Effect of post-ruminal guanidinoacetic acid supplementation on creatine synthesis and plasma homocysteine concentrations in cattle

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

BACKGROUND

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.

METHODS

Eighteen healthy Kazakh rams (27.46 ± 0.10 kg of body weight and 3-month old) were categorized into control, test group I and test group II, which were fed a basal diet, 1500 mg/kg GAA and 1500 mg/kg GAA + 600 mg/kg RPB, respectively.

RESULTS

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).

CONCLUSION

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.

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 < 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 < 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 < 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.

Guanidine Acetic Acid Alters Tissue Bound Amino Acid Profiles and Oxidative Status in Finishing Pigs

This study aims to investigate the effects of guanidine acetic acid (GAA) on carcass traits, plasma biochemical parameters, tissue antioxidant capacity, and tissue-bound amino acid contents in finishing pigs. Seventy-two 140-day-old (body weight 86.59 ± 1.16 kg) crossbred pigs (Duroc × Landrace × Large White) were randomly assigned into four treatments with six replicate pens and three pigs per pen, which were fed the basal diets supplemented with 0, 0.05%, 0.10%, or 0.15% GAA, respectively. The plasma glucose concentration decreased, and creatine kinase activity and levels of GAA and creatine increased with the dietary GAA concentration. GAA linearly improved creatine content in the longissimus thoracis muscle (LM) and heart. The activities of superoxide dismutase, total antioxidant capacity, and glutathione peroxidase increased linearly in tissue or/and plasma, while the contents of malondialdehyde and protein carbonyl decreased linearly. GAA improved the contents of multiple-bound amino acids (such as proline or isoleucine) in the myocardium and LM. In conclusion, GAA enhanced the plasma biochemical parameters, oxidative status, and bound amino acid profiles of the heart and LM in finishing pigs.

Homocysteine-Potential Novel Diagnostic Indicator of Health and Disease in Horses

Homocysteine is an endogenous, non-protein sulfuric amino acid, an intermediate metabolite formed by the methionine transmethylation reaction. Its elevated serum concentration in humans, hyperhomocysteinemia, is a sensitive indicator and a risk factor for coagulation disorders, cardiovascular diseases and dementia. However, the role of homocysteine in veterinary species has not been unequivocally established. Although some research has been conducted in dogs, cats, cattle and pigs, relatively few studies on homocysteine have been conducted in horses. So far, it has been established in this species that homocysteine has an atherogenic effect, plays a role in early embryo mortality and is responsible for the induction of oxidative stress. These preliminary findings support establishing a reference range in a normal population of horses, including horses in training and merit further investigations into the role of this amino acid in health and disease in this species.

Dietary Guanidine Acetic Acid Addition Improved Carcass Quality with Less Back-Fat Thickness and Remarkably Increased Meat Protein Deposition in Rapid-Growing Lambs Fed Different Forage Types

The aim of this study was to investigate whether guanidine acetic acid (GAA) yields a response in rapid-growing lambs depending on forage type. In this study, seventy-two small-tailed Han lambs (initial body weights = 12 ± 1.6 kg) were used in a 120-d feeding experiment after a 7-d adaptation period. A 2 × 3 factorial experimental feeding design was applied to the lambs, which were fed a total mixed ration with two forage types (OH: oaten hay; OHWS: oaten hay plus wheat silage) and three forms of additional GAA (GAA: 0 g/kg; UGAA: Uncoated GAA, 1 g/kg; CGAA: Coated GAA, 1 g/kg). The OH diet had a greater dry matter intake, average daily gain, and hot carcass weight than the OHWS diet. The GAA supplementation increased the final body weight, hot carcass weight, dressing percentage, and ribeye area in the longissimus lumborum. Meanwhile, it decreased backfat thickness and serum triglycerides. Dietary GAA decreased the acidity of the meat and elevated the water-holding capacity in mutton. In addition, the crude protein content in mutton increased with GAA addition. Dietary GAA (UGAA or CGAA) might be an effective additive in lamb fed by different forage types, as it has potential to improve growth performance and meat quality.

Effects of guanidinoacetic acid supplementation on lactation performance, nutrient digestion and rumen fermentation in Holstein dairy cows

BACKGROUND

Considering the high energy demand of lactation and the potential of guanidinoacetic acid (GAA) addition on the increase in creatine supply for cows, the present study investigated the effects of 0, 0.3, 0.6 and 0.9 g kg^-1 dry matter (DM) of GAA supplementation on lactation performance, nutrient digestion and ruminal fermentation in dairy cows. The study used 40 mid-lactation multiparous Holstein cows and the study duration was 100 days.

RESULTS

DM intake was not affected, but milk and milk component yields and feed efficiency increased linearly with increasing GAA addition. The total-tract digestibility of DM, organic matter, neutral detergent fibre, acid detergent fibre and non-fibre carbohydrates increased linearly and that of crude protein increased quadratically with increasing GAA addition. When the addition level of GAA increased, ruminal pH, molar percentages of butyrate, isobutyrate and isovalerate and the acetate-to-propionate ratio decreased linearly, and the total volatile fatty acids concentration and propionate molar percentage also increased linearly, whereas the acetate molar percentage and ammonia-N concentration were unaltered. The activities of fibrolytic enzymes, α-amylase and protease increased linearly. The populations of total bacteria, fungi, Ruminococcus albus, Fibrobacter succinogenes, Ruminococcus flavefaciens, Ruminobacter amylophilus and Prevotella ruminicola increased linearly, whereas protozoa and methanogens decreased linearly with increasing GAA addition. As for the blood metabolites, concentrations of glucose, urea nitrogen and methionine were unchanged, total protein, albumin, creatine and homocysteine increased linearly, and folate decreased linearly with increasing GAA supply.

CONCLUSION

The results of the present study indicate that supplementation of GAA improved milk performance and rumen fermentation in lactating dairy cows. © 2022 Society of Chemical Industry.

One-carbon metabolite supplementation to heifers for the first 14 d of the estrous cycle alters the plasma and hepatic one-carbon metabolite pool and methionine-folate cycle enzyme transcript abundance in a dose-dependent manner

The objective of this study was to determine the dose of folate and vitamin B12 in beef heifers fed rumen protected methionine and choline required to maintain increased B12 levels and intermediates of the methionine-folate cycle in circulation. Angus heifers (n = 30; BW = 392.6 ± 12.6 kg) were individually fed and assigned to one of five treatments: 0XNEG: Total mixed ration (TMR) and saline injections at day 0 and 7 of the estrous cycle, 0XPOS: TMR, rumen protected methionine (MET) fed at 0.08% of the diet DM, rumen protected choline (CHOL) fed at 60 g/d, and saline injections at day 0 and 7, 0.5X: TMR, MET, CHOL, 5 mg B12, and 80 mg folate at day 0 and 7, 1X: TMR, MET CHOL, 10 mg vitamin B12, and 160 mg folate at day 0 and 7, and 2X: TMR, MET, CHOL, 20 mg B12, and 320 mg folate at day 0 and 7. All heifers were estrus synchronized but not bred, and blood was collected on day 0, 2, 5, 7, 9, 12, and 14 of a synchronized estrous cycle. Heifers were slaughtered on day 14 of the estrous cycle for liver collection. Serum B12 concentrations were greater in the 0.5X, 1X, and 2X, compared with 0XNEG and 0XPOS on all days after treatment initiation (P < 0.0001). Serum folate concentrations were greater for the 2X treatment at day 5, 7, and 9 of the cycle compared with all other treatments (P ≤ 0.05). There were no differences (P ≥ 0.19) in hepatic methionine-cycle or choline analyte concentrations by treatment. Concentrations of hepatic folate cycle intermediates were always greater (P ≤ 0.04) in the 2X treatment compared with the 0XNEG and 0XPOS heifers. Serum methionine was greater (P = 0.04) in the 0.5X and 2X heifers compared with 0XNEG, and S-adenosylhomocysteine (SAH) tended (P = 0.06) to be greater in the 0.5X heifers and the S-adenosylmethionine (SAM):SAH ratio was decreased (P = 0.05) in the 0.5X treatment compared with the 0XNEG, 0XPOS, and 2X heifers. The hepatic transcript abundance of MAT2A and MAT2B were decreased (P ≤ 0.02) in the 0.5X heifers compared with the 0XNEG, 0XPOS, and 2X heifers. These data support that beef heifers fed rumen protected methionine and choline require 20 mg B12 and 320 mg folate once weekly to maintain increased concentrations of B12 and folate in serum. Furthermore, these data demonstrate that not all supplementation levels are equal in providing positive responses, and that some levels, such as the 0.5X, may result in a stoichiometric imbalance in the one-carbon metabolism pathway that results in a decreased SAM:SAH ratio.

Guanidine acetic acid supplementation altered plasma and tissue free amino acid profiles in finishing pigs

Background

As a nutritive feed additive, guanidine acetic acid (GAA) participates in the metabolism of energy and proteins. This study aimed to investigate the effects of GAA on growth performance, organ index, plasma and tissue free amino acid profiles, and related metabolites in finishing pigs. A total of 72 crossbred pigs (body weight 86.59 ± 1.16 kg) were randomly assigned to 1 of 4 dietary treatments (GAA0, GAA500, GAA1000, and GAA1500). They were fed the basal diets supplemented with 0, 500, 1000, or 1500 mg/kg GAA for 42 days, respectively. The growth performance and organ weight were evaluated, and the contents of crude protein, free amino acids, and metabolites in plasma and tissues were determined. Spearman correlation between plasma and tissue free amino acids and related metabolites was also analyzed.

Results

Growth performance in pigs was not altered by GAA (P > 0.05). The absolute and relative weight of kidneys increased (quadratic, P < 0.05). As dietary GAA concentration was increased, the contents of plasma glycine, serine, leucine, ornithine, and ratio of ornithine/arginine decreased (linear or quadratic, P < 0.05), but the contents of plasma isoleucine and taurine and the ratios of alanine/branched-chain amino acids and proline/ornithine increased quadratically (P < 0.05). The hepatic γ-amino-n-butyric acid content increased linearly and quadratically (P < 0.001), while the carnosine content decreased (quadratic, P = 0.004). The contents of renal arginine, proline, cystine, glutamate, and total amino acids (TAA) decreased quadratically (P < 0.05), but the contents of glycine (quadratic, P = 0.015) and γ-amino-n-butyric acid (linear, P = 0.008) increased. The pancreatic tryptophan content (quadratic, P = 0.024) increased, while the contents of pancreatic proline (linear, P = 0.005) and hydroxyproline (quadratic, P = 0.032) decreased in response to GAA supplementation. The contents of cardiac essential amino acids (EAA), nonessential amino acids (NEAA), and TAA in GAA1000 were higher than those in GAA1500 (P < 0.05). Supplementing with GAA linearly increased the contents of methionine, threonine, valine, isoleucine, leucine, phenylalanine, tryptophan, lysine, histidine, arginine, serine, alanine, glutamine, asparagine, tyrosine, proline, taurine, cystathionine, α-aminoadipic acid, β-aminoisobutyric acid, EAA, NEAA, and TAA in the spleen (P < 0.05). A strong Spearman correlation existed between plasma and tissue free amino acids and related metabolites.

Conclusion

GAA supplementation did not altered pig growth performance, but it altered plasma and tissue free amino acid profiles and the contents of related metabolites in pigs in a tissue-dependent manner.

Safety and efficacy of a feed additive consisting of guanidinoacetic acid for all animal species (Alzchem Trostberg GmbH)

Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of guanidinoacetic acid (GAA) when used as nutritional additive in feed and water for drinking for all animal species. The FEEDAP Panel concludes that GAA at 1,200 mg/kg complete feed is safe for chickens for fattening, piglets and pigs for fattening. This concentration in complete feed would correspond to maximum concentrations in water of 600 mg GAA/L for chickens for fattening, piglets and pigs for fattening. The Panel is not in a position to conclude on a safe level of GAA in laying/reproductive birds. In the absence of data on ruminants and salmonids, the FEEDAP Panel cannot conclude on the safety of GAA for all animal species. There is no concern on consumer safety resulting from the use of GAA in feed for poultry and pigs at the proposed conditions of use. The limited data do not allow to conclude on the safety for the consumer when the additive is used in feed for ruminants or fish. GAA is not toxic by inhalation, it is not an irritant to skin and eyes, and it is not a dermal sensitiser. The FEEDAP Panel concludes that the use of GAA as feed additive is not expected to pose a risk to the environment. The use of the additive under assessment in animal nutrition at the proposed conditions of use has the potential to be efficacious in all growing avian, Suidae and ruminant (except for preruminants) species; in growing fin fish other than salmonids and in frog. It is not possible to conclude on the efficacy of the additive in other species, and in reproductive animals.

Effects of Dietary Guanidinoacetic Acid on the Feed Efficiency, Blood Measures, and Meat Quality of Jinjiang Bulls

An experiment was conducted to determine the effects of supplementing the diet of Jinjiang bulls with guanidinoacetic acid (GAA) on their feed efficiency [feed efficiency were evaluated with feedlot average daily gain (ADG), average daily feed intake (ADFI), and feed-to-gain ratio (F:G)], blood measures, and meat quality. Forty-five Jinjiang bulls (24 ± 3 months old and 350.15 ± 30.39 kg by weight) were randomly distributed among five experimental groups (each n = 9) and each group was randomly fed with one of five diets (concentrate: roughage ratio of 60:40): (1) control; (2) 0.05% GAA; (3) 0.1% GAA; (4) 0.2% GAA; and (5) 0.4% GAA, respectively. After a 52-days feeding trial, five bulls from the control group and five bulls from the optimal GAA supplementing group were randomly selected and slaughtered for collection of the longissimus thoracis (LT) and semitendinosus (SM) muscles to determine meat quality. The results showed that dietary GAA improved the ADG, decreased the value of F:G, and affected blood measures and antioxidant variables. Supplementing 0.2% GAA into the diet was optimal for feeding efficiency and most of the measured blood measures. Supplementing 0.2% GAA into the diet increased the a^* (redness) values, and b^* (yellowness) values, and the amount of creatine kinase (CK), muscle glycogen, creatinine (CRE), and laminin (LN) in LT muscles. However, it decreased the drip loss, L^* (lightness) value, and lactate dehydrogenase (LDH) content of LT muscles. Drip loss and shear force decreased in SM muscles, as did the amount of type IV collagen (CV-IV). In conclusion, supplementing 0.2% GAA into the diet could enhance feed efficiency to improve beef growth and meat quality.

Effects of guanidinoacetic acid supplementation on nitrogen retention and methionine flux in cattle

Creatine stores high-energy phosphate bonds in muscle and is synthesized in the liver through methylation of guanidinoacetic acid (GAA). Supplementation of GAA may therefore increase methyl group requirements, and this may affect methyl group utilization. Our experiment evaluated the metabolic responses of growing cattle to postruminal supplementation of GAA, in a model where methionine (Met) was deficient, with and without Met supplementation. Seven ruminally cannulated Holstein steers (161 kg initial body weight [BW]) were limit-fed a soybean hull-based diet (2.7 kg/d dry matter) and received continuous abomasal infusions of an essential amino acid (AA) mixture devoid of Met to ensure that no AA besides Met limited animal performance. To provide energy without increasing the microbial protein supply, all steers received ruminal infusions of 200 g/d acetic acid, 200 g/d propionic acid, and 50 g/d butyric acid, as well as abomasal infusions of 300 g/d glucose. Treatments, provided abomasally, were arranged as a 2 × 3 factorial in a split-plot design, and included 0 or 6 g/d of l-Met and 0, 7.5, and 15 g/d of GAA. The experiment included six 10-d periods. Whole body Met flux was measured using continuous jugular infusion of 1-13C-l-Met and methyl-2H3-l-Met. Nitrogen retention was elevated by Met supplementation (P < 0.01). Supplementation with GAA tended to increase N retention when it was supplemented along with Met, but not when it was supplemented without Met. Supplementing GAA linearly increased plasma concentrations of GAA and creatine (P < 0.001), but treatments did not affect urinary excretion of GAA, creatine, or creatinine. Supplementation with Met decreased plasma homocysteine (P < 0.01). Supplementation of GAA tended (P = 0.10) to increase plasma homocysteine when no Met was supplemented, but not when 6 g/d Met was provided. Protein synthesis and protein degradation were both increased by GAA supplementation when no Met was supplemented, but decreased by GAA supplementation when 6 g/d Met were provided. Loss of Met through transsulfuration was increased by Met supplementation, whereas synthesis of Met from remethylation of homocysteine was decreased by Met supplementation. No differences in transmethylation, transsulfuration, or remethylation reactions were observed in response to GAA supplementation. The administration of GAA, when methyl groups are not limiting, has the potential to improve lean tissue deposition and cattle growth.

Machine learning applied to serum and cerebrospinal fluid metabolomes revealed altered arginine metabolism in neonatal sepsis with meningoencephalitis

Background

Neonatal sepsis with meningoencephalitis is a common complication of sepsis, which is a leading cause of neonatal death and neurological dysfunction. Early identification of neonatal sepsis with meningoencephalitis is particularly important for reducing brain damage. We recruited 70 patients with neonatal sepsis, 42 of which were diagnosed as meningoencephalitis, and collected cerebrospinal fluid (CSF) and serum samples. The purpose of this study was to find neonatal sepsis with meningoencephalitis-related markers using unbiased metabolomics technology and artificial intelligence analysis based on machine learning methods.

Results

We found that the characteristics of neonatal sepsis with meningoencephalitis were manifested mainly as significant decreases in the concentrations of homo-l-arginine, creatinine, and other arginine metabolites in serum and CSF, suggesting possible changes in nitric oxide synthesis. The antioxidants taurine and proline in the serum of the neonatal sepsis with meningoencephalitis increased significantly, suggesting abnormal oxidative stress. Potentially harmful bile salts and aromatic compounds were significantly increased in the serum of the group with meningoencephalitis. We compared different machine learning methods and found that the lasso algorithm performed best. Combining the lasso and XGBoost algorithms was successful in predicting the concentration of homo-l-arginine in CSF per the concentrations of metabolite markers in the serum.

Conclusions

On the basis of machine learning combined with analysis of the serum and CSF metabolomes, we found metabolite markers related to neonatal sepsis with meningoencephalitis. The characteristics of neonatal sepsis with meningoencephalitis were manifested mainly by changes in arginine metabolism and related changes in creatinine metabolism.

Relative bioavailability of guanidinoacetic acid delivered ruminally or abomasally to cattle

This study assessed the relative bioavailability of guanidinoacetic acid (GAA) in cattle. Seven ruminally cannulated Holstein steers (initial body weight of 280 kg) were used in an experiment with a 5 × 5 Latin square design; the two additional steers received a treatment sequence identical to two steers in the Latin square. Treatments were: control (no GAA, water infusion), ruminal infusion of 10 or 20 g/d GAA, and abomasal infusion of 10 or 20 g/d GAA, with all infusions delivered continuously. Periods were 7 d in length, and on day 7, blood and urine samples were collected to determine the concentrations of GAA and its associated metabolites. Plasma creatine concentrations increased linearly (P < 0.01) with GAA infusion to the abomasum and tended to increase linearly (P = 0.06) when GAA was infused ruminally. Urinary creatine concentrations increased linearly with increasing amounts of GAA infused in the abomasum (P < 0.01) and the rumen (P < 0.05). There were no significant effects of GAA infusion to either the abomasum or rumen on plasma or urinary concentrations of GAA. Plasma creatinine concentrations were not affected by GAA infusion to the abomasum or rumen. Urinary creatinine concentrations decreased when GAA was infused abomasally (P < 0.05). Because plasma and urinary creatine concentrations yielded the statistically strongest linear responses, they were selected as the primary response criteria for quantifying ruminal escape of GAA. Calculated by slope-ratio methodology, estimates for the ruminal escape of GAA based on plasma creatine and urinary creatine concentrations were 47% and 49%, respectively. Ruminally infused GAA was about half as effective as abomasally infused GAA in elevating plasma and urinary concentrations of creatine.