Digestibility and metabolism of dietary guanidino acetic acid fed to broilers.

Performance, meat quality, and pectoral myopathies of broilers fed either corn or sorghum based diets supplemented with guanidinoacetic acid.

Guanidinoacetic acid (GAA; also known as glycocyamine or guanidinoacetate) is the natural precursor of creatine, and under investigation as a novel dietary agent. It was first identified as a natural compound in humans ~80 years ago. In the 1950s, GAA's use as a therapeutic agent was explored, showing that supplemental GAA improved patient-reported outcomes and work capacity in clinical populations. Recently, a few studies have examined the safety and efficacy of GAA and suggest potential ergogenic benefits for physically active men and women. The purpose of this review is to examine possible applications of GAA supplementation for exercise performance enhancement, safety, and legislation issues.

Guanidinoacetic acid as a performance-enhancing agent

This study aimed to investigate the effects of creatine monohydrate (CMH) and guanidinoacetic acid (GAA) supplementation on the growth performance, meat quality, and creatine metabolism of finishin

Creatine Monohydrate and Guanidinoacetic Acid Supplementation Affects the Growth Performance, Meat Quality, and Creatine Metabolism of Finishing Pigs.

Poultry feather was hydrolyzed at relatively mild high temperature ranging from 433 to 473 K and autogenous pressure by intensification of microwave heating The hydrolysate mainly contains arginine, alanine, threonine, glycine, praline, serine, glutamic acid, aspartic acid, cystine and tyrosine, which corresponds with hydrochloric acid catalytic hydrolysis Based on the orthogonal experimental result, the total yield of amino acid attains about 5472% with feather containing about 7183% keratin at optimum reaction condition of temperature 473 K, time 20 min and weight ratio of water/feather 375 The high yield of amino acid and high efficiency of hydrolysis indicate that the microwave has better intensification on hydrolysis comparing with traditional strong acid catalytic or sub-critical hydrolysis The apparent activation energies (Ea) are 8512 and 6300 kJ/mol as to the hydrolysis of feather and the degradation of produced amino acid with consecutive pseudo-first-order reaction kinetic model, and the great decrease of the values comparing with non-microwave heating should be the reason of the enhanced effect of microwave

Microwave-enhanced hydrolysis of poultry feather to produce amino acid

An experiment was conducted to determine the response of broiler chickens to guanidinoacetic acid (GAA) added to diets with different energy levels during fattening to 35 days of age. Ross 308 male chicks were allotted to 10 treatments, each consisting of six replicates of 140 birds/pen. Five maize-soyabean meal isonitrogenous diets with decreasing AMEn levels (100, 99, 98, 97 and 96% of requirement) with or without supplements of 0.6 g/kg CreAMINO® containing a minimum of 96% GAA were formulated. The criteria of response were feed intake, body weight gains, feed conversion ratio and carcass, breast meat, leg meat and abdominal fat yields. Supplementation of broiler diets with 0.06% GAA resulted in a significant (P < 0.05) decrease in voluntary feed intake. With decreasing AMEn level, voluntary feed intake and consequently protein and amino acid intakes increased which was manifested by improved growth performance (P < 0.01). GAA supplements significantly (P < 0.001) improved feed conversion ratio and efficiency of AMEn utilization and significantly (P < 0.01) increased breast meat yield. With decreasing AMEn level, the effects of GAA supplementation tended to diminish.

Effects of Guanidinoacetic Acid Supplementation to Broiler Diets With Varying Energy Content

The response of broilers to various conditions of expander processing of full-fat soybeans (FFSB) was studied in an experiment involving 5040 birds allocated to 10 dietary treatments with six replicates. In treatments 1-8, the proportions of FFSB in starter, grower, and finisher diets were 40, 39-43, and 34-37%, respectively. Diets for treatments 9 and 10 contained commercial soybean meal (SBM) as a main protein source. All diets were isocaloric and were formulated to contain standardized ileally digestible amino acids at levels corresponding to 95% (treatments 1-7 and 10) or 100% (treatments 8 and 9) of requirement. In treatment 1, raw FFSB was used while diets for treatments 2-8 contained FFSB processed by various combinations of times and temperatures used during conditioning and expanding. Urease activity, protein dispersibility index, and trypsin inhibitor activity of FFSB decreased as processing time and/or temperature increased while protein solubility remained relatively unchanged. Concurrently, growth performance of chickens improved and their relative pancreas weight decreased. The best results in terms of feed intake, growth rate, feed conversion ratio, and carcass quality of FFSB-fed birds were obtained using expanding for 15 s at 125 degC preceded by short-term (1 min, 100 degC) and long-term (5 min, 100 degC) conditioning. These results were not significantly different from those achieved with SBM-based diets. Numerically better performance was found in 100% amino acid diets as compared with 95% diets. Switching the raw FFSB diet to SBM diet caused relative pancreas weight decrease by 31% during 3 days. An opposite switch resulted in a 65% increase in relative pancreas weight during 4 days.

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Impact of different processıng of full-fat soybeans on broiler performance

Allometric growth of body constituents and apparent efficiency of amino acid and nitrogen retention were examined in slow-growing laying-type cockerels (SG) and in fast-growing male broiler hybrids (FG) during the growth period from hatch to Day 22. The respective allometric coefficients for water, pro - tein (N × 6.25), ash and fat in relation to body weight were 0.971, 1.080, 1.096 and 1.284 for SG chickens and 0.977, 1.099, 0.993, and 1.198 for FG chickens. The respective allometric coefficients describing the relationships of water, fat and ash weight with protein weight were 0.894, 1.014, and 1.186 for SG chickens and 0.893, 0.910, and 1.097 for FG chickens. High allometric coefficients for ash in both genotypes likely indicate the rapid growth of skeletal tissues which requires adequate mineral nutrition during this period of growth. The deposition of ash relative to protein was significantly higher ( P < 0.05) in SG chickens thus suggesting that the relative growth of ash may be affected by genotype. Allometric coefficients relating amino acids to body protein were less than unity in most cases which indicates that an increasing amount of non- protein N is deposited in the body with advancing age. Except for cysteine, the apparent efficiency of amino acid retention was lower in SG as compared to FG chickens. The high retention efficiency of cysteine in SG genotype was likely associated with the conversion of surplus methionine to cysteine, required for feather protein synthesis in laying-type birds at an early age.

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Allometric growth of protein, amino acids, fat and minerals in slow- and fast-growing young chickens.

An experiment with broiler chickens was conducted to compare the relative bioavailability of liquid methionine hydroxy analogue free acid (MHA-FA) with that of DL-methionine (DLM) during fattening to 35 days of age. Ross 308 male chicks were allotted to 9 treatments, each consisting of six replicates of 140 birds/pen. Four graded levels (0.04, 0.08, 0.16, and 0.28 %) of MHA-FA or DLM products (weight/weight comparison) were added to a maize-wheat-soyabean meal basal diet deficient in sulphur amino acids. The criteria of response were body weight, feed conversion ratio, carcass yield and breast meat yield. Significant responses to graded levels of both methionine sources were observed in all response criteria. Using a multi-exponential model describing the dose-response relationships, the bioavailability estimates of MHA-FA relative to DLM on a weight-to-weight basis were 68, 70, 54 and 59 % for body weight, feed conversion, carcass yield and breast meat yield, respectively. If MHA-FA was compared with DLM on equimolar basis its bioavailability was 77.7, 79.0, 59.3 and 64.6 for body weight, feed conversion, carcass yield and breast meat yield, respectively. The bioavailability of MHA-FA for carcass yield and breast meat yield was significantly (P < 0.05) lower than that of DLM on a weight-to-weight and on equimolar basis.

Bioavailability of liquid methionine hydroxy analogue-free acid relative to dl-methionine in broilers

The distribution and biological half-life of radiocaesium (137Cs) in broiler chickens after three oral applications (in course of 1 day at the age of 14 days) of artificially contaminated feed mixture were studied. There was a rapid uptake of the orally administered 137Cs (within a few hours) and also a rapid loss of 137Cs which varied in the different organs (the initial biological half-life was: liver 0.6 day, intestine 0.6 day, breast meat 2 days, leg meat 1.2 days). More than one-half of the total administered 137Cs activity (55%) was excreted from the body within the 1st day after dosage, and after 14 days more than 90% had been excreted. The highest accumulation of 137Cs occurred in meat (50%–90%), and the proportion of total activity in breast and leg meat varied during decontamination. The transfer of radiocaesium from feed into the chicken body (measured as ratios of the 137Cs activity concentrations in the organ to the 137Cs activity concentration in the applied dose) 1 day after application was: 0.0220, 0.0294, 0.0216 and 0.0195 for breast meat, leg meat, intestine and liver, respectively. Significant differences between the values were demonstrated (P<0.05) except between those of breast meat and intestine. For the first 3 days there was a higher proportion of 137Cs activity in leg meat, whereas from the 4th day a greater part of total activity was found in breast meat. The latter results were confirmed in a subsequent study. Data from this study suggest that if broiler chickens are contaminated by radiocaesium to a level of 5 kBq/chicken in the course of 1 day at the age of 14 days, then immediate feeding with uncontaminated feed mixture for 18 days should be effective in decontaminating the chicken's meat below the intervention levels for radiocaesium in animal products, i.e. below 1000 Bq ⋅ kg–1.

Jiří Zelenka

Papers

Effects of Guanidinoacetic Acid Supplementation to Broiler Diets With Varying Energy Content

Impact of different processıng of full-fat soybeans on broiler performance

Allometric growth of protein, amino acids, fat and minerals in slow- and fast-growing young chickens.

Bioavailability of liquid methionine hydroxy analogue-free acid relative to dl-methionine in broilers

Dynamics and distribution of radiocaesium in broiler chicken.