Nursery pig health and performance

Abstract

The growth performance and the presence of common respiratory pathogens were studied. Fifty nurseries were sampled including farms that routinely used in-feed antimicrobials (conventional), and farms that used no antimicrobials. These latter farms were classified as “raised-without-antibiotics” (RWA) and organic. No difference was found between the growth rates of RWA and conventional nursery pigs (P > 0.05), while organic pigs grew slower than conventional pigs (P < 0.001). Based on serology, approximately a third of nurseries were seropositive for porcine reproductive and respiratory syndrome virus and this had a negative impact on individual pig growth rates. 80 % of nurseries were seropositive for influenza A virus. It was observed that most farms vaccinated weaned pigs for Mycoplasma hyopneumoniae so seroprevalence was not possible to assess. Despite vaccination, 73 % of these nurseries were classified as seronegative based on samples taken from pigs at the end of the nursery stage.