Dietary Arginine Supplementation Research Articles

Dietary Arginine Supplementation Improves Intestinal Mitochondrial Functions in Low-Birth-Weight Piglets but Not in Normal-Birth-Weight Piglets.

Our previous studies revealed that L-arginine supplementation had beneficial effects on intestinal barrier functions of low-birth-weight (LBW) piglets, which were associated with the enhanced antioxidant capacity. Moreover, mitochondrial functions are closely related to the redox state. This study was to explore potential mechanisms of L-arginine-induced beneficial effects against intestinal dysfunction by regulating mitochondrial function of LBW piglets. Twenty 4-day-old normal birth weight (NBW) piglets (BW: 2.08 ± 0.09 kg) and 20 LBW siblings (BW: 1.16 ± 0.07 kg) were artificially fed either a basal diet or a basal diet supplemented with 1.0% L-arginine for 21 d, respectively. Growth performance, intestinal morphology, redox status, mitochondrial morphology, and mitochondrial functions were examined. Data were subjected to two-way analysis of variance. LBW piglets presented lower (p < 0.05) ADG, shorter (p < 0.05) intestinal villus height, lower (p < 0.05) jejunal adenosine triphosphate (ATP) content and higher (p < 0.05) concentrations of Ca2+ and 8-OH-dG in jejunal mitochondria, compared with NBW piglets. Supplementation with 1.0% L-arginine significantly increased (p < 0.05) ADG, the activities of CAT, SOD, and GPx, intestinal villus height and mRNA abundances of ZO-1 (2-fold) in the jejunum of LBW piglets, but not in NBW piglets. Furthermore, the concentrations of ATP and the transcription of COX IV, COX V genes were up-regulated (p < 0.05) and the concentration of Ca2+ and 8-OH-dG were decreased (p < 0.05) in arginine-treated LBW piglets. The results suggest that mitochondrial morphology is affected, and mitochondrial functions are impaired in the jejunum of LBW piglets. While supplementation with 1.0% L-arginine relieved intestinal dysfunction through enhancing antioxidant capacity and improving mitochondrial functions via repairing mitochondrial morphology, normalizing mitochondrial calcium, and increasing ATP concentration in the jejunum of LBW piglets. However, supplementation with L-arginine has no significant beneficial effects on intestinal health in NBW piglets.

Effects of L-arginine and L-citrulline supplementation in reduced protein diets for broilers under normal and cyclic warm temperature.

Heat stress causes significant economic losses in the broiler industry. Dietary supplementation of arginine (Arg) and citrulline (Cit) might increase the performance of broilers raised under warm temperature due to vasodilation effects. This study investigated the effects of L-Arg or L-Cit supplementation in broilers fed a reduced protein wheat-based diet deficient in Arg under thermoneutral (NT) and cyclic warm temperature (WT). Ross 308 cockerels (n = 720) were randomly allocated to 4 dietary treatments with 12 replicates of 15 birds per pen from d 7 to 21. The 4 treatments were: normal protein (NP), i.e., 22.3% and 20.9% crude protein in grower and finisher, respectively; reduced protein (RP), i.e., 2.5% lower protein and deficient in Arg; and RP supplemented with 0.28% Arg (RP-Arg) or 0.28% Cit (RP-Cit). A factorial arrangement of treatments was applied during the finisher phase (21 to 35 d). Factors were: diet (4 diets above); and temperature, NT (24 °C) or cyclic WT (33 ± 1 °C for 6 h per day) with 6 replicate pens per treatment. During 7 to 35 d and 21 to 35 d, the birds fed the RP diet had lower body weight gain (BWG) and higher FCR compared to the NP diet (P < 0.01). The addition of Arg or Cit to RP decreased FCR compared to RP (P < 0.01). During 21 to 35 d, the birds exposed to WT had lower feed intake (FI), lower BWG (P < 0.001) but similar FCR (P > 0.05) compared to birds exposed to NT. Diet by temperature interactions were not observed for performance parameters during the period of WT (P > 0.05). On d 35, the RP-fed birds had a lower yield of thigh and drumstick, higher fat pad, lower femur ash, and breaking strength but similar serum uric acid level and higher nitrogen digestibility on d 21 compared to those offered NP (P < 0.05). Supplementation of Arg or Cit to RP resulted in increased femur ash on d 35 (P < 0.05). Thus, feeding the NP diets is necessary to maintain growth performance in broilers regardless of the temperature conditions.

Dietary Arginine Supplementation during Gestation and Lactation Increases Milk Yield and Mammary Lipogenesis in Rats.

Arginine, an essential amino acid during the reproductive period, has been shown to enhance lactation performances in livestock. Whether it could help mothers with breastfeeding difficulties is not known. This study aimed to determine whether dietary arginine supplementation would enhance milk production in rat dams nursing large 12-pup litters and, if so, what mechanisms are involved. In 3 series of experiments, differing in dam killing timing, 59 primiparous, pregnant Sprague-Dawley rats (mean±SD weight: 254±24.7g) were randomly assigned to receive either 1) an AIN-93G diet supplemented with l-arginine at 2.0% (ARG diet), through lactation and gestation (AGL group); 2) a control AIN-93G diet including at 3.5% an isonitrogenous mix of amino acids that are not essential for lactation (MA diet), during gestation and lactation (MA group); or 3) the MA diet during gestation and the ARG diet during lactation (AL group). Milk flow was measured using deuterated water enrichment between days 11 and 18. Plasma hormones and mammary expression of genes involved in lactation were measured using ELISA and qRT-PCR, respectively, at lactation days 12, 18, or 21 in the 3 experiments. Data were analyzed by ANOVA. Dam food intake, pup weight gain, milk flow normalized to dam weight, and milk fat concentration were 17%, 9%, 20%, and 20% greater in the AGL group than in the MA group, respectively (P<0.05). Genes involved in lipogenesis and lipid regulation were overexpressed ≤2.76-fold in the mammary gland of AGL dams compared with MA dams (P<0.05) and plasma leptin concentration was 39% higher (P=0.008). Milk flow and composition and mammary gene expression of the AL group did not differ from those of the MA group, whereas milk fat concentration and flow were 26% and 37% lower than in the AGL group, respectively. Arginine supplementation during gestation and lactation enhances milk flow and mammary lipogenesis in rats nursing large litters.

Dietary arginine requirement in diets of GIFT strain of Nile tilapia, Oreochromis niloticus : Effects on growth performance, whole‐body composition, growth‐related gene expression and haemato‐biochemical responses

This study aims to evaluate the effects of dietary arginine supplementation on growth performances, whole-body composition, haemato-biochemical responses and growth-related gene expression in juvenile GIFT tilapia. Five corn-soy-based isonitrogenous (322 g/kg) and isoenergetic (17.4 MJ/kg) diets were formulated to contain graded levels of dietary arginine (14.7, 15.5, 16.4, 17.6 and 18.5 g/kg of diet). Each diet was randomly assigned to triplicate groups of 30 fish (4.4 ± 0.2 g) per experimental unit, which were fed thrice a day (09:00, 13:00 and 17:00 h) for 60 days. Growth performances and feed utilization were improved in fish fed arginine at 16.4 g/kg of diet compared with other dietary treatments. No significant differences were observed in the whole-body proximate composition, amino acid profile and haematological responses of fish fed graded levels of dietary arginine. However, significant interactions were observed in the blood biochemical responses and mRNA expression of MyoD, Myogenin, GH, IGF-1, GHR-1 and Pax7 in fish fed diets with graded levels of arginine, while dietary arginine levels had no effect on the mRNA expression of myostatin and IGF-2. Second-order polynomial regression analysis of weight gain and nitrogen gain against dietary arginine levels indicated that the optimum dietary arginine requirement for maximum growth and feed utilization of juvenile GIFT tilapia was estimated to be 16.7–16.8 g/kg of diet or 51.8–52.2 g/kg of protein.

Effects of dietary arginine supplementation on cytokine‐ and antioxidant‐related gene expressions in common carp ( Cyprinus carpio ) fingerling during ammonia toxicity

This study investigated the effects of dietary arginine supplementation on plasma ammonia and urea levels, and immune- and antioxidant-related gene expressions of common carp (Cyprinus carpio), exposed to ambient ammonia. Fish (10.5 ± 0.74 g) were fed diets containing arginine (0: control diet, 0.25: 0.25Arg and 0.5%: 0.5Arg) for 14 days and then subjected to ammonia exposure for three hours. The results showed that arginine significantly decreased plasma ammonia level, whereas increased the plasma urea level. Arginine supplementation significantly up-regulated head kidney il1b, il10, tnfa and liver sod, cat, gpx and gst gene expressions, whereas significantly down-regulated hsp70 gene expression in liver. Ammonia exposure led to a significant increase in plasma ammonia and urea levels. There were elevations in head kidney il1b, and liver sod, cat, gpx, gst and hsp70 gene expression in fish after challenged with ammonia. The interaction effects of arginine supplementation and ammonia exposure on head kidney il10, and liver gst and hsp70 gene expressions were observed, as arginine prevented ammonia-induced down-regulation in il10 expression, mitigated ammonia-induced up-regulation in hsp70 expression and intensified up-regulation in gst expression. In conclusion, it is suggested that two-week supplementation of arginine (0.5% of diet) is useful to mitigate the adverse effects of ambient ammonia when in the farm, common carp is at risk of ammonia toxicity.

Effects of rumen-protected arginine supplementation on the plasma amino acids and gut microbiota of sika deer (Cervus nippon)

In this study, we examined the effects of rumen-protected arginine on antler growth, plasma biochemical values and the gut microbiota of sika deer (Cervus nippon). Twenty-four male sika deer were randomly allocated to one of four experimental diets: a basal diet with no arginine (CON, 0 g/day) or arginine supplementation groups that received 1 (LArg), 2 (MArg), or 3 (HArg) g/day of rumen-protected arginine. After an 8-week feeding trial, plasma metabolite levels were measured, and the faecal bacterial community was examined based on 16S rRNA gene sequencing. The final weight (P = 0.04) and daily gain of velvet antler (P = 0.04) in the HArg group were higher than those in the CON group. The glucose (P = 0.01) and triglyceride concentrations (P < 0.01) in plasma increased linearly, whereas the ALT (P = 0.01) and AST (P < 0.01) concentrations decreased linearly with the increase of arginine supplementation. In addition, the phosphoserine (P = 0.01), citrulline (P = 0.02), cystathionine (P = 0.01), ammonia (P = 0.01), and arginine (P = 0.01) levels increased linearly with the increase of arginine supplementation. Prevotella spp. were the dominant bacteria in the faeces of sika deer among the four groups. Principal coordinates analysis results showed that the bacterial communities and predicted functions of the CON group were different from those of the LArg, MArg and HArg groups based on the Bray-Curtis dissimilarity matrix (P < 0.01), unweighted UniFrac distance (P < 0.01), and weighted UniFrac distance (P < 0.01). The Firmicutes-to-Bacteroidetes ratios were higher (P < 0.01) in the arginine supplementation groups than that in the CON group. The relative abundances of Bacteroides spp., Rikenellaceae RC9, Treponema 2, Turicibacter spp., Romboutsia spp., Alistipes spp., and Phascolarctobacterium spp. were increased with dietary arginine supplementation, whereas the abundance of Prevotella spp. was decreased. Comparison of potential functions also showed enrichment of the fructose and mannose metabolism, pyruvate metabolism, propionate metabolism, and butyrate metabolism pathways. These results suggested that supplemental rumen-protected arginine affected sika deer metabolism and the gut microbiota.

Influence of Eimeria spp. infection and dietary inclusion of arginine on intestine histological parameters, serum amino acid profile and ileal amino acids digestibility in broiler chicks

Coccidiosis is considered to be one of the most important challenge in the poultry industry causes economic losses due to the destruction in the digestive tract of chicken. It disturbs amino acids profile and their digestibility, leading to weight lost and economic burden. Using dietary arginine may decrease the adverse effects of coccidiosis on chicken digestive tract. This study aimed to evaluate the effects of dietary inclusion of arginine on intestine histological parameters, serum amino acid concentration and ileal amino acid digestibility of broiler chicks infected with coccidiosis. A total number of 384 one-d-old broiler chicks (Ross 308) of mixed sex with initial weight of 42 ± 2 g was allocated into 8 groups with 8 birds/pen from grower period. At 21 days of age, broiler chicks were infected with a mixture of Eimeria spp. Broiler chicks were divided into infected and un-infected groups and received arginine at recommended levels of 85, 100, 125 and 150 %. Intestinal morphology and lesions, serum amino acid concentration and ileal amino acid digestibility were evaluated. Broiler chicks infected with Eimeria spp. showed lower villus height and villus height: crypt depth ratio and also higher intestinal lesions (P < 0.05). Coccidia infection decreased the ileal amino acid digestibility for all studied amino acids and also reduced serum concentrations of amino acids, except lysine and isoleucine (P < 0.05). Dietary supplementation of arginine especially in higher levels significantly increased villus height and villus height:crypt depth ratio and decreased lesions (P < 0.05). Moreover, dietary supplementing of arginine increased the serum concentration of arginine (P < 0.05), but it did not have any significant effect on its digestibility (P > 0.05). In sum, coccidiosis decreases amino acid digestibility and serum amino acid concentration, but dietary inclusion of higher levels of arginine significantly improved histological parameters of broiler chicks infected with coccidiosis.

Dietary arginine and citrulline supplementation modulates the immune condition and inflammatory response of European seabass

The present study was designed to determine the modulatory effects of arginine and citrulline dietary supplementation on the immune condition and inflammatory response of European seabass, Dicentrarchus labrax. Four diets were manufactured: a control diet (CTRL) was formulated to meet the indispensable amino acids profile established for seabass. Based on this formulation, three other diets were supplemented with l-arginine at two different levels (0.5% and 1%, ARG1 and ARG2, respectively) and l-citrulline at 0.5% (CIT). Fish were fed these diets for 2 or 4 weeks under controlled conditions. At the end of 4 weeks, fish from all dietary treatments were intraperitoneally-injected with Photobacterium damselae piscicida and sampled after 4, 24 our 48 h. Immune status was characterized by a lymphocyte time-dependent decrease regardless of dietary treatment, whereas peroxidase values dropped in time in fish fed ARG1 and ARG2 and was lower at 4 weeks in fish fed ARG1 than in fish fed CTRL. Up-regulation of several genes was more evident in ARG1-and CIT-fed fish, though pro-inflammatory cytokines were down-regulated by CIT dietary treatment. Following immune stimulation, seabass fed ARG1 showed a decrease in neutrophils and monocytes circulating numbers. On the other hand, expression of 17 selected immune and inflammatory responses genes was barely affected by dietary treatments. Based on the analyzed parameters, results suggest an active role of dietary arginine/citrulline supplementation in modulating immune defences that seem to translate into a suppressed immune repertoire, mostly at the cell response level. The observed changes due to citrulline dietary supplementation were in part similar to those caused by arginine, suggesting that citrulline might have been used by macrophages as an arginine precursor and then engaged in similar immune-impairment leading mechanisms.

Short-Term Supplementation of Dietary Arginine and Citrulline Modulates Gilthead Seabream (Sparus aurata) Immune Status.

Several amino acids (AA) are known to regulate key metabolic pathways that are crucial for immune responses. In particular, arginine (ARG) appears to have important roles regarding immune modulation since it is required for macrophage responses and lymphocyte development. Moreover, citrulline (CIT) is a precursor of arginine, and it was reported as an alternative to ARG for improving macrophage function in mammals. The present study aimed to explore the effects of dietary ARG and CIT supplementation on the gilthead seabream (Sparus aurata) immune status. Triplicate groups of fish (23.1 ± 0.4 g) were either fed a control diet (CTRL) with a balanced AA profile, or the CTRL diet supplemented with graded levels of ARG or CIT (i.e., 0.5 and 1% of feed; ARG1, CIT1, ARG2, and CIT2, respectively). After 2 and 4 weeks of feeding, fish were euthanized and blood was collected for blood smears, plasma for humoral immune parameters and shotgun proteomics, and head-kidney tissue for the measurement of health-related transcripts. A total of 94 proteins were identified in the plasma of all treatments. Among them, components of the complement system, apolipoproteins, as well as some glycoproteins were found to be highly abundant. After performing a PLS of the expressed proteins, differences between the two sampling points were observed. In this regard, component 1 (61%) was correlated with the effect of sampling time, whereas component 2 (18%) seemed associated to individual variability within diet. Gilthead seabream fed ARG2 and CIT2 at 4 weeks were more distant than fish fed all dietary treatments at 2 weeks and fish fed the CTRL diet at 4 weeks. Therefore, data suggest that the modulatory effects of AA supplementation at the proteome level were more effective after 4 weeks of feeding and at the higher inclusion level (i.e., 1% of feed). The bactericidal activity increased in fish fed the highest supplementation level of both AAs after 4 weeks. Peripheral monocyte numbers correlated positively with nitric oxide, which showed an increasing trend in a dose-dependent manner. The colony-stimulating factor 1 receptor tended to be up-regulated at the final sampling point regardless of dietary treatments. Data from this study point to an immunostimulatory effect of dietary ARG or CIT supplementation after 4 weeks of feeding in the gilthead seabream, particularly when supplemented at a 1% inclusion level.

Dietary citrulline improves survival of rainbow trout Oncorhynchus mykiss juveniles challenged with Vibrio anguillarum

Arginine is a versatile amino acid that plays important roles in various physiological functions. However, supplementation with arginine can also increase urea excretion of the fish. Thus, given than ornithine and citrulline can potentially be used to increase arginine availability or improve fish immunity, this study aimed to compare the effects of dietary supplementation of arginine, ornithine, and citrulline on the survival of rainbow trout Oncorhynchus mykiss against Vibrio anguillarum. Dietary treatment consisted of a control diet (CTRL) and three treatment diets comprising CTRL supplemented with 2% L-arginine (+ARG), L-ornithine (+ORN), or L-citrulline (+CIT). Protein and lipid content of the diets were confirmed at 48.9 and 18.9%, 53.1 and 18.7%, 51.7 and 18.1% and 52.9 and 18.9% for the CTRL, +ARG, +ORN & + CIT diets respectively. Postprandial plasma amino acid levels were measured at 6, 15, and 30 h after feeding. A feeding trial was conducted for 30 days, and at the end of the trial, the rainbow trout were challenged with V. anguillarum. At 24 h post-injection, plasma amino acid and renal gene expression levels were examined. Fish exhibited better weight gain in +ARG treatment compared to +CIT treatment. Similar postprandial levels of plasma arginine were observed in +ARG and + CIT, and the levels in both treatments were significantly higher than those in CTRL. A survival analysis revealed that fish in +CIT (69.2%) were more resistant than those in CTRL (25.0%). There was significantly higher inducible nitric oxide synthase (iNOS) expression in the kidneys of fish in +CIT than those in CTRL. A significant difference in interleukin-1-beta expression was found between +ORN and CTRL treatments, while there was no significant difference in arginase II expression among the treatments. These result shows that citrulline supplementation can be used to increase arginine availability and better at enhancing the immune performance of rainbow trout compared to arginine supplementation when challenged with V. anguillarum.

Dietary l-arginine supplementation ameliorates inflammatory response and alters gut microbiota composition in broiler chickens infected with Salmonella enterica serovar Typhimurium

This study was conducted to investigate the effects of dietary arginine (Arg) supplementation on the inflammatory response and gut microbiota of broiler chickens subjected to Salmonella enterica serovar Typhimurium. One hundred and forty 1-day-old Arbor Acres male birds were randomly assigned to a 2 × 2 factorial arrangement including diet treatment (with or without 0.3% Arg supplementation) and immunological stress (with or without S. typhimurium challenge). Samples were obtained at 7 D after infection (day 23). Results showed that S. typhimurium challenge caused histopathological and morphological damages, but Arg addition greatly reduced these intestinal injuries. S. typhimurium challenge elevated the levels of serum inflammatory parameters, including diamine oxidase, C-reactive protein, procalcitonin, IL-1β, IL-8, and lipopolysaccharide-induced tumor necrosis factor-alpha factor (LITNF) homolog. However, Arg supplementation decreased the serum procalcitonin, IL-1β, IL-8, and LITNF concentration. S. typhimurium challenge significantly increased jejunal IL-1β, IL-8, IL-10, and IL-17 mRNA expression and tended to upregulate IL-22 mRNA expression, but Arg supplementation remarkably reduced IL-8 mRNA expression, tended to downregulate IL-22 mRNA expression, and dramatically elevated IFN-γ and IL-10 mRNA expression. In addition, sequencing data of 16S rDNA indicated that the population of Proteobacteria phylum; Enterobacteriaceae family; Escherichia–Shigella, and Nitrosomonas genera; and Escherichia coli and Ochrobactrum intermedium species were more abundant, but the population of Rhodocyclaceae and Clostridiaceae_1 families and Candidatus Arthromitus genus were less abundant in the ileal digesta of birds with only S. typhimurium infection when compared with the controls. Treatment with Arg in birds subjected to S. typhimurium challenge increased the abundances of Firmicutes phylum, Clostridiaceae_1 family, Methylobacterium and Candidatus Arthromitus genera but decreased the abundance of Nitrosomonas genus and Rhizobium cellulosilyticum and Rubrobacter xylanophilus species as compared with the only S. typhimurium–challenged birds. In conclusion, Arg supplementation can alleviate intestinal mucosal impairment by ameliorating inflammatory response and modulating gut microbiota in broiler chickens challenged with S. typhimurium.

Effects of arginine and ornithine supplementation to a high-protein diet on selected cellular immune variables in adult cats.

BackgroundDietary protein and amino acid intake and composition can modulate immune function.ObjectivesTo evaluate the effects of high‐protein intake and arginine and ornithine supplementation on feline immune cells.AnimalsTen healthy cats.MethodsExperimental study. Cats received a high‐protein basal diet as a single daily meal. A crossover design was applied with treatments being basal diet (w/o); basal diet with arginine supplementation (+50, 75, 100% compared to the arginine provision by the basal diet; Arg 1‐3); and basal diet with ornithine supplementation (+100, 150, 200% compared to the arginine provision by the basal diet; Orn 1‐3). Blood samples were collected at the end of each 11‐day treatment period.ResultsMitogen‐stimulated proliferative activity of blood leukocytes revealed a quadratic effect for the dietary supplementation of arginine (P = .02) and ornithine (P = .03) (means for ConA‐stimulation: w/o = 6.96; Arg 1 = 9.31; Arg 2 = 11.4; Arg 3 = 8.04; Orn 1 = 15.4; Orn 2 = 9.43; Orn 3 = 9.28; pooled SEM: 0.96). The number (% gated) of phagocytic granulocytes linearly decreased with increasing dietary concentrations of arginine (P = .05) and ornithine (P = .03) (means: w/o = 95.5; Arg 1 = 93.0; Arg 2 = 92.5; Arg 3 = 92.6; Orn 1 = 92.6; Orn 2 = 92.6; Orn 3 = 91.5; pooled SEM = 0.44).Conclusions and Clinical ImportanceThis study could demonstrate immunomodulating properties of dietary arginine and ornithine in cats.

Arginine, ornithine and citrulline supplementation in rainbow trout: Free amino acid dynamics and gene expression responses to bacterial infection

Supplementing the diet with functional ingredients is a key strategy to improve fish performance and health in aquaculture. The amino acids of the urea and nitric oxide (NO) cycles - arginine, ornithine and citrulline - perform crucial roles in the immune response through the generation of NO and the synthesis of polyamine used for tissue repair. We previously found that citrulline supplementation improves and maintains circulating free arginine levels in rainbow trout more effectively than arginine supplementation. Here, to test whether supplementation of urea cycle amino acids modulates the immune response in rainbow trout (Oncorhynchus mykiss), we supplemented a commercial diet with high levels (2% of total diet) of either arginine, ornithine or citrulline during a 7-week feeding trial, before challenging fish with the bacterium Aeromonas salmonicida. We carried out two separate experiments to investigate fish survival and 24 h post-infection to investigate the immediate response of free amino acid levels, and transcriptional changes in genes encoding urea cycle, NO cycle and polyamine synthesis enzymes. There were no differences in percentage fish mortality between diets, however there were numerous highly significant changes in free amino acid levels and gene expression to both dietary supplementation and infection. Out of 26 amino acids detected in blood plasma, 8 were significantly changed by infection and 9 by dietary supplementation of either arginine, ornithine or citrulline. Taurine, glycine and aspartic acid displayed the largest decreases in circulating levels in infected fish, while ornithine and isoleucine were the only amino acids that increased in concentration. We investigated transcriptional responses of the enzymes involved in arginine metabolism in liver and head kidney; transcripts for polyamine synthesis enzymes showed highly significant increases in both tissues across all diets following infection. The paralogous arginase-encoding genes, Arg1a, Arg1b, Arg2a and Arg2b, displayed complex responses across tissues and also due to diet and infection. Overall, these findings improve our understanding of amino acid metabolism following infection and suggests new potential amino acid targets for improving the immune response in salmonids.

PSVIII-8 Effects of heat stress and arginine on intestinal morphology and hepatic metabolism in finishing pigs

Abstract Heat stress can affect growth performance and some physiological metabolism in finishing pigs. In this study, we investigated the effects of intermittent heat stress and arginine on the growth performance, intestinal health and liver metabolism of finishing pigs. Forty-eight Landrace barrow pigs (about 70kg) were randomly assigned to 6 groups, each group 8 pigs. The pigs were treated as follows: (1) LR (fed ad libitum at 22°C), (2) HR (ad libitum fed at 35°C), (3) LL(at 22°C, but fed the amount consumed by those kept at 35°C), (4) LR+1% Arg, (5) HR+1%Arg, (6) LL+1%Arg. The temperature of HR and HR+1%Arg groups was controlled for cycles of 35 ± 2 ℃ for 12 hours, 22 ± 2 ℃ for the other 12 hours. The experiment lasted for 30 days. The results showed that the ADFI and ADG of pigs in LR group were much higher than those in HR group or LL group, the latter having the highest F:G (P &amp;lt; 0.05). Jejunal HE staining results showed that heat stress decreased the villus height of jejunum and villus height to crypt depth ratio, adding 1% arginine can alleviate the damage by heat stress (P &amp;lt; 0.05). Heat stress decreased the abundance of transcripts of tight junction protein ZO-1, occludin and mucin-2 in the mucosa of the jejunum (P &amp;lt; 0.05). Moreover, dietary arginine supplementation increased occludin transcripts (P &amp;lt; 0.05). The results of hepatic metabolomics showed that heat stress significantly affected the metabolism of carbohydrate, energy and protein of liver (P &amp;lt; 0.05). In conclusion, these data indicated that intermittent heat stress has negatively influence on the intestinal health and liver metabolism of finishing pigs, and adding 1% arginine had a positive effect on intestinal mucosal morphology caused by heat stress.

The impact of dietary supplementation of arginine during gestation in a commercial swine herd: II. Offspring performance.

Arginine (Arg) is an important amino acid of pig fetal development; however, whether Arg improves postnatal performance is ill-defined. Therefore, the influence of Arg supplementation at different gestational stages on offspring performance was evaluated in a commercial swine herd. Sows (n = 548) were allocated into 4, diet by stage of gestation treatments: Control (n = 143; 0% suppl. Arg), or dietary treatments supplemented with 1% L-Arg (free-base; Ajinomoto Animal Nutrition North America, Inc., Chicago, IL): from 15 to 45 d of gestation (n = 138; Early-Arg); 15 d of gestation to farrowing (n = 139; Full-Arg); and from day 85 of gestation to farrowing (n = 128; Late-Arg). All offspring were individually identified and weighed at birth; at weaning, a subset was selected for evaluation of carcass performance at market. All data were analyzed using birth weight (BiWt) and age as covariates. Wean weights (WW) and prewean (PW) ADG tended to increase (P = 0.06) in progeny from sows supplemented with Arg, as compared to progeny from Control sows. Preplanned contrast comparisons revealed an increased (P = 0.03) BiWt for pigs from sows receiving 1% L-Arg prior to day 45 of gestation (Early-Arg and Full-Arg; 1.38 kg/pig), as compared to pigs from sows not supplemented prior to day 45 of gestation (Control and Late-Arg; 1.34 kg/pig). No difference in BiWt was observed (1.36 kg/pig; P = 0.68) for Arg supplementation after day 85 of gestation (Full-Arg and Late-Arg), as compared to those not receiving Arg supplementation after day 85 (Control and Early-Arg); although WW and PW ADG were greater (P = 0.02), respectively. A 3.6% decrease (P = 0.05) in peak lean accretion ADG occurred when dams received 1% L-Arg prior to day 45 of gestation (Early-Arg and Full-Arg), however, no other significant differences were detected in finishing growth parameters or carcass characteristics (P ≥ 0.1). Pig mortality rates tended (P = 0.07) to decrease in progeny of dams supplemented Arg after day 85 (3.6%) compared to dams not provided additional Arg during late gestation (4.9%). Collectively, these data suggest that Arg provided during late gestation may improve WW and PW ADG, however, finishing performance was not affected. While Arg supplementation provided some moderate production benefits, further investigation is warranted to comprehensively understand the gestational timing and biological role of Arg supplementation during fetal and postnatal development in commercial production systems.

In vivo and in vitro protective effect of arginine against intestinal inflammatory response induced by Clostridium perfringens in broiler chickens

BackgroundNecrotic enteritis is a widespread disease in poultry caused by Clostridium perfringens. We previously reported that dietary arginine supplementation protected the intestinal mucosa of broiler chickens with necrotic enteritis, but the related protective mechanisms remain unclear. The in vivo trial was designed as a 2 × 2 factorial arrangement to evaluated the effects of arginine supplementation on inflammatory responses, arginine transporters, arginine catabolism and JAK-STAT signalling pathway in broiler chickens challenged with C. perfringens or without C. perfringens. Furthermore, we validated the in vivo results using intestinal epithelial cells of chicken embryos.ResultsC. perfringens infection markedly increased gut gross pathological and histopathological lesion scores, promoted liver C. perfringens invasion, reduced serum arginine levels, and elevated jejunal mucosal lysozyme activities (P < 0.05), but these effects were significantly reversed by arginine supplementation in vivo (P < 0.05). The challenge significantly increased serum procalcitonin levels, jejunal mucosal iNOS activities and jejunal IL-6, TGF-β3, cationic amino acid transporter (CAT)-1, and CAT-3 mRNA expression (P < 0.05), whereas arginine supplementation significantly reduced jejunal IFN-γ, IL-1β, IL-6, IL-10, TGF-β3, and CAT-3 mRNA expression (P < 0.05). Arginine supplementation significantly attenuated the C. perfringens challenge-induced increases in jejunal iNOS, arginase 2, arginine decarboxylase, arginine:glycine amidinotransferase, JAK1, JAK3, STAT1, and STAT6 mRNA expression (P < 0.05). The in vitro experiment showed that C. perfringens challenge markedly increased cellular cytotoxicity and the mRNA expression of IL-1β, IL-8, IL-10, CAT-1 and CAT-3 (P < 0.05), which were significantly reversed by 50 μmol/L and/or 400 μmol/L arginine pre-treatment (P < 0.05).ConclusionsArginine prevented C. perfringens challenge-induced circulated arginine deficiency, normalized intestinal arginine transport and catabolism, down-regulated JAK-STAT signalling pathway and attenuated the inflammatory response, which exerted protective effects on the intestine of broiler chickens.

The impact of dietary supplementation of arginine during gestation in a commercial swine herd: I. Gilt reproductive performance.

Supplemental arginine (Arg) during gestation purportedly benefits fetal development. However, the benefits of a gestational Arg dietary strategy in commercial production are unclear. Therefore, the objectives of this study examined Arg supplementation during different gestational stages and the effects on gilt reproductive performance. Pubertal gilts (n = 548) were allocated into 4 treatment groups: Control (n = 143; 0% supplemental Arg) or 1 of 3 supplemental Arg (1% as fed) treatments: from 15 to 45 d of gestation (n = 138; Early-Arg); from 15 d of gestation until farrowing (n = 139; Full-Arg); or from 85 d of gestation until farrowing (n = 128; Late-Arg). At farrowing, the number of total born (TB), born alive (BA), stillborn piglets (SB), mummified fetuses (MM), and individual piglet birth weights (BiWt) were recorded. The wean-to-estrus interval (WEI) and subsequent sow reproductive performance (to third parity) were also monitored. No significant effect of supplemental Arg during any part of P0 gestation was observed for TB, BA, SB, or MM (P ≥ 0.29). Offspring BiWt and variation among individual piglet birth weights did not differ (P = 0.42 and 0.89, respectively) among treatment groups. Following weaning, the WEI was similar among treatments (average of 8.0 ± 0.8 d; P = 0.88). Litter performance over 3 parities revealed a decrease (P = 0.02) in BA for Early-Arg fed gilts compared with all other treatments, whereas TB and WEI were similar among treatments over 3 parities (P > 0.05). There was an increased proportion of sows with average size litters (12 to 16 TB) from the Full-Arg treatment sows (76.8% ± 3.7%) when compared with Control (58.7% ± 4.2%; P = 0.01); however, the proportion of sows with high (>16 TB) and low (<12 TB) litters was not different among treatments (P = 0.20). These results suggest that gestational Arg supplementation had a minimal impact on reproductive performance in first parity sows. These data underscore the complexity of AA supplementation and the need for continued research into understanding how and when utilizing a gestational dietary Arg strategy can optimize fetal development and sow performance.

Dietary arginine and citrulline supplementation during a short-term feeding period improves the gilthead seabream (Sparus aurata) immune status

Dietary arginine and citrulline supplementation during a short-term feeding period improves the gilthead seabream (Sparus aurata) immune status

Effects of dietary arginine supplementation on ureagenesis and amino acid metabolism in common carp (Cyprinus carpio) exposed to ambient ammonia

The aim of the present study was to determine the effects of dietary arginine supplementation on resistance and responses to ammonia toxicity in common carp (Cyprinus carpio). In the first experiment, the fish were fed with four diets supplemented with 0% (control diet), 0.25% (0.25Arg), 0.5% (0.5Arg) or 1% (1Arg) for 14 days and challenged with 0.7, 0.8, 0.9, 1.1, 1.3 mg/L water unionized ammonia for 3 h. The results showed that 0.7 mg/L ammonia caused no mortality in the treatments, but 1.3 mg/L ammonia killed all the fish. In the second experiment, the fish fed either the control or the 0.5Arg diet for 14 days and exposed to 0.7 mg/L ammonia for 3 h, and plasma ammonia and free amino acids were determined. The results showed that arginine administration significantly increased plasma arginine, urea, ornithine, glutamate, aspartate and histidine, whereas decreased plasma ammonia, citrulline, glutamine and other amino acids except for glycine, asparagine and serine. Ammonia exposure led to significant elevations in plasma ammonia and urea, and significant declines in plasma arginine, ornithine, citrulline and other amino acids. In conclusion, common carp is ureagenic under ammonia exposure and tries to detoxify ammonia by converting to urea, as well as formation of glutamine. To keep glutamate levels constant during ammonia toxicity, common carp may utilize alanine, aspartate, glycine and serine for α-ketoglutarate formation as a substrate for glutamate synthesis. Arginine administration provides high levels of ornithine, which is used to convert ammonia to urea after ammonia toxicity. The benefits of arginine in common carp resistance to ammonia toxicity seem to be related to its stimulatory effects on ureageneis; however, other health benefits of the amino acid (anti-stress, antioxidant and anti-anemic) should not be neglected.

Effect of different arginine-to-lysine ratios in broiler chicken diets on the occurrence of breast myopathies and meat quality attributes

This study was carried out to evaluate the effect of different digestible arginine-to-lysine (dig Arg:Lys) ratio in broiler diets on the occurrence of breast myopathies, productivity, and meat quality traits. A total of 1,755 1-day-old Ross 308 male chicks was randomly divided in 3 experimental groups (9 replications/group): CON, fed a 4 feeding-phases commercial diet (dig Arg:Lys ratio = 1.05, 1.05, 1.06, 1.07, respectively in starter, grower I, grower II and finisher phase), and ARG2 and ARG3 groups fed CON diet supplemented respectively with 20 and 30% higher levels of crystalline L-arginine (dig Arg:Lys ratio = 1.25, 1.25, 1.26, 1.27 and 1.35, 1.35, 1.36, 1.37, respectively). Productive performance was recorded throughout the rearing cycle. At processing (43 d), breasts (n = 150/group) were randomly collected to evaluate the incidence and severity of white striping (WS), wooden breast (WB), and spaghetti meat (SM) defects (3-points scale). Meat quality traits, such as color, pH, drip and cook losses, marinade performances, and proximate composition were determined on 12 fillets/group. Although productive performance and meat quality traits resulted not significantly affected, the occurrence of some breast myopathies was modified by the dietary treatments. ARG2 and ARG3 exhibited a significantly higher percentage of breast without WS compared to CON (28 and 41 vs. 17%, respectively; P < 0.001). ARG3 reported the lowest percentage of breasts with severe WS (11 vs. 27 and 31%, respectively for ARG3, ARG2, and CON; P < 0.001) and the highest of those showing no SM abnormality (81 vs. 69 and 65%, respectively for ARG3, ARG2, and CON; P < 0.01). Furthermore, a numerical reduction of breasts with severe WB was observed in ARG3 (12 vs. 25 and 19%, respectively for ARG3, ARG2, and CON; P = 0.12). In conclusion, the dietary supplementation of arginine to increase the dig Arg:Lys ratio by about 30% in respect to the current recommendations for broiler chickens has positive implications on the occurrence of some breast meat abnormalities.