Table 2.

Effect of different stocking densities and concentrations of dl-methionine supplementation on growth performance of broilers¹

Density		Normal		High			P-value
Methionine	Period	100%	130%	100%	130%	SEM	Density	MET	Interaction
BW, g/chick	Starter2	345a	336ab	332b	336ab	2.14	0.13	0.52	0.12
	Grower	1,203a	1,187ab	1,152b	1,180ab	24.3	0.04	0.66	0.13
	Finisher	2,956a	2,907ab	2,832b	2,854ab	83.1	0.03	0.72	0.36
ADG, g/chick/d	Starter	27.6a	26.8ab	26.8ab	26.5b	0.36	0.13	0.53	0.13
	Grower	57.2a	56.8ab	54.7b	56.3ab	0.82	0.06	0.46	0.20
	Finisher	103	101	98.8	98.5	1.95	0.89	0.55	0.68
	Overall	67.8a	66.7ab	64.9b	65.4ab	0.89	0.03	0.72	0.36
FI, g/chick/d	Starter	42.9a	41.8a	37.5b	36.6b	0.57	<0.01	0.09	0.85
	Grower	107a	105ab	100c	101bc	1.63	<0.01	0.84	0.33
	Finisher	180a	169b	164bc	160c	4.73	<0.01	0.01	0.32
	Overall	122a	118ab	117b	115b	1.65	0.02	0.06	0.53
Feed/Gain	Starter	1.59a	1.56a	1.42a	1.38b	0.02	<0.01	0.12	0.53
	Grower	1.88	1.86	1.83	1.80	0.02	0.06	0.33	0.83
	Finisher	1.75a	1.68ab	1.67ab	1.62b	0.03	0.03	0.06	0.67
	Overall	1.76	1.72	1.76	1.71	0.02	0.77	0.70	0.78

¹Data are expressed as means (n = 10). The main effects (the stocking density and concentration of supplemental dl-methionine) were analyzed by two-way ANOVA and Duncan’s multiple range test was used to compare the treatment means. Means in the same row without a common letter differ significantly (P < 0.05).

²During the starter phase, all the four groups of chickens were fed the same corn and soybean meal basal diet with recommended dl-MET supplementation while different stocking densities were applied to these groups.