Can pigs see colors? If so, are they attracted to or repulsed by different colors? - Swine [Skip to Content]

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Can pigs see colors? If so, are they attracted to or repulsed by different colors?


Dear Jack, I must admit to you that when I first read this question, my immediate reaction was to reply no. This was because until a few years ago, we felt that mammals were color-blind. However, knowing this was no longer the belief, I went looking for the answer, for which there is practically no information published. I talked to Dr. Stan Curtis, Professor Emeritus, in our Department of Animal Sciences, and a world-renowned expert in Animal Behavior and Environmental Physiology and he provided me with the following information. This comes from the revision of his book, now entitled "Environmental Aspects of Animal Care" edited by Dr. Curtis and three of his colleagues. It will be published in 2002 by Iowa State University Press. Color Vision of Mammals. Primates are the only mammals known to be trichromatic (have three types of cone photopigments) and it has long been assumed that most other mammals are color-blind. However, recent evidence indicates that most mammalian species have two classes of cone photopigments and therefore are dichromatic. Their color vision may not be as rich as humans' but they do have some capability for color discrimination. The retina of the domestic pig, e.g., has a substantial number of cones with sensitivity peaks at wavelengths ~.4 and ~.56. The domestic rat, a primarily nocturnal animal having only one type of cone, has long thought to be monochromatic with poor color vision. But experiments in the early 1990's identified in rats a second type of cone photopigment that responds maximally to ultraviolet radiation, part of the electromagnetic spectr;um that humans cannot perceive.

If you desire further information regarding color vision of pigs, please contact the following individual, who is the person that wrote the above information. Dr. Tina Widowski Assistant Professor Animal and Poultry Science Department University of Guelph Email:

Sincerely, Gilbert Hollis Extension Swine Specialist Department of Animal Sciences University of Illinois Phone: 217-333-0013

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