7Sheehan T,Numan M.Estrogen,progesterone,and pregnancy termination alter neural activity in brain regions that control maternal behavior in rats[J].Neuroendocrinology,2002,75 (1):12-23.
8Tanida H, Miura A, Tanaka T, et al. Behavioral responses of piglets to darkness and shadows[J]. Applied Animal Behav- iour Science, 1996, 49:173-183.
9Koba Y, Tanida H. How do miniature pigs discriminate be tween people? Discrimination between people wearing coveralls of the same colour[J]. Applied Animal Behaviour Science, 2001, 73: 45-58.
10Johan J Z, Linda Cornelissen, Maaike Wolthuis Filler, et al. Visual acuity of pigs at different light intensities[J]. Applied Animal Behaviour Science, 2008, 111: 28-37.
