| Summary: | Responses of broiler chickens to dietary glycine equivalent (Gly<sub>equi</sub>) are affected by dietary cysteine and choline. Hence, this study investigated interactive effects among dietary Gly<sub>equi</sub>, cysteine, and choline on the growth of broiler chickens. Male Ross 308 broiler chickens were maintained in 105 metabolism units (10 birds/unit) from days 7 to 22. Excreta were collected in 12-h intervals from days 18 to 21. Blood was sampled on day 22 (1 bird/unit). Five levels each of Gly<sub>equi</sub> (9–21 g/kg), cysteine (2–5 g/kg), and choline (0.5–1.7 g/kg) were tested under 15 diets in 7 replicates each following a fractional central composite design. Another diet was provided to five metabolism units (15 birds/unit) to measure prececal amino acid digestibility. Data were evaluated using neural networks. The gain:feed ratio (G:F) increased with digestible Gly<sub>equi</sub> intake. Differences between low and high digestible cysteine intake were low. Effects of choline intake on G:F were low. Nitrogen-utilization efficiency (NUE) was high (≥77%), with low variation among treatments. Plasma metabolites varied among treatments and indicated that metabolism of Gly<sub>equi</sub>, cysteine, and choline was influenced. These findings showed that interactive effects of dietary Gly<sub>equi</sub>, cysteine, and choline on growth were small, possibly because NUE was barely influenced.
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