Table 2. Effects of environmental enrichment on growth performance in weanling pigs

Item	Control	EE-1	EE-2	EE-4	SEM	p-value
Phase 1 (d 0–14)
ADG (kg)	288.10^b	302.02^ab	323.69^a	316.31^a	8.58	0.002
ADFI (kg)	417.13^b	429.92^ab	460.26^a	447.75^ab	12.84	0.016
G/F	0.69	0.70	0.70	0.71	0.01	0.168
Phase 2 (d 15–28)
ADG (kg)	406.79^b	409.88^ab	414.40^ab	433.21^a	9.14	0.039
ADFI (kg)	617.08^b	620.33^ab	626.43^ab	654.04^a	12.43	0.030
G/F	0.66	0.66	0.66	0.66	0.01	0.892
Overall (d 0–28)
ADG (kg)	347.44^b	355.95^ab	369.05^a	374.76^a	7.36	0.006
ADFI (kg)	517.10^b	525.13^ab	543.34^ab	550.89^a	10.36	0.014
G/F	0.67	0.68	0.68	0.68	0.01	0.212

Means with different superscripts in the same row differ significantly (p < 0.05).
EE-1, inclusion of play object until one week after weaning; EE-2, inclusion of play object until two weeks after weaning; EE-4, inclusion of play object until four weeks after weaning; ADG, average daily gain; ADFI, average daily feed intake; G/F, gain to feed ratio.