In the U.S., prophylactic antibiotics are frequently included in the diets of weanling pigs to prevent postweaning diarrhea (PWD). Despite this, PWD still causes substantial losses to the swine industry through both mortalities and morbidity. Additionally, the use of prophylactic antibiotics has become a concern among some groups regarding their potential contribution to the spread and creation of antibiotic resistant bacteria. The objective of this study was to determine if dietary inclusion of Colicin E1 (ColE1) altered pigs behavior and postures when challenged with E. coli over a 24 h period. Two postures (active and inactive) and two behaviors (drinking and feeding) were compared over three dietary treatments; treatment 1 had no ColE1 (C; n=8), treatment 2 added 1.1 mg of purified ColE1 (L; n=8), and treatment 3 added 16.5 mg (H; n=8) of purified ColE1. Regardless of treatment, nursery aged pigs generally engaged in higher levels of active postures, drinking behaviors, and feeding behaviors during the afternoon and night (13:00 to 22:00). Inversely, the pigs were generally inactive during the late night and morning hours (22:00 to 13:00). Nursery pigs in the H groups displayed slightly higher levels of active postures and feeding behaviors over a 24 h period indicating that ColE1 had some positive effects on the well-being of pigs infected with E. coli.