Dietary Arginine Supplementation Research Articles

Effects of dietary arginine supplementation in pregnant mares on maternal metabolism, placental structure and function and foal growth

Foals born to primiparous mares are lighter and less mature than those born to multiparous dams. Factors driving this difference are not totally understood. Using 7 multiparous and 6 primiparous standardbred mares, we demonstrated that, in late gestation, primiparous mares were less insulin resistant compared to multiparous mares, and that their foals had reduced plasma amino-acid concentrations at birth compared to foals born to multiparous mares. Vascular development, as observed through structure and gene expression, and global DNA methylation were also reduced in primiparous placentas. Another group of 8 primiparous mares was orally supplemented with L-arginine (100 g/day, 210d to term). L-arginine improved pregnancy-induced insulin resistance and increased maternal L-arginine and L-ornithine plasma concentrations but foal plasma amino acid concentrations were not affected at birth. At birth, foal weight and placental biometry, structure, ultra-structure and DNA methylation were not modified. Placental expression of genes involved in glucose and fatty acid transfers was increased. In conclusion, maternal insulin resistance in response to pregnancy and placental function are reduced in primiparous pregnancies. Late-gestation L-arginine supplementation may help primiparous mares to metabolically adapt to pregnancy and improve placental function. More work is needed to confirm these effects and ascertain optimal treatment conditions.

Arginine induces skeletal muscle fiber type conversion by upregulating Akirin2 and AMPK/PGC-1α in mice

We have previously reported that arginine promotes slow myosin heavy chain expression in cell culture via Akirin2 and the AMP-activated protein kinase (AMPK) signaling pathway. Our goal in the present study was to investigate whether arginine has similar functions and molecular mechanisms in vivo. Kunming mice were fed a diet supplemented with arginine and actively immunized with Akirin2. The study lasted for 40 d. Tibialis anterior (TA) muscle was harvested for analysis. We found that Kunming mice supplemented with arginine significantly increased the oxidative fibers expression and decreased the expression of glycolytic fiber. Expressions of peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α) and AMPK were increased in the TA muscle of arginine-treated Kunming mice. We also find that dietary supplementation of arginine increased the succinate dehydrogenase and malate dehydrogenase activities and decreased the lactate dehydrogenase activity. But active immunization against Akirin2 got opposite results. These results indicated that arginine induced muscle fiber transition from type II to type I, which may be mediated by Akirin2 and AMPK//PGC-1α signaling pathway.

Effects of arginine supplementation on growth performance and plasma arginine, ornithine and citrulline dynamics of rainbow trout, Oncorhynchus mykiss

This study aimed to re-evaluate the effect of excessive arginine supplementation on growth and feed efficiency of rainbow trout, and to assess the effect of dietary arginine supplementation on hepatic amino acid composition, expression of arginase Ⅱ (ARG 2), inducible nitric oxide synthase (iNOS), and heat shock protein 70 (HSP70) genes in the intestine, and plasma arginine, ornithine, citrulline and urea levels at 0, 6, 12 and 18 hr-postprandial. Rainbow trout (body weight: 60.5–65 g) were fed diets containing 1.47 (control [CTRL]), 3.89 (3.89A) and 5.64% (5.64A) arginine for nine weeks. Higher muscle protein content was observed in 3.89A than CTRL (p < 0.05). In postprandial study, plasma arginine of 5.64A kept increased until 12 hr-postprandial and reached identical value (around 150 µg/ml) until 18 hr-postprandial in 5.64A. Significant increase of plasma arginine level was only observed in arginine supplemented group. Meanwhile, plasma citrulline level in CTRL was significantly higher than in 5.64A at 18 hr-postprandial. A significantly higher hepatic citrulline level was also observed in CTRL than in 5.64A (p < 0.05). Significantly higher plasma and hepatic free ornithine level was observed in 5.64A than CTRL while significantly higher expression of intestinal ARG2 and HSP70 was found in arginine supplemented groups. These results suggest that citrulline availability seems to be stimulated by arginine deficiency in the CTRL and the presence of arginase in the intestine to regulate excess dietary arginine.

The effect of l-arginine and flaxseed on plasma testosterone concentration, semen quality and some testicular histology parameters in old broiler breeder roosters

The objective of this study was to investigate the effect of dietary supplementation of l-arginine and flaxseed on testosterone and lipid parameters of serum and semen quality, as well as histological and morphometric parameters of testes in old broiler breeder rooster. Thirty six 52-week-old Ross 308 broiler breeder roosters with similar weights (4900 g ± 210) were used for a 8-weeks trial period in a 3 × 3 factorial arrangement of dietary treatments that three levels of l-arginine (0.52, 0.68 and 0.83%) and flaxseed (0, 2 and 4%) with four replications in each. The ratio of left testicle weight/total testicular weight was significantly higher in A68F0 group. The maximum and minimum seminiferous tubule diameters were recorded for roosters fed no flaxseed and F2 flaxseed, respectively. The roosters fed A68 showed the highest serum testosterone. Seminal volume and sperm concentration, were not significantly affected by l-arginine × flaxseed interaction; however, sperm forward motility were significantly affected by arginine × flaxseed interaction (P < 0.05). A68F0 had significantly greatest tubular differentiation indices (TDI) in all of the treatments. Also, repopulation indices (RI) and spermiogenesis indices (SI) in A68F0 were significantly higher than other groups, but A52F0 and A52F4. However, testis index, testis density, serum lipids (cholesterol, LDL, HDL and HDL: LDL ratio), epithelium height of seminiferous tubules and number of Sertoli cells were not affected by the treatments. It is concluded that dietary supplementation of arginine (0.68%) has positive effects on blood testosterone, semen quality and spermatogenesis index of aged roosters.

Effects of dietary arginine supplementation on growth, biochemical, and immunological responses of common carp (Cyprinus carpio L.), stressed by stocking density

The present study aimed to investigate interaction effects of dietary arginine and stocking density on common carp (Cyprinus carpio) growth performance, stress response, innate immunity and immune gene expression. Three diets with deficient (4.1% of dietary protein; DA), optimum (5.3% of dietary protein; OA) and surplus (8.1% of dietary protein; SA) arginine levels were formulated. The diets were offered for 30 days to common carp reared at two different stocking densities, 10 or 20 g/L. Then blood leukocyte count, and plasma cortisol, glucose, total protein, globulin, total immunoglobulin (Ig), lysozyme and complement (ACH50), and head kidney interleukin-1 beta (IL-1beta), interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNF-a) were determined. Results showed that increased stocking density led to decreased growth performance; similarly, both DA and SA groups had significantly lower growth performance compared to the OA group. Increased stocking density led to increased plasma cortisol, glucose, lysozyme, proteins and ACH50 and decreased plasma total Ig and blood WBC, and the head kidney’ cytokine genes expression. Both DA and SA groups had significantly higher plasma cortisol and glucose, and lower plasma lysozyme, proteins, ACH50, and head kidney's cytokine gene expression compared to the OA treatment; the SA group had more adverse effects on these parameters than the DA group. Dietary arginine at optimum level significantly inhibited the stress-induced cortisol and lysozyme elevation and mitigated the stress-induced IL-1beta and IL-8 genes down-regulation. In conclusion, dietary arginine deficient or surplus levels significantly impair common carp growth performance and health conditions. Moreover, surplus dietary arginine level has no benefit on the fish growth and health under high stocking density condition.

Dietary L-arginine supplementation increased mammary gland vascularity of lactating sows

The present study aimed to evaluate the mechanisms modulated by dietary arginine supplementation to sows during lactation regarding antioxidant capacity and vascularization of mammary glands. At 109 days of gestation, animals were transferred to individual farrowing crates equipped with manual feeders and automatic drinker bowls. Environmental temperature and humidity inside the farrowing rooms were registered every 15 min. At farrowing, sows were assigned in a completely randomized design to a control diet (CON) or the CON diet supplemented with 1.0% L-arginine (ARG). A total of three gilts and two sows were fed the CON diet, whereas three gilts and three sows were fed ARG diets. Sows were fed a fixed amount of 6.0 kg/day, subdivided equally in four delivery times (0700, 1000, 1300 and 1600 h) for 21 days. At weaning, sows were slaughtered and mammary tissue samples and blood from the pudendal vein were collected. Data were analyzed considering each sow as an experimental unit. Differences were considered at P<0.05. L-arginine fed sows presented lower messenger RNA (mRNA) expression for prolactin receptor (P=0.002), angiopoietin1 (P=0.03) and receptor tyrosine kinase (P=0.01); higher mRNA expression for prostaglandin synthase 1 (P=0.01); a trend of decrease for glucocorticoid receptor (P=0.06) and IGF receptor 1 (P=0.07); and a trend (P=0.05) for an increased glutathione peroxidase mRNA expression. The angiopoietin2:angiopoietin1 mRNA ratio tended to increase (P=0.07) in ARG fed sows. L-arginine fed sows had greater (P=0.04) volumetric proportion of blood vessels and a trend of enhance (P=0.07) in the number of blood vessels per mm2. These findings show that 1.0% ARG supplementation to sows activates proliferative mechanisms, may improve mammary tissues’ angiogenesis and tended to increase mRNA expression of genes that encode antioxidant enzymes in mammary gland of sows.

Effect of dietary arginine to lysine ratios on productive performance, meat quality, plasma and muscle metabolomics profile in fast-growing broiler chickens

BackgroundDue to the important functions of arginine in poultry, it should be questioned whether the currently adopted dietary Arg:Lys ratios are sufficient to meet the modern broiler requirement in arginine. The present study aimed, therefore, to evaluate the effects of the dietary supplementation of L-arginine in a commercial broiler diet on productive performance, breast meat quality attributes, incidence and severity of breast muscle myopathies and foot pad dermatitis (FPD), and plasma and muscle metabolomics profile in fast-growing broilers.ResultsA total of 1,170 1-day-old Ross 308 male chicks was divided into two experimental groups of 9 replicates each fed either a commercial basal diet (CON, digestible Arg:Lys ratio of 1.05, 1.05, 1.06 and 1.07 in each feeding phase, respectively) or the same basal diet supplemented on-top with crystalline L-arginine (ARG, digestible Arg:Lys ratio of 1.15, 1.15, 1.16 and 1.17, respectively). Productive parameters were determined at the end of each feeding phase (12, 22, 33, 43 d). At slaughter (43 d), incidence and severity of FPD and breast myopathies were assessed, while plasma and breast muscle samples were collected and analyzed by proton nuclear magnetic resonance-spectroscopy. The dietary supplementation of arginine significantly reduced cumulative feed conversion ratio compared to the control diet at 12 d (1.352 vs. 1.401, P < 0.05), 22 d (1.398 vs. 1.420; P < 0.01) and 33 d (1.494 vs. 1.524; P < 0.05), and also tended to improve it in the overall period of trial (1.646 vs. 1.675; P = 0.09). Body weight was significantly increased in ARG compared to CON group at 33 d (1,884 vs. 1,829 g; P < 0.05). No significant effect was observed on meat quality attributes, breast myopathies and FPD occurrence. ARG birds showed significantly higher plasma concentration of arginine and leucine, and lower of acetoacetate, glutamate, adenosine and proline. Arginine and acetate concentrations were higher, whereas acetone and inosine levels were lower in the breast of ARG birds (P < 0.05).ConclusionsTaken together, these data showed that increased digestible Arg:Lys ratio had positive effects on feed efficiency in broiler chickens probably via modulation of metabolites that play key roles in energy and protein metabolism.

'Dietary Arginine Supplementation Affects Intestinal Function by Enhancing Antioxidant Capacity of a Nitric Oxide–Independent Pathway in Low-Birth-Weight Piglets

BackgroundLow-birth-weight (LBW) neonates are susceptible to intestinal dysfunction. Furthermore, the antioxidant capacity of LBW neonates is significantly lower compared with that of normal-birth-weight (NBW) neonates both at birth and at weaning. In LBW neonates, dietary supplementation with arginine has shown beneficial effects on intestinal function. ObjectiveThe present study explored the potential mechanisms of arginine-induced protective effects against intestinal dysfunction in LBW piglets. MethodsForty 4-d-old LBW piglets [body weight (BW): 1.05 ± 0.04 kg] (Large White × Landrace) were assigned to 4 treatments and artificially fed a whole-milk powder– and whey protein concentrate–based diet (containing 0.65% arginine) either not supplemented with arginine (LBWC) or supplemented with 0.5%, 1.0%, or 1.5% l-arginine for 21 d. In addition, 10 NBW siblings (BW: 1.96 ± 0.03 kg) were selected and fed the basal diet. Growth performance, intestinal morphology, mRNA expression of tight junction protein, redox-sensitive genes and nitric oxide (NO) synthase, cytokines, and redox indexes were determined. Data were subjected to 1-factor ANOVA. ResultsLBW piglets exhibited poorer growth performance (29.9%), lower Claudin1 mRNA level (63.6%), lower antioxidant capacity (22.9 ∼ 24.3%), and higher jejunum interleukin 1 (IL-1) concentration (18.8%) compared with NBW piglets. Dietary supplementation with 0.5% and 1.0% l-arginine significantly enhanced daily BW gain of LBW piglets by 13.6% and 18.2%, respectively. Compared with LBWC, dietary supplementation with 1.0% l-arginine increased the serum insulin concentration (32.2%) and villus height in the jejunum (12.2%) and ileum (20.5%). In the jejunum, the mRNA levels for Claudin1 (105%) and glutathione peroxidase (36%) were higher, and the concentrations of IL-1 (31.7%) and tumor necrosis factor α (TNF-α) (30%) were lower in arginine-treated piglets than in the LBWC group. However, NO synthase activity and NO concentration in the jejunum of LBW piglets were not influenced by l-arginine supplementation. ConclusionThe results suggested that supplementation with 1.0% l-arginine not only promoted growth performance and improved intestinal functions in LBW piglets but also improved intestinal barrier functions and enhanced antioxidant capacity by an NO-independent pathway.

Arginine promotes skeletal muscle fiber type transformation from fast-twitch to slow-twitch via Sirt1/AMPK pathway

This study investigated the effect of arginine on skeletal muscle fiber type transformation in mice and in C2C12 myotubes. Our data showed that dietary supplementation of arginine in mice significantly up-regulated the slow myosin heavy chain (MyHC), troponin I-SS, sirtuin1 (Sirt1) and peroxisome proliferator activated receptor-γ coactivator-1α (PGC-1α) protein expressions, as well as significantly down-regulated the fast MyHC protein expression. In C2C12 myotubes, arginine significantly increased the protein level of slow MyHC and the number of slow MyHC-positive cells, as well as significantly decreased the protein level of fast MyHC and the number of fast MyHC-positive cells. We also showed that arginine increased the activities of succinic dehydrogenase and malate dehydrogenase and decreased the activity of lactate dehydrogenase in mice and in C2C12 myotubes. Here we found that AMP-activated protein kinase (AMPK) was activated by arginine in mice and in C2C12 myotubes. However, inhibition of AMPK activity by compound C significantly attenuated the effects of arginine on slow MyHC and fast MyHC expressions in C2C12 myotubes. Finally, we showed that inhibition of Sirt1 expression by EX527 attenuated arginine-induced increase in the protein levels of phospho-AMPK and slow MyHC, the mRNA level of nitric oxide synthase (NOS) and the contents of NOS and NO, as well as decrease in fast MyHC protein level. Together, our findings indicated that arginine promotes skeletal muscle fiber type switching from fast-twitch to slow-twitch via Sirt1/AMPK pathway.

Adeno-associated viral gene therapy corrects a mouse model of argininosuccinic aciduria

Argininosuccinic aciduria (ASA) is the second most common genetic disorder affecting the urea cycle. The disease is caused by deleterious mutations in the gene encoding argininosuccinate lyase (ASL); total loss of ASL activity results in severe neonatal onset of the disease, which is characterized by hyperammonemia within a few days of birth that can rapidly progress to coma and death. The long-term complications of ASA, such as hypertension and neurocognitive deficits, appear to be resistant to the current treatment options of dietary restriction, arginine supplementation, and nitrogen scavenging drugs. Treatment-resistant disease is currently being managed by orthotopic liver transplant, which shows variable improvement and requires lifetime immunosuppression. Here, we developed a gene therapy strategy for ASA aimed at alleviating the symptoms associated with urea cycle disruption by providing stable expression of ASL protein in the liver. We designed a codon-optimized human ASL gene packaged within adeno-associated virus serotype 8 (AAV8) as a vector for targeted delivery to the liver. To evaluate the therapeutic efficacy of this approach, we utilized a murine hypomorphic model of ASA. Neonatal administration of AAV8 via the temporal facial vein extended survival in ASA hypomorphic mice, although not to wild-type levels. Intravenous injection into adolescent hypomorphic mice led to increased survival and body weight and correction of metabolites associated with the disease. Our results demonstrate that AAV8 gene therapy is a viable approach for the treatment of ASA.

Maternal dietary supplementation of arginine increases the ratio of total cloned piglets born to total transferred cloned embryos by improving the pregnancy rate of recipient sows

The extremely low full-term developmental efficiency of cloned pig embryos limits the practical application of pig cloning techniques. Maternal dietary supplementation of the nutritionally important amino acid, arginine, can enhance prenatal developmental rate of in vivo fertilization-derived pig embryos. It was hypothesized that maternal dietary addition of arginine can also improve the developmental capacity of cloned pig embryos. To test this hypothesis, there was a comparison of the reproductive performance between recipient sows fed an L-arginine-supplemented diet (L-Arg group) and those fed the control diet (control group). There was a subsequent comparison of the developmental indexes of cloned piglets farrowed in the L-Arg and control groups of surrogate sows. Dietary supplementation of L-arginine during gestation days 14–75 increased the plasma concentrations of arginine and arginine metabolites, including nitric oxide, spermidine, and putrescine in recipient sows of transferred cloned pig embryos. Although maternal arginine addition did not affect the birth weight and placental development indexes of newborn cloned piglets, it significantly increased the ratio of total cloned piglets born to total transferred cloned pig embryos by increasing the pregnancy rate of recipient sows. The results of this study suggest that nutritional management of recipient sows is an effective approach to improve the developmental rate of cloned pig embryos.

Effects of Dietary Arginine Supplementation in Pregnant Mares on Maternal Metabolism and Foal Birthweight

Withers height is an important economic trait for the American Miniature Horses (AMHs) as the breeders' primary objective is to produce small and proportionate animals. Identification of Quantitative Trait Loci (QTLs) affecting height in this breed will result in a better understanding of the genetic architecture and biological pathways contributing to skeletal development. In earlier work, we genotyped 48 horses from 16 different breeds that represent extremes in body size, using the Equine SNP50 bead chip (Illumina Inc). In this study, we applied a dominant model Genome-wide association study (GWAS), a genome-wide fixation index (FST) estimation, as well as a cross-population composite likelihood ratio (XP-CLR) test between the eight large and eight small breeds from this data set. Our GWAS implicated the marker at ECA1:37,676,322 bp, positioned within an intron of the ANKRD1 gene, was significantly associated with height variation. An XP-CLR scan further supported a role in height for the ECA1:37,676,322 bp locus and the FST analysis supported correlations to IGF2BP2 at ECA19:23,815,750. To confirm our findings, we genotyped the candidate loci in an independent set of 89 AMHs. This set verified that the locus at ANKRD1 gene indeed correlates to height under a dominant mode of inheritance, but not the locus at the IGF2BP2 gene. ANKRD1, a transcription factor involved in myocyte growth and differentiation, may contribute to height by influencing the overall growth of the horses. This marker will be a valuable tool for the selection of breeding stock in breeds with height restrictions for registration.

Effects of Dietary Arginine, Ornithine, and Zeolite Supplementation on Uremic Toxins in Cats.

To test if arginine and ornithine, both components of the Krebs-Henseleit cycle, or zeolite, a potential ammonium absorber, can modulate the excretion of harmful bacterial metabolites, intestinal microbial protein fermentation was stimulated by feeding a high-protein (60.3%) diet as a single daily meal to 10 adult cats. The diet was supplemented without or with arginine (+50, 75, 100% compared to arginine in the basal diet), ornithine (+100, 150, 200% compared to arginine in the basal diet), or zeolite (0.125, 0.25, 0.375 g/kg body weight/day). The cats received each diet for 11 days. Urine, feces, and blood were collected during the last 4 days. Arginine and ornithine enhanced the postprandial increase of blood urea, but renal urea excretion was not increased. Zeolite decreased renal ammonium excretion and fecal biogenic amines. The data indicate an increased detoxification rate of ammonia by arginine and ornithine supplementation. However, as urea was not increasingly excreted, detrimental effects on renal function cannot be excluded. Zeolite had beneficial effects on the intestinal nitrogen metabolism, which should be further evaluated in diseased cats. Clinical studies should investigate whether dietary arginine and ornithine might improve hepatic ammonia detoxification or could be detrimental for renal function.

Su1949 - Dietary Arginine Supplementation Modulates the Colonic Microbiome and Improves Colitis Induced by C. Rodentium or Dextran Sulfate Sodium

Su1949 - Dietary Arginine Supplementation Modulates the Colonic Microbiome and Improves Colitis Induced by C. Rodentium or Dextran Sulfate Sodium

Effect of dietary arginine supplementation on body weight changes and productivity of sows

Effect of dietary arginine supplementation on body weight changes and productivity of sows

Dietary arginine supplementation enhances the growth performance and immune status of broiler chickens

This experiment was conducted to investigate the effects of dietary Arg on growth performance and immunity in broiler chickens. Three hundred 1-d-old broiler chickens were divided into 5 treatments with 6 cages and 10 chickens per cage. The broiler chickens in the 5 treatments were fed with the basal diet (Arg-deficient diet, 8.6% Arg in diet from 0 to 21 d and 6.8% Arg in diet from 21 to 42 d) supplemented with 0%, 0.45%, 0.90%, 1.35%, and 1.80% Arg, respectively. The effects of dietary Arg on performance and immune status were assessed. The results showed that, with increasing of dietary Arg content, body weight was increased quadratically on d 21 (P < 0.01) and 42 (P < 0.01). The daily weight gain (P < 0.01) and feed conversion (P < 0.05) were improved quadratically during the entire period. In addition, with increasing of dietary Arg content, serum concentrations of growth hormone (P < 0.01), insulin-like growth factors-1 (P < 0.01), insulin (P < 0.01), IgA (P < 0.01), and IFN-γ (P < 0.01), as well as thymus weight (P < 0.05) of broiler chickens, were improved quadratically on d 21; and lymphocyte proliferation (P < 0.01), the antibody titers to newcastle disease (linear, P < 0.01; quadratic, P < 0.01), and serum IgM concentration (P < 0.05) were increased linearly or quadratically on d 42. The results indicated that incorporating Arg in excess of the 1994 NRC requirement improves the growth and immunity of broiler chickens.

Dietary rumen-protected arginine and N-carbamylglutamate supplementation enhances fetal growth in underfed ewes.

The present study was conducted with an ovine intrauterine growth restriction (IUGR) model to test the hypothesis that dietary rumen-protected l-arginine (RP-Arg) or N-carbamylglutamate (NCG) supplementation in underfed ewes is effective in enhancing fetal growth. Between Days 35 and 110 of pregnancy, 32 multiparous ewes carrying two fetuses were randomly assigned to one of four groups: a control (CG) group (n=8; 100% National Research Council (NRC) requirements for pregnant sheep), a nutrient-restricted (RG) group (n=8; fed 50% NRC requirements, and two treatment (ARG and NCG) groups (n=8 in each group; fed 50% NRC requirements supplemented with 20gday-1 RP-Arg or 5gday-1 NCG. All ewes were killed on Day 110 of pregnancy to determine fetal weight and fetal organ weights, and metabolites and hormones in fetal plasma, amino acid concentrations in the fetal liver and longissimus dorsi muscle, and expression of mRNAs in the somatotropic axis. Maternal and fetal bodyweight and the weight of most fetal organs expressed as a percentage of bodyweight increased in response to ARG and NCG compared with values for fetuses from RG ewes. Fetal plasma concentrations of insulin, insulin-like growth factor 1, total amino acids, lactate, thyroxine, and the thyroxine/tri-iodothyronine ratio were lower in fetuses from RG ewes compared with the other treatment groups, but concentrations of growth hormone, non-esterified fatty acids, and total cholesterol were greater in fetuses from RG ewes. Maternal RP-Arg or NCG supplementation increased concentrations of amino acids in fetal tissues and expression of mRNAs for somatotropic axis proteins in fetuses from RG ewes. These findings suggest that maternal RP-Arg and NCG supplementation of underfed ewes decreases fetal IUGR by improving metabolic homeostasis of fetal endocrinology, increasing the availability of amino acids in the fetal liver and longissimus dorsi muscle and affecting the expression of somatotropic axis genes.

Effect of different dietary lipid sources and arginine supplementation on body-composition and gonadal development of young Nile tilapia (Oreochromis niloticus)

Effect of different dietary lipid sources and arginine supplementation on body-composition and gonadal development of young Nile tilapia (Oreochromis niloticus)

Dietary arginine supplementation does not improve nutrient utilisation in gilthead seabream

The aim of this study was to evaluate the beneficial effects of dietary arginine supplementation on growth performance, urea biosynthesis, and N excretion of juvenile gilthead sea bream (Sparus aurata) fed fish meal and plant-feedstuffs based diets. For that purpose, five isonitrogenous (45% crude protein) diets were formulated as follows: two diets were fish meal-based and contained 3.0 and 4.0% arginine; three diets were plant feedstuff-based and contained 1.6, 3.0, and 4.0% arginine. Triplicate groups of gilthead seabream juveniles (24g) were fed each diet for 10weeks. At the end of the trial, growth performance of fish fed the fish meal-based diets was higher than that of the other groups. Dietary arginine content did not affect growth performance.Ammonia excretion was not affected by diet composition, while urea excretion was directly related with arginine intake. Carbamyl phosphate synthase activity was not detected in the liver, while arginase activity increased and ornithine carbamyl-transferase decreased with dietary arginine content.Overall, an excess of dietary arginine had no beneficial effects on growth performance and feed utilisation of gilthead seabream juveniles fed plant feedstuffs-based diets. A functional urea cycle was not detected in the liver of gilthead sea bream juveniles.

Effects of dietary glutamine and arginine supplementation on performance, intestinal morphology and ascites mortality in broiler chickens reared under cold environment

ObjectiveAn experiment was conducted to evaluate the effects of dietary glutamine (Gln) and arginine (Arg) supplementation on performance, intestinal morphology and ascites mortality in broilers.MethodsA total of 675 day old chicks were randomly allocated to 9 experimental groups in a 3×3 factorial arrangement based on a completely randomized design with 5 replicates of 15 chicks. Three levels of dietary Gln (0%, 0.5%, and 1%) and Arg (100%, 130%, and 160% of Ross recommendation) supplementation were used in ascites inducing condition (15°C ±1°C) from 7 to 42 days of age.ResultsDietary supplementation of Gln increased body weight gain during grower, finisher and total periods (p<0.05) and increased feed intake during total period. Ascites mortality was decreased by Gln supplementation (p<0.05). Gln supplementation increased the villus height (VH) and crypt depth (CD) in duodenum and jejunum (p<0.05). Arg supplementation decreased CD in duodenum and jejunum, and increased ileum villus width (VW) and also VH/CD ratio in duodenum and jejunum (p<0.05). Both Gln and Arg increased the goblet cell number (GCN) in duodenum whereas Gln supplementation decreased GCN in jejunum and ileum (p<0.05). The Gln×Arg interaction were observed for right ventricle (RV)/total ventricular (TV) ratio, VH, VW, CD, VH/CD.ConclusionIt was concluded that dietary 0.5% Gln alone or along with 130% Arg of Ross requirement, improve the intestinal morphology and performance and hence decrease the ascites mortality in broiler chickens with cold induced ascites.