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
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)
Objective—To determine the effects of pasteurization
of colostrum on serum lactoferrin concentration and
neutrophil oxidative function by comparing values
from calves given pasteurized (76 C, 15 minutes)
colostrum versus calves given fresh frozen colostrum.
Animals—8 Holstein bull calves were used to study
the effects of pasteurization of colostrum on the
absorption of lactoferrin and neutrophil oxidative burst.
Three additional calves were used to study the effect
of exogenous lactoferrin on neutrophil oxidative burst.
Methods—Calves were fed fresh frozen or heat pasteurized
colostrum (76 C for 15 minutes) via
esophageal feeder within 4 hours of birth. Neutrophils
were isolated from whole blood samples. Neutrophil
oxidative burst was induced by phorbol ester (300
ng/ml) stimulation of cells (1 × 106 cells) at 37 C.
Serum lactoferrin concentrations were compared,
using immunoblot analysis. Serum IgG concentrations
were determined by radial immunoassay.
Comparisons were made between the use of the 2
types of colostrum in calves by measuring subsequent
serum IgG and lactoferrin concentrations and
neutrophil superoxide production.
Results—Serum IgG and lactoferrin concentrations
increased more in calves receiving fresh frozen
colostrum. Neutrophil superoxide production was higher
in neutrophils prepared from calves receiving fresh
frozen colostrum. Colostral lactoferrin addition to neutrophil
incubations resulted in increased oxidative burst.
Conclusions and Clinical Relevance—Compared
with calves given fresh frozen colostrum, calves given
pasteurized colostrum had decreased serum IgG and
lactoferrin concentrations and neutrophil superoxide
production 24 hours after administration. These
results suggest that pasteurizing bovine colostrum at
76 C for 15 minutes has substantial effects on passive
transfer of proteins and neutrophil function. (Am J Vet