In most of our studies, between 40 and 50 newborn pigs farrowed by five sows have been used in each trial. Using this procedure, experimental pigs are born on the same day or have a difference in age of 1 day. To minimize the exposure of newborn pigs to the sow environment, newborn pigs are moved out of the farrowing room into the isolation room within 1 to 2 minutes after they are born. Pigs are kept warm, with a heating lamp, in either a disinfected cage or cardboard box until the end of farrowing when they are identified by ear notches and weighed.
Values are means standard deviation.
Newborn pigs weighing less than 1.0 kg are seldom used for experimental purposes.