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Although boron (B) is necessary for plant growth and development, excessive concentrations of it can be harmful. Toxicity due to boron can occur naturally in the soils of arid and semiarid areas. Soluble forms of Ca were applied as foliar sprays at 1.1 and 2.2 g L−1 on three pistachio rootstocks, namely Pistacia vera L. 'Ghazvini', P. vera L. 'Badami-Riz' and P. atlantica subsp. Atlantica. Effects of the foliar sprays were assessed on growth and physiological responses of the three rootstocks while an excess of B was added to the irrigation water under saline soil (ECe ≅12 dS/m). Four-month plants were irrigated with water containing B as boric acid (20 and 40 mg L−1). Calcium treatments occurred either as aminochelate or chloride, and were sprayed on the foliage once a week. The experiment lasted for 12 wk and terminated when 50% of the plants showed symptoms of B toxicity. Excess B retarded growth and affected physiological parameters including plant height, leaf number, leaf area, leaf dry weight, stem diameter, shoot dry weight, root length, root dry weight, leaf proline content, SPAD value and RWC. Boron concentrations increased in the plant tissues, due to the boric acid in the irrigation water, while foliar sprays of calcium reduced B content in the leaves, stems and roots. Applications of Ca-Chelate and CaCl2 (2.2 g L−1 each) significantly improved growth and physiological responses of all rootstocks. The Ca-Chelate was more effective than CaCl2 in ameliorating B toxicity. In terms of rootstock tolerance to B toxicity, 'Ghazvini' and 'Atlantica' were more tolerant than 'Badami'. The results indicate that foliar sprays of Ca are effective in mitigating excess boron symptoms in pistachio rootstocks grown under saline conditions. [ABSTRACT FROM AUTHOR]

To assess the relative bioavailability of bis-glycinate bound Cu, 90 Angus-cross steers (265 ± 21 kg) were blocked by body weight (BW) to pens with GrowSafe bunks and randomly assigned to dietary treatments (14 to 18 steers/treatment): 0 mg supplemental Cu/kg dry matter (DM; CON), 5 or 10 mg supplemental Cu/kg DM as Cu sulfate (CS5; CS10) or bis-glycinate bound Cu (GLY5; GLY10). Steers received a high antagonist growing diet (analyzed 4.9 mg Cu/kg DM, 0.48% S, and 5.3 mg Mo/kg DM). Steers were weighed at the beginning (days 1 and 0) and end (days 125 and 126) of the trial to determine average daily gain (ADG) and gain:feed (G:F). Blood was collected from all steers on days 0, 28, 56, 84, and 126. Liver samples were collected on days −3 or −2 and day 123 or 124. Data were analyzed using ProcMixed of SAS (experimental unit = steer; fixed effect = treatment and block). Plasma Cu was analyzed as repeated measures (repeated effect = day). Plasma and liver Cu concentrations were regressed against total Cu intake using ProcGLM to calculate relative bioavailability of GLY. Final BW and overall ADG were greatest for CS5 and CS10 and least for CON and GLY5 (P = 0.01). Overall, DMI was not affected by treatment (P = 0.14), but overall G:F tended to be greatest for CS5, CS10, and GLY5 and least for CON (P = 0.08). Total and supplemental Cu intake was greatest for steers supplemented either source at 10 mg Cu/kg DM and least for CON (P < 0.01). However, total and supplemental Cu intake was greater for CS5 than GLY5 (P < 0.01). Final liver Cu concentrations were greatest for CS10, least for CON, CS5, and CS10, and intermediate for GLY10 (P < 0.01). Final plasma Cu was greatest for steers supplemented either source at 10 mg Cu/kg DM (P < 0.01). Relative bioavailability of GLY was 82% compared to CS based on liver Cu (P < 0.01) but did not differ based on plasma Cu (P = 0.60). The lesser bioavailability of GLY relative to CS could be due to a high concentration of dietary antagonists and lower solubility of GLY (68.9% relative to CS) in pH conditions (5.2) similar to the ruminal pH of a beef animal consuming a high concentrate diet. Future studies should examine the effects of bis-glycinate bound Cu fed in blended combination with inorganic Cu sulfate to determine the most effective blend of sources for feedlot cattle experiencing varying amounts of dietary Cu antagonists. [ABSTRACT FROM AUTHOR]

Abstract The use of vegetable ingredients may alter the mineral balance of feeds for gilthead seabream (Sparus aurata) due to the differences in mineral composition between marine and vegetable ingredients. Whereas seabream fed low levels of zinc (Zn) and manganese (Mn) may present reduced growth and performance, as well as alterations in mineral deposition and oxidative stress resistance, information on the type of sources of these two minerals is almost inexistent. In the present study, vegetable meal and oil (VM/VO) based diets were formulated including the target minerals, zinc (Zn) and manganese (Mn) in two different delivery forms, oxides and chelated to amino acids. Gilthead seabream of 8.2g were fed one of five different diets containing either non mineral supplementation, Zn and Mn oxides, amino acid chelates and their combinations. During the experimental period, fish fed Zn oxide presented higher growth, a higher deposition of protein and lower lipid contents in whole body, whereas there was an increase in whole body TBARs and up-regulation of CuZnsod in fish fed diets supplemented with amino acids chelated Zn. Highlights • Dietary mineral uptake varies depending on the source used. This study aims to overcome the shortcomings of other studies regarding mineral-specific effects in Sparus aurata. • Zn and Mn supplementation improve seabream growth, body composition and mineral retention when gilthead seabream are fed diets containing high levels of plant ingredients • Zn oxide improved growth, feed efficiency, lipid and protein deposition and oxidative status related parameters. The effects were not so clear for the Mn sources [ABSTRACT FROM AUTHOR]

Magnesium (Mg2+) plays a crucial role in over 80% of all metabolic functions. It is becoming increasingly apparent that magnesium deficiency (hypomagnesemia) may play an important role in chronic disease. To counteract magnesium deficiency, there is an unmet clinical need to develop new fully characterized, highly bioavailable, and substantially water-soluble magnesium supplements. To this end, triglycine (HG3), a tripeptide of the amino acid glycine, was chosen as a chelating ligand for magnesium, given its natural occurrence and water solubility, and entropically-driven metal binding. Herein, we discuss the synthesis, chemical and physical characterization, and cellular uptake of a magnesium triglycine chelate (MgG3), an octahedral complex with extraordinary water solubility and improved cellular uptake in CaCo-2 cells than select commonly used magnesium supplements.

Abstract Apical uptake of zinc as ionic Zn(II) or as Zn-methionine (Zn-Met) was studied in RTgutGC cell line in vitro under media compositions mirroring the gut luminal ionic concentration of freshwater (FW) and seawater (SW) acclimated salmonids. Viability of the RTgutGC cells exposed to experimental media preparations showed a time-dependent decrease in SW treated cells, with the effect being significant at 48 h (P < 0.01), but not at 12 h or 24 h. Half effective concentration of Zn exposure over 12 h (EC 50 , in μM) was not differentially affected by media composition (FW, 59.7 ± 12.1 or SW, 83.2 ± 7.2; mean ± SE, P = 0.43). Zinc (65Zn) influx in RTgutGC was not different between FW or SW treated cells, but increased significantly in the presence of methionine (2 mM, L-Met or DL-Met). An interaction effect was observed between Zn concentration and media ionic composition on the impact of Met on apical Zn uptake (L-met, P < 0.001; DL-met, P = 0.02). In the presence of Met, apical Zn uptake in SW medium was significantly lower compared to FW, but only at higher Zn concentrations (12 and 25 μM, P < 0.01). Further, Met facilitated Zn uptake was reduced in cells treated with an amino acid transport system blocker with the effect being more significant and stereospecific in SW ionic conditions. The findings of this study showed that (i) Zn speciation in the presence of Met improved apical Zn uptake in RTgutGC cells and Zn-Met species were possibly taken up through Met uptake system. (ii) The effect was differentially affected by the ionic composition of the medium. Implications and limitations of the observations towards practical Zn nutrition of salmonids are discussed. [ABSTRACT FROM AUTHOR]

Zinc is both a vital nutrient and an important toxicant to aquatic biota. In order to understand the interplay between nutrition and toxicity, it will be important to determine the mechanisms and the factors that regulate zinc uptake. The mechanism of apical intestinal Zn(II) uptake in freshwater rainbow trout and its potential modification by the complexing amino acid histidine was investigated using brush-border membrane vesicles (BBMVs). Following characterisation of the BBMV preparation, zinc uptake in the absence of histidine was both time- and concentration-dependent and consisted of two components. A saturable phase of uptake was described by an affinity constant of 57±17 μM and a transport capacity of 1867±296 nmol mg membrane protein−1 min−1. At higher zinc levels (>500 μM) a linear, diffusive component of uptake was evident. Zinc transport was also temperature-dependent, with Q10 values suggesting zinc uptake was a carrier-mediated process. Zinc uptake by vesicles in the presence of histidine was correlated to a mono-histidine species (Zn(His)+) at all Zn(II) concentrations examined. [Copyright &y& Elsevier]

Magnesium (Mg2+) plays a crucial role in over 80% of all metabolic functions. It is becoming increasingly apparent that magnesium deficiency (hypomagnesemia) may play an important role in chronic disease. To counteract magnesium deficiency, there is an unmet clinical need to develop new fully characterized, highly bioavailable, and substantially water-soluble magnesium supplements. To this end, triglycine (HG3), a tripeptide of the amino acid glycine, was chosen as a chelating ligand for magnesium, given its natural occurrence and water solubility, and entropically-driven metal binding. Herein, we discuss the synthesis, chemical and physical characterization, and cellular uptake of a magnesium triglycine chelate (MgG3), an octahedral complex with extraordinary water solubility and improved cellular uptake in CaCo-2 cells than select commonly used magnesium supplements. [ABSTRACT FROM AUTHOR]

To assess the efficacy of bis-glycinate bound Zn, 36 crossbred wethers (34 ± 2 kg) were sorted by body weight into three groups and stagger started on a Zn-deficient diet (18 mg Zn/kg dry matter [DM]; 22.5% neutral detergent fiber [NDF]) for 45 d prior to a 15-d metabolism period (10 d adaptation and 5 d collection). On day 46, lambs were randomly assigned to dietary treatments (four lambs treatment-1group-1): no supplemental Zn (CON) or 15 mg supplemental Zn/kg DM (ZINC) as Zn sulfate (ZS) or bis-glycinate (GLY; Plexomin Zn, Phytobiotics). Blood was collected from all lambs on days 1, 44, 56, and 61. Liver, jejunum, and longissimus dorsi samples were collected after euthanasia on day 61. Gene expression was determined via quantitative real-time polymerase chain reaction. Data were analyzed using ProcMixed of SAS (experimental unit = lamb; fixed effects = treatment, group, and breed) and contrast statements assessed the effects of supplemental Zn concentration (ZINC vs. CON) and source (GLY vs. ZS). After 15 d of Zn supplementation, plasma Zn concentrations were greater for ZINC vs. CON and GLY vs. ZS (P ≤ 0.01); tissue Zn concentrations were unaffected (P ≥ 0.27). Liver Cu concentrations were lesser for ZINC vs. CON (P = 0.03). Longissimus dorsi Mn concentrations were greater for ZINC vs. CON (P = 0.05) and tended to be lesser for GLY vs. ZS (P = 0.09). Digestibility of DM, organic matter (OM), and NDF was lesser for ZINC vs. CON (P ≤ 0.05); acid detergent fiber digestibility tended to be greater for GLY vs. ZS (P = 0.06). Nitrogen retention (g/d) tended to be greater for GLY vs. ZS (P = 0.10), and N apparent absorption was lesser for ZINC vs. CON (P = 0.02). Zinc intake, fecal output, retention, and apparent absorption were greater for ZINC vs. CON (P ≤ 0.01). Apparent absorption of Zn was -5.1%, 12.8%, and 15.0% for CON, ZS, and GLY, respectively. Nitrogen and Zn retention and apparent absorption were not correlated for CON (P ≥ 0.14) but were positively correlated for ZINC (retention: P = 0.02, r = 0.52; apparent absorption: P < 0.01, r = 0.73). Intestinal expression of Zn transporter ZIP4 was lesser for ZINC vs. CON (P = 0.02). Liver expression of metallothionein-1 (MT1) tended to be greater for GLY vs. ZS (P = 0.07). Although Zn apparent absorption did not differ between sources (P = 0.71), differences in post-absorptive metabolism may be responsible for greater plasma Zn concentrations and liver MT1 expression for GLY-supplemented lambs, suggesting improved bioavailability of GLY relative to ZS., (© The Author(s) 2021. Published by Oxford University Press on behalf of the American Society of Animal Science.)