Mn Amino Acid Research Articles

Effect of manganese amino acid complexes on growth performance, meat quality, breast muscle and bone development in broilers

ABSTRACT 1. This study was conducted to investigate the effects of dietary supplementation of manganese (Mn) amino acid complexes on growth performance, Mn deposition, meat quality, breast muscle and bone development of broilers. 2. A total of 504, one-day-old male Arbor Acres broilers were randomly divided into seven treatments; control diet (CON; basal diet, no extra Mn addition), manganese diet (MnN as Numine®-Mn; CON + 40, 80, 120 or 160 mg Mn/kg), manganese-S group (MnS; CON + 120 mg Mn/kg as MnSO4·H2O), manganese-A diet (MnA as Mn from hydrolysed feather meal; CON + 40 mg Mn/kg as MnA). 3. There were no significant differences for average daily gain (ADG) or feed intake (ADFI) among diets during the feed phases (p > 0.05). The FCR in the starter and over the whole period were quadratically affected by dietary MnN dosage and gave the lowest FCR at 80 mg/kg (p < 0.05). The Mn content of thigh muscle, jejunum, heart, pancreas, liver and tibia increased linearly with MnN addition (p < 0.05). 4. For meat quality, MnN significantly increased colour (a*), pH45 min and pH24 h, reduced shear force, drip loss and pressure loss of breast muscle (p < 0.05). 5. Moreover, MnN significantly upregulated MYOD expression at d 21 and SOD expression at d 42, decreased MuRF1 and Atrogin-1 mRNA level at d 42 in breast muscle. Transcriptome analysis revealed that the regulating effect of MnN on muscle development significantly enriched signalling pathways such as adhesion, ECM-receptor, MAPK, mTOR and AMPK. Furthermore, dietary MnN significantly affected tibia length and growth plate development (p < 0.05) and promoted growth plate chondrocytes by increasing SOX-9, Runx-2, Mef2c, TGF-β, Ihh, Bcl-2 and Beclin1 and decreasing Bax and Caspase-3 (p < 0.05) expression which affect longitudinal tibial development. 6. In conclusion, Mn amino acid complexes could improve growth performance, tissue Mn deposition, breast muscle development, meat quality and bone development.

Evaluation of the molecular response of corpora lutea to manganese-amino acid complex supplementation in gilts.

Porcine pregnancy establishment and maintenance are dependent on the formation of functional corpora lutea (CL). Manganese (Mn) is critical for CL function as it is a cofactor for Mn superoxide dismutase and enzymes involved in cholesterol synthesis. Previously, we have shown that luteal Mn content increased and luteal progesterone (P4) concentration decreased in the CL of gilts fed diets supplemented with an Mn–amino acid complex (Availa-Mn; Zinpro Corporation) compared with controls fed Mn sulfate. Importantly, serum P4 increased from 0 (estrus onset) to 12 d post estrus (dpe), as expected, but P4 abundance in circulation was not affected by dietary Mn source (P = 0.15). We hypothesized that a more bioavailable Mn source (which results in increased luteal Mn content) would alter the luteal proteome and abundance of mRNA associated with steroid biogenesis during the mid-luteal phase of the estrous cycle. Postpubertal gilts (n = 32) were assigned to one of the four gestation diets. The control diet (CON) contained 20 ppm of supplemental Mn in the form of Mn sulfate. Three additional diets included 20 (TRT1), 40 (TRT2), or 60 (TRT3) ppm of supplemental Mn in the form of a Mn–amino acid complex instead of Mn sulfate. Dietary treatment began at estrus synchronization (approximately 20 d before estrus) and continued through 12 dpe when gilts were euthanized and tissues were collected. Protein and total RNA extracts from the CL were used for proteomic analysis via label-free liquid chromatography with tandem mass spectrometry to assess global protein abundance and quantitative real-time polymerase chain reaction (qRT-PCR) to assess specific mRNA abundance, respectively. Compared with CON, 188, 382, and 401 proteins were differentially abundant (P < 0.10) in TRT1, TRT2, and TRT3, respectively. Gene Ontology enrichment software revealed that proteins involved in P4 signaling and cholesterol synthesis were downregulated in CL of gilts fed Mn–amino acid complex compared with controls. Quantitative RT-PCR showed that relative transcript abundance of genes encoding steroidogenic enzymes (CYP11A1 and StAR) in CL tissue was decreased in gilts from TRT2 compared with CON (P = 0.02), but TRT1 and TRT3 were not affected (P ≥ 0.30). Collectively, these data support our hypothesis that a more bioavailable dietary Mn source may influence luteal function by altering the abundance of protein and mRNA involved in steroidogenesis.

Impact of manganese amino acid complex on tissue-specific trace mineral distribution and corpus luteum function in gilts.

Functional corpora lutea (CL) are required for pregnancy establishment and gestational maintenance in swine, and CL function is susceptible to environmental influences. Manganese (Mn) could be critical in regulating CL function since it is a component of the antioxidant enzyme Mn superoxide dismutase (MnSOD) as well as enzymes involved in cholesterol and steroid hormone synthesis. We hypothesized that a more bioavailable dietary Mn source would increase Mn content in the CL thereby influencing luteal function during the mid-luteal phase of the estrous cycle. Postpubertal gilts (n = 32) were assigned to one of four gestation diets. The control diet (CON) met or exceeded National Research Council (2012) requirements and was formulated to contain 20 parts per million (ppm) of added Mn in the form of Mn sulfate. Three additional diets included 20 (treatment [TRT]1), 40 (TRT2), or 60 (TRT3) ppm of added Mn from a Mn-amino acid complex (Availa-Mn; Zinpro Corporation) instead of Mn sulfate. Dietary treatment began at estrus synchronization onset and continued through 12 days post estrus (dpe) of the ensuing estrous cycle. Blood samples were collected at estrus onset, which was assigned as 0 dpe, as well as 4, 8, and 12 dpe. Gilts were euthanized and tissues were collected at 12 dpe. Serum progesterone (P4) increased (P < 0.01) from 0 to 12 dpe but was unaffected by dietary treatment (P = 0.15) and there was no effect of the interaction between day and treatment (P = 0.85). Luteal Mn content increased (P ≤ 0.05) by 19%, 21%, and 24% in gilts fed TRT1, TRT2, and TRT3, respectively, compared to CON. Luteal P4 concentrations decreased (P = 0.03) 25%, 26%, and 32% in gilts fed TRT1, TRT2, and TRT3, respectively, compared to CON. Relative to CON gilts, CL calcium content decreased (P = 0.02) by 36%, 24%, and 34% for TRT1, TRT2, and TRT3 gilts, respectively. Collectively, these data support the hypothesis that feeding a more bioavailable Mn source increases Mn accumulation in CL tissue. If and how this influences CL function may be related to altered luteal P4 concentrations.

29 Influence of dietary manganese source on the corpus luteum proteome in pigs

Abstract Functional corpora lutea (CL) are required for pregnancy establishment and gestational maintenance in swine. Manganese (Mn) could be critical in regulating CL function since it is a cofactor for the enzyme Mn superoxide dismutase (Mn-SOD) as well as enzymes involved in progesterone (P4) synthesis. We hypothesized a more bioavailable dietary Mn source would increase CL Mn content thereby influencing luteal function during the mid-luteal phase of the estrous cycle. Post-pubertal gilts (n = 32) were assigned to one of four gestation diets. The control diet (CON) met or exceeded NRC requirements and was formulated to contain 20 ppm added Mn in the form of Mn sulfate. Three additional diets included 20 (TRT1), 40 (TRT2) or 60 (TRT3) ppm Mn from a Mn-amino acid complex (Availa-Mn; Zinpro Corporation) in place of Mn sulfate. Dietary treatment began at estrus synchronization onset and continued through D12 of the ensuing estrous cycle when gilts were euthanized. Mn content increased (P ≤ 0.06) 19, 21 and 24% in CLs of gilts fed TRT1, TRT2, and TRT3, respectively, and luteal P4 concentration decreased (P ≤ 0.03) 25, 26, and 32% in gilts fed TRT1, TRT2, and TRT3, respectively, compared to CON. Total CL protein was extracted and liquid chromatography with tandem mass spectrometry (LC-MS/MS) was performed to assess global protein abundance. Compared to CON, 29, 105, and 118 proteins were differentially abundant (P &amp;lt; 0.01) in TRT1, TRT2, and TRT3, respectively. KEGG pathway analysis revealed proteins involved in P4 signaling (membrane-associated P4 receptor component 2) and cholesterol synthesis and transport (mevalonate kinase, diphosphomevalonate decarboxylase, low density lipoprotein receptor) were downregulated in response to Availa-Mn. Collectively, these data support the posit that dietary Mn source affects Mn accumulation and P4 concentration in CL tissue and influences protein abundance which may affect CL function.

Effects of Amino Acid-Bound Zinc and Manganese Feed Additives on MHC Haplotype Chickens Challenged with Infectious Bronchitis Coronavirus.

Major histocompatibility complex (MHC) congenic chicken lines have been used as a model to study infectious bronchitis virus (IBV) immune responses in chickens. Zinc (Zn) and manganese (Mn) are trace minerals that act as enzyme cofactors in cellular reactions. In addition, Zn is an important modulator of immune responses, especially in the respiratory tract. Zinc and Zn + Mn amino acid complex supplements were tested to alleviate the effects of an IBV challenge using relatively resistant and susceptible MHC congenic chicken lines. Prior to the challenge with IBV, the amino acid-bound supplements induced better weight gain in the IBV-resistant chicken line (331/B2) compared to the birds fed with the sulfate-delivered supplements. No body weight differences were detected between IBV-challenged and unchallenged 331/B2 birds supplemented with Zn in amino acid complex. A reduction of respiratory signs was observed in 335/B19 birds fed with the diet supplemented with Zn in amino acid complexes at 4 dpi. Compared to the sulfate-bound trace minerals, 331/B2 chickens fed with the amino acid-bound supplements presented milder clinical sign trends at 6 dpi and less severe airsacculitis at 14 dpi. The total antibody response in serum in 331/B2 birds fed with the amino acid-bound Zn ration was the highest among all groups tested. Both amino acid-delivered trace mineral supplements induced a slightly higher antibody response than the sulfate-bound ration in both chicken lines. This experiment provides insights into the effect of Zn and Mn on the immunity of chickens with known different susceptibilities to IBV.

Foliar spray time affects the efficacy of applied manganese on enhancing cucumber resistance to Podosphaera fuliginea

Foliar application of manganese (Mn) is an effective factor in enhancing of plant resistance to fungal diseases, but the efficiency of this method strongly depends on the application time. The present study was aimed to investigate the effect of application time of Mn on cucumber resistance against powdery mildew, caused by Podosphaera fuliginea. For this purpose, high levels of Mn in cucumber leaves were provided by foliar spray of MnSO4, and Mn-amino acid complexes (Mn-Lysine and Mn-Methionine) at 14, 10, 7, and 4 days before inoculation (dbi) by P. fuliginea. The excess levels of Mn led to a significant reduction in fungal disease. The highest reduction in disease severity was observed when Mn solutions were applied 4 dbi. The cucumber plants treated by Mn at 4 dbi accumulated the higher level of Mn in their leaves than those treated at 14, 10 and 7 dbi. The concentration of Mn in leaf was more important factor than the changes of shoot and root dry masses, PO and PPO activities and leaf cell wall lignin content in effectiveness of applied Mn. The Mn-amino acid complexes were more effective than MnSO4 in increase of dry mass and leaf lignin content. Mn-Lys was the most effective source of Mn in decrease of disease severity. Based on the results, application time is a significant factor determining the efficiency of foliar Mn application on increase of crop resistance to P. fuliginea.

Synthesis, characterization and antimicrobial activity of Mn(ii) and Zn(ii) complexes with leucine and alanine

Background: Transition metals are essential metallic element and they exhibit great biological activity. In recent time, researches have shown significant progress in the utilization of transition metal complexes as drugs for treatment of several human disorders like cancer, infections and neurological disorders, amongst others.Objective: The study attempted to obtain neutral complexes of MLn.nH2O type (M = Mn/Zn and L = leucine/alanine), characterize, and then study their biological activities.Methods: 2mmols of the ligands were dissolved each, in 20 ml distilled water and 0.33 ml of 30% NaOH was added. Then 1 mmol of the metal salts was dissolved in 2 ml of water and stirred, the salt solution was added to the solution of the ligand and stirred. The dark brown and white precipitates for manganese amino acid complex and zinc amino acid complexe respectively were filtered off, washed, dried in air and then weighed to establish the percent of complexation. The complexes were then subjected to both spectroscopic and non-spectroscopic method of analysis.Result: The result suggested the coordination of the ligand to the central metal.Conclusion: The results suggested monoclinic crystal system for all the complexes formed. The antimicrobial studies showed an enhanced biological sensitivity for the complexes when compared with that of the ligands, and the structure of the newly synthesized complexes were proposed to be octahedral for Mn-amino acid and tetrahedral for the Zn-amino acid.  Â

Effects of long-term supplementation with amino acid-complexed manganese on performance, egg quality, blood biochemistry and organ histopathology in laying hens

The current study was conducted to evaluate the effects of long-term dietary supplementation of amino acid-complexed manganese (Mn) on production performance, egg quality, blood biochemistry and organ histopathology in laying hens. A total of 756 Hy-Line Brown layers were randomly assigned into 7 dietary groups with 6 replicates. Each replicate contained 18 birds. Layers were fed a basal diet (Mn, 21.95 mg/kg) or the basal diet supplemented with 20, 40, 80, 120, 400 or 800 mg/kg Mn in amino acid-complexed form, respectively. The feeding trial lasted for 24 wks. Compared with the basal diet (control), dietary supplementation with 80 mg/kg Mn increased egg production and decreased feed conversion ratio (FCR) during 1–12 and 1–24 wk (P < 0.05). Manganese supplementation at 40 mg/kg increased egg production (1–12, 13–24 and 1–24 wk), egg mass (13–24 and 1–24 wk), and decreased FCR (13–24 and 1–24 wk, P < 0.05). Higher values of eggshell breaking strength were observed in dietary Mn addition ≥20 mg/kg treatments (P < 0.05) at different sampling time points, and they occurred in 40 mg/kg more frequently than any other Mn supplementation level. Dietary supplementation of 40 or 80 mg/kg Mn increased total superoxide dismutase (T-SOD) activity in serum (P < 0.05), but this benefit diminished when the inclusion exceeded 120 mg/kg. Besides, higher values of white blood cell (WBC), platelet and creatinine occurred in 400 and 800 mg/kg Mn addition groups (P < 0.05), accompanied with local inflammation of kidney tissues. In conclusion, dietary supplementation with Mn can improve productive performance, eggshell breaking strength and redox status, at a level of 40 mg/kg from Mn-amino acid complexes, and overdose of Mn supplementation (≥ 400 mg/kg) would cause detrimental effects to Hy-Line Brown laying hens.

Effects of Different Manganase Sources and Levels in the Diets on the Performance, Reproductive Characteristics and Some Blood Parameters of Breeder Japanese Quail

An experiment with breeder Japanese quails was conducted to determine the effects of different manganese (Mn) sources and levels in diet on the performance, reproductive characteristics and blood constituents during for five-28 day periods. In the experiment, a total of three hundred and sixty quails (female:male ratio, 2:1) at seven weeks of age was fed on diets containing 0, 60, 120, 180 and 240 mg kg -1 Mn levels from inorganic (MnSO 4 .H 2 O) or organic (Mn-amino acid chelate, Glycinoplex-Mn) source. Ten treatments combination of 2 Mn source and 5 Mn levels in 2X5 factorial arrangement were used with six replicate consisting of 4 female and 2 male quails each. The diets in mash form and water were given as adlibitum and 16 hours ligthting was provided in a day. In the experiment, final body weight (BW), body weight gain (BWG), livability, hen day egg production (EP), egg weight (EW) and egg mass (EM), feed consumption (FC) and feed conversion ratio (FCR), chick weights at hatching, fertility, hatchability of eggs set (%), hatchability of fertile eggs (%), embryonic mortalities and glucose, total cholesterol and protein, albumin, BUN, GGT, SGOT, SGPT, calcium, phosphorus and magnesium content of blood serum were measured. Dietary Mn source and levels as the main factor did not significantly affect the performance and reproductive traits which was measured in the experiment. Nevertheless the interaction between source and levels of Mn had a significant effect on average EW and chick weights at hatching over the experimental period. Egg weight of quails fed diet with 60 mg kg -1 Mn from inorganic form was higher (P<0.01) than those of quails fed with 0, 180 and 240 mg kg -1 Mn from inorganic and 0, 60, and 240 mg kg -1 Mn from organic form, again chick weights at hatching of quails fed diet with 60 mg kg -1 inorganic Mn, was significantly higher (P<0.05) compared with quails fed with all other levels of inorganic and organic Mn. In the experiment, while dietary Mn levels do not significantly affect any blood parameters, the serum glucose level of the quails fed with organic Mn was significantly higher than that of the quails fed with inorganic Mn and also serum phosphorus level of the quails fed with inorganic Mn was higher than that of the quails fed with organic Mn (P<0.01). The interaction between source and levels of Mn significantly affected the total protein, albumin and calcium levels of blood serum (P<0.05). These parameters were found to be higher in quail fed diets containing 60 mg kg -1 Mn in inorganic form than quails with some other diets. These results have shown that addition of 60 mg kg -1 Mn in inorganic form to breeder quail diets (containing 21.56 mg kg -1 Mn, found in analysis) based on corn + soybean meal may be beneficial.

Manganese influences the expression of fatty acid synthase and malic enzyme in cultured primary chicken hepatocytes.

Two experiments were designed to investigate the effects of Mn source and concentration on the mRNA expression and enzymatic activities of fatty acid synthase (FAS) and malic enzyme (ME) in cultured primary broiler hepatocytes. In Expt 1, primary broiler hepatocytes were treated with 0 (control), 0·25, 0·50 or 0·75 mmol/l of Mn as inorganic manganese chloride (MnCl2.4H2O) for 24 and 48 h. In Expt 2, primary broiler hepatocytes were incubated with 0 (control), 0·25 or 0·50 mmol/l of Mn as either manganese chloride or Mn-amino acid chelate for 48 h. The mRNA levels and activities of FAS and ME in the hepatocytes were measured in Expts 1 and 2. The results in Expt 1 showed that only at 48 h mRNA expression levels of FAS and ME in the hepatocytes decreased linearly (P0·33) on any of the measured cellular parameters. The results suggested that Mn might reduce cell damage and regulate FAS and ME expression at a transcriptional level in primary cultured broiler hepatocytes.

The Effect of Foliar-Applied Manganese in Mineral and Complex Forms with Amino Acids on Certain Defense Mechanisms of Cucumber (Cucumis sativus L.) Against Powdery Mildew

Manganese (Mn) is an essential micronutrient with positive effects on enhancing plant tolerance against fungal diseases. On the other hand, it has been suggested that metal–amino acid complexes are more effective than mineral sources in supplying Mn and improving the translocation and distribution of these metal nutrients in plants. Meanwhile, certain amino acids, that is, lysine and methionine, play an important role in crop resistance to biotic stresses. Little information is, however, available regarding the effect of foliar-applied Mn in mineral and complex forms with amino acids on crop tolerance to powdery mildew caused by Podosphaera fuliginea. In this nutrient solution experiment, the effect of foliar-applied Mn, in the form of MnSO4, Mn-methionine (Mn-Met) and Mn-lysine (Mn-Lys), on certain defense mechanisms of cucumber (Cucumis sativus L. cv. Espadana RZ) against powdery mildew was investigated. Different Mn sources were applied as foliar spray 4 days before and 6 days after inoculation with P. fuliginea. The results revealed that Mn application prior to pathogen inoculation decreased the disease in the treated and newly growing leaves; however, the efficiency of Mn–amino acid complexes in disease suppression was greater than that of MnSO4. Post-inoculation spray of Mn had no effect on the disease reduction of the newly growing leaves, but all Mn sources diminished disease severity equally in the treated leaves. In such leaves, regardless of the application time, the higher content of cell wall lignin was found in the plants treated with MnSO4, in comparison with those treated with Mn–amino acid complexes. In the newly growing leaves, the foliar application of Mn–amino acid complexes before inoculation resulted in a significant increase of leaf cell wall lignin content, whereas MnSO4 was ineffective. Pre-inoculation spray of MnSO4 led to increasing PO and PPO activities in the treated leaves, whereas Mn–amino acid complexes had no significant effect on the activity of these enzymes in the same leaves. Application of Mn-Met and Mn-Lys after pathogen inoculation led to a significant decrease of PPO activity in the treated leaves. In general, the results of the present study revealed that the time of Mn foliar application could have a considerable effect on controlling cucumber powdery mildew. Foliar application of Mn before infection with P. fuliginea could strengthen the defensive structures of the plant and help to prevent the disease incidence.

Mn(II)-containing layered double hydroxide composites: synthesis, characterization and an application in Ullmann diaryl etherification

Mn(II)-containing layered double hydroxides were prepared having the Mn(II) ions in various positions (i) on the layers as dopants, (ii) in the layers as their constituents and (iii) among the layers in the form of intercalated Mn(II) amino acid complexes. The substances were characterized by a range of instrumental methods (XRD, SEM, SEM–EDX) to indicate the positions of the Mn(II) ions. The catalytic activities of the composites were studied in the Ullmann-type etherification reaction. All materials promoted the reaction actively. However, only those having the Mn(II) ions in the structure of the LDH samples, the latter two, proved to be recyclable, i.e. they were real catalysts; the activity of the one prepared by doping deteriorated rapidly on reuse.

Effect of supplementation of amino acid chelate of Zn, Cu, Mn and Co heptagluconate on performance of Barbari goat kids

Male Barbari kids (56), 7 to 8 months of age and weighing19.2± 2.9 kg were randomly divided into 4 equal groups to assess the effect of source (inorganic or organic) and level of Zn, Cu, Co and Mn on intake and growth performance. The kids of control group were fed inorganic source of Zn, Cu, Co and Mn while other groups were fed organic complex (Zn, Cu and Mn amino acid and Co as cobalt heptagluconate at 50, 75 and 100 % of inorganic requirement. Feeding cum growth experiment lasted for 105 days. The live weight of kids at initiation of experiment varied from 19.12 to 19.67 kg, and final live weight ranged between 23.4 to 25.01 kg among the four groups. Total gain and average daily gain varied from 4.82 to 5.34 kg and 45.9 to 50.9 g respectively, which were not different among the four groups. The feed intake varied from 3.9 to 4.0 % of live weight. Live weight change remained lower in kids supplemented 75 and 100% organic trace minerals and had a pooled 6.9 and 9.8% lower average daily gain respectively. The feed efficiency and feed conversion ratio was similar among the four groups. Supplementation of 50% organic minerals provided daily gain equal to inorganic supplemented kids, while 75 and 100 % organic supplementation deteriorated daily gain. Therefore, at 50% organic supplementation levels, the bio-availability of Zn, Cu, Co and Mn have met the daily requirement of kids in relation to recommended requirements of inorganic minerals.

Interaction Modes and Absolute Affinities of α‐Amino Acids for Mn2+: A Comprehensive Picture

Manganese is involved as a cofactor in the activation of numerous enzymes as well as the oxygen-evolving complex of photosystem II. Full understanding of the role played by the Mn(2+) ion requires detailed knowledge of the interaction modes and energies of manganese with its various environments, a knowledge that is far from complete. To bring detailed insight into the local interactions of Mn in metallopeptides and proteins, theoretical studies employing first-principles quantum mechanical calculations are carried out on [Mn-amino acid](2+) complexes involving all 20 natural α-amino acids (AAs). Detailed investigation of [Mn-serine](2+), [Mn-cysteine](2+), [Mn-phenylalanine](2+), [Mn-tyrosine](2+), and [Mn-tryptophan](2+) indicates that with an electron-rich side chain, the most stable species involves interaction of Mn(2+) with carbonyl oxygen, amino nitrogen, and an electron-rich section of the side chain of the AA in its canonical form. This is in sharp contrast with aliphatic side chains for which a salt bridge is formed. For aromatic AAs, complexation to manganese leads to partial oxidation as well as aromaticity reduction. Despite multisite binding, AAs do not generate strong enough ligand fields to switch the metal to a low- or even intermediate-spin ground state. The affinities of Mn(2+) for all AAs are reported at the B3LYP and CCSD(T) levels of theory, thereby providing the first complete series of affinities for a divalent metal ion. The trends are compared with those of other cations for which affinities of all AAs have been previously obtained.

The Effects of Trace Mineral Source on Performance and Health of Newly Received Steers and the Impact of Cobalt Concentration on Performance and Lipid Metabolism During the Finishing Phase

<h2>ABSTRACT</h2> Two hundred sixteen Angus crossbred steers (230kg ± 3.6) purchased from sale barns were utilized to determine the impact of trace mineral source and concentration on performance, tissue metabolites, and lipid metabolism. Treatments during the 27-d receiving phase consisted of 1) inorganic trace mineral (125mg CuSO₄/d per head, 360mg ZnSO₄/d per head, 200mg MnSO₄/d per head, and 12.5mg CoCO₃/d per head) or 2) organic trace mineral (iso-amounts of Cu, Zn, Mn amino acid complexes, and Co glucoheptonate). On d 0 and 27, blood samples were collected from 3 steers per pen (pen = experimental unit). On d 28, steers were transitioned to a high concentrate finishing diet containing different concentrations of Co. Treatments during the finishing phase consisted of 1) control (no supplemental Co); 2) 0.10mg Co/kg DM from cobalt glucoheptonate; and 3) 1.0mg Co/kg DM from cobalt glucoheptonate. The same 3 steers per pen were bled on d 84 and 224 of the finishing phase. During the receiving phase, red blood cell superoxide dismutase activity was greater (P < 0.03) for organic- vs. inorganic-supplemented steers. During the finishing phase, overall ADG tended (P < 0.06) to be greater for steers receiving 1.0mg Co/kg DM. Steers receiving 1.0mg Co/kg DM had greater YG (P < 0.04) and back fat thickness (P < 0.04) than steers receiving 0.10mg Co/kg DM. Serum, liver, and LM B₁₂ concentrations increased (P < 0.04) as dietary Co concentration increased.

Gene Expression of Manganese-Containing Superoxide Dismutase as a Biomarker of Manganese Bioavailability for Manganese Sources in Broilers

The goal of this study was to determine whether Mn-containing superoxide dismutase (MnSOD) gene expression in heart tissue would reflect differences among bioavailabilities of Mn sources earlier than other indices. Broilers were divided into 5 groups and fed a Mn-unsupplemented basal diet (control) or the basal diet supplemented with 120 mg of Mn/kg as Mn sulfate or Mn methionine E (Mn Met E), Mn amino acid B (Mn AA B), or Mn amino acid C (Mn AA C) with weak, moderate, or strong chelation strength, respectively. Heart MnSOD mRNA levels were analyzed using quantitative reverse transcription-PCR at 7, 14, or 21 d. The results showed that heart MnSOD mRNA level increased as dietary Mn level increased at any age. At 7 d, chicks fed the diet supplemented with Mn AA B had higher MnSOD mRNA levels than those fed the diet supplemented with Mn sulfate and Mn Met E, and the same tendency was observed at 14 or 21 d. The results suggest that MnSOD gene expression, which is regulated by dietary Mn at transcriptional level, could reflect differences among bio-availabilities of organic Mn sources as early as 7 d. Therefore, the estimation of relative bioavailabilities of Mn sources based on heart MnSOD mRNA level could require a shorter experimental period and a smaller number of animals, and thus less cost.

Influence of dietary inclusion level of manganese on pork quality during retail display

Boneless pork loins ( n = 112) were used to test the influence of dietary manganese (Mn) inclusion level on pork quality traits during retail display. Crossbred barrows and gilts were fed diets formulated with 0, 20, 40, 80, 160, or 320 ppm Mn from Availa ®Mn (AvMn; a Mn–amino acid complex) from 23.8 to 106.8 kg live weight. At approximately 48 h postmortem, boneless pork loins were fabricated into longissimus thoracis et lumborum (LM) chops, which were subsequently placed in open-topped, coffin-chest display cases (2.6 °C) under continuous warm-white, fluorescent lighting (1600 lx) for 7 days. Dietary Mn level had no effect on LM pH ( P = 0.47), purge volume ( P = 0.60) and loss ( P = 0.53), or moisture loss ( P = 0.95) during retail display. Chops from pigs fed 80 ppm Mn received higher ( P < 0.05) American and Japanese color scores than pigs fed 0 and 40 ppm Mn. Even though the LM from pigs fed 80, 160, and 320 ppm Mn tended to be darker (lower L ∗ values; P = 0.07) than chops from pigs fed 40 ppm Mn, a ∗ (redness) and b ∗ (yellowness) values, as well as hue angle and chroma, were not ( P ⩾ 0.19) affected by dietary Mn. On days 0 and 1, the reflectance ratio of 630 nm/580 nm was similar ( P > 0.05) among dietary Mn supplementation levels; yet, by day 4 of retail display, chops from pigs fed 80 ppm Mn had higher ( P < 0.05) reflectance ratios than chops from pigs fed 0, 20, 40, and 160 ppm, whereas LM chops from pigs fed 40 ppm Mn had lower ( P < 0.05) reflectance ratios than all other dietary treatments on day 7 (Mn supplementation level × display day; P = 0.04). Although TBARS were greater ( P < 0.001) on day 7 than 0 of retail display, TBARS values did not ( P = 0.43) differ among dietary Mn levels. Results indicate that supplementing swine diets with 80 ppm Mn may improve pork color during retail display without increasing the likelihood of lipid oxidation.

Effect of Manganese Source on Manganese Absorption by the Intestine of Broilers

Two experiments were conducted to investigate the effect of Mn source on Mn absorption by the intestine of broilers. In Experiment 1, the effect of Mn source, including MnSO4, 2 Mn-amino acid chelates (Mn-Gly and Mn-Met) synthesized in our laboratory, 3 Mn-amino acid complexes with different complex strengths (Mn-Met E, Mn-AA A, and Mn-AA B), and 2 mixtures of MnSO4 with Gly or Met, on Mn absorption was assessed with ligated loops of different small intestinal segments of broilers. In Experiment 2, the absorption of Mn from MnSO4, Mn-AA A, and Mn-AA B was compared with intact broilers fed ad libitum. The criterion used for comparison was the Mn content of hepatic portal vein plasma. The absorption of Mn was higher (P < 0.0002) by ligated ileal loops than by duodenal and jejunal ones. Met supplementation increased (P < 0.03) the absorption of Mn as MnSO4. The absorption of Mn as Mn-AA A and Mn-AA B with moderate and strong complex strengths, respectively, were higher (P < 0.05) than those of Mn as MnSO4 and Mn-Met E with weak complex strength. On d 7 and 9 of Experiment 2, the Mn content of portal vein plasma was higher (P < 0.03) for Mn-AA B with strong complex strength than for MnSO4. On d 9, Mn content in plasma was higher (P < 0.01) for Mn-AA B with strong complex strength than for Mn-AA A with a moderate one. The results from this study confirm that the ileum was the main site of Mn absorption for broilers, and Met was more effective in facilitating Mn absorption than Gly as a ligand. Organic Mn was more efficiently absorbed than inorganic Mn (MnSO4); the absorption of organic Mn with moderate and strong complex strengths was greater than that of the organic Mn, which was weak, and the absorption of organic Mn with strong complex strength was greater than that of the organic Mn with a moderate strength.

Effects of manganese source and calcium on manganese uptake by in vitro everted gut sacs of broilers' intestinal segments

Three experiments were conducted with everted gut sacs to investigate the effects of Mn source and Ca on Mn absorption in different intestinal segments of broilers. In Experiment 1, the Mn uptake by everted sacs of duodenum, jejunum, and ileum after different incubation times was compared to determine an optimum incubation time. In Experiment 2, 8 different Mn sources, including MnSO4, organic Mn sources (Mn-amino acid chelates, Mn-amino acids complexes with different complex strength), and mixtures of MnSO4 with Gly or Met were used to assess the effect of Mn source on Mn uptake. In Experiment 3, the effect of Ca in media on the uptake of Mn from MnSO4 and Mn-amino acids complexes was investigated. The uptake percentages of Mn by everted ileal sacs were significantly higher than those by duodenal and jejunal sacs. The uptake of Mn as Mn-Met chelate was significantly higher than that of Mn as Mn-Gly chelate. The uptake percentages of Mn as Mn-amino acid complex with moderate complex strength (Mn-AA A) and Mn-amino acid complex with strong complex strength (Mn-AA B) were significantly higher than that of Mn as MnSO4. The uptake of Mn as Mn-AA B by jejunal sacs was significantly higher than that of Mn as Mn-AA A in media containing high level of Ca. The uptake percentages of Mn at high Ca level were significantly higher than those at normal level. The results indicate that when incubated in vitro, ileum was the main site of Mn absorption for broilers. The absorption of Mn as organic sources were higher than that of Mn as inorganic Mn. The absorption of Mn as Mn-AA B with strong complex strength by jejunal sacs was higher than that of Mn as Mn-AA A with moderate complex strength in media containing high level of Ca. As a ligand, Met was more effective in facilitating Mn absorption than Gly. Furthermore, the transportation of Mn through intestinal cells was enhanced by adding Ca as CaCl2 to the buffer solutions.

Bioavailability of organic manganese sources in broilers fed high dietary calcium

A total of 624-day-old Arbor Acres male broilers were used to investigate the relative bioavailabilities of supplemental organic manganese sources for broilers fed high calcium diets. The broilers were randomly allotted to six replicate cages (eight chicks per cage) for each of 13 treatments in a completely randomized design involving a 4×3 factorial arrangement of treatments (four sources of Mn×three levels of added Mn, plus the control with no added Mn). Dietary treatments included the high calcium basal diet (the Control, containing 18.5 g Ca/kg and 20 mg Mn/kg) and the basal diet supplemented with 60, 120, or 180 mg Mn/kg as Mn sulphate (MnSO 4·H 2O) or Mn methionine E (Mn Met E) with weak chelation strength [formation quotient ( Q f) = 3.2, containing 82.7 g Mn/kg], Mn amino acid B (Mn AA B) with moderate chelation strength ( Q f = 45.3, containing 64.8 g Mn/kg), or Mn amino acid C (Mn AA C) with strong chelation strength ( Q f = 115.4, containing 78.6 g Mn/kg). Heart manganese-containing superoxide dismutase (MnSOD) mRNA level and heart Mn concentration increased as supplemental dietary Mn increased ( P<0.001). Heart MnSOD mRNA level ( P=0.020) was a more sensitive criterion than heart Mn concentration ( P=0.037) for detecting differences among Mn sources. Relative to Mn sulphate (assigned 1), bioavailability of the three organic Mn sources with weak, moderate, or strong chelation strength were 1.12, 1.45, and 1.48 for heart MnSOD mRNA level, respectively. Compared with the study with normal dietary calcium (relative bioavailability of the above three organic Mn sources were 0.99, 1.32, and 1.13 for heart MnSOD mRNA level if Mn sulphate was set as 1, respectively), the results herein show higher relative bioavailability, implying that organic Mn sources with moderate or strong chelation strength offer partial or complete resistance to interference from high dietary calcium during digestion.