Evaluation of assays for determination of passive transfer status in neonatal llamas and alpacas.
OBJECTIVE
To evaluate several practice-adapted assays for determination of passive transfer status in crias.


METHODS
24 llama and 9 alpaca crias.


METHODS
Prospective study.


METHODS
Serum IgG concentration was measured by use of a radial immunodiffusion assay when crias were 45 to 51 hours old. Results were compared with serum gamma-glutamyltransferase (GGT) activity, serum total protein, albumin, globulin, and total solids concentrations, and results of commercially available and traditional sodium sulfite turbidity (SST) tests.


RESULTS
Mean (+/- SD) serum IgG concentration was 1,762 +/- 1,153 mg/dl. On the basis of a threshold value of 1,000 mg of IgG/dl at 48 hours of age, 5 of 33 (15.15%) crias had failure of passive transfer. Serum total solids, protein, and globulin concentrations were significantly associated with serum IgG concentration, whereas serum GGT activity and serum albumin concentration were not. Serum IgG concentrations were significantly different among crias with negative, 2+, and 3+ scores on the traditional SST test. Serum IgG concentrations were not significantly different between crias with negative and 100 mg/dl scores or 100 and 300 mg/dl scores on the commercially available SST test. However, all other comparisons between crias with different scores revealed significant differences. Sensitivity and specificity ranged between 0 and 1, depending on the test and endpoint selected.


CONCLUSIONS
The commercially available SST test and determination of serum total protein and globulin concentrations are suitable methods for assessing passive transfer status in llama and alpaca crias.
Weaver
D M
DM
Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia 65211, USA.
Tyler
J W
JW
Marion
R S
RS
Wallace
L M
LM
Nagy
J K
JK
Holle
J M
JM
D000818:Animals; D000831:Animals, Newborn / Q000276:immunology*; D001774:Blood Chemical Analysis / Q000662:veterinary; D001798:Blood Proteins / Q000032:analysis; D002161:Camelids, New World / Q000276:immunology*; D003126:Colostrum / Q000276:immunology; D007112:Immunity, Maternally-Acquired; D005779:Immunodiffusion / Q000662:veterinary; D007074:Immunoglobulin G / Q000097:blood*; D009391:Nephelometry and Turbidimetry / Q000662:veterinary; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D012709:Serum Albumin / Q000032:analysis; D012712:Serum Globulins / Q000032:analysis; D005723:gamma-Glutamyltransferase / Q000097:blood
D001798:Blood Proteins; D007074:Immunoglobulin G; D012709:Serum Albumin; D012712:Serum Globulins; D005723:gamma-Glutamyltransferase