Effects of guanidinoacetic acid and complex antioxidant supplementation on growth performance, meat quality, and antioxidant function of broiler chickens

Optimizing broiler growth, health, and meat quality with citric acid- assessing the optimal dose and environmental impact: Citric acid in Broiler Health and Production

The need for sustainable and safe alternatives to antibiotic growth promoters has driven researchers to explore organic acids (OAs) inclusion in broiler diets. Citric acid (CA), a notable OA, has emerged as a promising alternative due to its various physiological benefits, including improved nutrient digestibility, antioxidant properties, and enhanced weight gain. Despite the improved growth performance, the feed conversion ratio (FCR) does not seem to be consistently affected by CA inclusion. A considerable number of research papers suggest that CA can replace antibiotic growth promoters and has proved to be more effective when combined with other additives like probiotics and microbial phytase. However, despite numerous trials, the near-accurate dose remains in doubt. Dietary addition between 1.65 % and 2.65 % seems to positively affect broiler performance. Being an organic acid, CA brings no risk to the environment and does not economically burden producers. It has the capability to enhance certain meat qualities and extend shelf life. However, there is a risk of acidic stress and liver damage with excessive inclusion. This review study seeks to offer a thorough and all-encompassing summary of the present level of understanding regarding the use of CA supplementation in broiler diets by describing its impacts on growth efficiency, nutrient utilization, intestinal condition, immune response, meat quality, optimal dose, and environmental sustainability. Further research focused on determining precise dosage levels and understanding the synergistic or antagonistic effects of citric acid when combined with other feed additives is essential for optimizing broiler performance.

Guanidinoacetic acid supplementation and stocking density effects on broiler performance: behavior, biochemistry, immunity, and small intestinal histomorphology

BACKGROUND

Rearing poultry under stressful high stocking density (HSD) conditions is a common commercial practice to increase profitability, despite its negative effects on broiler physiology and welfare. Many feed additives are used to alleviate the negative impact of such practices. This study investigated the ameliorative effects of guanidinoacetic acid (GAA) on growth performance, ingestive behavior, immune response, antioxidant status, stress indicators, and intestinal histomorphometry of broilers subjected to HSD. A total of 364 male broilers were randomly allocated into four treatments with 7 replicates each in a 2 × 2 factorial arrangement: two stocking densities (SD) (10 and 16 birds/m2) and two GAA levels (0 and 0.6 g/kg feed).

RESULTS

Body weight, weight gain, feed intake, feed conversion ratio, production efficiency factor, dressing yield, and ingestive behavior were negatively affected by HSD, whereas the mortality rate was unaffected (P > 0.05). GAA improved the overall growth performance and dressing percentage (P < 0.05). In the HSD group, the immune response decreased at d 21 (P < 0.05). Creatine kinase, glutathione peroxidase (GPX), superoxide dismutase, catalase, triglycerides, and villus length and width (ileum) were reduced, whereas corticosterone (CORT) was increased (P < 0.05). Moreover, GAA increased the hemagglutination-inhibition titer at 21 days and the levels of lactate dehydrogenase, GPX, and catalase and decreased the levels of creatinine, alanine aminotransferase, nitrite, triglycerides, and CORT (P < 0.05). SD and GAA did not affect malondialdehyde or other biochemical parameters (P > 0.05).

CONCLUSIONS

Dietary GAA supplementation can improve productivity and antioxidant status and reduce stress in broilers reared in a HSD environment.

Effects of Guanidine Acetic Acid on the Growth and Slaughter Performance, Meat Quality, Antioxidant Capacity, and Cecal Microbiota of Broiler Chickens

The objective of this research was to assess the impact of guanidine acetic acid (GAA) on the growth performance, slaughter outcomes, meat quality, antioxidant capacity, and cecal microbiota of broiler chickens. A total of 128 Arbor Acres broilers were randomly divided into two experimental groups. One group served as the control and was provided with a standard diet, whereas the group treated with GAA received a diet enhanced with 400 mg/kg of GAA. The duration of the experiment was 42 days. Measurements for growth performance, serum biochemical parameters, and antioxidant capacity were conducted both during and at the conclusion of the study, while assessments of slaughter performance and meat quality were carried out solely at the end. Notable differences were observed in terms of growth performance, blood biochemistry, and metabolic parameters between the control and GAA-treated groups (p < 0.05). Hence, these findings imply that dietary GAA supplementation can favorably affect growth, carcass quality, biochemical indicators, and antioxidant capacity in broiler chickens.

Investigation of guanidino acetic acid and rumen-protected methionine induced improvements in longissimus lumborum muscle quality in beef cattle

This study examined the impact of dietary guanidino acetic acid (GAA) and rumen-protected methionine (RPM) on beef quality in Simmental bulls. For 140 days, forty-five bulls (453.43 ± 29.05 kg) were randomly divided into control (CON), 0.1% GAA (GAA), and 0.1% GAA + 0.1% RPM (GAM) groups with 15 bulls in each group and containing 3 pen with 5 bulls in each pen. Significant improvements in eye muscle area, pH48h, redness (a*) value, and crude protein (CP) content of longissimus lumborum (LL) muscles were observed in the GAA and GAM groups (P < 0.05). Conversely, the lightness (L*) value, drip loss, cooking loss, and moisture contents decreased (P < 0.05). Additionally, glutathione (GSH) and glutathione peroxidase (GSH-PX) concentrations of LL muscles in GAM were higher (P < 0.05), while malondialdehyde (MDA) content of LL muscles in GAA and GAM groups were lower (P < 0.05). Polyunsaturated fatty acids (PUFA) profiles were enriched in beef from GAM group (P < 0.05). The addition of GAA and RPM affected the expression of genes in LL muscle, such as HMOX1, EIF4E, SCD5, and NOS2, which are related to hypoxia metabolism, protein synthesis, and unsaturated fatty acid synthesis-related signaling pathways. In addition, GAA and RPM also affected the content of a series of metabolites such as L-tyrosine, L-tryptophan, and PC (O-16:0/0:0) involved in amino acid and lipid metabolism-related signaling pathways. In summary, GAA and RPM can improve the beef quality and its nutritional composition. These changes may be related to changes in gene expression and metabolic pathways related to protein metabolism and lipid metabolism in beef.

Comparative Study of an Antioxidant Compound and Ethoxyquin on Feed Oxidative Stability and on Performance, Antioxidant Capacity, and Intestinal Health in Starter Broiler Chickens

Concerns over the safety of ethoxyquin (EQ) highlight the need for safer, more effective feed antioxidants. This study investigated a healthier antioxidant compound (AC) as a potential alternative to EQ in broilers. A total of 351 one-day-old Arbor Acres Plus male broilers were randomly assigned to three treatments for 21 days: control (CON), EQ group (200 g/ton EQ at 60% purity), and AC group (200 g/ton AC containing 18% butylated hydroxytoluene, 3% citric acid, and 1% tertiary butylhydroquinone). AC supplementation reduced the acid value, peroxide value, and malondialdehyde content in stored feed, decreased feed intake and the feed conversion ratio without affecting body weight gain, and enhanced antioxidant capacity (liver total antioxidant capacity and superoxide dismutase; intestinal catalase and glutathione peroxidase 7). It improved intestinal morphology and decreased barrier permeability (lower diamine oxidase and D-lactate), potentially by promoting ZO-1, Occludin, and Mucin2 expression. The AC also upregulated NF-κB p50 and its inhibitor (NF-κB p105), enhancing immune regulation. Additionally, the AC tended to increase beneficial gut microbiota, including Lactobacillus, and reduced Bacteroides, Corprococcus, and Anaeroplasma. Compared to EQ, the AC further enhanced feed oxidative stability, the feed conversion ratio, intestinal morphology and barrier functions, and inflammatory status, suggesting its potential as a superior alternative to EQ for broiler diets.

Effects of bamboo leaf flavonoids on growth performance, antioxidants, immune function, intestinal morphology, and cecal microbiota in broilers

BACKGROUND

Bamboo leaf flavonoids (BLF) are the main bioactive ingredients in bamboo leaves. They have antioxidant, anti-inflammatory, antibacterial, and other effects. In this study, the effects of dietary BLF on growth performance, immune response, antioxidant capacity, and intestinal microbiota of broilers were investigated. A total of 288 broilers were divided into three groups with eight replicates and 12 birds in each replicate. Broilers were fed a basic diet or the basic diet supplemented with 1000 or 2000 mg kg-1 BLF for 56 days.

RESULTS

The results showed that supplementation of BLF increased body weight (BW) and average daily weight gain (ADG), and reduced average daily feed intake (ADFI) (P < 0.05). The serum immunoglobulin A (IgA), immunoglobulin M (IgM), and interleukin 10 (IL-10) content of broilers in the BLF1000 group was increased and the interleukin 1β (IL-1β) and tumor necrosis factor-α (TNF-α) content was decreased (P < 0.05). The levels of IgM and IL-10 in jejunum mucosa were found to be enhanced by BLF (P < 0.05). The BLF1000 group exhibited a significant reduction in the concentration of TNF-α (P < 0.05). Serum and jejunum mucosa total antioxidant capacity (T-AOC) levels in the BLF1000 group were increased (P < 0.05). The serum catalase (CAT) and glutathione peroxidase (GSH-Px) effects of the BLF1000 group and serum CAT effects of BLF2000 group were increased (P < 0.05). The CON group demonstrated a lower relative abundance of Christensenellaceae_R-7_group and Oscillibacter than the BLF group (P < 0.05).

CONCLUSION

Dietary BLF inclusion enhanced the growth performance, immune, and antioxidant functions, improved the intestinal morphology, and ameliorated the intestinal microflora structure in broiler. Adding 1000 mg kg-1 BLF to the broiler diet can be considered as an effective growth promoter. © 2024 Society of Chemical Industry.

Effect of Guanidinoacetic Acid on Production Performance, Serum Biochemistry, Meat Quality and Rumen Fermentation in Hu Sheep

Guanidinoacetic acid (GAA) can effectively improve the metabolism of energy and proteins by stimulating creatine biosynthesis. We present a study exploring the impact of GAA on production performance, serum biochemistry, meat quality and rumen fermentation in Hu sheep. A total of 144 weaned male Hu sheep (body weight 16.91 ± 3.1 kg) were randomly assigned to four groups with three replicates of twelve sheep in each group. The diets were supplemented with 0 (CON), 500 (GAA-1), 750 (GAA-2) and 1000 mg/kg (GAA-3) of GAA (weight of feed), respectively. After a comprehensive 90-day experimental period, we discovered that the supplementation of GAA had a remarkable impact on various muscle parameters. Specifically, it significantly enhanced the average daily growth (ADG) of the animals and improved the shear force and fiber diameter of the muscle, while also reducing the drip loss and muscle fiber density. Furthermore, the addition of GAA to the feed notably elevated the serum concentrations of high-density lipoprotein cholesterol (HDL-C), total protein (TP) and globulin (GLB), as well as the enzyme activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px). Concurrently, there was a decrease in the levels of triglycerides (TG) and malondialdehyde (MDA) in the serum. In addition, GAA decreased the pH and the acetate-to-propionate ratio and increased the total volatile fatty acids (TVFA) and ammoniacal nitrogen (NH3-N) levels of rumen fluid. Additionally, GAA upregulated acetyl-CoA carboxylase (ACC) gene expression in the Hu sheep's muscles. In conclusion, our findings suggest that GAA supplementation not only enhances muscle quality but also positively affects serum biochemistry and ruminal metabolism, making it a potential candidate for improving the overall health and performance of Hu sheep.

Comparative effects of dietary herbal mixture or guanidinoacetic acid supplementation on growth performance, cecal microbiota, blood profile, excreta gas emission, and meat quality in Hanhyup-3-ho chicken

Phytogenic feed additives are renowned for their growth promotion, gut health enhancement, and disease prevention properties, which is important factors for sustaining prolonged poultry rearing. The study aimed to evaluate the effect of herbal mixture (mixture of ginseng and artichoke) or guanidinoacetic acid (GAA) on growth performance, cecal microbiota, excretal gas emission, blood profile, and meat quality in Hanhyup-3-ho chicken. A total of 360 one-day-old chickens (half males and half females) were allocated into one of 3 dietary treatments (12 replicate cages/treatment; 10 broilers/replicate cage) for 100 d of age. Experimental diets were CON: basal diet; TRT1: basal diet combined with 0.05% herbal mixture; and TRT2: basal diet combined with 0.06% GAA. All birds received a basal diet during the first 30 d, but from d 31 to 100, an experimental diet was supplied. The addition of 0.05% herbal mixture improved the average body weight gain and feed conversion ratio from d 31 to 100 as well as the overall experimental period. The cecal Lactobacillus, Escherichia coli, and Salmonella count remained consistent across all dietary treatments. Blood albumin and Superoxide Dismutase (SOD) levels increased in the herbal mixture supplemented diet. Additionally, there was a notable reduction in excretal NH3 and H2S emissions in the herbal mixture group. Furthermore, the herbal mixture group exhibited increased breast muscle weight, improved breast muscle color, improved water holding capacity, and a decrease in abdominal fat compared to the control group. Additionally, the supplementation of 0.06% GAA did not demonstrate any statistically significant impact on any evaluated parameter throughout the experiment. The results from the present investigation underscore the potential of ginseng together with artichoke extract supplementation as a viable feed additive, conferring improvements in growth performance, feed efficiency, excreta gas emission, meat quality parameters, and defense mechanism against oxidative stress in Hanhyup-3-ho 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.

Effects of three different plant-derived polysaccharides on growth performance, immunity, antioxidant function, and cecal microbiota of broilers

BACKGROUND

This study investigated the effects of dietary plant polysaccharides on growth performance, immune status and intestinal health in broilers. We randomly divided 960 one-day-old Arbor Acres broiler chicks into four groups. The control (CON) group was fed a basal diet, and the remaining groups were fed a basal diet supplemented with 1000 mg kg-1 Ginseng polysaccharide (GPS), Astragalus polysaccharide (APS), or Salvia miltiorrhiza polysaccharide (SMP) for 42 days.

RESULTS

Dietary supplementation with SMP significantly increased body weight (BW) at 21 and 42 days of age, average daily gain (ADG) and average daily feed intake (ADFI) during the starter and whole experimental period, decreased the concentrations of interleukin-1 beta (IL-1β), tumor necrosis factor α (TNF-α) and malondialdehyde (MDA), increased the levels of interleukin-4 (IL-4) and interleukin-10 (IL-10) and catalase (CAT) activity in the serum (P < 0.05). GPS, APS, and SMP supplementation increased serum levels of immunoglobulins, activities of glutathione peroxidase (GSH-Px), total superoxide dismutase (T-SOD) and total antioxidant capacity (T-AOC), and cecal concentrations of acetic acid and propionic acid of broilers (P < 0.05). Furthermore, high-throughput sequencing results showed that the relative abundance of Firmicutes was decreased while the relative abundance of Bacteroidota, Alistipes, and Prevotellaceae_NK3B31_group were increased (P < 0.05) in the GPS, APS, and SMP groups compared with the CON group.

CONCLUSION

Dietary GPS, APS, and SMP supplementation could improve growth performance, enhance immune function by increasing serum immunoglobulin and regulating cytokines, improve antioxidant function by increasing serum antioxidant enzyme activity, increase volatile fatty acid levels and improve the microbial composition in the cecum of broilers. Dietary SMP supplementation had the optimal effect in this study. © 2023 Society of Chemical Industry.

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.

Effect of guanidinoacetic acid on the growth performance, myofiber, and adenine nucleotide of meat-type rabbits

OBJECTIVE

This study aimed to investigate the effect of dietary guanidinoacetic acid (GAA) on the growth performance, slaughter traits, myofiber, and adenine nucleotide of meat-type rabbits.

METHODS

Experimental treatments consisted of control (CON) and GAA addition at 0.04% (T1), 0.08% (T2), and 0.12% (T3) of diet. A total of 240 weaned rabbits (meat-type male Chinese black rabbits) were randomly distributed into four groups with six replicates of ten rabbits each.

RESULTS

Results showed that the three doses of GAA increased (p<0.05) final body weight, carcass weight, the density and area of quadriceps femoris fiber; and T3 showed significant effects (p<0.05) on weight gain, feed/gain, and dressing percentage, and the traits of longissimus fiber, compared to CON. Dietary GAA increased (p<0.05) the meat color a* and b* in longissimus and quadriceps; and T3 showed the lowest (p<0.05) shear force of longissimus. Furthermore, GAA increased (p<0.05) the contents of adenosine triphosphate and total adenine nucleotide in longissimus and quadriceps. In longissimus adenosine triphosphate, total adenine nucleotide, and adenylate energy charges, T3 treatment was most effective (p<0.05); while T2 and T3 treatment was more effective (p<0.05) than T1 in quadriceps. Additionally, linear or quadratic responses (p<0.05) to the increased doses of GAA were found on body weight gain, meat color, total adenine nucleotide, and adenylate energy charges.

CONCLUSION

It is concluded that GAA can be used in the rabbit diet to improve growth and carcass traits, and these are related to the high levels of muscle adenine nucleotide.

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.

Effects of feeding guanidinoacetic acid on oxidative status and creatine metabolism in broilers subjected to chronic cyclic heat stress in the finisher phase

Dietary guanidinoacetic acid (GAA) has been shown to affect creatine (Cr) metabolic pathways resulting in increased cellular Cr and hitherto broiler performances. Yet, the impact of dietary GAA on improving markers of oxidative status remains equivocal. A model of chronic cyclic heat stress, known to inflict oxidative stress, was employed to test the hypothesis that GAA could modify bird's oxidative status. A total of 720-day-old male Ross 308 broilers were allocated to 3 treatments: 0, 0.6 or 1.2 g/kg GAA was added to corn-SBM diets and fed for 39 d, with 12 replicates (20 birds each) per treatment. The chronic cyclic heat stress model (34°C with 50-60% RH for 7 h daily) was applied in the finisher phase (d 25-39). Samples from 1 bird per pen were taken on d 26 (acute heat stress) and d 39 (chronic heat stress). GAA and Cr in plasma were linearly increased by feeding GAA on either sampling day, illustrating efficient absorption and methylation, respectively. Energy metabolism in breast and heart muscle was greatly supported as visible by increased Cr and phosphocreatine: ATP, thus providing higher capacity for rapid ATP generation in cells. Glycogen stores in breast muscle were linearly elevated by incremental GAA, on d 26 only. More Cr seems to be directed to heart muscle as opposed to skeletal muscle during chronic heat stress as tissue Cr was higher in heart but lower in breast muscle on d 39 as opposed to d 26. The lipid peroxidation marker malondialdehyde, and the antioxidant enzymes superoxide dismutase and glutathione peroxidase showed no alterations by dietary GAA in plasma. Opposite to that, superoxide dismutase activity in breast muscle was linearly lowered when feeding GAA (trend on d 26, effect on d 39). Significant correlations between the assessed parameters and GAA inclusion were identified on d 26 and d 39 using principal component analysis. To conclude, beneficial performance in heat-stressed broilers by GAA is associated with enhanced muscle energy metabolism which indirectly may also support tolerance against oxidative stress.

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.

Supplementation of Paraformic Acid as a Substitute for Antibiotics in the Diet Improves Growth Performance and Liver Health in Broiler Chickens

The current study aimed to explore the effects of supplementing paraformic acid (PFA) into broilers’ diet on growth performance, inflammatory responses, and liver protection. A total of 567 healthy one-day-old broilers were used in a 42-d study, and they were randomized into three groups. Broilers were fed a basal diet (CON group) or the basal diet supplemented with either 50 mg/kg aureomycin (AB group) or 1000 mg/kg PFA (PFA group). The results showed that the PFA and AB groups had a higher feed conversion rate than the CON group from day 21 to 42 (p < 0.05). Dietary PFA or aureomycin supplementation decreased serum levels of interleukin (IL)-1β, IL-6, IL-10, alanine transaminase, diamine oxidase, and D-lactate, and significantly increased serum concentrations of immunoglobulin (Ig) A, IgM, and complement C4 (p < 0.05). Moreover, dietary PFA or aureomycin supplementation decreased hepatic levels of caspase-1, NOD-like receptor family pyrin domain containing 3 (NLRP3), tumor necrosis factor-alpha, IL-6, and IL-18, as well as NF-κB mRNA expression (p < 0.05). Above all, PFA supplementation into the broilers’ diet improved growth performance, inhibited inflammatory responses, and benefited liver protection. The protective effects of PFA on the liver might be related to inhibition of caspase-1-induced pyroptosis via inactivating the NF-κB/NLRP3 inflammasome axis in broiler chickens.

Effect of guanidine acetic acid on meat quality, muscle amino acids, and fatty acids in Tibetan pigs

This study investigated the effects of guanidine acetic acid (GAA) supplementation on growth performance, carcass traits, and meat quality in Tibetan pigs. A total of 18 male Tibetan pigs (21.35 ± 0.99 kg) were randomly assigned to the control (basal diet) and GAA (basal diet + 800 mg/kg GAA) groups for 125 days. Growth performance, carcass traits, and meat quality in pigs, and the chemical composition of Longissimus thoracis (LT) were not altered by GAA. In LT, compared to the control group, dietary GAA increased the superoxide dismutase activity, transcripts of stearoyl CoA desaturase (SCD) and fatty acid synthase (FAS), and contents of glutamate, glutamine, C24:0, C20:3n-6, C20:4n-6, and polyunsaturated fatty acids (P < 0.05), but it decreased the malondialdehyde content (P < 0.001). In back fat, dietary GAA reduced the transcript of peroxisome proliferator-activated receptor γ (PPARγ) and the contents of C10:0, C12:0, C14:0, and C16:0 (P < 0.05), whereas it increased the contents of C22:0, C20:1, C22:1, C24:1, C20:2, C20:3n-3, and C22:2 (P < 0.05). These findings will provide a basis for high-quality Tibetan pork production.

Guanidine acetic acid exhibited greater growth performance in younger (13–30 kg) than in older (30–50 kg) lambs under high-concentrate feedlotting pattern

Guanidine acetic acid (GAA) is increasingly considered as a nutritional growth promoter in monogastric animals. Whether or not such response would exist in rapid-growing lambs is unclear yet. The objective of this study was to investigate whether dietary supplementation with uncoated GAA (UGAA) and coated GAA (CGAA) could alter growth performance, nutrient digestion, serum metabolites, and antioxidant capacity in lambs. Seventy-two small-tailed Han lambs initially weighed 12 ± 1.6 kg were randomly allocated into six groups in a 2 × 3 factorial experimental design including two forage-type rations [Oaten hay (OH) vs. its combination with wheat silage (OHWS)] and three GAA treatment per ration: no GAA, 1 g UGAA, and 1 g CGAA per kg dry matter. The whole experiment was completed in two consecutive growing stages (stage 1, 13–30 kg; stage 2, 30–50 kg). Under high-concentrate feeding pattern (Stage 1, 25: 75; Stage 2, 20: 80), UGAA or CGAA supplementation in young lambs presented greater dry matter intake (DMI) in stage 1 and average daily gain (ADG) in the whole experimental period; lambs in OH group had higher ADG and DMI than that in OHWS group in stage 1 and whole experimental period, but this phenomenon was not observed in stage 2. Both UCGA and CGAA addition increased dietary DM, organic matter (OM), neutral detergent fiber (NDF), and acid detergent fiber (ADF) digestion in both stages. In blood metabolism, UCGA and CGAA addition resulted in a greater total protein (TP) and insulin-like growth factor 1(IGF-1) levels, as well as antioxidant capacity; at the same time, UCGA and CGAA addition increased GAA metabolism-creatine kinase and decreased guanidinoacetate N-methyltransferase (GAMT) and L-Arginine glycine amidine transferase catalyzes (AGAT) activity. In a brief, the results obtained in the present study suggested that GAA (UGAA and CGAA; 1 g/kg DM) could be applied to improve growth performance in younger (13–30 kg) instead of older (30–50 kg) lambs in high-concentrate feedlotting practice.

The combined impact of xylo-oligosaccharides and gamma-irradiated astragalus polysaccharides on the immune response, antioxidant capacity and intestinal microbiota composition of broilers

The present study investigated the individual and combined effects of xylo-oligosaccharides (XOS) and gamma-irradiated astragalus polysaccharides (IAPS) on the immune response, antioxidant capacity and intestinal microbiota composition of broiler chickens. A total of 240 newly hatched Ross 308 chicks were randomly allocated into 5 dietary treatments including the basal diet (control), or the basal diet supplemented with 50 mg/kg chlortetracycline (CTC), 100 mg/kg XOS (XOS), 600 mg/kg IAPS (IAPS), and 100 mg/kg XOS + 600 mg/kg IAPS (XOS + IAPS) respectively. The results showed that birds in the control group had lower the thymus index and serum lysozyme activity than those in the other 4 groups (P < 0.05). Moreover, there was an interaction between XOS and IAPS treatments on increasing the serum lysozyme activity (P < 0.05). Birds in the CTC and XOS + IAPS groups had lower serum malondialdehyde concentration and higher serum total antioxidant capacity activity and mucosal interleukin 2 mRNA expression of jejunum than those in the control group (P < 0.05). In addition, birds in the control groups had lower duodenal and jejunal IgA-producing cells number than these in other 4 groups (P < 0.05). As compared with the CTC group, dietary individual XOS or IAPS administration increased duodenal IgA-producing cells number (P < 0.05). Meanwhile, there was an interaction between XOS and IAPS treatments on increasing duodenal and jejunal IgA-Producing cells numbers (P < 0.05). Dietary CTC administration increased the proportion of Bacteroides, and decreased the proportion of Negativibacillus (P < 0.05). However, dietary XOS + IAPS administration increased Firmicutes to Bacteroidetes ratio, the proportion of Ruminococcaceae, as well as decreased the proportion of Barnesiella and Negativibacillus (P < 0.05). In conclusion, the XOS and IAPS combination could improve intestinal mucosal immunity and barrier function of broilers by enhancing cytokine gene expression, IgA-producing cell production and modulates cecal microbiota, and the combination effect of XOS and IAPS is better than that of individual effect of CTC, XOS, or IAPS in the current study.

Guanidinoacetic Acid as a Nutritional Adjuvant to Multiple Sclerosis Therapy

Tackling impaired bioenergetics in multiple sclerosis (MS) has been recently recognized as an innovative approach with therapeutic potential. Guanidinoacetic acid (GAA) is an experimental nutrient that plays a significant role in high-energy phosphate metabolism. The preliminary trials suggest beneficial effects of supplemental GAA in MS, with GAA augments biomarkers of brain energy metabolism and improves patient-reported features of the disease. GAA can also impact other metabolic footprints of MS, including demyelination, oxidative stress, and GABA-glutamate imbalance. In this mini-review article, we summarize studies evaluating GAA effectiveness in MS, explore mechanisms of GAA action, and discuss the challenges of using dietary GAA as an element of MS therapy.

Regulative Mechanism of Guanidinoacetic Acid on Skeletal Muscle Development and Its Application Prospects in Animal Husbandry: A Review

Guanidinoacetic acid is the direct precursor of creatine and its phosphorylated derivative phosphocreatine in the body. It is a safe nutritional supplement that can be used to promote muscle growth and development. Improving the growth performance of livestock and poultry and meat quality is the eternal goal of the animal husbandry, and it is also the common demand of today's society and consumers. A large number of experimental studies have shown that guanidinoacetic acid could improve the growth performance of animals, promote muscle development and improve the health of animals. However, the mechanism of how it affects muscle development needs to be further elucidated. This article discusses the physical and chemical properties of guanidinoacetic acid and its synthesis pathway, explores its mechanism of how it promotes muscle development and growth, and also classifies and summarizes the impact of its application in animal husbandry, providing a scientific basis for this application. In addition, this article also proposes future directions for the development of this substance.

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.