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. Animals—24 llama and 9 alpaca crias. Design—Prospective study. Procedure—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 γ-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...