Fig. 7From: Progress towards reduced-crude protein diets for broiler chickens and sustainable chicken-meat productionQuadratic relationship (r = 0.841; P = 0.00003) between free threonine plasma levels and FCR across five studies where y = 1.611–0.004×Thr + 0.0000004×Thr2. Adapted from Moss et al. [8]; Chrystal et al. [11,12,13,14]Back to article page