and Lawsonia intracellularis (Enterisol Ileitis
Boehringer Ingelheim B.V., Alkmaar, the Netherlands);
at 6 to 7 wk of age against Actinobacillus pleuropneumoniae
(APP; Porcilis APP; MSD Animal Health) and
influenza A virus (Gripovac3; Merial B.V., Velserbroek,
the Netherlands); and at 8 to 9 wk of age against APP
and influenza A virus (Porcilis APP and Gripovac3, respectively)
by subcutaneous injection in the neck or, in
the case of Enterisol, by oral drench. Piglets of both LSC
and HSC treatments were housed in the same rooms
until weaning (±24 d of age). After weaning, LSC and
HSC pigs were group housed in different rooms to prevent
cross-vaccination by the 2 living vaccines used in
the HSC piglets (Enterisol Ileitis and Porcilis PRRS).