Fig. 5From: Progress towards reduced-crude protein diets for broiler chickens and sustainable chicken-meat productionQuadratic relationship (r = 0.632; P = 0.0017) between free systemic plasma concentrations of threonine and glycine in birds offered maize-based diets with four crude protein concentrations where y = 920.01–0.738×Thr + 0.000268×Thr2. Adapted from Chrystal et al. [12]Back to article page