and > 10% for Fe and Se. The Target Hazard Quotient was <1 for all plants, indicating no health risk from consumption of these plants from urban sites. The ubiquitous and climate resilient A. philoxeroides had a higher mean content of Mn, Fe, Se, Cu, Ca and K than the more popular, I. aquatica. Promoting the consumption of A. philoxeroides, an invasive weed in many countries, would help to keep its rampant growth in check ensuring better protection of the environment.

Physical And Chemical Characteristics Of Cassava Leaf Chlorophyll As Natural Dye Powder (Manihot esculenta Cranzt) With Tween 80 And Alkaline Type Variations

Cassava leaves are a good source of minerals Ca, Mg, Fe, Mn, Zn, vitamins A and B2 (riboflavin). In addition, cassava leaves contain bioactive compounds that are beneficial to the body, namely chlorophyll. Chlorophyll is a natural green dye that is generally found in plants whose composition is contained in the chloroplasts. The amount of chlorophyll in cassava leaves is classified as good, namely 18.141 mg/l. This is one of the potentials to utilize cassava leaves as natural dyes. Production of cassava leaf coloring powder using foam mat drying. Foam mat drying is a method of foaming technique by adding foam. The foaming agent used is tween 80 which can produce foam or froth and speed up drying. Chlorophyll can be easily degraded due to exposure to heat (temperature), acids, light and alcohol. The use of NaHCO3 can increase the levels of chlorophyll in the leaves. In addition, the use of MgCO3 can maintain the green color of leaf chlorophyll. The purpose of this study was to determine the interaction of tween 80 variations and types of bases on the physical and chemical profiles of cassava leaf natural dye powder. The research design used a laboratory experimental method with two variations, namely tween 80 and base type. In this study there were four treatment combinations. This study used several test parameters including physical and chemical tests, namely dissolving time, color (L, a, b), total dissolved solids, pH, water content, and chlorophyll content. The results showed that the variation of tween 80, the type of base and the interaction of the two had a significant effect on the b color value and the L color value in cassava leaf natural dye powder.

Glacial meltwater and sediment resuspension can be important sources of dissolved and total dissolvable aluminum and manganese to coastal ocean surface waters

AbstractThe supply of aluminum (Al) and manganese (Mn) to the Gulf of Alaska from coastal sources is poorly constrained. Here, we investigate the seasonality of sources to better constrain Al and Mn cycling in the coastal Gulf of Alaska region and add to our understanding of seasonal and interannual inputs. We examine Mn and Al behavior over the shelf to distinguish between redox‐induced release of dissolved trace metals (i.e., diffusion from sediments), sediment resuspension, and meltwater release. Data suggest that, prior to the onset of stratification in the spring, shelf sediment resuspension from deep mixing is an important mechanism for trace metal delivery to surface waters. As spring and summer ensue, increased meltwater discharge coupled with increased surface water temperatures result in stratification of the water column within the coastal Gulf of Alaska, and meltwater becomes a more important source of Al and Mn to the surface waters. The limited data available suggest that a redox‐driven flux of Mn from shelf sediments is not as important as the meltwater flux during the summer. In addition, dissolved trace metal concentrations in meltwater‐influenced plumes over the shelf exhibit conservative mixing, while particulate trace metal concentrations do not behave conservatively. This indicates that there are different physical controls (particle settling vs. mixing) on the spatial distributions of dissolved and particulate Al and Mn in coastal waters, the manifestation of which are likely highly variable and dependent on the trace metal composition of the river and the hydrodynamics governing this interaction at any given time.

Technosols in coal mining areas: Viability of combined use of agro-industry waste and synthetic gypsum in the restoration of areas degraded

This study assessed the viability of the combined use of coal processing waste (CPW), rice processing waste (RPW), poultry agro-industry sludge (PAS), synthetic gypsum (SG), topsoil (TS), and B horizon soil (BH) to reclaim areas degraded by coal mining. A Classification, Potentiality, Quantity/viability, and Application (CPQvA) systematic was employed to assess the feasibility of using these waste and materials to construct technosols. An experiment consisting of five technosols (T-1–T-5) was replicated four times in a completely randomized block design. Technosols fertility was analyzed 12 months after the establishment of the experiment. The mean fertility parameters, presented as mean ± 1 SD, were subjected to one-way analysis of variance, and the differences were tested using Tukey's test (P < 0.05). The results confirmed that RPW was the main source of Mg (1584 mg kg−1), K (1955 mg kg−1), Mn (708 mg kg−1), and Fe (1511 mg kg−1); PAS was the main source of Organic Matter (OM) (465 g k−1), N (42 g k−1), Al (2880 mg kg−1), and Zn (394 mg kg−1); while SG was the main source of Ca (30,494 mg kg−1). The T-4 and T-5 technosols, composed of equal amounts of SG + RPW + PAS and TS + SG + RPW + PAS, respectively, presented the best fertility results, with the higher mean values of K (96.3 ± 19.6 mg dm−3), Ca (1044 ± 165 mmolc dm−3), OM (62 ± 14 g kg−1) and cation exchange capacity (CEC) (1066 ± 168 mmolc dm−3) observed in T-4, and P (40.4 ± 12.6 mg dm−3) in T-5. Notably, T-4 did not include TS in its composition, which is important because it does not require commissioning of natural areas to reclaim degraded areas. Each hectare of 0.2 m of T-4 would cost USD 23,291.64, considering just the waste transporting costs. The results demonstrate the feasibility of the combined use of waste tested in this study to reclaim degraded areas by coal mining.

Effect of organic and inorganic manganese supplementation on performance and eggshell quality in aged laying hens.

Manganese (Mn) is an important trace element for laying hen's nutrition, which is required in small amounts in the diet. Its deficiency results in lowered production performance and eggshell quality. This experiment was conducted to investigate the influence of different sources and levels of Mn on egg production performance and eggshell quality in aged laying hens. A total of 720, 83-week-old Hy-Line W-36 laying hens were fed a non-Mn supplemented basal diet for 4-week (to ime Mn-exhaustion of body) and then were allocated to a completely randomized design with 10 treatments, six replicates and 12 birds each. Concentration of Mn in the non-Mn supplemented basal diet was 10.34 mg/kg (treatment 1), the added doses of dietary Mn were included 30, 60, and 90mg/kg of three different sources (Mn-oxide, Mn-sulphate, and Mn-organic) for treatments 2-10, respectively. The experiment lasted for 12 week. Dietary supplementation with either organic or inorganic Mn sources significantly enhanced egg production (EP), egg mass (EM), feed conversion ratio (FCR), and relative eggshell weight (RESW) compared with the non-Mn supplemented diet. However, the experimental diets did not influence feed intake (FI), egg weight, and other eggshell quality traits. Based on the broken line regression models, the performance traits were optimized at 30-40mg/kg Mn concentration when supplemented by Mn-sulphate or Mn-organic. Although, it was 80-90mg/kg when supplemented by Mn-oxide. The relative bio-efficacy of inorganic Mn sources include Mn-oxide and Mn-sulphate in compare with Mn-organic were estimated 45% and 87% (for EP trait), 30% and 94% (for EM trait), 36% and 99% (for FCR trait), and 37% and 78% (for RESW trait), respectively. In the aged laying hens, Mn requirement is higher than the NRC's recommendation. Sulphate and organic sources of Mn are more effective than Mn-oxide.

Meta-analysis of the effects of sulfate versus hydroxy trace mineral source on nutrient digestibility in dairy and beef cattle

Trace mineral (TM) source can potentially alter nutrient digestibility through effects on microbial populations. A meta-analysis was conducted to determine whether sulfate versus hydroxy (IntelliBond) sources of supplemental Cu, Zn, and Mn had any effect on dry matter intake (DMI), dry matter digestibility, and neutral detergent fiber (NDF) digestibility. All available cattle studies (8 studies, 12 comparisons) were used to estimate the effect size (hydroxy mean - sulfate mean). Factors included in the analysis were method of digestibility analysis (total collection, marker-based, or 24 h in situ), study design (randomized design or Latin square), beef (n = 5) versus dairy (n = 7) cattle, and days on treatment; these factors were retained when P < 0.05. Dry matter digestibility was increased by hydroxy TM in beef (1.64 ± 0.35 units) but not in dairy models (0.16 ± 0.13 units) relative to sulfate TM. The NDF digestibility increased significantly with hydroxy versus sulfate TM, but digestibility assessment method influenced this response. Studies using total collection or undigested NDF as a flow marker showed a significant increase (2.68 ± 0.40 units and 1.08 ± 0.31 units, respectively) in NDF digestibility for hydroxy versus sulfate TM; but studies utilizing 24-h in situ incubation did not detect any change (-0.03 ± 0.23 units). These observations may reveal differences in precision of measurement or may indicate mineral effects beyond the rumen; total collection is considered the gold standard method. Hydroxy TM did not affect DMI per animal or per unit of body weight relative to sulfate TM. In conclusion, feeding hydroxy versus sulfate TM does not appear to affect DMI but, depending on type of cattle and method of measurement, can increase dry matter digestibility and NDF digestibility, which may be explained by differences in solubility of the TM sources in rumen, differentially affecting fermentation.

Specific countermeasures to intrinsic capacity decline issues and future direction of LiMn2O4 cathode

Spinel LiMn2O4 cathodes are particularly attractive in lithium-ion batteries (LIBs) owing to the non-toxic Mn sources, abundant reserves, and high specific power. However, poor cycling stability due to the significant capacity decay becomes the key limitation for its application. With the continuous exploration, some deep-rooted causes of capacity decay are being challenged. To date, three intrinsic mechanisms have been shown to cause capacity loss, including the Jahn-Taller (J-T) effect, Mn disproportionation, and oxygen vacancy formation. Specifically, the capacity loss especially below 3 V caused by J–T distortion hinders the achievement of theoretical capacity. Besides, the irreversible phase transitions arising from Mn(III) disproportionation exacerbates Mn dissolution. Even worse, the Mn ions migration due to oxygen loss during the electrochemical cycling also leads to severe phase transition. Although some reviews have involved various strategies to overcome the related drawbacks, a summary of more comprehensive and specific coping strategies along with recent advances and future development direction is still lacking. Herein, we first introduce the comprehensive intrinsic capacity fading mechanisms of LiMn2O4. Then, recent progress in suppressing the J-T distortion, Mn disproportionation, and Mn migration is systematically reviewed, with a special focus on the advances in the up-to-date strategies such as cation disorder and epitaxial coating. We also put forward future research directions and opportunities for the development of longer-life LiMn2O4 cathode. This review aims to offer some guidance for the rational designing of sufficiently durable LiMn2O4 cathodes and the maximizing of their inherent capacity for meeting the high demands in LIBs.

Environmental exposure to manganese and health risk assessment from personal sampling near an industrial source of airborne manganese

Manganese (Mn), despite being a trace element necessary in small quantities for the correct functioning of the organism, at higher concentrations can induce health disorders, mainly in motor and cognitive functions, even at levels found in non-occupational environments. For this reason, US EPA guidelines define safe reference doses/concentrations (RfD/RfC) for health.In this study, the individualised health risk of exposure to Mn through different media (air, diet, soil) and routes of entry into the organism (inhalation, ingestion and dermal absorption) was assessed according to the procedure defined by the US EPA. Calculations related to Mn present in ambient air were made on the basis of data obtained from size-segregated particulate matter (PM) personal samplers carried by volunteers recruited in a cross-sectional study conducted in the Santander Bay (northern Spain), where an industrial source of airborne Mn is located.Individuals residing in the vicinity of the main Mn source (within 1.5 km) were found to have a hazard index (HI) higher than 1, indicating that there is a potential risk for these subjects to develop health alterations. Also, people living in Santander, the capital of the region, located 7–10 km from the Mn source, may have some risk (HI > 1) under some wind conditions (SW). In addition, a preliminary study of media and routes of entry into the body confirmed that inhalation of PM2.5-bound Mn is the most important route contributing to the overall non-carcinogenic health risk related to environmental Mn.

A facile and novel synthesis of bimetallic copper-manganese oxide nanoparticles anchored on carbon nanotubes

In the current contribution, copper-manganese bimetallic oxide nanoparticles attached to carbon nanotube surfaces have been created utilizing a straightforward method rather than complicated machinery. The employed sources of Cu and Mn were copper sulfate and potassium permanganate, which were combined with modified carbon nanotubes and thermally treated at 250, 350, and 450 °C, respectively. As the annealing temperature rises from 250 to 450 °C, the copper-manganese bimetallic oxide nanoparticles adhered to the surface of the carbon nanotubes gradually grow in size from 9 to 45 nm. XRD and FTIR methods were used to study structural characteristics. The existence of copper-manganese bimetallic oxide phases was established based on the results. The peak height and sharpness of the XRD data were also improved by increasing the annealing temperature, reflecting an improvement in the crystallinity. A broadband dielectric spectroscopy (BDS) was used to show how the applied frequency affected the dielectric characteristics.

Varied sediment archive of Fe and Mn contents under changing reservoir mixing patterns, oxygenation regimes, and runoff inputs

Water hypoxia intensification in lakes and reservoirs has become a global problem under global warming. The Mn/Fe ratio is frequently employed to reconstruct historical redox conditions, but interpretation of this ratio may be problematic when the accumulation of Fe and Mn is governed by factors in addition to redox processes. We tested the Fe and Mn contents and bacterial diversity of a 250 cm sediment column in a monomictic reservoir. The deposition time frame and sedimentary rate (approximately 60 cm/y) were determined by integrating the Fe and Mn contents with the hydrological time series, providing a sufficient archive to reconstruct the intra-year variation in water qualities. The inapplicability of the Mn/Fe ratio observed because redox processes, mixing patterns, and biological activity jointly affected the net accumulation of Fe and Mn in the sediment. The causes of the vertical variations in the sediment Fe and Mn contents are discussed, considering the runoff sediment input, hydrodynamic and thermodynamic characteristics of this reservoir, and bacterial distributions in the sediment column. High-speed deposition intensively occurred in summer and autumn; thus, during this period, fluvial sediment was the main source of Fe and Mn. Another source was biochemical sedimentation due to mixing and oxygenation in this reservoir, which played a larger role in spring and winter. Our study showed that the easily accessible current hydrological data of the reservoir provide a reference time frame for identifying historical environmental events and that the use of the Fe/Mn ratio alone is inconclusive for interpreting the historic oxygenation regimes of reservoirs. Future applications of this method should consider the individual reservoir characteristics that impact the mobility and net accumulation of Fe and Mn in the sediment.

Distribution and off–shelf transport of dissolved manganese in the East China Sea

To gain a better understanding of the geochemical behavior of dissolved manganese (Mn) in the marginal seas with respect to distribution and exchange fluxes, more than 200 water samples were collected in the East China Sea (ECS) in May, August, and October of 2013. The concentration of dissolved Mn in the ECS ranged from 1.1 to 81.5 nM, with a gradual decrease with distance from the shore. Seasonal distribution of dissolved Mn varies significantly in the Changjiang estuary, mainly regulated by freshwater input from the Changjiang (Yangtze River) and redox variations. The ECS continental shelf is an important source of Mn for adjacent waters, and the export of Mn–rich coastal waters had an important effect on its re-distribution and internal cycling. The dynamic variation fluxes of water and dissolved Mn across the 100– and 200–m isobaths in the ECS were calculated with an aid of the Finite−Volume Coastal Ocean Model (FVCOM). The ECS continental shelf exported (5.69 ± 1.14) × 108 mol/yr of Mn into the East/Japan Sea from the Tsushima Strait. The Kuroshio surface waters receive an additional (1.02 ± 3.12) × 108 mol/yr of Mn from the ECS continental shelf through a cross–shelf exchange process, which could potentially affect dissolved Mn in the Northwest Pacific. Our data suggest that off-shelf transport from the ECS continental shelf is essential for understanding the biogeochemical cycles of trace metals in the Northwest Pacific Ocean and the East/Japan Sea.

The content of ten elements in pig feed and manure and its relationship with element concentration in earthworms on swine farms

The aim of this investigation is to determine the content of ten elements, Cr, Mn, Co, Ni, Fe, Zn, As, Cu, Se, and Cd, in pig feed, manure and earthworms (Lumbricus terrestris). Samples were collected during 2015 and 2017, on four pig farms in Serbia, and analyzed for elements by inductively coupled plasma mass spectrometry. According to the mean concentrations, the elements show the following trends: Fe > Mn > Zn > Cr > Ni > Cu > Cd > Se > As > Co in monocalcium phosphate, Zn > Mn > Fe > Cu > Co > Cr > Ni > Se > As > Cd in vitamin-mineral premixes, Fe > Zn > Mn > Cu > Ni > Cr > Se > Co > As > Cd in complete feed, and Fe > Zn > Mn > Cu > Ni > Cr > Co > Se > Cd > As in pig manure. The obtained results show that monocalcium phosphate and vitamin-mineral premixes are the main source of Mn, Zn, and Fe in complete feed mixtures. The Cd concentration in one sample of monocalcium phosphate exceeds the maximum permissible level. Only one out of six investigated complete feed mixtures was in accordance with the national and EU regulations. The presence of Fe, Zn, and Mn in earthworms reflects their concentration in pig manure, but this is not noticed for Cr, Cu, Se, As, Ni, Co, and Cd.

Effects of breed on preferential intake of hydroxychloride and sulfate sources of trace minerals in growing beef heifers

Abstract This study evaluated the effects of breed on voluntary preferential intake of two sources of Cu, Mn, and Zn when added to white salt-based trace mineral supplement (days 0 to 55; experiment 1) and protein supplement (days 56 to 112; experiment 2). On day 0, Nelore and ½ Angus × ½ Nelore heifers (n = 20/breed) were stratified by breed, body weight (BW = 347 ± 82 kg), and age (12 to 30 mo), and randomly allocated into 1 of the 40 drylot pens (1 heifer/pen). Both experiments were divided into washout (days 0 to 27 in experiment 1 and days 56 to 83 in experiment 2) and preferential intake periods (days 28 to 55 in experiment 1 and days 84 to 112 in experiment 2). During the respective preferential intake period, heifers were provided simultaneous free-choice access to sulfate (SUL) and hydroxychloride (HYD) sources of Cu, Mn, and Zn mixed into salt-based trace mineral supplements from days 28 to 55 (experiment 1) and then protein supplements from days 84 to 112 (experiment 2). Heifers were provided free-choice access to Tifton 85 (Cynodon sp.) hay from days 0 to 112. Effects of breed × source × day of the study were detected (P ≤ 0.05) for daily trace mineral intake from days 28 to 56 and days 84 to 112. Angus × Nelore heifers consumed a greater amount of SUL vs. HYD supplements on days 31 to 33 (P = 0.02) and HYD vs. SUL supplements on days 37 to 42 (P ≤ 0.02), whereas Nelore heifers consumed more HYD vs. SUL supplements on days 31 to 33 and 43 to 51 (P ≤ 0.05). Both breeds consumed (P ≤ 0.05) a greater amount of protein supplement containing HYD vs. SUL from days 84 to 112, but the differences in protein supplement intake increased (P ≤ 0.04) in greater magnitude for Nelore vs. Angus × Nelore heifers. Supplement intake coefficient of variation (CV) from days 28 to 41 and days 84 to 97 tended (P = 0.06) to be greater for Nelore vs. Angus × Nelore heifers. Effects of breed × source were detected (P = 0.02) for supplement intake CV from days 84 to 112. Intake CV of supplements added with HYD did not differ (P ≥ 0.40) between Nelore vs. Angus × Nelore heifers but was greater (P &amp;lt; 0.01) for Nelore vs. Angus × Nelore heifers fed SUL supplements. Overall, Nelore heifers had greater preferential intake for mineral and protein supplements containing hydroxychloride vs. sulfate sources compared to Angus × Nelore heifers. Hydroxychloride sources encouraged voluntary intake and reduced variation in supplement consumption compared to SUL sources of the same metals.

PLA/starch biodegradable fibers obtained by the electrospinning method for micronutrient mineral release

&lt;abstract&gt; &lt;p&gt;Developments in nanofibers seek to increasingly expand the field of support and release of actives, such as fertilizers. Using nanofibers as materials for mineral nutrients aims to increase the efficiency of contact release of the fertilizer to the plant root in the soil. Poly lactic acid (PLA) is a polymer with biocompatibility characteristics and spinning conditions. The starch biopolymer combined with PLA can improve the biodegradation properties and hydrophilicity of the fibers and allow the solubilization of the fertilizer source for the plant. Thus, the present paper sought to find a polymeric matrix in the form of PLA/starch nanofibers that could act in the release of the mineral micronutrient manganese as a model asset. The electrospinning method was employed to obtain the fibers varying the starch concentration from 10 to 50% (w/w) in the polymeric matrix. The nanocomposite containing manganese carbonate as a source of Mn&lt;sup&gt;2+&lt;/sup&gt; ions was produced from the best membrane composition. The results showed that the analyzed PLA/starch blends with 20% (w/w) provided better fiber affinity with water, which is fundamental for fiber degradation time. Regarding fertilizer release, the starch present in the PLA fiber at a concentration of 20% (m/m) promoted better control in the release of Mn&lt;sup&gt;2+&lt;/sup&gt;. The total release occurred after 5 d in contact with the 2% citric acid extractive medium. Thus, PLA/starch fiber becomes an alternative in the packaging of particulate fertilizers, providing increased contact area during root application with gradual delivery of mineral nutrients and minimizing loss by leaching.&lt;/p&gt; &lt;/abstract&gt;

Enhancing catalytic efficiency of carbon dots by modulating their Mn doping and chemical structure with metal salts.

Nanozymes are emerging materials in various fields owing to their advantages over natural enzymes, such as controllable and facile synthesis, tunability in catalytic activities, cost-effectiveness, and high stability under stringent conditions. In this study, the effect of metal salts on the formation and catalytic activity of carbon dots (CDs), a promising nanozyme, is demonstrated. By introducing Mn sources that possess different counter anions, the chemical structure and composition of the CDs produced are affected, thereby influencing their enzymatic activities. The synergistic catalytic effect of the Mn and N-doped CDs (Mn&N-CDs) is induced by effective metal doping in the carbogenic domain and a high proportion of graphitic and pyridinic N. This highly enhanced catalytic effect of Mn&N-CDs allows them to respond sensitively to the interference factors of enzymatic reactions. Consequently, ascorbic acid, which is an essential nutrient for maintaining our health and is a reactive oxygen scavenger, can be successfully monitored using color change by forming oxidized 3,3',5,5'-tetramethylbenzidine with H2O2 and Mn&N-CDs. This study provides a basic understanding of the formation of CDs and how their catalytic properties can be controlled by the addition of different metal sources, thereby providing guidelines for the development of CDs for industrial applications.

Mn release behaviors from electrolytic manganese residue-based slow-release fertilizer using acid/alkali-activated geopolymers as binders: A comparative study

In this study, acid/alkali-activated geopolymers and electrolytic manganese residue (EMR) were used as a binder and Mn source, respectively, to prepare EMR-based slow-release fertilizers (SRFs) and Mn release behaviors from SRFs were comparatively investigated. Mn release from SRFs prepared by acid/alkali-based geopolymers follows first-order kinetics and the Ritger-Peppas model. For alkali activator attack, the easily leachable manganese salt (MnSO4·H2O) in EMR is converted to stable fractions (such as MnO2, Mn4Si8O20, and Ca4Mn4Si8O24) in the SRFs. The K-(A)-S-H gel in SRFs prepared using alkali-based geopolymers (SRFs-alGo) restricts rapid Mn release through physical encapsulation and ion exchange. In contrast, SRFs prepared using acid-based geopolymers (SRFs-acGo) mainly limit Mn release through pediocratic NH4MnPO4·H2O formation and physical adsorption/encapsulation of phosphoric acid-activated geopolymer gel (Si–O–Si–O–P–O). Phosphoric acid attack did not significantly changed the proportion of the exchangeable fraction of Mn in SRFs, which was maintained at approximately 40%. Moreover, Mn in SRFs-alGo was uniformly distributed on the surface and bulk phases (SEM-EDS and XPS co-analysis), while most of the Mn in SRFs-acGo was distributed on the surface of particles, leading to readily released Mn and even higher Mn release concentrations of SRFs-acGo. This study provides a theoretical basis for strategically applying EMR-based SRFs to plants with different Mn requirements and guides subsequent field experiments.

Sources and levels of copper and manganese supplementation influence performance, carcass traits, meat quality, tissue mineral content, and ileal absorption of broiler chickens

This study was conducted to evaluate the effects of different levels and sources of Cu and Mn (sulfate or hydroxychloride - H) on growth performance, carcass traits, meat and skin quality, footpad dermatitis severity, litter quality, liver and plasma mineral content, and ileal mineral absorption. A total of 1,920 one-day-old male Cobb 500 broiler chicks were assigned randomly to one of 2×3+2 factorially arranged treatments: CuH (15 and 150 ppm)×MnH (40, 80, 120 ppm)+15 ppm Cu Sulfate with 80 ppm Mn Sulfate (control 1) or 150 ppm Cu Sulfate with 120 ppm Mn sulfate (control 2) for 42 d. Each treatment consisted of 8 replicates of 30 birds. At 42-day-old were slaughtered for carcass yield and meat quality analyses. At 43-day-old, it was determined the apparent ileal absorption of minerals and the concentration of Cu and Mn in the liver and plasma. The resistance and elasticity of the skin, and footpad dermatitis severity were also evaluated. The level 150 ppm CuH improved the FCR compared to the 15 ppm CuH and 15 ppm Cu Sulfate level. Broilers fed diets containing 150 ppm CuH showed higher breast yield compared to those fed diets containing 15 ppm. Breast yield was positively influenced by the inclusion of 40 ppm MnH. There was an interaction between the CuH and the MnH for skin elasticity, and the highest elasticity was found when the supplementation levels were 150 ppm CuH and 40 ppm MnH. High levels of copper decreased the incidence of footpad dermatitis. The hydroxychloride source determined a higher mineral concentration in the liver and plasma and greater apparent ileal absorption of Cu and Mn. In conclusion, dietary supplementation with 150 ppm CuH and 40 or 80 ppm MnH enhance breast yield and improves skin resistance. The inclusion of 150 ppm CuH has the possibility to improve the FCR and decrease leg injuries. Furthermore, the hydroxychloride source seems to be more bioavailable than the sulfate source.