TY - JOUR
T1 - Monitoring the prevalence of Lawsonia intracellularis IgG antibodies using serial sampling in growing and breeding swine herds
AU - Marsteller, Thomas A.
AU - Armbruster, Greg
AU - Bane, David P.
AU - Gebhart, Connie J.
AU - Muller, Roger
AU - Weatherford, Jane
AU - Thacker, Brad
PY - 2003/5
Y1 - 2003/5
N2 - Objective: To determine seroprevalence of Lawsonia intracellularis and the time of seroconversion in growing and breeding swine herds using the immunoperoxidase monolayer assay (IPMA). Methods: Blood was collected from individually identified growing pigs in 16 herds at weaning (approximately 3 weeks of age) and in those herds, plus four others, at 3-week intervals until market weight (total 20 herds). Blood was collected from individually identified breeding animals (replacement gilts) at entry into nine breeding herds and then at 3-week intervals. Samples were tested at a dilution of 1:30 using the IPMA, which identifies IgG antibodies. Results: Fifteen of twenty growing herds (75%) were seropositive for L intracellularis at some time between weaning and 24 weeks of age. Within-herd seroprevalence in positive growing herds ranged from 11 to 92% and peaked near marketing (18 to 24 weeks of age). Seven of nine breeding herds (78%) were seropositive. Within-herd seroprevalence in breeding herds ranged from 5 to 61% and peaked near the time of herd entry and again late in the study. Implications: As L intracellularis IgG serum antibodies were short-lived in this study, serial blood sampling at intervals of 3 weeks or less may prove useful in determining L intracellularis serological status in a swine production system. On the basis of these results, blood samples to detect exposure to L intracellularis should be collected from growing swine at 18 to 24 weeks of age, and from replacement gilts at entry into the breeding herd and at first lactation.
AB - Objective: To determine seroprevalence of Lawsonia intracellularis and the time of seroconversion in growing and breeding swine herds using the immunoperoxidase monolayer assay (IPMA). Methods: Blood was collected from individually identified growing pigs in 16 herds at weaning (approximately 3 weeks of age) and in those herds, plus four others, at 3-week intervals until market weight (total 20 herds). Blood was collected from individually identified breeding animals (replacement gilts) at entry into nine breeding herds and then at 3-week intervals. Samples were tested at a dilution of 1:30 using the IPMA, which identifies IgG antibodies. Results: Fifteen of twenty growing herds (75%) were seropositive for L intracellularis at some time between weaning and 24 weeks of age. Within-herd seroprevalence in positive growing herds ranged from 11 to 92% and peaked near marketing (18 to 24 weeks of age). Seven of nine breeding herds (78%) were seropositive. Within-herd seroprevalence in breeding herds ranged from 5 to 61% and peaked near the time of herd entry and again late in the study. Implications: As L intracellularis IgG serum antibodies were short-lived in this study, serial blood sampling at intervals of 3 weeks or less may prove useful in determining L intracellularis serological status in a swine production system. On the basis of these results, blood samples to detect exposure to L intracellularis should be collected from growing swine at 18 to 24 weeks of age, and from replacement gilts at entry into the breeding herd and at first lactation.
KW - Immunoperoxidase monolayer assay
KW - Lawsonia intracellularis
KW - Porcine proliferative enteritis
KW - Serology
KW - Swine
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M3 - Article
AN - SCOPUS:0037730386
SN - 1537-209X
VL - 11
SP - 127
EP - 130
JO - Journal of Swine Health and Production
JF - Journal of Swine Health and Production
IS - 3
ER -