Table 2. Laying hen farms used in this study

Farms	Region	Breed	Ages (weeks)	No. of hens/house
A	Kyeongbuk	Hyline Brown	52	45,000
B	Kyeongbuk	Hyline Brown	72	30,000
C	Jeonnam	Isa Brown	42	15,000
D	Jeonnam	Tetra	44	16,500