Fig. 1

Methionine-deficiency reduced growth performance, feather formation and feather follicle development. A Flowchart of animal experiment. B Growth performance of broiler chickens in the pre-trial period (n = 6). The results are presented as mean ± SEM, *P < 0.05, the same as below. C Methionine and SAM concentration in skin tissue and serum of broiler chickens with methionine-deficiency (n = 12). D and E Feather weight (D) and feather length (E) of broiler chickens with methionine-deficiency (n = 12). F Feather follicle development of broiler chickens with methionine-deficiency (n = 6). Scale bar at 200 μm. Control, Control group; Met-deficiency, Methionine deficiency group; Met-rescue, Methionine supplement group; BW, Body weight; ADG, Average daily gain; ADFI, Average daily feed intake; F/G, Feed to gain ratio; Met, Methionine; SAM, S-Adenosylmethionine