Mg Of Methionine Research Articles

The potential of in ovo-fed amino acids to alleviate the effects of heat stress on broiler chickens: effect on performance, body temperature, and oxidative status during the finisher phase

The aim of the current study was to investigate the potential of in ovo-fed amino acids (AA) to reduce the effects of heat stress on finishing broiler chickens. To achieve this, a total of 1,400 fertile hatching eggs were randomly distributed into 5 groups (n = 280/group) and injected with one of the following in ovo treatments on embryonic day 18: 52 µL of sterile diluent/egg (CTRL), CTRL + 1.0 mg of L-Leucine (T1), CTRL + 0.45 mg of leucine + 1.15 mg of methionine (T2), CTRL + 3.0 mg of methionine + 2.0 mg of cysteine (T3), and CTRL + 0.40 mg of leucine + 1.60 mg of methionine + 1.60 mg of cysteine (T4). After hatch, chicks were allocated according to a complete randomized block design comprising 2 thermal conditions: thermoneutral (24°C, 45% RH) and heat stress (34°C, 55-60% RH) with 5 pens/group/condition. The cyclical heat stress regimen (10 h/d) was then applied from d 29 to d 34. Compared to the CTRL group, T3 and T4 exhibited a higher BW during the starter phase (P < 0.001). T4 also had a lower feed conversion ratio (FCR) than CTRL during this same phase (P = 0.03). During the grower phase, males of all treatment groups consistently exhibited higher BW compared to the CTRL group, which was not observed among female birds (PSex × TRT = 0.005). During the finisher phase, the in ovo treatment effect on performance was not significant. However, heat-stressed birds from treatment group T3 and T4 exhibited lower facial temperatures (Pday × TRT < 0.001) as well as lower plasma (Pcondition x TRT = 0.039) and liver (Pcondition x TRT < 0.001) malonaldehyde concentrations compared to the CTRL group. In conclusion, in ovo-fed AA have the potential to modulate the effects of heat stress on finishing broiler chickens by limiting its detrimental consequences, including increased body temperature and oxidative damage.

Determination of Sulfur Amino Acids in Milk and Plant Proteins

A method for the determination of the sulfur amino acids methionine and cysteine in milk- and plant-derived protein powders and in protein-based nutritional products is described. Samples and calibration standards are prepared by acid hydrolysis (6-M HCl, 110 °C, 24 h) with 3,3’dithiopropionic acid, evaporation, and resuspension. The released methionine and cysteine mixed disulfide are quantified by direct LC/UV, without pre- or post-column chromophore/fluorophore derivatization. Since tyrosine is also released by the acid hydrolysis and elutes in the same chromatogram, it was included in all determinations. Method performance has been defined by assessments of linearity (R2 averaged > 0.999, n = 10, for 5-point plots of each analyte), intermediate precision (within-day RSD < 2%, n = 3, and day-to-day RSD < 3%, n = 3 days, for each analyte), accuracy (cystine spike recovery = 101%; measured methionine, cystine, and tyrosine concentrations were 95–111% of published concentrations), selectivity (reagent blanks and peak purity found analyte bias ≤ 2%), and quantitation limit (25 mg of methionine and tyrosine, and 50 mg of cystine, per 100 g of protein powder). The method provides a relatively simple means for the accurate and precise determination of both sulfur amino acids in protein powders and in nutritional products, and may be performed by conventional LC/UV, without specialized amino acid analysis instrumentation.

Sensory and nutritional evaluation of beverages developed using malted ragi (Eleusine coracana)

Five milk based beverages were developed by supplementing malted ragi and were organoleptically evaluated for sensory attributes by semi-trained panel of 10 judges. Control samples were developed by using milk, fruits (banana, kiwi, strawberry, papaya and mango) and honey and in test samples malted ragi was added at different levels ranging from 5-15 percent. Results revealed that banana based malted ragi beverage supplemented with 5 percent malted ragi was overall highly acceptable in terms of all sensory attributes. The most accepted level was chemically analysed for proximate composition, amino acids, vitamins, minerals, available carbohydrates and antinutritional components by using standard methods. The most acceptable malted ragi beverage was estimated to have 11.78±0.06 g crude protein, 6.81±0.51 g of crude fat, 1.21±0.07 g of crude fibre, 27.44±1.03 g of carbohydrates, 594.3±4.5 mg of tryptophan, 517.6±23.2 mg of methionine, 372.3±8.5 mg of lysine, 172.6 mg of calcium, 3.73 mg of iron, 102.2 mg of phosphorus and 0.596 mg of zinc per 100 ml. The anti-nutritional components were 155.8±11.3 mg of phytates, 15.4±2.3 mg of total phenols and 0.32±0.01 mg of trypsin inhibitor activity. Total sugars were found to be 5.44±0.21 g, 3.16±0.15 g of reducing sugars, 2.28±0.14 g of non-reducing sugars and 1.06±0.05 g of starch. It may be concluded that malted ragi can be utilized successfully up to 5 percent level to prepare beverages with high nutritional value without imposing negative impact on sensory attributes which may prove a boon to osteoporotic patients.

Effect of dietary levels of methionine + cystine on performance of broiler breeders

The objective of this experiment was to evaluate levels of methionine + cystine levels for broiler breeders from 40 to 60 weeks of age. It was used 288 Cobb broiler breeders, distributed in a randomized experimental design with six levels of methionine+ cystine in the diets (0.39; 0.47; 0.55; 0.63; 0.71 and 0.79%), eight repetitions and six breeders per experimental unit. The diets were isocaloric and isoprotein (2,850 kcal ME/kg and 12.58% CP) and oferred at a fixed amount (155 g) per bird. For the entire studied period, by using polynomial analysis, it was observed a quadratic effect of methionine + cystine levels on the percentage of egg production, on number of eggs per hen housed, on number of eggs per hen and egg weight. There was also a linear effect on shell weight when it was calculated in relation to egg weight. The total methionine + cystine requirement for broiler breeders was calculated at 0.521% for percentage of egg production and number of eggs per hen, which corresponds to a daily intake of 808 mg of methionine + cystine/day. The digestible methionine + cystine requirement for broiler breeders was estimated at 727 mg for laying percentage and number of eggs per hen.

Suitability of teicoplanin–aglycone bonded stationary phase for simulated moving bed enantioseparation of racemic amino acids employing composition-constrained eluents

The suitability of a teicoplanin–aglycone based chiral stationary phase for the simulated moving bed (SMB) enantioseparation of amino acids under enzyme-compatible conditions was shown following a procedure that is based solely on model-based simulations and HPLC experiments. A set of eight amino acids could be separated employing aqueous solvent containing only 10% (v/v) methanol, five of them with baseline resolution. The impact of type and concentration of organic modifier and pH modifier and pH on the separation characteristics of racemic methionine was investigated. Invariant elution profiles of repetitive adsorption/desorption of large amounts of methionine representing SMB-like conditions suggest stable adsorption behavior. Competitive loading capacity (20 mg of methionine per g of chiral stationary phase (CSP)) and SMB productivity (1 g of d-methionine per g of CSP per day) were predicted. The applied transport-dispersive model based on a competitive Bi-Langmuir isotherm was validated and its parameter estimated by model-based experimental analysis.

Nutrient Intake and Nutritional Indexes in Adults With Metastatic Cancer on a Phase I Clinical Trial of Dietary Methionine Restriction

Animal studies have shown that dietary methionine restriction selectively inhibits growth of a variety of human tumor xenografts but has relatively few deleterious effects on normal tissues. The objectives of the present study were to determine whether enteral methionine restriction is safe and tolerable in adults with metastatic cancer and whether it reduces plasma methionine levels. Eight patients with a variety of metastatic solid tumors were enrolled in a phase I clinical trial. A commercially available methionine-free medical food served as the primary dietary protein source for all patients. Patients were prescribed diets containing 0.6-0.8 g of protein, 25-35 kcal, and 2 mg of methionine per kilogram per day. Participants remained on the experimental diet for an average of 17.3 wk (range 8-39 wk). Plasma methionine levels fell from 21.6 ± 7.3 to 9 ± 4 μM within 2 wk, representing a 58% decline. Serum albumin and prealbumin levels remained stable or increased. Mean energy intake increased during participation compared with baseline, and protein intake was maintained at target levels. The only side effect was weight loss of ~0.5% of body mass index (0.5 kg) per week. We conclude that enteral dietary methionine restriction is safe and tolerable in adults with metastatic solid tumors and results in significant reduction in plasma methionine levels.

Free methionine supplementation limits alcohol-induced liver damage in rats.

Alcohol feeding to rats that were submitted to a jejunoileal bypass operation has been shown to result in liver damage being comparable with alcohol-induced liver disease in man. In the present study, a striking effect of free methionine consumption on histological liver injury, triglyceride accumulation, and energy-rich nucleoside content in the liver of rats with a jejunoileal bypass is demonstrated. The animals obtained 0, 30, and 120 mg of methionine in the control group and 0, 30, 120, and 240 mg in the alcohol-fed group per day and per kilogram of body weight for 12 weeks. Methionine was found to strongly improve the alcohol-induced histological changes in the liver. Triglyceride content of the liver was found to decrease in a dose-dependent manner with increasing methionine ingestion (from 255 +/- 20.7 to 49.7 +/- 6.1 micromol/g of protein in the control group and from 233 +/- 17.3 to 42.1 +/- 7.2 micromol/g of protein in the alcohol group). Hepatic adenosine triphosphate content increased significantly with higher methionine consumption (13.5 +/- 0.8 vs. 26.9 +/- 2.8 micromol/g of protein in the control group and 11.9 +/- 1.4 vs. 20.5 +/- 2.5 micromol/g of protein in the alcohol group), whereas no differences were found in the protein and DNA content of the liver. These results underscore the impairment of the transmethylation/transsulfuration pathway in the development of alcohol-induced liver diseases.

Plasma homocysteine as a risk factor for vascular disease. The European Concerted Action Project.

Elevated plasma homocysteine is a known risk factor for atherosclerotic vascular disease, but the strength of the relationship and the interaction of plasma homocysteine with other risk factors are unclear. To establish the magnitude of the vascular disease risk associated with an increased plasma homocysteine level and to examine interaction effects between elevated plasma homocysteine level and conventional risk factors. Case-control study. Nineteen centers in 9 European countries. A total of 750 cases of atherosclerotic vascular disease (cardiac, cerebral, and peripheral) and 800 controls of both sexes younger than 60 years. Plasma total homocysteine was measured while subjects were fasting and after a standardized methionine-loading test, which involves the administration of 100 mg of methionine per kilogram and stresses the metabolic pathway responsible for the irreversible degradation of homocysteine. Plasma cobalamin, pyridoxal 5'-phosphate, red blood cell folate, serum cholesterol, smoking, and blood pressure were also measured. The relative risk for vascular disease in the top fifth compared with the bottom four fifths of the control fasting total homocysteine distribution was 2.2 (95% confidence interval, 1.6-2.9). Methionine loading identified an additional 27% of at-risk cases. A dose-response effect was noted between total homocysteine level and risk. The risk was similar to and independent of that of other risk factors, but interaction effects were noted between homocysteine and these risk factors; for both sexes combined, an increased fasting homocysteine level showed a more than multiplicative effect on risk in smokers and in hypertensive subjects. Red blood cell folate, cobalamin, and pyridoxal phosphate, all of which modulate homocysteine metabolism, were inversely related to total homocysteine levels. Compared with nonusers of vitamin supplements, the small number of subjects taking such vitamins appeared to have a substantially lower risk of vascular disease, a proportion of which was attributable to lower plasma homocysteine levels. An increased plasma total homocysteine level confers an independent risk of vascular disease similar to that of smoking or hyperlipidemia. It powerfully increases the risk associated with smoking and hypertension. It is time to undertake randomized controlled trials of the effect of vitamins that reduce plasma homocysteine levels on vascular disease risk.

Effects of amino acids administered to a perfused area of the skin in Angora goats.

The effect of infusion of supplemental amino acids on growth of mohair by Angora goats was investigated using a skin perfusion model. Four Angora wethers (average BW 32 +/- 2 kg) were implanted bilaterally with silicon catheters into the superficial branches of the deep circumflex iliac artery and vein. For the first 14 d of the experiment, goats were arterially infused with either a mixture of amino acids (one side) or saline (contralateral side). The hourly infusion rates of amino acids were .36 mg of methionine, .36 mg of lysine, and .72 mg of leucine. The area of skin supplied by the deep circumflex iliac artery was approximately 300 cm2; a tattoo 10 cm x 15 cm was made in the middle of the perfused region for quantifying mohair production and characteristics. Two weeks after cessation of infusions goats were shorn and the mohair from the tattooed regions was examined. Greasy and clean mohair production from the tattooed region were increased by amino acid infusion compared with the contralateral side infused with saline (3.51 vs 3.16 g, P < .04 and 3.13 vs 2.70 g, P < .07, respectively). Although mohair length and diameter were not significantly altered, venous concentrations of valine, threonine, arginine, glycine, and histidine were decreased by infusion of the amino acids (P < .05), no differences in T3, T4, or insulin concentrations in venous blood were detected, but plasma cortisol concentration was reduced (1.38 vs 2.61 micrograms/dL, P < .05) with amino acid infusion.(ABSTRACT TRUNCATED AT 250 WORDS)

The response of broiler breeder hens to dietary lysine and methionine

1. Broiler breeder hens were used in an experiment lasting 10 weeks (29 to 38 weeks of age) to measure the responses to dietary lysine and methionine, the main objective being to determine whether the coefficients of response to these amino acids were the same for broiler breeders and for laying pullets. 2. The hens were offered 150 g/d of one of 20 dietary treatments, 10 being lysine-limiting and 10 being methionine-limiting. The diets were mixed by diluting one of two concentrate (summit) mixes with a protein-free dilution mixture. The lysine-limiting summit diet was designed to supply approximately 1300 mg lysine/bird d, while the other supplied 520 mg methionine/bird d, when fed at 150 g/bird d. 3. Birds on the 5 lowest concentrations of both lysine and methionine did not consume the allotted amount of food, the amount decreasing, in a curvilinear fashion, to approximately 105 g/bird d. 4. The minimum egg weight recorded was 0.8 of the maximum, whereas the rate of lay of birds fed on the diets with the lowest amino acid concentrations was 0.2 of the maximum. 5. Using the Reading Model, the coefficients of response were calculated to be (for lysine) 16.88 E and 11.2 W, and for methionine, 7.03 E and 1.52 W, where E = egg output, g/bird d, and W = body mass, kg/bird. An average, individual, broiler breeder of 3 kg, producing 45 g of egg output per day, would need 793 mg of lysine and 321 mg of methionine daily. This intake of methionine is similar to that estimated by means of coefficients used for laying pullets, but the lysine requirement would be underestimated by 0.18 if the coefficients for laying pullets were used. 6. The coefficients for maintenance for both lysine and methionine, determined in this experiment, are considerably lower than values published previously, whilst the coefficients for egg output are, in both cases, higher. The resultant flock response curves therefore differed significantly from those in which the coefficients of response for for laying pullets were used.(ABSTRACT TRUNCATED AT 400 WORDS)

The effects of dietary amino acid levels upon lysine and methionine requirements for growing rats.

The amino acid requirement has been investigated by many laboratories since 1931. Authors considered that the requirement was influenced by the protein level of the basal diet and also by the experimental method. In light of those earlier studies, the present study investigated the effect on lysine and methionine requirements by modifying total nitrogen level or essential amino acid level. The result of our study confirmed that when the amino acid requirement for maximum growth was expressed as the dietary percentage, amino acid to total amino acid ratio, and amino acid to total nitrogen ratio, the requirement had changed according to not only essential amino acids but also to nonessential amino acids. Furthermore, we investigated the relationship between amino acid intake and body protein gain, and found that 6.2 mg lysine and 9.0 mg methionine were required for the maintenance of a rat weighing 80 g and 71.6 mg of lysine and 48.8 mg of methionine were required for one gram of body protein gain. The lysine and methionine intakes required for one gram of protein gain were equivalent to 100% and 124% of amino acid contents of body protein, respectively.

マーケットバスケット方式による日本人の８種ビタミン，９種アミノ酸，３種ミネラルの１日摂取量の推定

According to the market basket studies proposed by the Ministry of Health and Welfare, the given kinds of foodstuffs were purchased on October, 1984, from the selected foodshops at the nine points of Sapporo, Sendai, Tokyo, Kofu, Nagano, Osaka, Wakayama, Matsue, and Kitakyusyu and the foodstuffs collected were classified into eight groups. Each group was analyzed with reference to the 20 kinds of food additives. Each analytical value in the present work was represented as the sum of the amount of the components added to the foodstuffs artificially and the components included in the foodstuffs naturally as elements. The intake of each foodadditive per capita per day was follows; 0.074mg of retinol, 0.36mg of thiamine, 0.43mg of riboflavin, 16.5mg of ascorbic acid, 1.48mg of nicotinic acid, 0.65mg of nicotinamide, 2.82mg of pantothenate, 14.98mg of total tocopherol, 166.6mg of threonine, 344.1mg of alanine, 230.9mg of valine, 80.6mg of methionine, 187.6mg of isoleusine, 247.8mg of phenylalanine, 260.3mg of lysine, 145.5mg of histidine, 285.1mg of arginine, 5.69 mg of iron, 147.0mg of magnesium and 3.41mg of alminium.

Methionine and arginine supplementation of casein-based high fat diets: Effects on rat growth

The effects of methionine and arginine supplementation on protein adequacy of two commercial caseins (ANRC and U.S. Biochemicals) in diets containing 20% fat were investigated in weanling rats. They were fed basal 18% protein (20% casein) diets and basal diets supplemented with 0.25% L-methionine, 0.35% L-arginine or methionine + arginine for a period of four weeks. The unsupplemented basal diets contained 1.38–1.41 mg of methionine + cystine and 1.46–1.49 mg of arginine per kilocalorie and were similar in nutrient composition to those utilized for evaluation of dietary oils. The methionine and arginine supplemented diets contained 1.92–1.96 mg of methionine + cystine and 2.23±2.27 mg of arginine per kilocalorie. Dietary supplementation with methionine, arginine or methionine + arginine had no significant (P>0.05) effects on food consumption; weight gain; protein efficiency ratio; net protein ratio; liver protein utilization; or liver, heart and kidney weight in rats. These results suggest that all amino acid requirements for rat growth are met by 20% unsupplemented casein of the types tested here.

Protein and Sulfur Amino Acid Requirements of Broiler Breeder Hens

Two experiments were conducted with Cobb color-sexed broiler breeder hens to determine their protein and sulfur amino acid requirement. A daily intake between 400 and 478 mg of methionine and between 722 and 839 mg of total sulfur amino acids was necessary for maximum egg production, the latter in a diet of 13.07% protein. Slightly lower levels supported maximum body weights. Hens laying at the highest rate consumed 23.4 g of protein per day.

Effects of different feeding regimes during lay of egg-type pullets fed either high or low-protein diet during rearing

The performance of two groups of pullets reared on either high or low-protein diets was compared under six feeding regimes from 20 to 68 weeks of age. Pullets fed the low-protein (10 per cent) diet from 4 to 20 weeks ate about 20 per cent less food during rearing, were significantly lighter at 20 weeks and were delayed in attaining maturity compared with pullets reared on the high-protein diet. In the period from 20 to 36 weeks of age, pullets reared on the high protein diet laid at a higher rate when fed a laying diet containing 17 per cent protein than with a diet containing 15 per cent protein supplemented with methionine, or 13 per cent protein supplemented with methionine and lysine to the N.R.C. (1971) levels. In contrast, pullets reared on the low-protein diet laid fewer eggs on the 17 per cent protein diet than on the other two diets during the same period. However, no significant rearing x laying interaction was observed in average rate of lay during the whole laying year. The low-protein group laid fewer eggs from 20 to 68 weeks than the other group of birds, but the difference in production was not significant when calculated from maturity. Average rate of lay was not affected by the level of protein in the laying diet, but egg size tended to increase with increasing the level of protein. Increasing the level of protein gradually with the advance in lay had no effect on performance relative to birds fed the 15 or 17 per cent protein diet throughout lay. Restricting the feed intake during lay to 94 per cent of that consumed by full-fed controls, or restricting the time of feeding to four hours daily, reduced egg production by 7 and 6 per cent respectively, regardless of the rearing treatment. Rate of mortality throughout the experiment was not affected by any of the rearing or laying treatments. The results of this experiment indicate that the requirement during lay of pullets reared on a low-protein diet is between 51 and 53 g protein and 900 and 1000 mg of methionine per 4.1 9 MJ (1000 Kcal) ME. This protein concentration should be increased to between 58 and 60 g protein per 4.19 MJ ME if the pullets were reared on conventional diets. Restricting feeding during lay by either of the methods used in this experiment is detrimental to egg production.

Utilization of Nitrogen to Sulfur Ratio for Evaluating Sulfur‐Containing Amino Acid Concentrations in Seed of Glycine max and G. soja1

A screening procedure using the ratio of total N to total S (N/S) was developed for indexing methionine and cystine concentrations in seed of soybeans—Glycine max (L.) Merrill—and its putative ancestor G. soja Sieb. and Zucc. Percent N was determined by the standard micro‐Kjeldahl procedure. Total S was analyzed by reducing SO4‐S (from nitric acid‐perchloric acid digestion) to H2S and then percent S was determined by titration with HgCl2 using dithizone as an indicator.The N/S values found in the soybean genetic type collection ranged from 24.5 to 15.4 with the mean being 18.3. The N/S values found in plant introductions of G. max that were formerly known as G. gracilis Skvortz. ranged from 20.1 to 16.3 with the mean being 18.4. The N/S values found in plant introductions of G. soja ranged from 21.5 to 12.5 with the mean being 17.5.Results from a 2‐year investigation on the effect of growing seasons on the N/S ratios in seed revealed that the N/S ratios were quite stable from year to year in G. max and somewhat less stable in G. gracilis and G. soja. Attempts to identify the source of variation indicated that the variation in N/S values in seed of G. gracilis and G. soja largely were due to N content.The reasonably high correlation coefficients between mg of methionine and cystine with percent S (r = 0.846) and g methionine and cystine/16 g N with N/S ratios (r = 0.787) suggest that rapid screening for N and S Glycine germplasm would be helpful in directing investigators to lines that warranted further study.

The effect of vitamin B 12 and methionine on folic acid uptake by rat liver.

SummaryThe liver uptake of intravenously administered 3H folic acid in rats fed a vitamin B12-methionine diet was only 55% of that found in normal rats. Supplementation of the deficient diet for 30 hr with 100 μg of B12/kg did not alter folate uptake significantly, but if vitamin B12 was fed together with 0.7% methionine, the rate of uptake was rapidly increased to control values. When uptake was stimulated in this way it was observed that plasma folate levels decreased from 72 to 45 ng/ml and liver folate concentrations increased from 5 to 8 μg/g—an increment of 48 μg of folate/liver in 30 hr. Intraperitoneal injection of 2.5 μg of B12 and 40 mg of methionine together in deficient animals, demonstrated that the depressed rate of folate uptake could be restored to control values even within 10 hr. Injection of 225 mg of methionine stimulated 3H folic acid uptake in the absence of any additional vitamin B12. It is suggested that vitamin B12 and or methionine can influence folate metabolism in rat liver by ...

Methionine Excretion. Effect of Diet and Methionine Ingestion in Normal Subjects

Observations on a series of 80 normal male subjects, on a normal control diet, indicated an average daily urinary excretion of approximately 318 ± 9 mg of methionine. The increase in methionine excretion during the 6- and 24-hour periods following the ingestion of a 1.0 or 1.5 g supplement of methionine in addition to that of the usual protein intake only amounted to approximately 9 and 15% respectively of the intake of the free amino acid.

Inhibiting Effect of Methionine, Choline and Betaine on Rabbit's Susceptibility to Infection with Vaccinia.

In the course of experiments to determine what factors in a rabbit's diet are essential to virus multiplication it was observed that the subcutaneous injection of methionine increased the rabbit's resistance to dermal infection with vaccinia. Six experiments have been performed with methionine. The results of a typical experiment are shown in Table I. In this experiment and others described below rabbits weighing approximately 2 kg were used. The experimental rabbits received 300 mg of methionine subcutaneously daily for 2 days preceding and 5 days following vaccination. In other experiments the conditions of the experiment were varied as to the amount of methionine and the times at which it was given. These experiments showed that if the methionine was given 48 hr before vaccination, the resistance was increased 14 fold; if given immediately following vaccination, the increase was 10 fold; if delayed until 48 hr after vaccination the increase was 5 fold. In addition to these quantitative changes in resis...