Louis Clyde Gale, The Golden Hamster Manual (1949)
“ Special advantages in culling for sex ratio lie in the fact that one may raise the right proportion of females to sell for breeders, or may raise all males if filling laboratory orders specifying same. Cull according to your production purpose, and save yourself from feeding unwanted animals. For convenience in culling, feeding and other servicing of pens, there are advantages in mating all females to be housed in the same 4-pen unit so as to litter at about the same time. ”
