Guanidinoacetic Acid as a Dietary Additive for Lambs: A Meta-Analysis on Performance, Antioxidant Status, Nutrient Digestibility, Ruminal Fermentation and Meat Quality

Abstract

Simple Summary Guanidinoacetic acid is the immediate precursor of creatine and plays an important role in regulating cellular energy metabolism. This study analyzed the results of 12 research studies published between 2016 and 2026 to evaluate the effects of dietary supplementation with guanidinoacetic acid in lambs. The results showed that guanidinoacetic acid improved feed intake, weight gain, and feed utilization efficiency in lambs. Furthermore, guanidinoacetic acid enhances antioxidant capacity in lambs by increasing the concentration of endogenous antioxidant defense enzymes and reducing levels of compounds associated with cellular damage. Guanidinoacetic acid promotes feed digestibility and improves the production of volatile fatty acids in the rumen. In meat, guanidinoacetic acid reduces fluid loss and increases protein content. Taken together, these findings indicate that guanidinoacetic acid is a promising additive for improving productivity, health, and meat quality in lambs.