Objective—To determine serum lactoferrin concentrations
(SLFC) in neonatal calves before and after
ingestion of colostrum and to develop models that
predict SLFC as a function of colostral lactoferrin concentrations
(CLFC) in calves.
Animals—13 Holstein calves.
Procedure—Calves were fed 4 L of colostrum via
oroesophageal feeder within 3 hours after birth.
Serum samples were collected before ingestion of
colostrum (day 0) and 2, 4, 6, and 7 days after birth.
Colostrum and serum IgG concentrations were measured
by use of radial immunodiffusion. The CLFC and
SLFC were determined by use of an ELISA.
Results—Mean ± SD SLFC on days 0, 2, 4, 6, and 7
were 2.5 ± 1.6 (range 0.47 to 7.1), 6.0 ± 3.0 (range 2.0 to
16.6), 12.0 ± 12.4 (range 0.0 to 43.5), 17.1 ± 13.6 (range
2.2 to 39.4), and 13.6 ± 16.4 (range 0.0 to 43.8) mg/ml,
respectively. The SLFC on days 6 and 7 differed significantly
from SLFC on day 0. The model that best estimated
SLFC on day 6 predicted that (SLFC)2 was a function
of the logarithm of relative efficiency of passive
transfer (REPT) and ([CLFC]2 × [REPT]2), where R2 = 0.4.
The model for SLFC on day 7 predicted that (SLFC)2 was
a function of log(REPT), where R2 = 0.44.
Conclusions and Clinical Relevance—Definitive evidence
for passive transfer of lactoferrin via colostrum
is lacking, because SLFC on day 2 or 4 were not significantly
different than day 0. Relative efficiency of
lactoferrin absorption was directly related to SLFC on
day 6 but inversely related to SLFC on day 7.
(Am J Vet Res 2002;63:476–478)
Objective—To determine whether serum IgG concentrations
in neonatal calves are adversely affected
by short-term frozen storage of colostrum.
Sample Population—Experiment 1 consisted of 10
pairs of Holstein calves (n = 20) fed matched aliquots
of either fresh (n = 10) or frozen and thawed (10)
colostrum. In experiment 2, 26 Holstein calves were
fed either fresh (n = 13) or frozen and thawed (n = 13)
Procedure—Experiment 1 consisted of calves resulting
from observed parturitions; calves were randomly
assigned to treatment groups (fresh or frozen and
thawed colostrum) in pairs. Calves were fed 4 L
aliquots of colostrum via oroesophageal intubation at
3 hours of age. Serum IgG concentrations at 2 days of
age were compared between the 2 groups by use of
a paired t-test. Experiment 2 consisted of calves
resulting from observed parturitions; calves were randomly
assigned to treatment groups (fresh or frozen
and thawed colostrum). Calves were fed 4 L aliquots
of colostrum via oroesophageal intubation at 3 hours
of age. Regression analysis was used to determine
whether calf serum IgG concentration was a function
of colostral IgG concentration and colostrum storage
Results—Significant differences were not observed
between the 2 groups in experiment 1. No significant
relationship was observed between colostrum storage
group and serum IgG concentration in experiment
2. The model that best predicted serum IgG concentrations
accounted for 20% of the variability in
serum IgG concentration.
Conclusion and Clinical Relevance—Frozen
colostrum is an adequate source of IgG for calves. (J
Am Vet Med Assoc 2001;219:357–359)