Does balancing for color affect pigs’ preference for different flavored tail-models?

Abstract

In previous work using rope flavored with various solutions as a model to study tail biting, pigs generally show a preference for the blood-flavored models compared to untreated models or models soaked in NaCl solutions or different fractions of blood. However, in these studies tail models were not balanced for color and it is unclear what stimuli may be serving to attract pigs to blood. In this study, pigs’ preference for different flavored tail-models balanced for color was determined. The chewing behavior of 16 individually housed pigs was observed twice daily for 10 days. Water-soaked, salt-flavored or blood-flavored tail-models were dyed with a red food coloring agent to appear similar in color. Pigs preferred to chew on tail models soaked in blood and dye to either of those soaked in just red food dye or salt solution plus red dye ( P<0.05). It appears that pigs are using olfactory or taste cues to discriminate among the different models.