Dietary Arginine Supplementation Research Articles

Effects of Dietary Supplementation of Arginine on Growth Performance of Broiler Chickens

The purpose of this research added arginine to increase the growth of broiler chickens in Nangarhar University, Agriculture research farm in Afghanistan, study discovered Over 96 one-day broiler chickens in 42 days based on the record of their daily behaviors, Hence, record of the chickens have divided into Four groups, each group being divided into three replications. Each replication of each group consisted of eight chickens, the first group was control and the other three were treatment groups, such as, in T1 group (0.1%) on the arginine Dose given, the second T2 group 0.2% arginine was added to the Dose, and T3 group added arginine (0.3%) through the factor of FCR such as Weight gain, feed intake. Nevertheless, by statistical analysis, that Null hypothesis is fail to rejected, p-value is greater than 0.05 means there is no significant change amongst with the experimental groups in the first three weeks and also in the control group as well as at the fourth, fifth, and sixth weeks, P value is less than 0.05, hence Null hypothesis is rejected (Type 1error), there is a significant difference between the treatment groups and the control group. Furthermore, all group feed conversion ratio (H0) is rejected. Study emphasized that’s adding 0.3 per cent of arginine to daily diet chickens increase weight by less consumed feed as well reduce of mortality rate. According to this study, it is recommended that 0.3% arginine should be added to the chicken diet after the third week, to gain more weight by consuming a small amount of diet.

Effects of dietary arginine supplementation on growth performance, antioxidant capacity, intestinal digestive enzyme activity, muscle transcriptome, and gut health of Siniperca chuatsi

Our study investigated the effects of dietary arginine supplementation on the growth performance, antioxidant capacity, intestinal digestive enzyme activity, muscle transcriptome, and gut health of Chinese perch (Siniperca chuatsi). Four isonitrogenous and isolipidic diets (50% crude protein, 11% crude lipid) with graded levels (2.61%, 2.99%, 3.37%, and 3.82%) of arginine were formulated and processed. A total of 360 Chinese perch (approximately 45–46 g) were randomly divided into four groups with triplicates of 30 fish per cage in each group. Our results revealed that although there was no significant improvement in the growth performance of Chinese perch, their antioxidant capacity and nutritional metabolism were significantly improved. Compared to the control group (without arginine supplementation, 2.61% group), feeding graded arginine levels could significantly (P < 0.05) decrease serum glucose and malondialdehyde (MDA) contents, as well as increase total superoxide dismutase (TSOD) activity. Fish fed a 3.37% arginine diet had the highest TSOD activity in the serum and liver. The intestinal morphological structure was clearer and more uniform in the 2.99% and 3.37% arginine groups. Fish fed with 3.82% arginine had significantly decreased (P < 0.05) muscle valine, glutamate, tyrosine, and total non-essential amino acid contents, with decreased (P < 0.05) intestinal amylase activity. Transcriptome analysis showed that graded arginine levels significantly (P < 0.05) influenced muscle gene expression involved in the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways of energy metabolism (amino acid, glucose, fatty acid), signaling pathways (mTOR, PI3K-Akt, MAPK, foxO, and insulin pathway), etc. The microbial community structure did not change significantly. Mycoplasma showed the highest abundance in the control group, and Cetobacterium had the highest abundance in the dietary arginine supplementation groups. Network analysis showed that the network complexity of the control group was higher than those of arginine groups. Our finding would help advance the field of arginine nutrition and guide the development of future fish feeds. Based on antioxidant and intestinal health indicators, the optimal dietary arginine requirement for Chinese perch was 2.99%–3.37% of the dry diet (6.08%–6.79% of dietary protein).

Impact of Dietary Arginine Supplementation on Hemato-Biochmical, Histological, Antioxidant, and Immunity Variables of Geese under Heat Stress Condition in Egypt

Impact of Dietary Arginine Supplementation on Hemato-Biochmical, Histological, Antioxidant, and Immunity Variables of Geese under Heat Stress Condition in Egypt

Effect of Dietary Supplementation of Arginine, Tryptophan, and Taurine on Productive Performance, Egg Quality, and Health Status of Laying Hens Raised Under Heat Stress Conditions

Effect of Dietary Supplementation of Arginine, Tryptophan, and Taurine on Productive Performance, Egg Quality, and Health Status of Laying Hens Raised Under Heat Stress Conditions

Effect of dietary arginine supplementation on protein synthesis, meat quality and flavor in growing lambs

This study aimed to assess the effect of dietary arginine supplementation on protein synthesis, meat quality and flavor in lambs. Eighteen Dorper (♂) × Small Tailed Han sheep (♀) crossed ewe lambs of similar weight (27.29 ± 2.02 kg; aged 3 months) were assigned to two groups, the control group was fed the basal diet (Con group), and the arginine group (Arg group) was supplemented with 1% l-arginine based on the Con group for 90 d. The results suggested that dietary arginine significantly increased final body weight, loin eye muscle area, muscle fiber diameter, cross-sectional area (P < 0.050), and decreased shear force value and cooking loss (P < 0.050), as well as altered the composition and contents of volatile flavor compounds in lambs. Importantly, the total protein (TP) content, alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (AKP) activities in serum, branched-chain aminotransferase (BCAT), AST, ALT activities and neuronal nitric oxide synthase (nNOS) gene expression and content were elevated (P < 0.050), while content of urea nitrogen (BUN) in serum and 3-methylhistidine (3-MH) were decreased in arginine fed lambs (P < 0.050). In addition, arginine triggered muscle protein synthesis through protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathway, while minimized protein degradation by regulating gene expression of myogenin (MyoG), myostatin (MSTN), muscle atrophy F-box (MAFbx) and forkhead box O3 family (FoxO3) (P < 0.050). Taken together, this study suggested that arginine can be used to improve protein deposition and meat quality in lamb production.

The positive effects of dietary arginine on juvenile hybrid snakehead (Channa maculata♀×Channa argus♂) fed high-carbohydrate diets: Liver inflammation antioxidant response, and glucose metabolism

The aim of this study was to investigate the effects of arginine supplementation on liver morphology, antioxidant capacity, inflammatory response, insulin signaling pathway and glucose metabolism in hybrid snakehead. Five experimental diets (2.31 %, 2.42 %, 2.72 %, 2.92 %, and 3.12 % arginine) were prepared by adding different levels of arginine to the basal diet containing high (27 %) level of carbohydrate. The results showed that the activities of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD) and glutathione peroxidase (GSH-Px) of fish fed with arginine diets were significantly higher than those in control group (p < 0.05), accompanied by the lower malondialdehyde (MDA) content in the same groups (p < 0.05). There were obvious mild inflammatory cell infiltration and increased perihepatic pancreatic space in control group, while the pathological state of the liver was relieved in fish fed with arginine diets. Dietary arginine supplementation resulted in significantly higher glucose metabolism-related genes glucokinase (GK), phosphoenolpyruvate carboxkinase (PEPCK), glycogen synthase (GS) and pyruvate kinase (PK) and insulin signaling pathway key genes insulin receptor subset-1 (IRS-1), protein kinase B (Akt) and phosphoenolpyruvate carboxykinase (PI3K)(p < 0.05). Immune-related genes transforming growth factor β (TGF-β), heat shock protein 70 (HSP70) and heat shock protein 90 (HSP90) were significantly higher in the arginine supplemented diet than in the control group (p < 0.05). Immune-related genes interleukin-8 (IL8), interleukin-1β (IL1β) and tissue tumor necrosis factor-α (TNF-α) in fish fed with arginine diets were significantly lower than those in control group (p < 0.05). In conclusion, dietary arginine can alleviate the adverse effects of high carbohydrate diet on hybrid snakeheads by improving glucose metabolism and enhancing antioxidant, anti-inflammatory and non-specific immune functions.

Dietary arginine requirements of oriental river prawns (Macrobrachium nipponense) assessed using growth and biomarkers of antioxidant capacity

An 8-week feeding trial was carried out to determine the dietary arginine requirement of oriental river prawns (Macrobrachium nipponense). Prawns of initial tank biomass (10.0 g) were fed isonitrogenic (ca 38% protein) and isolipidic diets (ca 7.5% lipid) with incremental concentrations of arginine (0.75, 1.19, 1.61, 2.02, 2.46, and 2.81%). The prawns were randomly assigned into 24 cylindrical polypropylene tanks (1000L), with 50 prawns in each tank replicated four times in a completely randomized design, and were fed three times daily to apparent satiation. Muscle samples were used to analyze the amino acid profiles. Hepatopancreas were collected for antioxidant activity and immune-related gene expression. The results indicated that the survival, growth performance and feed utilization were significant higher (p < 0.05) in prawns fed with 2.02% dietary arginine than in other treatments except the treatment with 2.46% dietary arginine. The highest biomass increase (25.5 ± 0.5 g), protein efficiency ratio (1.05 ± 0.08) and survival (87.0 ± 2.7%) were found in prawns fed with dietary 2.02%, and the lowest feed conversion ratio (2.53 ± 0.18) was observed in the same group. Whole-body crude protein content (15.4 ± 0.1%), lipid content (2.5 ± 0.1%) and muscle arginine content (1.47 ± 0.03%) significantly increased in prawn fed with dietary 2.02% arginine compared with other groups except dietary 2.46% arginine (p < 0.05). With increased dietary arginine supplementation up to 2.02%, the activities of hepatopancreas superoxide dismutase (25.07 ± 0.64 U/mg prot) and glutathione peroxidase (461.89 ± 8.79 U/mg prot) were increased (p < 0.05); nevertheless, the glutathione content (23.45 ± 3.47 μmol /mg prot) in the 2.02% dietary arginine group was similar with that of the control group (p > 0.05). Moreover, the hepatopancreas gene expressions of Toll-like receptor, dorsal, immune deficiency, and relish were significantly upregulated in the prawn fed with1.61% dietary arginine (p < 0.05). Broken-line, quadratic and cubic regression models are used to evaluate the optimal arginine requirements. The broken-line regression of biomass increase, based on the highest R2 value, showed that the optimum arginine requirement of oriental river prawns was 2.12% of dry matter (5.61% dietary protein). The optimum dietary arginine requirement, according to the cubic regression analysis for superoxide dismutase activity, was 2.27% of dry matter (6.01% of dietary protein). The ideal arginine concentration for antioxidant enzymes activity was thought to be higher than that for growth.

Effects of dietary arginine supplementation on production performance, serum biochemicals, antioxidant capacity, and immunity of laying Wulong geese

This study investigated the effects of dietary arginine supplementation on the production performance, serum biochemicals, antioxidant capacity, and immunity of laying Wulong geese. A total of 150 Wulong geese (34-wk old) with similar body weights were randomly divided into 6 groups with 5 replicates and 5 geese each (1 male and 4 female). The geese in the control group were fed a corn-rapeseed meal basal diet, and the geese in the treatment groups were fed the basal diet supplemented with 0.1, 0.2, 0.3, 0.4, and 0.5% arginine. The experiment lasted for 17 wk. Our results showed that dietary arginine increased the egg production rate (LR) and average egg weight (AEW) of geese in a quadratic manner (P < 0.05). Dietary arginine had a quadratic effect on the contents of total protein (TP) and triglyceride (TG) (P < 0.05) in the serum. Dietary arginine quadratically decreased the content of malondialdehyde (MDA) and increased the activity of total superoxide dismutase (T-SOD) (P < 0.05). Dietary arginine supplementation linearly and quadratically increased the contents of immunoglobulin A (IgA) and immunoglobulin G (IgG), and linearly increased the content of nitric oxide (NO) (P < 0.05). In conclusion, dietary arginine supplementation can significantly improve the production performance, serum biochemicals, antioxidant capacity, and immunity of laying Wulong geese. Therefore, 0.3% arginine (actual content: 1.02%) is recommended in the diet.

Comparison of dietary arginine or/and inulin supplementation on growth, digestive ability and ammonia tolerance of juvenile yellow catfish Pelteobagrus fulvidraco

Most fish have limited use of arginine, and increasing arginine availability by adding other nutrients is an effective method. Inulin is thought to have potential synergistic effects with arginine. Four experiment groups were carried out to test the hypothesis that inulin can increase arginine availability of yellow catfish, including control, arginine, inulin and arginine mixed with inulin groups. The results showed that dietary arginine supplementation improved growth (weight gain and whole-body protein increased; IGF 1, MyoD, MyoG and Myf5 genes up-regulated), digestive ability (intestine protease and lipase increased), blood health (total protein and high-density lipoprotein cholesterol increased) and ammonia tolerance (cumulative mortality reduced; serum lysozyme, 50% hemolytic complement, respiratory burst and phagocytic indices increased) of yellow catfish, and reduced intestine inflammation (tumor necrosis factor and interleukin 1 decreased). Meanwhile, the addition of inulin to arginine-rich diets was further enhanced growth, digestive ability, intestine internal environment (butyric acid and total volatile fatty acids increased), blood health and ammonia tolerance (argininosuccinate synthetase, argininosuccinate lyase, arginase and ornithine transcarboxylase increased) of yellow catfish, and further relieved intestine inflammation. This study indicates that inulin can promote the utilization of dietary arginine; the potential synergistic effects between arginine and inulin were found in growth, digestive ability and ammonia tolerance of yellow catfish.

Evaluation of dietary arginine supplementation to increase placental nutrient transporters in aged mares.

Nine pregnant mares (18.2 ± 0.7 yr; 493.82 ± 12.74 kg body weight [BW]) were used to test the hypothesis that dietary supplementation of l-arginine would enhance placental vascularity and nutrient transport throughout gestation in aged mares. Mares were balanced by age, BW, and stallion pairing, and assigned randomly to dietary treatments of either supplemental l-arginine (50 mg/kg BW; n = 7) or l-alanine (100 mg/kg BW; n = 6; isonitrogenous control). Mares were individually fed concentrate top-dressed with the respective amino acid treatment plus ad libitum access to Coastal Bermudagrass hay. Treatments began on day 14 of gestation and were terminated at parturition. Mare BW, body condition score (BCS), and rump fat were determined, and body fat percentage was calculated every 28 d and concentrate adjusted accordingly. Doppler blood flow measurements including resistance index (RI) and pulsatility index for uterine artery ipsilateral to the pregnant uterine horn were obtained beginning on day 21 and continued every 7 d until day 154 of gestation, and prior to parturition. Parturition was attended with foaling variables and placental measures recorded. Placental tissue from the pregnant horn was analyzed histologically to assess cell-specific localization of vascular endothelial growth factor (VEGF) and cationic amino acid transporter 1 (SLC7A1) proteins. Semiquantitative analyses were performed using 10 nonoverlapping images per sample fixed in a 10× field (Fiji ImageJ v1.2). Mare performance data were analyzed using PROC MIXED in SAS and foaling and placental data were analyzed using PROC GLM. Gestation length at parturition was not influenced (P > 0.05) by supplemental arginine. Compared with arginine-supplemented mares, control mares had a thicker rump fat layer (P < 0.01) and greater percent body fat (P = 0.03), and BCS (P < 0.01) at parturition. Arginine-supplemented mares had a lower RI than control mares prior to parturition (P < 0.01). Body length, height, and BW of foals at birth, as well as placental weight and volume, and immunohistochemical staining for VEGF and SLC7A1 at parturition, were not affected (P > 0.05) by maternal arginine supplementation. These results indicate that dietary arginine supplementation (50 mg/kg BW) is safe for gestating mares. A larger number of mares is required to extend knowledge of effects of supplemental arginine on embryonic/fetal survival and growth in mares.

219 Evaluation of Dietary Arginine Supplementation to Increase Placental Nutrient Transporters of Aged Mares

Abstract Nine pregnant mares (18.2 ± 0.7 y; 493.82 ± 13 kg BW) were used to test the hypothesis that dietary supplementation of arginine would enhance placental vascularity and nutrient transport throughout gestation in aged mares. Mares were balanced by age, BW, and stallion pairing, and randomly assigned to one of two dietary treatments consisting of supplemental L-arginine (50 mg/kg BW; n=5) or L-alanine (100 mg/kg BW; n=4; isonitrogenous control). Mares were individually fed concentrate top-dressed with the respective amino acid treatment plus ad libitum access to Coastal bermudagrass hay. Treatments began on d 14 of gestation and were terminated at parturition. Mare BW, BCS, and rump fat were determined every 28 d and concentrate adjusted accordingly. Parturition was attended with foaling variables and placental measures recorded. Placental tissue from the pregnant horn underwent histological analyses to assess cell-specific localization of vascular endothelial growth factor (VEGF) and cationic amino acid transporter 1 (CAT1) proteins. Semiquantitative analyses were performed using 10 non-overlapping images per sample fixed in a 10X field (Fiji ImageJ v1.2). Data were analyzed using SAS PROC MIXED procedure. BW increased (P &amp;lt; 0.01) in all mares with advancing gestation. BW, BCS, and gestation length of mares were not influenced (P &amp;gt; 0.05) by supplemental arginine. Compared with arginine-supplemented mares, control mares had a thicker rump fat layer (P &amp;lt; 0.01) at parturition. Body length, height, and BW of foals at birth, as well as placental weight, volume, and positive staining for VEGF and CAT1 at parturition were not affected (P &amp;gt; 0.05) by maternal arginine supplementation. These results indicate dietary arginine supplementation (50 mg/kg BW) is safe for gestating mares and promotes mobilization of white adipose tissue. A larger number of mares is required to determine effects of supplemental arginine on embryonic/fetal survival and growth in mares.

P210. Effects of dietary arginine supplementation on pig growth performance and health status following weaning stress

P210. Effects of dietary arginine supplementation on pig growth performance and health status following weaning stress

Effect of dietary supplementation of Tryptophan, Arginine, and Glutamine on growth performance, gut morphology, immune response and meat quality of broiler chicken

Two experiments were conducted to evaluate the supplemental effects of Arginine (Arg), Glutamine (Gln) and Tryptophan (Trp) on growth performance, gut morphology, immune response and meat quality of broilers. In experiment 1, 312 one-day-old Ross×Ross broiler chicks with similar body weight were randomly assigned to 4 dietary treatments (C, control having no amino acids; Arg, a diet with 0.5% L-Arg; Gln, a diet with 0.5% L-Gln and Trp, a diet with 0.5% L-Trp), each containing 6 replicate cages with 13 birds per cage. For further confirmation, experiment 2 considered similar treatments as of experiment 1. Body weight and feed intake were measured weekly. At 2ndand 6thweeks of age, 12 birds per treatment were killed in both experiments to measure gut morphology, serum IgG and IgA and meat quality of broilers. In Expt 1, results showed that dietary Arg, Gln and Trpsupplementation significantly increased (P&lt; 0.05) weight gain and feed intake of broilers than those of control group. In experiment 2, a similar performance trend was obtained compared to Experiment 1. Circulating levels of IgG and IgA were increased with supplementation of AAs in the diet. In both experiments, the breastand drumstick muscles of the group of birds feed amino acids had a higher pH and redness (a*) values, but lower lightness (L*) and yellowness (b*) values of meat. Chicks fed diet with Arg, Gln and Trp had longer villi height and villi to crypt depth ratio, and shorter crypt depth as compared with the control (P&lt;0.05). Thus the addition of Arg, Trp and Gln each at 0.5% in the diet of broiler chicken enhanced growth performance, immunity, gut morphology and meat quality characteristics of broiler.

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.