Objective—To evaluate diagnostic utility of a commercially
available immunoassay for assessing adequacy
of passive transfer of immunity in neonatal
Procedure—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
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 and Clinical Relevance—Results suggest
that the immunoassayperforms well in detecting
calves with inadequate passive transfer of immunity.
(J Am Vet Med Assoc 2002;220:791–793)
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