Evaluation of a commercially available immunoassay for assessing adequacy of passive transfer in calves.
OBJECTIVE
To evaluate diagnostic utility of a commercially available immunoassay for assessing adequacy of passive transfer of immunity in neonatal calves.


METHODS
Prospective study.


METHODS
123 calves.


METHODS
Blood and serum samples were obtained from the calves prior to 2 weeks of age. The immunoassay was performed, along with refractometry and an 18% sodium sulfite turbidity test. Serum IgG concentration was determined with a radial immunodiffusion assay. Sensitivity and specificity of the immunoassay, refractometry, and the sodium sulfite test were calculated by comparing results with results of the radial immunodiffusion assay.


RESULTS
Sensitivity and specificity of the blood IgG immunoassay were 0.93 and 0.88, respectively, compared with 1.00 and 0.53 for the sodium sulfite test. For refractometry, sensitivity and specificity were 0.71 and 0.83, respectively, when a serum total solids concentration of 5.2 g/dl was used as the cutoff between positive and negative test results.


CONCLUSIONS
Results suggest that the immunoassay performs well in detecting calves with inadequate passive transfer of immunity.
Dawes
Maisie E
ME
Department of Veterinary Medicine and Surgery College of Veterinary Medicine, University of Missouri, Columbia 65211, USA.
Tyler
Jeff W
JW
Hostetler
Douglas
D
Lakritz
Jeff
J
Tessman
Ronald
R
D000818:Animals; D000831:Animals, Newborn / Q000097:blood / Q000276:immunology*; D002417:Cattle / Q000097:blood / Q000276:immunology*; D007112:Immunity, Maternally-Acquired; D007118:Immunoassay / Q000592:standards / Q000662:veterinary*; D005779:Immunodiffusion / Q000662:veterinary; D007074:Immunoglobulin G / Q000097:blood*; D009391:Nephelometry and Turbidimetry / Q000662:veterinary; D011446:Prospective Studies; D011933:Reagent Kits, Diagnostic / Q000592:standards / Q000662:veterinary; D012031:Refractometry / Q000662:veterinary; D012680:Sensitivity and Specificity; D013447:Sulfites
D007074:Immunoglobulin G; D011933:Reagent Kits, Diagnostic; D013447:Sulfites; C025026:sodium sulfite