Guanidinoacetic acid supplementation: A narrative review of its metabolism and effects in swine and poultry

Abstract

Guanidinoacetic acid (GAA) is an amino acid derivative and precursor for creatine which plays a significant role in energy metabolism. However, because of creatine’s instability during the manufacturing process and cost, GAA has been explored as an effective alternative to creatine supplements. GAA has been tested as a potential feed additive to enhance energy utilization and growth performance in the poultry and swine industries. Moreover, GAA has been combined with methionine to improve growth outcomes and may also act as an arginine-sparing agent in birds. The safety of the GAA supplements for animals, consumers, and the environment and its efficacy in numerous livestock species have been proven. This narrative review discusses the scientific evidence regarding the metabolism and effects of GAA supplementation in swine and poultry, identifying the knowledge gaps and future directions for further research on GAA supplementation. A systematic search of the literature identified published research findings related to GAA supplementation in swine and poultry and their findings are summarized in this narrative review to confirm the impacts of GAA supplementation on growth performance, reproductive performance, and meat quality in swine and poultry. Amongst its many demonstrated benefits, GAA is effective at improving body creatine concentration, growth parameters, feed conversion ratio, and performance of animals. Although GAA exerts many non-creatine roles, including the stimulation of insulin secretion, neuromodulation, and vasodilation, further research may require in-depth elaboration.

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

“…Besides its role in the gut, it has been demonstrated that GAA is a beneficial and safe dietary supplement in humans and animals. Among its many demonstrated benefits, GAA, likely via conversion to creatine, promotes growth, physical performance, reproductive parameters, and meat quality in commercial animals [ 10 , 11 ].…”

“…Moreover, GAA also seems to have several beneficial noncreatine roles in cellular metabolism. For example, GAA can directly or indirectly affect endocrine functions, neuromodulation, and oxidant–antioxidant processes [ 10 , 11 ].…”

An Assessment of the Effects of Guanidinoacetic Acid on the Performance and Immune Response of Laying Hens Fed Diets with Three Levels of Metabolizable Energy

“…Given the growing demand for poultry products, the use of food additives that favor muscle growth and the development of birds, including secondary metabolites, probiotics, prebiotics, and antimicrobial peptides (AMPs), among others, has increased [ 2 ]. Among these alternatives is guanidinoacetic acid (GAA), the natural precursor of creatine (Cr), which is synthesized from arginine and glycine in organs such as the kidneys, pancreas, liver, endocrine tissues, and skin [ 3 , 4 ]. The main function of GAA is to optimize energy use, which is achieved through the efficient conversion of Cr.…”

“…Recent research has shown that GAA, as a feed additive, has considerable potential to improve production performance, thereby improving the quality of beef [ 6 ] and poultry [ 3 ]. The catabolism of GAA occurs in the small intestine via the action of pancreatic enzymes such as trypsin and elastase in conjunction with dipeptidases produced at the border of the intestinal barrier, releasing arginine and glycine.…”

“…Besides the activation of the mTOR signaling pathway by arginine and glycine, it has been reported that GAA, through the increase in Cr, enhances skeletal muscle development and the regulation of different genes, such as myogenic regulatory factors (MRFs) and myocyte enhancer factor 2 [ 6 ]. Administering 1.2 g/kg of GAA in the diet of commercial birds increases productivity parameters [ 3 ], and under caloric stress, the joint administration of GAA and Cr increases these parameters without the need to add arginine to the diet [ 11 ]. Meanwhile, in broilers, supplementation with 0.5 g/kg of GAA increases the size, width, and absorption surface area of the intestinal villi in the duodenum, jejunum, and ileum [ 12 ].…”