Comparison of pregnancy diagnosis in dairy cattle by use of a commercial ELISA and palpation per rectum.
OBJECTIVE
To compare agreement between 2 pregnancy tests in dairy cattle.


METHODS
Evaluation study.


METHODS
976 and 507 cattle for phases 1 and 2, respectively.


METHODS
Blood samples were collected, and palpation per rectum (PPR) was performed on cattle. Blood samples for the pregnancy-specific protein B (PSPB) ELISA were sent by courier to a commercial laboratory with results returned later. Results of PPR were extracted from herd records. Statistical comparison of results was performed by use of a mixed linear model and N analysis.


RESULTS
Of 571 cattle classified as pregnant by the PSPB ELISA in phase 1, 30 (5%) were nonpregnant by PPR. Mean +/- SE adjusted optical density (OD) of cattle classified pregnant by both tests was significantly higher (0.31 +/- 0.01), compared with the adjusted OD of cattle classified pregnant by the PSPB ELISA and nonpregnant by PPR (0.22 +/- 0.02). Of 255 cows classified pregnant by the PSPB ELISA in phase 2, 31 (12%) were nonpregnant by PPR. Mean +/- SE adjusted OD of cattle classified pregnant by both tests was significantly higher (0.26 +/- 0.01), compared with the adjusted OD of cattle classified pregnant by the PSPB ELISA and nonpregnant by PPR (0.21 +/- 0.01). The N value was 0.82 and 0.81 for phases 1 and 2, respectively.


CONCLUSIONS
Good agreement existed between the 2 tests, especially at longer intervals after insemination. Discrepant results appeared to be attributable to a nonviable fetus, embryonic loss, or fetal loss.
Breed
Matthew W
MW
Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA.
Guard
Charles L
CL
White
Maurice E
ME
Smith
Mary C
MC
Warnick
Lorin D
LD
D000818:Animals; D015415:Biomarkers / Q000097:blood; D002417:Cattle / Q000097:blood / Q000502:physiology*; D051517:Digital Rectal Examination / Q000379:methods / Q000662:veterinary*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods / Q000662:veterinary*; D005069:Evaluation Studies as Topic; D005260:Female; D005328:Fetal Viability / Q000502:physiology; D011247:Pregnancy; D011258:Pregnancy Tests / Q000379:methods / Q000592:standards / Q000662:veterinary*; D011268:Pregnancy-Specific beta 1-Glycoproteins / Q000032:analysis*; D012680:Sensitivity and Specificity
D015415:Biomarkers; D011268:Pregnancy-Specific beta 1-Glycoproteins