Guanidinoacetic Acid Supplementation Research Articles

Effects of guanidino acetic acid and betaine supplementation on growth, dietary nutrient digestion and intestinal creatine metabolism in sheep.

The intestine of young ruminants is in the developmental stage and has weaker resistance to the changes of external environment. Improving intestinal health is vital to promoting growth of young ruminants. This study investigated effects of guanidino acetic acid (GAA) and rumen-protected betaine (RPB) supplementation on growth, dietary nutrient digestion and GAA metabolism in the small intestine of sheep. Eighteen healthy Kazakh rams (27.46±0.10kg of body weight and 3-month old) were categorized into control, test group I and test group II, which were fed a basal diet, 1500mg/kg GAA and 1500mg/kg GAA+600mg/kg RPB, respectively. Compared with control group, test group II had increased (p<0.05) average daily gain, plasma creatine level, ether extract (EE) and phosphorus digestibility on day 30. On day 60, the EE apparent digestibility, jugular venous plasma GAA, GAA content in the duodenal mucosa and GAA content in the jejunal and ileal mucosa of test group II were higher (p<0.05) than other groups. Transcriptome analysis revealed that the differentially expressed genes (DEGs) involved in the duodenal pathways of oxidative phosphorylation and non-alcoholic fatty liver disease were significantly altered in test group II versus test group I (p<0.05). Moreover, in the jejunum, the MAPK signalling pathway, complement and coagulation cascade and B-cell receptor signalling pathway were significantly enriched, with ATPase, solute carrier transporter protein, DHFR, SI, GCK, ACACA and FASN being the significantly DEGs (p<0.05). Dietary supplementation of RPB on top of GAA in sheep diets may promote sheep growth and development by improving the body's energy, amino acid, glucose and lipid metabolism capacity.

Dietary Methionine Enhances Portal Appearance of Guanidinoacetate and Synthesis of Creatine in Yucatan Miniature Piglets

BackgroundCreatine plays a significant role in energy metabolism and positively impacts anaerobic energy capacity, muscle mass, and physical performance. Endogenous creatine synthesis requires guanidinoacetic acid (GAA) and methionine. GAA can be an alternative to creatine supplements and has been tested as a beneficial feed additive in the animal industry. When pigs are fed GAA with excess methionine, creatine is synthesized without feedback regulation. In contrast, when dietary methionine is limited, creatine synthesis is limited, yet, GAA does not accumulate in plasma, urine, or liver. ObjectiveWe hypothesized that portal GAA appearance requires adequate dietary methionine. MethodsYucatan miniature piglets (17–21 d old; n = 20) were given a 4 h duodenal infusion of complete elemental diets with supplemental GAA plus 1 of 4 methionine concentrations representing either 20%, 80%, 140%, or 200% of the dietary methionine requirement. Arterial and portal blood metabolites were measured along with blood flow to determine mass balance across the gut. [3H-methyl] methionine was infused to measure the methionine incorporation rate into creatine. ResultsGAA balance across the gut was highest in the 200% methionine group, indicating excess dietary methionine enhanced GAA absorption. Creatine synthesis in the liver and jejunum was higher with higher concentrations of methionine, emphasizing that the transmethylation of GAA to creatine depends on sufficient dietary methionine. Hepatic GAA concentration was higher in the 20% methionine group, suggesting low dietary methionine limited GAA conversion to creatine, which led to GAA accumulation in the liver. ConclusionsGAA absorption and conversion to creatine require a sufficient amount of methionine, and the supplementation strategies should accommodate this interaction.

Effects of guanidinoacetic acid supplementation on liver and breast muscle fat deposition, lipid levels, and lipid metabolism-related gene expression in ducks.

Exogenous supplementation of guanidinoacetic acid can mechanistically regulate the energy distribution in muscle cells. This study aimed to investigate the effects of guanidinoacetic acid supplementation on liver and breast muscle fat deposition, lipid levels, and lipid metabolism-related gene expression in ducks. We randomly divided 480 42 days-old female Jiaji ducks into four groups with six replicates and 20 ducks for each replicate. The control group was fed the basal diet, and the experimental groups were fed the basal diet with 400, 600, and 800 mg/kg (GA400, GA600, and GA800) guanidinoacetic acid, respectively. Compared with the control group, (1) the total cholesterol (p = 0.0262), triglycerides (p = 0.0357), malondialdehyde (p = 0.0452) contents were lower in GA400, GA600 and GA800 in the liver; (2) the total cholesterol (p = 0.0365), triglycerides (p = 0.0459), and malondialdehyde (p = 0.0326) contents in breast muscle were decreased in GA400, GA600 and GA800; (3) the high density lipoprotein (p = 0.0356) and apolipoprotein-A1 (p = 0.0125) contents were increased in GA600 in the liver; (4) the apolipoprotein-A1 contents (p = 0.0489) in breast muscle were higher in GA600 and GA800; (5) the lipoprotein lipase contents (p = 0.0325) in the liver were higher in GA600 and GA800; (6) the malate dehydrogenase contents (p = 0.0269) in breast muscle were lower in GA400, GA600, and GA800; (7) the insulin induced gene 1 (p = 0.0326), fatty acid transport protein 1 (p = 0.0412), and lipoprotein lipase (p = 0.0235) relative expression were higher in GA400, GA600, and GA800 in the liver; (8) the insulin induced gene 1 (p = 0.0269), fatty acid transport protein 1 (p = 0.0234), and lipoprotein lipase (p = 0.0425) relative expression were increased in GA400, GA600, and GA800 in breast muscle. In this study, the optimum dosage of 600 mg/kg guanidinoacetic acid improved the liver and breast muscle fat deposition, lipid levels, and lipid metabolism-related gene expression in ducks.

Effect of Guanidinoacetic Acid Supplementation on Growth Performance, Rumen Fermentation, Blood Indices, Nutrient Digestion, and Nitrogen Metabolism in Angus Steers

Guanidinoacetic acid (GAA) functions as a precursor for creatine synthesis in the animal body, and maintaining ample creatine reserves is essential for fostering rapid growth. This study aimed to explore the impact of GAA supplementation on growth performance, rumen fermentation, blood indices, nutrient digestion, and nitrogen metabolism in Angus steers through two experiments: a feeding experiment (Experiment 1) and a digestive metabolism experiment (Experiment 2). In Experiment 1, thirty-six Angus steers (485.64 ± 39.41 kg of BW) at 16 months of age were randomly assigned to three groups: control (CON), a conventional dose of GAA (CGAA, 0.8 g/kg), and a high dose of GAA (HGAA, 1.6 g/kg), each with twelve steers. The adaptation period lasted 14 days, and the test period was 130 days. Weighing occurred before morning feeding on days 0, 65, and 130, with rumen fluid and blood collected before morning feeding on day 130. Experiment 2 involved fifteen 18-month-old Angus steers (575.60 ± 7.78 kg of BW) randomly assigned to the same three groups as in Experiment 1, with a 7-day adaptation period and a 3-day test period. Fecal and urine samples were collected from all steers during this period. Results showed a significantly higher average daily gain (ADG) in the CGAA and HGAA groups compared to the CON group (p = 0.043). Additionally, the feed conversion efficiency (FCE) was significantly higher in the CGAA and HGAA groups than in the CON group (p = 0.018). The concentrations of acetate and the acetate:propionate ratio were significantly lower in the CGAA and HGAA groups, while propionate concentration was significantly higher (p &lt; 0.01). Serum concentration of urea (UREA), blood ammonia (BA), GAA, creatine, and catalase (CAT) in the CGAA and HGAA groups were significantly higher than in the CON group, whereas malondialdehyde (MDA) concentrations were significantly lower (p &lt; 0.05). Digestibility of dry matter (DM) and crude protein (CP) and the nitrogen retention ratio were significantly higher in the CGAA and HGAA groups than in the CON group (p &lt; 0.05). In conclusion, dietary addition of both 0.8 g/kg and 1.6 g/kg of GAA increased growth performance, regulated rumen fermentation and blood indices, and improved digestibility and nitrogen metabolism in Angus steers. However, higher doses of GAA did not demonstrate a linear stacking effect.

Effects of Guanidinoacetic Acid (GAA) Supplementation on Zootechnical Performance and Biochemical Parameters of Broiler Chickens in Dakar Region, Senegal

Effects of Guanidinoacetic Acid (GAA) Supplementation on Zootechnical Performance and Biochemical Parameters of Broiler Chickens in Dakar Region, Senegal

Effects of guanidinoacetic acid on in vitro rumen fermentation and microflora structure and predicted gene function.

The fermentation substrate was supplemented with 0% guanidinoacetic acid (GAA) (control group, CON), 0.2% GAA (GAA02), 0.4% GAA (GAA04), 0.6% GAA (GAA06) and 0.8% GAA (GAA08) for 48 h of in vitro fermentation. Gas production was recorded at 2, 4, 6, 8, 12, 24, 36, and 48 h of fermentation. The gas was collected, and the proportions (%, v/v) of H2, CH4 and CO2 were determined. The rumen fermentation parameters, including pH, ammonia nitrogen (NH3-N), microbial protein (MCP) and volatile fatty acids (VFAs), were also determined. Furthermore, the bacterial community structure was analyzed through 16S rRNA high-throughput sequencing. The gene functions were predicted using PICRUSt1 according to the Kyoto Encyclopedia of Genes and Genomes (KEGG). The results showed that with the increase in GAA supplementation levels, the MCP and the concentration of rumen propionate were significantly increased, while the concentration of isovalerate was significantly decreased (p < 0.05). The results of microbial diversity and composition showed that the Shannon index was significantly decreased by supplementation with GAA at different levels (p < 0.05), but the relative abundance of norank_f_F082 and Papillibacter in the GAA06 group was significantly increased (p < 0.05). Especially in group GAA08, the relative abundances of Bacteroidota, Prevotella and Prevotellaceae_UCG-001 were significantly increased (p < 0.05). The results of gene function prediction showed that the relative abundances of the functions of flagellar assembly, bacterial chemotaxis, plant-pathogen interaction, mismatch repair and nucleotide excision repair were significantly decreased (p < 0.05), but the relative abundances of bile secretion and protein digestion and absorption were significantly increased (p < 0.05). In conclusion, supplementation with 0.8% GAA enhanced in vitro rumen fermentation parameters, increased the relative abundance of Prevotella and Prevotellaceae_UCG-001 in the rumen, and increased the metabolic pathways of bile secretion and protein digestion and absorption.

Guanidinoacetic acid ameliorates hepatic steatosis and inflammation and promotes white adipose tissue browning in middle-aged mice with high-fat-diet-induced obesity.

Guanidinoacetic acid (GAA) is a naturally occurring amino acid derivative that plays a critical role in energy metabolism. In recent years, a growing body of evidence has emerged supporting the importance of GAA in metabolic dysfunction. Hence, we aimed to investigate the effects of GAA on hepatic and adipose tissue metabolism, as well as systemic inflammatory responses in obese middle-aged mice models and attempted to explore the underlying mechanism. We found that dietary supplementation of GAA inhibited inguinal white adipose tissue (iWAT) hypertrophy in high-fat diet (HFD)-fed mice. In addition, GAA supplementation observably decreased the levels of some systemic inflammatory factors, including IL-4, TNF-α, IL-1β, and IL-6. Intriguingly, GAA supplementation ameliorated hepatic steatosis and lipid deposition in HFD-fed mice, which was revealed by decreased levels of TG, TC, LDL-C, PPARγ, SREBP-1c, FASN, ACC, FABP1, and APOB and increased levels of HDL-C in the liver. Moreover, GAA supplementation increased the expression of browning markers and mitochondrial-related genes in the iWAT. Further investigation showed that dietary GAA promoted the browning of the iWAT via activating the AMPK/Sirt1 signaling pathway and might be associated with futile creatine cycling in obese mice. These results indicate that GAA has the potential to be used as an effective ingredient in dietary interventions and thus may play an important role in ameliorating and preventing HFD-induced obesity and related metabolic diseases.

Heat stress ameliorative effect of guanidinoacetic acid and bee pollen supplementation on growth, nutrient utilization and blood biochemical status in broiler chicken

Heat stress ameliorative effect of guanidinoacetic acid and bee pollen supplementation on growth, nutrient utilization and blood biochemical status in broiler chicken

Effect of guanidinoacetic acid on performance, egg quality, yolk fatty acid composition, and nutrient digestibility of aged laying hens fed diets with varying substitution levels of corn with low-tannin sorghum

A study was conducted to evaluate the efficiency of guanidinoacetic acid (GAA) in diets containing varying levels of corn replacement with low-tannin sorghum (LTS) for laying hens in the later stage of production. In a 12-wk study, a total of 288 laying hens at 52 wk of age were divided into 6 treatment groups. Each treatment group had 8 replicates, each of which consisted of 6 hens. A 2 × 3 factorial design was used to investigate the impact of substituting corn with LTS at 3 levels (100% corn, 50% LTS, and 100% LTS) with 2 doses of GAA supplementation (0 and 0.6 g/kg). The results indicate that there were interaction effects (P < 0.05) between diet type and GAA supplementation on protein digestibility and AMEn, with the GAA supplement being more effective in the 100% LTS group. Replacing corn with LTS at both levels had no negative effects on performance and metabolic profile. In contrast, the 100% LTS diet increased monounsaturated fatty acids in the yolk (P < 0.05), but decreased the yolk color index, the ratio of polyunsaturated fatty acids (PUFA) to saturated fatty acids (SFA) in the yolk, ileal digestibility of energy, and AMEn when compared to the 100% corn diet (P < 0.05). Regardless of the diet, dietary supplementation with GAA resulted in increases (P < 0.05) in shell-breaking strength, the PUFA to SFA ratio in egg yolk, and concentrations of creatine and nitric oxide in serum. There was also a decrease (P < 0.05) in serum malondialdehyde concentration with GAA supplementation. In conclusion, the positive effects of GAA on protein digestibility and AMEn were found to be more pronounced when corn was completely replaced with LTS. However, the positive effects of GAA on egg-laying performance, eggshell quality, antioxidant status, and yolk fatty acid composition remained consistent regardless of the extent to which corn was substituted with LTS.

399 Methionine and Guanidinoacetic Acid Supplementation Throughout the Periconceptual Period of Gestation Alters Metabolite Concentrations and Fetal Development

Abstract Recent research reported changes in fetal growth due to increased methyl donor availability through periconceptual supplementation of the dam. We hypothesized that maternal supplementation of methionine (MET) or guanidinoacetic acid (GAA) during the periconceptual period will result in a methyl donor surplus or deficiency in maternal serum and ultimately influence fetal body and organ weight at d +63 gestation. The objectives of this study were to evaluate effects of methyl donor surplus or deficiency during the periconceptual period of gestation on metabolite concentrations in the heifer and the effects on early fetal development. Eighty MARC II heifers (n = 20 per treatment, initial BW = 346 ± 8 kg) were stratified by age and weight to one of four treatment groups to receive 100 g of supplement: ground corn carrier as control (CON), MET (10 g/d) in ground corn, GAA (40 g/d) in ground corn, and MET + GAA (10 g/d MET + 40 g/d GAA) in ground corn. Supplementation began 63 d before breeding (d –63) until d 63 of gestation (d +63), and serum samples were collected before feeding on d -63, at breeding, and d +63. Heifers were bred using male sexed semen from the same sire, and 35 heifers were confirmed pregnant (CON, n = 10; MET, n = 8; GAA, n = 7; MET + GAA, n =10) and harvested at d +63 of gestation to collect maternal and fetal samples. Data were analyzed as a 2 × 2 factorial design with 2 levels of MET and 2 levels of GAA. Methionine concentrations in maternal serum were greater (P = 0.05) in MET and MET + GAA supplemented heifers at d 0 and d +63 compared with CON and GAA at d -63, d 0, and d +63. There were no differences (P ≥ 0.15) in the concentration of GAA or creatine due to supplementation; however, both were decreased at breeding (P &amp;lt; 0.01) compared with d -63 and d +63. Fetuses from MET supplemented heifers had greater (P = 0.01) brain weight and Longissimus muscle than dams not receiving MET. We conclude that MET supplementation during the periconceptual period can alter methyl donor availability and increase fetal muscle development. USDA is an equal opportunity provider and employer.

242 Methionine and Guanidinoacetic Acid Supplementation During the Periconceptual Period of Gestation Shifts Methionine Metabolism of Fetal Bull Calves at D 63 of Gestation

Abstract Recent research has demonstrated that feeding rumen protected methionine (MET) products increases circulating methionine while feeding guanidinoacetic acid (GAA) may result in a methyl deficiency. Therefore, we hypothesized that maternal MET or GAA supplementation from 63 days before breeding until d 63 of gestation would increase fetal hepatic methyl donors or result in a fetal hepatic methyl donor deficiency, respectively. Eighty MARC II heifers (n = 20 per treatment; initial BW = 344 ± 8 kg; day -63) were weighed and assigned to one of four breeding groups and four treatments stratified by age and starting weight. Heifers were fed a total mixed ration to gain 0.68 kg/d and received 100 g of one of four treatments top dressed: control supplement of ground corn (CON), MET (10 g/d) in a ground corn carrier, GAA (40 g/d) in a ground corn carrier, or MET + GAA (10 g/d MET + 40 g/d GAA) in a ground corn carrier. At breeding (d 0), all heifers were bred to a single sire using male sexed semen. At d 63 of gestation, 35 heifers (CON n = 10, MET n = 8, GAA n = 7, MET + GAA, n = 10) confirmed pregnant with bull calves were humanely slaughtered and fetal liver tissues were collected and sent to Metabolon Inc. for global metabolomics analysis. Data were analyzed as a 2 x 2 factorial with 2 levels of GAA and 2 levels of MET with breeding group included in the model. For this abstract, only metabolites from the methionine cycle and adjacent pathways will be reported and only metabolites with significant P-values will be discussed (P ≤ 0.05). There were no main effects or interactions for the abundance of methionine, GAA, creatine, SAM, SAH or homocysteine. Glycine was decreased and sarcosine increased in fetuses from MET supplemented dams. Serine was affected by a MET x GAA interaction being decreased in livers of CON, MET, and MET + GAA fetuses compared with GAA. Cystathione, S-methylcysteine, s-methylcysteine sulfoxide, and hypotaurine were greater in fetuses of MET supplemented heifers and pyridoxal phosphate was reduced in fetal liver of MET supplemented heifers. The abundance of urea was greater in GAA supplemented fetuses. These results indicate that fetuses from dams fed methionine may be able to maintain balance in methionine supply by shunting methionine through adjacent pathways including the transsulfuration pathway. We also interpret these data to imply that excess methionine is not utilized by the fetus and is metabolized to products that can be excreted. Lastly, GAA did not alter the fetal methyl supply. USDA is an equal opportunity provider and employer. Funded by (USDA-NIFA-AFRI # 2022-67015-36196).

Guanidinoacetic Acid Attenuates Adipogenesis through Regulation of miR-133a in Sheep.

Guanidinoacetic acid (GAA) is an amino acid derivative, previously described in the skeletal muscle of vertebrates, that serves as an important regulator of cellular bioenergetics and has been widely used as a feed additive. Nevertheless, the effect of GAA on adipose tissue growth remains unclear. Here, we hypothesized that dietary GAA negatively affected adipose tissue development in lambs. Lambs were individually fed diets with (0.09%) or without GAA for 70 d ad libitum, and the subcutaneous adipose tissues were sampled for analysis. The results showed that dietary GAA supplementation decreased the girth rib (GR) value (p < 0.01) of lamb carcasses. Both real-time PCR and Western blot analysis suggested that dietary GAA inhibited the expression of adipogenic markers, including peroxisome proliferator-activated receptor γ (PPARγ, p < 0.05), CCAAT/enhancer-binding protein α (C/EBPα, p < 0.01) and sterol-regulatory-element-binding protein 1c (SREBP1C, p < 0.01) in subcutaneous adipose tissue. In vitro, GAA inhibited sheep stromal vascular fraction (SVF) cell proliferation, which was associated with downregulation of proliferating cell nuclear antigen (PCNA, p < 0.05), cyclin-dependent kinase 4 (CDK 4, p < 0.05) and cyclin D1 (p < 0.01). GAA suppressed adipogenesis of SVF cells. Furthermore, miRNA sequencing revealed that GAA affected the miRNA expression profile, and real-time PCR analysis confirmed that miR-133a expression in both subcutaneous adipose tissue and SVF cell was downregulated by GAA. Meanwhile, miR-133a promoted adipogenic differentiation of SVF cells by targeting Sirt1. miR-133a mimics alleviated the inhibitory effect of GAA on SVF cells' adipogenic differentiation. In summary, GAA attenuated adipogenesis of sheep SVF cells, which might occur through miR-133a-modulated Sirt1 expression.

Performance, haemato-biochemical indices and antioxidants status of broiler chickens fed diet with low metabolizable energy supplemented with graded levels of Guanidino Acetic Acid (GAA)

Abstract The growth, haemato-biochemical indices, and antioxidant status of broiler chickens fed varying levels of Guanidino Acetic Acid (GAA) were evaluated over the course of an eight-week feeding trial. In low ME (2700Kcal/kg) basal diets, the Guanidino Acetic Acid was supplemented at 0, 0.6, and 1.2g/kg, designated as diets I, II, and III, respectively. The average final weight of chickens fed diet III was the highest at the end of the feeding trial. The best feed conversion ratio was observed in birds fed diet III. The packed cell volume and haemoglobin were highest in birds fed diet I. Significantly higher Cholesterol and Albumin were recorded in diets III and II, respectively. All the antioxidant parameters were significant except Catalase. The glutathione peroxidase increased with increased Guanidino acetic Acid supplementation while Catalase reduced with increased GAA supplementation. According to the findings of this study, Guanidino Acetic Acid improved the health of broilers while having no negative effects on their health. It is therefore concluded that supplementation of Guanidino Acetic Acid at 1.2g/kg with low metabolizable energy promoted superior growth effect of the chickens and also reduce cost of production.

Effects of guanidinoacetic acid supplementation on growth performance, hypothalamus-pituitary-adrenal axis, and immunity of broilers challenged with chronic heat stress

Heat stress can cause systemic immune dysregulation and threaten the health of broilers. Guanidinoacetic acid (GAA) has been shown to be effective against heat stress, but whether it is beneficial for immunity is unclear. Therefore, the effects of dietary GAA supplementation on the immunity of chronic heat-stressed broilers were evaluated. A total of 192 Arbor Acres male broilers (28-day old) were randomly allocated to 4 treatments: the normal control group (NC, 22°C, ad libitum feeding), the heat stress group (HS, 32°C, ad libitum feeding), the pair-fed group (PF, kept at 22°C and received food equivalent to that consumed by the HS group on the previous day), and the GAA group (HG, 32°C, ad libitum feeding; basal diet supplemented with 0.6 g/kg GAA). Samples were collected on d 7 and 14 after treatment. Results showed that broilers exposed to heat stress exhibited a decrease (P < 0.05) in ADG, ADFI, thymus and bursa of Fabricius indexes, and an increase (P < 0.05) in feed conversion ratio and panting frequency, compared to the NC group. Levels of corticotropin-releasing factor, corticosterone (CORT), heat shock protein 70 (HSP70), IL-6, and TNF-α were elevated (P < 0.05) while lysozyme and IgG concentration was decreased (P < 0.05) in the HS group compared with the NC group after 7 d of heat exposure. The concentrations of IgG and IL-2 were decreased (P < 0.05) and CORT was increased (P < 0.05) in the HS group compared with the NC group after 14 d of heat exposure. Noticeably, GAA supplementation decreased the levels of CORT (P < 0.05) and increased the IL-2, IgG, and IgM concentrations (P < 0.05) compared with the HS group. In conclusion, chronic heat stress increased CORT release, damaged immune organs, and impaired the immunity of broilers. Dietary supplementation of 0.6 g/kg GAA can reduce the CORT level and improve the immune function of broilers under heat stress conditions.

Effects of L-arginine, guanidinoacetic acid and L-citrulline supplementation in reduced-protein diets on bone morphology and mineralization of laying hens.

The alterations in feed ingredients and the nutrient matrix to produce reduced-protein diets may affect bone morphology and mineralization in laying hens. This study was implemented to determine the effects of L-arginine (Arg), guanidinoacetic acid (GAA), and L-citrulline (Cit) supplementation to Arg-deficient reduced-protein diets on bone morphology, strength, and mineralization status of laying hens. Individually housed Hy-Line Brown laying hens were evenly distributed to five dietary treatments with 25 replicates per treatment from 20 to 40wk of age. Treatments consisted of a standard protein diet (17% crude protein, SP), a reduced-protein diet deficient in Arg (13% crude protein, RP), and RP supplemented with Arg (0.35% Arg, RP-Arg), GAA (0.46% GAA equivalent to 0.35% Arg, RP-GAA), or Cit (0.35% Cit equivalent to 0.35% Arg, RP-Cit) to reach the Arg level of SP diets. Birds fed the SP diet had similar bone weight, ash, length, width, Seedor index, breaking strength, and serum mineral concentration, but higher toe B level (P<0.001) compared to those fed the RP diet at wk 40. Birds fed the SP diet consumed more but also excreted more K and B compared to those fed the RP diet (P<0.01). Birds fed the SP diet had lower Cu digestibility (P=0.01) and higher B retention (P<0.01) compared to those offered the RP diet. Supplementation of Arg, GAA, and Cit to the RP diet increased relative femur weight and length (P<0.001). Citrulline supplementation also increased relative tibia and femur ash, and Zn digestibility (P<0.05). Supplementation of GAA to the RP diet decreased serum Ca, P, and Mg levels, decreased tibia Fe and Mg levels and toe Mg level, but increased Al, Fe, Zn, and Mn digestibility (P<0.05). The current findings demonstrated the capacity of laying hens to adapt to low mineral intake by increasing mineral utilization. Overall, bone morphology and breaking strength, and serum mineral level in laying hens were not influenced by dietary CP levels. Dietary Arg, GAA, or Cit supplementation were effective in improving bone morphology and mineralization in laying hens fed Arg-deficient RP diets.

Epigenetic reprogramming-induced guanidinoacetic acid synthesis promotes pancreatic cancer metastasis and transcription-activating histone modifications

BackgroundPancreatic ductal adenocarcinoma (PDAC) tends to undergo distant metastasis, especially liver metastasis, leading to a poor prognosis. Metabolic remodelling and epigenetic reprogramming are two important hallmarks of malignant tumours and participate in regulating PDAC tumorigenesis and metastasis. However, the interaction between these two processes during PDAC metastasis has not been fully elucidated.MethodsWe performed metabolomics analysis to identify the critical metabolites associated with PDAC liver metastasis and focused on guanidinoacetic acid (GAA). Intracellular GAA content was significantly increased in liver metastatic PDAC cells compared to primary cancer cells in mouse xenograft tumour models. The effects of GAA supplementation and glycine amidinotransferase (GATM) knockdown on PDAC metastasis were assessed by analysing cell migration, filopodia formation, epithelial-mesenchymal transition (EMT), and in vivo metastasis in different cell and animal models. Next, ChIP‒qPCR, 3C‒qPCR, and CRISPRi/dCas9-KRAB experiments were used to validate the “epigenome-metabolome" mechanism. Finally, the results of in vitro approaches, including RNA-seq, CUT&RUN, RT‒qPCR, and western blot analyses, as well as luciferase reporter gene assay and transwell assay, revealed the GAA-c-Myc-HMGA axis and transcription-activating histone modifications reprogramming.ResultsA high level of intracellular GAA was associated with PDAC liver metastasis. GAA could promote the migration, EMT, and liver metastasis of pancreatic cancer cells in vitro and in vivo. Next, we explored the role of GATM-mediated de novo GAA synthesis in pancreatic cancer metastasis. High expression of GATM was positively correlated with advanced N stage in PDAC. Knockdown of GATM significantly reduced the intracellular level of GAA, suppressed EMT, and inhibited PDAC liver metastasis, and these effects were attenuated by GAA supplementation. Mechanistically, we identified the active enhancers looped to the Gatm gene locus that promoted GATM expression and PDAC liver metastasis. Furthermore, we found that GAA promoted cell migration and EMT by regulating c-Myc-mediated high mobility group AT-hook protein expression. Moreover, GAA increased the H3K4me3 modification level by upregulating histone methyltransferases, which induced the transcription of metastasis-related genes, including Myc.ConclusionsThese findings revealed the critical role of the epigenome-metabolome interaction in regulating PDAC liver metastasis and suggested potential therapeutic strategies targeting GAA metabolism and epigenetic regulatory mechanisms.

Technique of Dietary Supplementation of Guanidinoacetic Acid for Growth Improvement of Catfish (Pangasius hypophthalmus)

The present study aims to determine the best technique of Guanidinoacetic acid (GAA) supplementation to improve retention of added GAA after immersion in water on the growth performance of Pangasius catfish (Pangasius hypophthalmus). Pangasius catfish juveniles with a mean body weight and length of 16.05 ± 0.47 g and 12.42 ± 0.30 cm were randomly distributed into 9 pond units (2 x 1 x 0,6 m). Three experimental diets were formulated to contain (0,5% kg-1 GAA) with different technique of GAA supplementation, i.e. control, pelleting technique and spray-coating technique fed to the fish for 60 days of culture. The results showed that average body weight and biomass of fish fed diet with by GAA supplementation with the pelleting technique was higher (p&lt;0.05) than that of spray-coating technique and control. In conclusion, the consumption of diets containing GAA with pelleting technique resulted the best growth performance of Pangasius catfish (Pangasius hypophthalmus). Penelitian ini bertujuan untuk menentukan metode terbaik dalam suplementasi Guanidinoacetic acid (GAA) pada pakan untuk meningkatkan retensi penambahan GAA setelah perendaman di air dalam meningkatkan kinerja pertumbuhan ikan patin (Pangasius hypophthalmus). Benih ikan patin dengan rata-rata bobot 16.05 ± 0.47 g dan panjang 12.42 ± 0.30 cm dipelihara di dalam 9 unit kolam dengan ukuran (2 x 1 x 0,6 m). Ikan diberikan pakan selama 60 hari pemeliharaan tiga perlakuan yaitu; kontrol (tanpa penambahan GAA); perlakuan pelleting (penambahan 0,5% kg/GAA); dan perlakuan spray coating (penambahan 0,5% kg/GAA). Hasil penelitian menunjukkan bahwa perlakuan penambahan 0,5% kg/GAA dengan metode pelleting memberikan rata-rata bobot ikan dan biomasa paling tinggi dibandingkan dengan perlakuan lain dan kontrol (p&lt;0.05). Kesimpulan dari penelitian ini adalah suplementasi GAA pada pakan ikan patin dengan metode pelleting menunjukkan kinerja pertumbuhan terbaik jika dibandingkan dengan metode spray coating pada ikan patin.

Dietary creatine and guanidinoacetic acid supplementation have limited effects on hybrid striped bass.

The effects of dietary supplementation of creatine and guanidinoacetic acid (GDA) have been studied to a limited extent in various fish species including red drum (Sciaenops ocellatus) and hybrid striped bass (HBS) (Morone saxatilis x M. chrysops). However, in HSB, there is a need to better understand the impact of creatine and GDA supplementation at elevated salinity which may be encountered by this euryhaline fish. Therefore, two separate feeding trials were conducted at a salinity ranging from 15 to 20g/L with juvenile HSB for 9 and 8weeks to evaluate the effects of dietary creatine and GDA. In each trial, four diets were formulated with either singular additions of creatine at 2% of dry weight, GDA at 1% of dry weight, or a combination of both. Fish grew adequately in both feeding trials but no significant (P > 0.05) effects of supplemental creatine or GDA were observed on weight gain, feed efficiency, survival, hepatosomatic index (HSI), intraperitoneal fat (IPF ratio), or protein conversion efficiency (PCE). However, fish fed diets supplemented with creatine had significantly (P < 0.05) increased ash and reduced lipid deposition in whole-body tissues in the first feeding trial. Supplemental creatine also resulted in significantly higher muscle yield in the second trial, but no other effects on growth performance or body composition were observed. The addition of GDA to the diet had little effect except for significantly increasing the creatine content in the liver of fish in both feeding trials due to its role as a precursor and a catalyst for synthesis of creatine within the body. Based on the results of these two trials, supplemental creatine and GDA had rather limited effects on HSB cultured in moderately saline water.

Effects of guanidinoacetic acid on the growth performance, meat quality, postmortem energy metabolism and muscle fibre types of finishing pigs

Context Meat quality is increasingly being paid more attention by customers and enterprises. However, the modern pursuit of pork production has led to a decline in pork quality. Muscle fibre type is one of the important factors affecting meat quality that can be used as a key control point. Aims This study set out to assess the effects of dietary guanidinoacetic acid (GAA) on the growth performance, meat quality, postmortem energy metabolism, and muscle fibre types of finishing pigs. Methods In total, 180 healthy Duroc × Landrace × Meishan cross castrated male pigs with the similar weight (average 90 kg) were randomly divided into three treatments, with five replicates (pens) per treatment and 12 pigs per pen, including a GAA-free basal diet and basal diet with 0.05% or 0.10% GAA for 15 days. Key results In longissimus thoracis muscle, the results indicated that GAA supplementation decreased the drip loss and the cooking loss in 0.10% GAA group. Meanwhile, in semitendinosus muscle, 0.10% GAA addition increased pH45 min, and decreased the cooking loss. Additionally, GAA addition increased the content of ATP and AMP in semitendinosus muscle. The mRNA expressions of MyHC-I and MyHC-IIa were increased, whereas MyHC-IIx and MyHC-IIb were decreased. Moreover, in longissimus thoracis muscle, GAA addition promoted the mRNA expressions of CaM and NFATc1; in semitendinosus muscle, dietary GAA up-regulated the CnA and NFATc1 mRNA expressions. Conclusions GAA addition improved the meat quality, enhanced postmortem energy metabolism and promoted the conversion of fast-muscle fibre to slow-muscle fibre via activating the CaN/NFAT signalling. Implications The addition of GAA can improve the meat quality of post-slaughter finishing pigs and provide a theoretical basis for the application of GAA in livestock production.

Reducing broiler breast myopathies through supplementation of guanidinoacetic acid in broiler diets

Reducing broiler breast myopathies through supplementation of guanidinoacetic acid in broiler diets