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  • Author or Editor: Richard S. Marion x
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Abstract

Objective—To evaluate precolostral hypogammaglobulinemia in neonatal llamas and alpacas, to determine when postcolostral peak serum IgG concentrations develop, to determine whether differences in postcolostral serum IgG concentrations between llamas and alpacas exist, and to determine postcolostral half-life of serum IgG in llamas and alpacas.

Design—Prospective observational study.

Animals—29 llama and 10 alpaca crias.

Procedure—Blood samples were collected prior to suckling and on days 1, 2, and 3 after parturition and analyzed for serum IgG concentration by use of a commercial radial immunodiffusion assay. Additional samples were collected on days 8, 13, and 18 from 8 crias to determine mean half-life of IgG.

Results—Llamas and alpacas are born severely hypogammaglobulinemic. Mean serum IgG concentrations for day-1, -2, and -3 samples for llamas were 1,578 mg/dl, 1,579 mg/dl, and 1,401 mg/dl, respectively, and for alpacas were 2,024 mg/dl, 1,806 mg/dl, and 1,669 mg/dl, respectively. Peak serum immunoglobulin concentration developed between days 1 and 2. Mean half-life of IgG for all crias was 15.7 days.

Conclusions and Clinical Relevance—Although increased mortality has been linked to failure of passive transfer, it is clearly possible to raise crias that have low serum immunoglobulin concentrations. Llamas and alpacas do not differ significantly with respect to immunoglobulin absorption or IgG concentration in neonates. The optimal sampling time for passive transfer status is between 1 and 2 days. (Am J Vet Res 2000;61:738–741)

Full access
in American Journal of Veterinary Research

Abstract

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 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.

Conclusion and Clinical Relevance—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. (J Am Vet Med Assoc 2000;216:559–563)

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in Journal of the American Veterinary Medical Association