FIGURE 7.

Recognition index during the test trial of the novel object recognition task as a measure of recognition memory. The dotted line at 0.50 indicates the chance performance value, and the recognition index greater than 0.50 indicates a novelty preference, and thus recognition memory. Note that an asterisk (*) on the PNW 8 sow-reared group denotes recognition memory as the recognition index was greater (P = 0.003) than the chance level (0.50 value). Other groups lacking an asterisk did not exhibit recognition memory (P > 0.05). AR, artificially reared pigs; PNW, postnatal week; SR, sow-reared pigs.