Dietary Methionine Supplementation Research Articles

Effects of dietary methionine supplementation on growth performance, intestinal morphology, antioxidant capacity and immune function in intra-uterine growth-retarded suckling piglets.

This study investigated the effects of dietary supplementation with L -methionine (L -Met), DL -methionine (DL -Met) and calcium salt of the methionine hydroxyl analog (MHA-Ca) on growth performance, intestinal morphology, antioxidant capacity and immune function in intra-uterine growth-retarded (IUGR) suckling piglets. Six normal birthweight (NBW) female piglets and 24 same-sex IUGR piglets were selected at birth. Piglets were fed nutrient adequate basal diet supplemented with 0.08% L -alanine (NBW-CON), 0.08% L -alanine (IUGR-CON), 0.12% L -Met (IUGR-LM), 0.12% DL -Met (IUGR-DLM) and 0.16% MHA-Ca (IUGR-MHA-Ca) from 7 to 21days of age respectively (n=6). The results indicated that IUGR decreased average daily milk (dry matter) intake and average daily gain and increased feed conversion ratio of suckling piglets (p<0.05). Compared with the NBW-CON piglets, IUGR also impaired villus morphology and reduced antioxidant capacity and immune homeostasis in the intestine of IUGR-CON piglets (p<0.05). Supplementation with L -Met enhanced jejunal villus height (VH) and villus area and ileal VH of IUGR piglets compared with IUGR-CON piglets (p<0.05). Similarly, DL -Met supplementation increased VH and the ratio of VH to crypt depth in the jejunum compared with IUGR-CON pigs (p<0.05). Supplementation with L -Met and DL -Met (0.12%) tended to increase reduced glutathione content and reduced glutathione: oxidized glutathione ratio and decrease protein carbonyl concentration in the jejunum of piglets when compared with the IUGR-CON group (p<0.10). However, supplementation with MHA-Ca had no effect on the intestinal redox status of IUGR piglets (p>0.10). In conclusion, supplementation with either L -Met or DL -Met has a beneficial effect on the intestinal morphology and antioxidant capacity of IUGR suckling piglets.

Ffects of dietary methionine and lysine supplementation on growth performance, meat composition and rumen fermentation pattern in goats

This experiment was conducted to determine the effect of methionine and lysine supplementation on growth performance, meat quality and rumen fermentation parameters in growing goats. Twenty Xiangdong black goats with initial body weights of 18.1 ± 2.07 kg were used and randomly assigned into four treatments including: no additive (Control), 1.27% Methionine (T1), 2.45% Lysine-HCl (T2), 1.27% Methionine plus 2.45% Lysine-HCl (T3). After 28 days of feeding, the goats were slaughtered and samples were collected for the study. Supplementation of methionine and lysine had no effect on growth performance, meat quality, tissue chemical composition and rumen fermentation parameters. These findings suggest that the mode of supplementation of methionine and lysine used failed to detect the variation.

Taurine and methionine supplementation as a nutritional strategy for growth promotion of meagre (Argyrosomus regius) fed high plant protein diets

The effect of methionine and taurine supplementation of plant protein based diet for meagre (Argyrosomus regius) juveniles was assessed on growth performance and metabolic hepatic enzymes activity. For that purpose, four isolipidic (180.0 g kg−1 crude lipids) and isoproteic (420.0 g kg−1) practical diets were formulated containing 820.0 g kg−1 of protein from plant origin and 180.0 g kg−1 from fishmeal. A 2 × 2 factorial arrangement of treatments was used with methionine at 7.5 and 10.0 g kg−1 dry diet, supplemented or not with taurine at 10.0 g kg−1 dry diet. The feeding trial was conducted with fish of 50.0 ± 0.6 g mean initial body weight and lasted for 65-day. Dietary taurine supplementation improved growth and feed utilization while methionine supplementation had no effect. Diets did not affect whole-body and liver composition. No interaction was observed between the supplemented amino acids. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities increased only with taurine supplementation, while glutamate dehydrogenase (GDH) activity was unaffected by dietary treatment. Fructose-1,6-bisphosphatase (FBPase) activity was affected both by methionine and taurine supplementation. In conclusion, dietary methionine supplementation was inefficient to overcome the decreased taurine level in plant-based diets and thus, taurine should be incorporated in plant protein-based diets, as an efficient nutritional strategy for the mitigation of growth limitations of meagre fed diets with high levels of plant feed ingredients. Moreover, as growth performance was not improved by increasing dietary methionine this suggests that under our experimental conditions meagre requirements are met with 7.5 g kg−1 dietary methionine.

Effects of dietary methionine and lysine supplementation on nutrients digestion, serum parameters and mRNA expression of related amino acid sensing and transporting genes in growing goats

Sufficient amino acid is necessary to the growth of animals. The experiment investigated the effects of dietary unprotected methionine (Met) and lysine (Lys) sources on nutrient digestion, nitrogen utilization and mRNA expression of related genes in growing goats fed a maize stover-based diet. Twenty Liuyang black weather goats were used and assigned randomly to 4 dietary treatments: (1) the control (basal) diet (NS:), (2) control diet with a supplementation of unprotected DL-Met (SM), (3) control diet with a supplementation of unprotected L-Lys-HCI (SL), (4) control diet with a supplementation of unprotected DL-Met and L-Lys-HCI (SML). The experiment showed that there were no differences of DMI (dry matter intake), fecal output, apparent digestibility, energy balance and N balance (P > 0.05). Adding Lys decreased serum threonine, isoleucine, phenylalanine, total amino acids (P < 0.05) comparing with NS, SM and SML (P < 0.05). SL and SML reduced serum Met and arginine compared with NS and SM (P <0.05). Compared to NS, SM and SL, SML lowered serum leucine (P = 0.057). SM, SL and SML had lessen: total cholesterol (TC) and SLC38A2 mRNA expression in jejunum compared to NS (P < 0.05). SM had the lowest mRNA expression of SLC7A7 in jejunum, SLC7A9 in ileum, SLC7A1 in cecum (P < 0.10). NS had the lowest mRNA expression of EIF4B in the duodenum (P = 0.057). Overall, adding a small amount of free Met and Lys did not affect apparent digestibility but changed serum AAs profile and tended to influence protein synthesis resulted from expression changes of related AAs transporters in the specific intestine tract and mTOR pathway. Our findings provided valuable information for improving animal production through amino acid nutrition regulation.

Improving pork quality traits by a short-term dietary hydroxy methionine supplementation at levels above growth requirements in finisher pigs.

The effects of dietary methionine (Met) supplies above growth requirements on tissue biology and pork quality were studied. At 70 kg, 45 crossbred pigs were fed a control (CONT) diet adequate in Met (0.22% Met) up to 105 kg. For the last 14 days before slaughter, pigs were fed with the CONT diet or with diets where the Met level was increased to Met3 (0.66% Met) or Met5 (1.10% Met). Growth performance and carcass composition did not change with the treatment. Pigs fed the Met5 treatment displayed lower TBARS and higher glutathione levels (P ≤ .05), along with higher ultimate pH (P < .01) and lower drip, lightness and hue (P ≤ .10) in the longissimus muscle, compared to the CONT and Met3 pigs. Extra-dietary Met improved ham's technological quality in the Met3 and Met5 groups (P ≤ .05). Thus, dietary Met supplementation improves pork quality without impairing growth or carcass traits.

Dietary inclusion of mealworm (Tenebrio molitor) meal as an alternative protein source in practical diets for juvenile rockfish (Sebastes schlegeli)

AbstractAn 8‐week feeding trial was designed to evaluate the potential of yellow mealworm (Tenebrio molitor) as a locally available nutrient‐rich feedstuff for juvenile rockfish (Sebastes schlegeli). Experimental diets containing elevated levels of mealworm meal (WM) supplemented with synthetic methionine were formulated to be isonitrogenous, isolipidic and isoenergetic to a WM‐free fishmeal (FM) based control diet (designated as WM0, WM8, WM16, WM24 and WM32, respectively). To determine the necessity of dietary methionine supplementation at the highest inclusion of WM, a diet was prepared to contain 32% WM without methionine supplementation (WM32‐AA). Triplicate groups of rockfish juveniles (Mean ± S.E.; 3.11 ± 0.01 g) were fed one of the experimental diets to apparent satiation twice daily for 8 weeks. Fish growth performance in terms of weight gain and specific growth rate increased with increasing dietary inclusion of WM from 0 to 16% and then tended to decrease with further increase in dietary WM levels to 32%. Protein retention (PR) values followed the same trend as growth rates with the highest values found in fish offered WM16 diet. Although fish fed WM32‐AA diet showed significantly lower growth rate and PR values compared to those fed WM16 diet, their performance was still comparable to that of the WM‐free control group. Plasma triglyceride level was negatively affected by dietary WM inclusion and the lowest values were observed in the WM32‐AA group. Whole‐body and fillet proximate and essential amino acid compositions were not altered by dietary treatment and these values were comparable to those of the WM0 group. These findings suggested that WM might prove to be a promising alternative to FM in practical diets for juvenile rockfish and could be used at an inclusion level of up to 32% without having any adverse consequences for the health and performance of the fish. Although the diet containing 32% WM seemed to support a performance similar to that of the control diet, the recommended dietary inclusion level was no more than 16% of the diet dry matter.

Supplementation of Cr Methionine During Dry Period of Dairy Cows and Its Effect on Some Production and Biochemical Parameters During Early Lactation and on Immunity of Their Offspring

This study aimed to investigate the effect of dietary chromium methionine (Cr-Met) supplementation on the production and immunological parameters of dairy cows during the dry and postpartum period and their offspring. Forty-five Holstein transition cows were randomly assigned to experimental groups with control, positive control (levamisole-injected cows), and treatment groups (5g dietary Cr-Met/day/cow). Production, immunological, and biochemical parameters were analyzed during the dry and postpartum period. Result revealed that in dry cows, monocyte count and serum glucose level significantly (p < 0.05) decrease in Cr-supplemented cows over control. Similarly, after parturition, the numbers of all immune cells (except monocytes) decreased significantly (p < 0.05); however, serum IgG, ALT, AST, glucose levels, and total leucocyte, neutrophil, and leucocyte count were increased significantly (p < 0.05) in Cr-supplemented cows over the control group. Days in milk (DIM) of treatment cows were significantly (p < 0.05) decreased over the control group; however, no significant (p > 0.05) differences were observed on milk production, colostrum, and IgG concentrations. As a conclusion, the supplementation of Cr had positive effects on immune cells of cows after parturition; however, serum biochemical parameters remained unaffected. Also, there were significant differences on the number of total leucocyte and neutrophil, on the activity of ALT at birthday, and on the number of total leucocyte at postpartum for calves.

The effect of taurine supplementation to a plant-based diet for barramundi (Lates calcarifer) with varying methionine content

The effect of variable taurine inclusion (Tau) (1g/kg DM to 15g/kg DM) in the diet of juvenile barramundi (Lates calcarifer) on growth and nutrient utilization was investigated at three levels of dietary methionine (Met) supplementation. Diets were fed to juvenile barramundi (starting weight: 26.8g) twice daily under a restricted pair-fed regime for a period of 42days. No significant effect of dietary Tau supply on growth or nutrient utilization was observed at any level of Met inclusion. Numerical variations suggested a positive effect of Tau provision at the mid-level of supplementation (6-8g/kg DM). The best-fit response model (5-SKM), fitted to the percentage body weight gain data of fish fed diets with an adequate level of Met, suggested a relatively weak pattern of response (R-2 = 0.183) and predicted a Tau requirement of 5.47g/kg DM (9.64 g/kg CP) similar to that reported for several other species. It was concluded that taurine appears to be conditionally essential to barramundi, whereby provision in the diet when sulphur amino acid supply is insufficient to meet biosynthetic demands may be beneficial, but that the predicted requirement is likely reasonably accurate for use as a minimum level of inclusion.

Effects of Dietary Chromium Methionine on Growth Performance, Hematological Characteristics and Carbohydrate Metabolic Enzyme Activities of Common Carp (Cyprinus carpio)

A 60-day feeding trial was conducted to evaluate the effects of dietary chromium methionine (Cr-Met) supplementation on growth performance, digestive enzymes, hematological characteristics, and carbohydrate metabolic key enzyme activities in juvenile common carp (Cyprinus carpio). Seven diets (32.2% crude protein, 6% crude lipids of dry matter) were formulated to contain graded levels of Cr3+ (0.31, 0.43, 0.57, 0.73, 1.13, 1.90 and 3.64 mg/kg, respectively). Each diet was randomly assigned to triplicate groups of 60 juvenile common carp (approximately 40.95±4.80 g), which were stocked in plastic tanks. The results indicated that the highest weight gain (WG), specific growth rate (SGR), feed efficiency (FE), and protein efficiency ratio (PER), were observed in fish fed the diet containing 1.13 mg/kg Cr3+. There were no significant differences in the wholebody compositions; however the glycogen levels in the muscle and hepatopancreas in fish fed the basal diet were lower than those fed the other diets. The insulin (INS) and glycogen (GC) concentrations in the serum were not significantly influenced by the dietary Cr-Met levels. However, fish fed the basal diet had higher glucose and cortisol concentrations, and lower insulin receptor (ISR) and LDH concentrations in the serum than those fed diets supplemented with Cr-Met. Fish fed the 1.13 mg/kg Cr3+ diet had significantly higher hexokinase (HK), 6-phosphofructo-1-kinase (6-PFK1), glucose-6-phosphate dehydrogenase (G6PDH), glycogen synthase (GS), and lower phosphoenolpyruvate carboxykinase (PEPCK) activities than those fed the basal diet. Based on the two-slope broken line model analysis between SGR and dietary Cr3+ levels, the optimal dietary Cr3+ supplement level was estimated to be 1.09 mg/kg for juvenile common carp.

Effect of Dietary Methionine on Taurine Distribution and Non-specific Immune Responses in Juvenile Blunt Snout Bream, Megalobrama amblycephala at A Constant Dietary Cystine Level

A 9-week feeding trial was conducted to investigate taurine distribution by supplementation of methionine in juvenile Megalobrama amblycephala at a constant dietary cystine level. Six semi-purified diets were formulated to contain graded dietary methionine levels from 0.39-1.54% in about 0.25% increments. At the end of feeding trial, plasma methionine content significantly increased with increasing dietary methionine level from 0.39 to 1.0% (P &lt; 0.05) and thereafter reached a plateau. The taurine content of muscle, intestine, liver, and eye in the fish fed dietary methionine level ranged from 1.24-1.54% and was significantly higher than that of the control group (P &lt; 0.05). Taurine content of the brain in fish fed 1.54% methionine diet was higher than the fish fed 0.39% (P &lt; 0.05). Cysteine sulfinic acid decarboxylase content significantly increased with increasing dietary methionine level from 0.39-0.85% (P &lt; 0.05) and thereafter stayed at a similar level. Supplementation with methionine significantly increased (P &lt; 0.05) plasma total protein (TP) content, complement 3 (C3) content and superoxide dismutase (SOD) activity (0.85% methionine diet groups), aspartate transaminase (AST) activity (1.24% methionine diet groups) and albumin content (1.0% methionine diet groups). Supplemented groups had significantly decreased plasma urea content (0.85% methionine diet groups) (P &lt; 0.05). In conclusion, these results indicate that crystalline methionine can be utilized efficiently, juvenile blunt snout bream were able to convert methionine to taurine directly, and appropriate dietary methionine supplementation improves non-specific immune responses in blunt snout bream.

Effects of Dietary Supplementation of Zinc Oxide and Zinc Methionine on Layer Performance, Egg Quality, and Blood Serum Indices.

The objective of this study was to evaluate the effectiveness of dietary zinc oxide (ZnO) and zinc methionine (Zn-Met) supplementation on layer performance, quality of egg, some blood constituents, and oxidative status in blood of laying hens. A total of 120 laying hens (Hisex Brown) 22-week-old were indiscriminately allotted into five groups of 24 hens with six replications (four birds/replicate). A complete randomized design experiment was performed including control (basal diet), two levels of ZnO (50 and 100mg/kg basal diet), and two levels of Zn-Met (50 and 100mg/kg basal diet) through 22 to 34weeks of age. Supplementation of 100mg of Zn-Met significantly (P=0.001) increased feed intake compared to other treatment groups. The groups supplemented with 50mg of ZnO and 100mg of Zn-Met reported the significantly higher egg production rate (P=0.002) and egg mass (P<0.001) compared to other treated groups. All traits of egg quality were not statistically (P<0.05 or 0.01) affected by ZnO or Zn-Met supplementation except shell thickness, Haugh unit score, and yolk to albumin ratio. Dietary supplementation of either ZnO or Zn-Met did not affect the oxidative parameters in serum except the activity of Cu-Zn-SOD. Serum triglyceride, total cholesterol, and LDL cholesterol (low-density lipoprotein) were significantly (P<0.05) affected by Zn supplementation, while HDL cholesterol (high-density lipoprotein) did not affect. Compared to the control group, supplementation of ZnO or Zn-Met increased serum content of zinc with no differences among supplemental zinc doses. It could be concluded that dietary inorganic (ZnO) and organic (Zn-Met) supplemented up to 50 and 100mg/kg, respectively, can be used as effective supplements to improve productivity of laying hens, serum zinc level, lipid profile (triglyceride and LDL cholesterol), and activity of Cu-Zn-SOD.

Effects of dietary L-methionine supplementation on intestinal integrity and oxidative status in intrauterine growth-retarded weanling piglets.

The present study investigated whether dietary methionine supplementation might protect against intrauterine growth retardation (IUGR)-induced damage in the intestine of piglets. Thirty normal birth weight (NBW) female piglets and sixty same-sex IUGR piglets were weaned at 21 days of postnatal age and fed the control diet (4.0g methionine per kg of feed, NBW-CON, and IUGR-CON groups) or the methionine-supplemented diet (5.2g methionine per kg of feed, IUGR-MET group) for 28 days (n=6). Piglets in the IUGR-CON group showed decreased average daily feed intake and average daily gain and an increased feed conversion ratio than those in the NBW-CON group. Compared with NBW-CON piglets, IUGR-CON piglets had decreased villus height (VH) and villus height-to-crypt depth ratio in both the jejunum and ileum. In addition, in comparison with the NBW-CON piglets, IUGR increased the concentration of malondialdehyde (MDA) and the index of apoptosis, while it decreased the concentrations of methionine and reduced glutathione (GSH), the ratio of reduced glutathione/oxidized glutathione (GSH/GSSG), and the protein expression of occludin (OCLN) in both the jejunum and ileum. Dietary methionine supplementation decreased the MDA and protein carbonyl concentrations and the apoptotic index, while it increased the VH level, methionine and GSH concentrations, GSH/GSSG ratio, and the OCLN protein expression in the jejunum of IUGR-MET piglets. Methionine may have beneficial effects in improving intestinal integrity and oxidative status in IUGR weanling piglets.

Short-term dietary methionine supplementation affects one-carbon metabolism and DNA methylation in the mouse gut and leads to altered microbiome profiles, barrier function, gene expression and histomorphology

BackgroundMethionine, a central molecule in one-carbon metabolism, is an essential amino acid required for normal growth and development. Despite its importance to biological systems, methionine is toxic when administered at supra-physiological levels. The aim of this study was to investigate the effects of short-term methionine dietary modulation on the proximal jejunum, the section of the gut specifically responsible for amino acid absorption, in a mouse model. Eight-week-old CBA/J male mice were fed methionine-adequate (MAD; 6.5 g/kg) or methionine-supplemented (MSD; 19.5 g/kg) diets for 3.5 or 6 days (average food intake 100 g/kg body weight). The study design was developed in order to address the short-term effects of the methionine supplementation that corresponds to methionine dietary intake in Western populations. Biochemical indices in the blood as well as metabolic, epigenetic, transcriptomic, metagenomic, and histomorphological parameters in the gut were evaluated.ResultsBy day 6, feeding mice with MSD (protein intake <10% different from MAD) resulted in increased plasma (2.3-fold; p < 0.054), but decreased proximal jejunum methionine concentrations (2.2-fold; p < 0.05) independently of the expression of neutral amino acid transporters. MSD has also caused small bowel bacteria colonization, increased the abundance of pathogenic bacterial species Burkholderiales and decreased the gene expression of the intestinal transmembrane proteins—Cldn8 (0.18-fold, p < 0.05), Cldn9 (0.24-fold, p < 0.01) and Cldn10 (0.05-fold, p < 0.05). Feeding MSD led to substantial histomorphological alterations in the proximal jejunum exhibited as a trend towards decreased plasma citrulline concentrations (1.8-fold, p < 0.07), as well as loss of crypt depth (by 28%, p < 0.05) and mucosal surface (by 20%, p < 0.001).ConclusionsTogether, these changes indicate that short-term feeding of MSD substantially alters the normal gut physiology. These effects may contribute to the pathogenesis of intestinal inflammatory diseases and/or sensitize the gut to exposure to other stressors.

Local immune response of two mucosal surfaces of the European seabass, Dicentrarchus labrax, fed tryptophan- or methionine-supplemented diets

Immune responses relies on an adequate provision of multiple nutrients that sustain the synthesis of key effector molecules. These needs are depicted in the already reported increase of circulating free amino acids in fish under stressful conditions. Since aquaculture and the inherent fish welfare are an emergent call, the immunomodulatory effects of amino acids on gut- and skin-associated lymphoid tissues of the European seabass (Dicentrarchus labrax) were studied under unstressed conditions and after an inflammatory insult. To achieve this goal, fish were distributed in duplicate tanks (fifteen fish per tank) and were fed for 14 days with methionine or tryptophan-supplemented diets at 2× dietary requirement level (MET and TRP, respectively) or a control diet meeting the amino acids requirement levels (CTRL). Afterwards, samples of skin and posterior gut were collected from 6 fish per dietary treatment for the assessment of the immune status while the remaining animals were intraperitoneally-injected with inactivated Photobacterium damselae subsp. piscicida and subsequently sampled either 4 or 24 h post-injection.The immune status of both mucosal surfaces was poorly affected, although a tryptophan effect was denoted after bacterial inoculation, with several immune-related genes up-regulated in the gut at 4 h post-injection, which seems to suggest a neuroendocrine-immune systems interaction. In contrast, skin mucosal immunity was inhibited by tryptophan dietary supplementation. Regarding methionine, results were often statistically non-significant, though increasing trends were denoted in a few parameters.Overall, dietary methionine did not significantly affect neither gut nor skin immunity, whereas tryptophan supplementation seems to induce modulatory mechanisms that might be tissue-specific.

Effects of dietary methionine and taurine supplementation to low-fish meal diets on growth performance and oxidative status of European sea bass (Dicentrarchus labrax) juveniles

This study aimed to evaluate the effects of dietary methionine (Met) and taurine (Tau) supplementation on growth performance, feed utilization, and oxidative status of European sea bass juveniles. For that purpose, a 12-week growth trial was performed to test four isolipidic (18%) and isonitrogenous (6.7%) practical diets, containing 82% of the protein from plant origin and 18% from fish meal. Diets were formulated to have a Met level below (LMet) or above (HMet) requirements and were supplemented or not with 1% Tau (LMetTau and HMetTau). No dietary Met or Tau effects were observed on growth, feed utilization, and whole-body composition. Increasing dietary Met level led to increased catalase (CAT) and glutathione peroxidase (GPX) activities in the liver and total (tGSH) and reduced (GSH) glutathione in the intestine, while decreasing glutathione reductase (GR) and GPX activities in the intestine. Most of these effects were only observed in fish fed diets not supplemented with Tau. Dietary Tau supplementation decreased intestinal tGSH, GSH and oxidised (GSSH) glutathione content, the activity of GPX both in liver and intestine, and glucose-6-phosphate dehydrogenase (G6PDH) activity in the liver. Dietary Tau supplementation also affected hepatic CAT and intestinal GR activities, but effects were dependent of the dietary Met level. Overall, European sea bass seems to cope well with a plant-protein rich diet without Met or Tau supplementation. Both dietary Met and Tau were shown to modulate fish antioxidant response but without altering the oxidative damage level.

Effect of dietary taurine and methionine supplementation on growth performance, body composition, taurine retention and lipid status of Persian sturgeon,Acipenser persicus(Borodin, 1897), fed with plant-based diet

The aim of this study was to investigate the effects of dietary taurine and methionine on Persian sturgeon (Acipenser persicus) fed with plant-based diets. To this purpose, sturgeons were fed with either of methionine + taurine-supplemented (MT), without taurine supplementation (M) or without methionine supplementation (T) diets. Growth performance, body composition, tissue amino acids and serum glucose and lipids were studied at the end of the experiment. Results showed that the treatments T and MT had similar growth performance and feed efficiency, which were significantly higher than the treatment M. Dietary taurine and methionine significantly altered carcass and liver taurine and methionine contents. The highest serum glucose was observed in the treatment M and the lowest in treatment MT. Serum cholesterol and triglyceride levels in the treatments T and MT were similar and significantly higher than those of the treatment M. This study showed that Persian sturgeon needs taurine supplementation when fed with plant-based diets, but the supplemented level seems to be lower than those of the other species. Taurine has hypoglycaemic and lipidogenesis effects on Persian sturgeon. However, further studies are required to illustrate taurine and methionine metabolism in Persian sturgeon.

Effects of rumen-protected methionine and choline supplementation on steroidogenic potential of the first postpartum dominant follicle and expression of immune mediators in Holstein cows

Multiparous Holstein cows were assigned in a randomized complete block design into four treatments from 21 d before calving to 30 d in milk (DIM). Treatments were: MET [n = 19, fed the basal diet + rumen-protected methionine at a rate of 0.08% (w/w) of the dry matter, Smartamine® M], CHO (n = 17, fed the basal diet + choline 60 g/d, Reashure®), MIX (n = 21, fed the basal diet + Smartamine® M at a rate of 0.08% (w/w) of the dry matter and 60 g/d Reashure®), and CON (n = 20, no supplementation, fed the close-up and fresh cow diets). Follicular development was monitored via ultrasound every 2 d starting at 7 DIM until ovulation (n = 37) or aspiration (n = 40) of the first postpartum dominant follicle (DF). Follicular fluid from 40 cows was aspirated and cells were retrieved immediately by centrifugation. Gene expression of TLR4, TNF, IL1-β, IL8, IL6, LHCGR, STAR, 3β-HSD, P450scc, CYP19A1, IRS1, IGF, MAT1A, and SAHH, was measured in the follicular cells of the first DF. Cows in CON had higher TNF, TLR4, and IL1-β mRNA expression (11.70 ± 4.6, 21.29 ± 10.4, 6.28 ± 1.4, respectively) than CHO (2.77 ± 0.9, 2.16 ± 0.9, 2.29 ± 0.7, respectively), and MIX (2.23 ± 0.7, 1.46 ± 0.6, 2.92 ± 0.8, respectively). Cows in CON had higher IL1-β expression (6.27 ± 1.4) than cows in MET (3.28 ± 0.6). Expression of IL8 mRNA was lower for cows in CHO (0.98 ± 0.3) than cows in CON (4.90 ± 0.7), MET (6.10 ± 1.7), or MIX (5.05 ± 1.8). Treatments did not affect mRNA expression of LHCGR, STAR, P450scc, CYP19A, SAHH, MAT1A, or IL6 however, 3β-HSD expression was higher for cows in MET (1.46 ± 0.3) and MIX (1.25 ± 0.3) than CON (0.17 ± 0.04) and CHO (0.26 ± 0.1). Supplementation of methionine, choline, and both methionine and choline during the transition period did not affect days to first ovulation or number of cows that ovulated the first follicular wave. Plasma and follicular fluid estradiol and progesterone concentrations were not different among treatments. Methionine concentrations in the follicular fluid of the first postpartum DF was higher for cows in MET (18.2 ± 0.1 μM) than cows in CON (11.1 ± 0.9 μM). In conclusion, supplementing choline and methionine during the transition period changed mRNA expression in follicular cells and dietary methionine supplementation increased plasma and follicular fluid concentrations of methionine of the first postpartum DF in Holstein cows.

Response of growing goslings to dietary supplementation with methionine and betaine

An experiment with a 2 × 3 factorial design with two concentrations of dietary betaine (0 and 600 mg/kg) and three dietary concentrations of methionine (0, 600 and 1200 mg/kg) was conducted using goslings to estimate growth, nutrient utilisation and digestibility of amino acids from 21 to 70 d of age.Three hundred geese were randomised at 18 d of age into 6 groups with 5 replicates per treatment and 10 geese per replicate.Increasing dietary concentrations of methionine gave a linear increase in body weight and average daily gain. The coefficient of crude fat retention increased as dietary methionine increased and there was a significant non-linear response to increasing dietary methionine. Similarly, increasing supplemental methionine gave linear increases in the digestibility of methionine and cysteine.The results of this study indicated that optimal dietary supplementation of methionine could increase growth performance and methionine and cysteine utilisation in growing goslings. Betaine supplementation had no apparent sparing effect on methionine needs for growth performance, but did improve the apparent cysteine digestibility.

Lamb survival, glutathione redox state and immune function of neonates and lambs from periparturient Merino ewes supplemented with rumen-protected methionine

ABSTRACTWool growth in Merino sheep demands a high level of sulphur amino acids, competing with body growth and the immune system, which may play a role in increasing the risk of lamb mortality. The hypothesis that dietary supplementation of methionine (Met) to Merino ewes during the late stages of pregnancy will improve foetal growth and alter immune competency of ewes and lambs was tested in a total of 120 grazing, pregnant Merino ewes. Sixty ewes were group-supplemented with 6.3 g/d rumen-protected Met (Met-Plus) per sheep from day 111 of pregnancy until day 7 after lambing, and the other 60 animals were used as a non-supplemented Control. Lambs from Met-supplemented ewes tended to be 10% heavier than Control lambs (p = 0.10), which did not affected the survival rate at weaning significantly. The supplemented ewes had slightly higher concentrations of total glutathione (GSH) in plasma at lambing (p < 0.06), but there were no differences between 1 and 3 months post-lambing in GSH, glutathione disulphide (GSSG) and the GSSG:GSH ratio. The GSSG:GSH ratio in the blood of ewes was elevated at lambing (p < 0.05), hinting that ewes were undergoing increased oxidative stress. The Met supplementation elevated the total IgG concentration (p < 0.05) in lambs aged 4 and 6 weeks, but did not change the IgG concentrations in colostrum and in plasma of 1-week-old lambs, and white blood cell counts and leukocyte types. The trend towards higher lamb birth weights in the Met-supplemented group requires further investigation as this may influence survival at birth and weaning.

Pigs experimentally infected with an enterotoxigenic strain of Escherichia coli have improved feed efficiency and indicators of inflammation with dietary supplementation of tryptophan and methionine in the immediate post-weaning period

This experiment tested the hypothesis that pigs challenged with an enterotoxigenic strain of E. coli (ETEC) will improve performance by dietary supplementation of sulfur amino acids (SAA) and tryptophan (Trp) above the current recommended levels in the immediate post-weaning period. Male pigs (n = 96) weighing 6.2 ± 0.78 kg (mean ± s.d.) and weaned at 21 days were stratified into one of four treatments based on weaning weight (n = 24). Four diets were formulated [11.2 MJ NE/kg; 20.1% crude protein, 1.25% standardised ileal digestible (SID) lysine (Lys)] according to a 2 × 2 factorial arrangement of treatments with two levels of SID SAA : Lys ratio (0.52 vs 0.60) and two levels of SID Trp : Lys ratio (0.16 vs 0.24). Diets did not contain any antimicrobial compounds. Pigs were individually housed and were fed diets for 14 days after weaning. Pigs were infected with ETEC (3.44 × 108 CFU/mL, serotype O149 : K91 : K88) on Days 5, 6, and 7 after weaning. Pigs were bled on Days 5, 8 and 14 and subsequently analysed for plasma levels of acute-phase proteins, urea, cytokines (Days 5 and 8 only) and amino acids (Days 5 and 8 only). Increasing Trp (P = 0.036) and SAA (P = 0.028) improved feed conversion ratio, and combined supplementation of SAA and Trp further improved FCR than individual supplementation of either SAA or Trp (P = 0.092). Dietary treatments had no impact on the incidence of post-weaning diarrhoea (P &gt; 0.05). Increasing SAA increased shedding of ETEC on Days 12 and 14 after weaning (P &lt; 0.019). Increasing dietary Trp reduced the intensity of inflammation (as measured by APP Index = [(C-reactive protein × PigMAP)/apolipoprotein A1]) immediately after infection with ETEC (P &lt; 0.05), while increasing dietary SAA reduced the APP index on 24 h and 7 days after ETEC infection (P &lt; 0.05). Increasing dietary SAA reduced plasma levels of interferon-gamma regardless of dietary Trp or day of sampling (P = 0.043). Increasing dietary SAA decreased plasma urea (PU) levels on Days 5, 8 and 14 (P &lt; 0.05). These data indicate that Trp supplementation reduced the intensity of inflammation and SAA supplementation decreased the pro-inflammatory interferon-gamma response and improved protein utilisation, as measured by PU, whereas supplementation with both Trp and SAA improved feed conversion ratio.