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In calves, FPT, defined as a plasma or serum IgG concentration < 10 g/L at 24 hours after birth, has been associated with increased calf morbidity and risk of death prior to weaning and decreased productivity as a mature cow. 1–3 Thus, it is

Full access
in Journal of the American Veterinary Medical Association

Summary

Total protein (tp), albumin, and IgG concentrations were measured in csf from the atlanto-occipital (ao) and lumbosacral (ls) sites and in serum of 15 clinically normal neonatal foals ≤ 10 days old (mean, 7.0 days). The albumin quotient (aq; csf albumin/serum albumin × 100) and IgG index ([csf IgG/serum IgG] × [serum albumin/csf albumin]), indicators of blood-brain barrier permeability and intrathecal IgG production, respectively, were then calculated.

Mean ± sd values obtained from the foals of this study were: serum albumin, 2,900 ± 240 mg/dl; serum IgG, 1,325 ± 686 mg/dl; ao csf total protein (tp), 82.8 ± 19.2 mg/dl; ls csf tp, 83.6 ± 16.1 mg/dl; ao csf albumin, 52.0 ± 8.6 mg/dl; ls csf albumin, 53.8 ± 15.7 mg/dl; ao csf IgG, 10.2 ± 5.5 mg/dl; ls csf IgG, 9.9 ± 5.7 mg/dl; ao aq, 1.86 ± 0.29; ls aq, 1.85 ± 0.51, ao IgG index, 0.52 ± 0.28; and ls IgG index, 0.48 ± 0.27. Significant difference between values for the ao and ls sites was not found. A csf albumin concentration > 85.2 mg/dl or aq > 2.4, as determined by mean ± 2 sd, may indicate increased blood-brain barrier permeability. An IgG index value >1.0 may indicate intrathecal IgG production.

Values obtained for foals of this study should serve as baseline for comparison in the evaluation of blood-brain barrier permeability and intrathecal IgG production in neonatal foals with neurologic disease.

Free access
in American Journal of Veterinary Research

Abstract

Objective—To evaluate equine IgG as a treatment for kittens with failure of passive transfer of immunity (FPT).

Animals—13 specific pathogen-free queens and their 77 kittens.

Procedure—Kittens were randomized at birth into 9 treatment groups. One group contained colostrumfed (nursing) kittens; the other groups contained colostrum-deprived kittens that were administered supplemental feline or equine IgG PO or SC during the first 12 hours after birth. Blood samples were collected at serial time points from birth to 56 days of age for determination of serum IgG concentrations. The capacity of equine IgG to opsonize bacteria for phagocytosis by feline neutrophils was determined via flow cytometry.

Results—Kittens that received feline or equine IgG SC had significantly higher serum IgG concentrations than those of kittens that received the supplements PO. In kittens that were administered supplemental IgG SC, serum IgG concentrations were considered adequate for protection against infection. The half-life of IgG in kittens treated with equine IgG was shorter than that in kittens treated with feline IgG. Feline IgG significantly enhanced the phagocytosis of bacteria by feline neutrophils, but equine IgG did not.

Conclusions and Clinical Relevance—Serum concentrations of equine IgG that are considered protective against infection are easily attained in kittens, but the failure of these antibodies to promote bacterial phagocytosis in vitro suggests that equine IgG may be an inappropriate treatment for FPT in kittens. (Am J Vet Res 2003;64:969–975)

Full access
in American Journal of Veterinary Research

Abstract

Objective—To determine the effect of timing of firstmilking colostrum collection on colostral IgG concentration.

Design—Prospective study.

Animals—13 healthy Holstein cows.

Procedures—All calvings were observed. After parturition, calves were not allowed to suckle and were separated from the dam. Colostrum was collected from a single randomly selected quarter at 2, 6, 10, and 14 hours after parturition until all 4 quarters were sampled. Colostral IgG concentration was determined via radial immunodiffusion.

Results—Mean colostral IgG concentration was 113, 94, 82, and 76 g/L at 2, 6, 10, and 14 hours after calving, respectively. Colostrum collected 6, 10, and 14 hours after calving had significantly lower IgG concentrations than did colostrum collected 2 hours after calving. Mean colostral IgG concentration at 14 hours after calving was significantly lower than that at 6 hours after calving. Cows in their third or greater lactation had mean colostral IgG concentrations 2 hours after calving (132 g/L) that were greater than the first and second lactation cows (mean, 95 and 100 g/L, respectively).

Conclusions and Clinical Relevance—Results indicate that early or immediate colostrum collection from dairy cows will maximize colostral IgG concentration. Adjustment of routine dairy farm management procedures may be required to maximize colostrum quality and minimize prevalence of failure of passive transfer in dairy calves. (J Am Vet Med Assoc 2005;226:1375–1377)

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine sensitivity and specificity of a cow-side immunoassay kit for assessing IgG concentration in colostrum.

Design—Prospective study.

Animals—76 dairy and 11 beef cows of various parities.

Procedure—Colostrum from first, second, and third milkings and milk samples were collected, and IgG concentration was determined by means of radial immunodiffusion. The immunoassay was performed according to the manufacturer’s instructions, and sensitivity and specificity were calculated by comparing results of the immunoassay (positive vs negative) with results of immunodiffusion (< 50 g/L vs ≥ 50 g/L).

Results—135 colostrum or milk samples were collected. Mean ± SD colostral IgG concentrations, determined by means of radial immunodiffusion for dairy and beef cows were 65.4 ± 51.4 g/L and 114.8 ± 42.7 g/L, respectively. Mean IgG concentrations for first-, second-, and third-milking colostrum samples and for milk samples were 92 ± 49.0 g/L, 74.6 ± 45.1 g/L, 47.5 ± 32 g/L, and 6.8 ± 3.8 g/L, respectively. Sensitivity of the immunoassay (ie, percentage of samples with IgG concentration < 50 g/L with a positive immunoassay result) was 93%, and specificity (ie, percentage of samples with IgG concentration ± 50 g/L with a negative immunoassay result) was 76%.

Conclusions and Clinical Relevance—Results suggested that the immunoassay kit was an acceptable cow-side test to identify colostrum samples with IgG concentrations < 50 g/L. The immunoassay kit should be useful in screening colostrum for adequate IgG concentration before feeding to calves or storage. (J Am Vet Med Assoc 2005;227:129–131)

Full access
in Journal of the American Veterinary Medical Association

SUMMARY

Reference intervals are reported for feline csf biochemical and serologic variables, IgG concentration, and electrophoretic fractionation, derived from 58 clinically normal adult cats that did not have histologic lesions of the cns. There was no apparent effect of age on any variable. The csf total protein concentration was significantly (P = 0.012) greater in males than in females, but all other variables were unaffected by gender. The only variable that had a statistically significant correlation with its corresponding blood concentration was IgG. Blood contamination of thecsf affected the following csf variables: total protein concentration, activities of lactate dehydrogenase and creatine kinase, IgG ratio, and γ-globulin percentage. The reference intervals proposed for feline csf were derived from 33 cats with csf rbc count < 31 cells/μl. Reference limits for csf with 31 to 1,700 rbc/μl also are reported.

Free access
in American Journal of Veterinary Research

SUMMARY

The kinetics of specific IgM and IgG antibody response was characterized in four 9-month-old Beagles after inoculation of 2 × 102 plaque-forming units (pfu) of Sheila Smith strain of Rickettsia rickettsii. Immunoglobulin M antibodies were first detected by indirect immunoflorescence on postinoculation (pi) day 9, peaked by pi day 20, and were no longer detectable by pi day 80. Immunoglobulin G antibodies became detectable between pi days 22 and 28, peaked by pi day 42, and decreased gradually through pi day 130. Subsequent challenges with R rickettsii on pi days 216 (2 × 102 pfu/dog) and 1,029 (5 × 104 tissue culture infective dose [tcid 50]/dog) resulted in slightly different serologic responses. The initial challenge exposure failed to increase the concentration of IgG antibodies and induced only low concentrations of IgM antibodies. After the second challenge inoculation, IgM antibodies were not detectable and the concentration IgG antibodies increased slightly. Clinical abnormalities and seroconversion were documented in control dogs following each challenge exposure.

Examination of acute and convalescent serum samples from 55 dogs in which Rocky Mountain spotted fever was suspected clinically suggested that sole evaluation of IgM antibodies in acute-phase serum would result in inaccurate diagnoses because of false-positive and -negative results. Use of a composite conjugate that detects IgM and IgG antibodies to R rickettsii appears to be satisfactory for diagnostic purposes; however, concurrent quantitation of IgM antibodies may facilitate serodiagnosis in a select group of dogs in which a four-fold increase in convalescent antibody titer is not detected by use of the composite conjugate.

With the exception of a dog with a serum antibody titer of 1:8,192, we were unable to detect IgM or IgG antibodies in csf samples from 9 dogs with experimentally and 3 dogs with naturally acquired infections.

Free access
in American Journal of Veterinary Research

SUMMARY

Effects of selenium (Se) deficiency and supplementation on production of colostral immunoglobulins by beef cows and transfer of antigen-specific and nonspecific immunoglobulins to their calves were examined. Eighty beef cows, with marginal to deficient Se status (blood Se concentration, 50 μg/L), were allotted by breed and age to 1 of 4 Se treatment groups (n = 20/group): no supplemental Se; parenteral administration of 0.1 mg of Se and 1 mg of vitamin E/kg of body weight; ad libitum consumption of 120 mg of Se/kg of salt-mineral mix (smm); and parenteral administration of 0.1 mg of Se and 1 mg of vitamin E/kg plus ad libitum consumption of 120 mg of Se/kg of smm. All cows were inoculated IM with lysozyme. Cows consumed Se-deficient pastures or hay (21 to 62 μg/kg) during the study that began at mid-gestation and ended at postpartum hour 24. Although the concentration of specific lysozyme antibodies was not affected, cows given 120 mg of Se/kg of smm (treatments 3 and 4) had higher colostral IgG concentration (P < 0.002) than did Se-deficient cows (treatments 1 and 2). Calves from cows in treatments 3 and 4 had higher postsuckle serum concentrations of IgG (P < 0.01) than did calves from cows in treatments 1 and 2. Colostral IgM and calf serum IgM concentrations did not differ among treatments.

Free access
in American Journal of Veterinary Research

Objective

To determine whether mammary gland or colostral characteristics at calving could be used to predict colostral immunoglobulin G1 (IgG1) concentration or intramammary infection (IMI) and whether leakage of colostrum affects IgG1 concentration.

Design

Prospective study.

Animals

113 multiparous Holstein cows.

Procedure

Cows were examined within 3 hours of calving, and mammary gland and colostral characteristics, colostral volume, somatic cell count, and concentrations of IgG1, fat, and protein were determined. Bacteriologic culture of mammary secretions was performed approximately 14 and 7 days before calving and at calving. Associations of gland and colostral characteristics with colostral IgG1 concentration, colostral volume, and IMI were examined.

Results

Thick or thin colostrum had higher IgG1 concentration than colostrum of intermediate viscosity. Colostrum from mammary glands that were firm had low IgG1 concentration. Colostral IgG1 concentration was weakly correlated with volume. Intramammary infection was likely to be detected if colostrum contained clots or blood or if the California Mastitis Test (CMT) score was ≥ 2. Somatic cell count was higher for glands with IMI than for uninfected glands, and CMT score was correlated with cell count.

Clinical Implications

Mammary gland and colostral characteristics were of little value in predicting IgG1 concentration. Our findings do not support recommendations that first milking colostrum that is thin (watery) or that is from cows producing large volumes not be fed to dairy calves. Colostral characteristics, particularly CMT score, were of value for predicting IMI. (J Am Vet Med Assoc 1999;214:1817-1823)

Free access
in Journal of the American Veterinary Medical Association

Summary

Polymorphonuclear neutrophils (pmn) from 4 cows were preincubated (30 minutes, 37 C) in either actinomycin D (100 μg/ml) or puromycin (10 μg/ ml), inhibitors of mRNA transcription and protein translation, or in medium 199. The pmn were incubated for a further 4.5 hours in medium containing 100 U of recombinant bovine interferon-γ (rbolfn-γ). The pmn were then incubated with bovine IgG1, IgG2, IgM, or aggregated IgG (algG; 4 C, 12 hours) for flow cytometric analysis, using fluoresceinated is-otype-specific antibody. The percentage of pmn binding the ligand and the logarithmic mean fluorescent channel (lmfc), an indicator of the amount of receptor (R) expression, were recorded. Competitive inhibition of ligand binding was measured by incubating pmn with fluoresceinated IgG2 in the presence or absence of 100-fold excess of IgG1, IgG2, and aIgG. Activation with rboIfn-γ induced a 4.5-fold increase in binding of IgG1 and a fivefold increase in lmfc for IgG2. These increases were inhibited by actinomycin D and puromycin. Percentage of pmn binding aIgG decreased after activation by rboIfn-γ. Interferon-γ treatment did not affect binding or lmfc of IgM. However, binding of IgM was reduced by treatment with actinomycin D. Binding of fluoresceinated IgG2 was inhibited by unlabeled IgG1, IgG2, and aIgG. Results indicate that bovine pmn Fc receptors (FcR) for IgG1 and IgG2 were rboIfn-γ inducible, that induction required de novo transcription and translation, that a heterogeneous population of FcR exist on bovine pmn, and that IgG1 and IgG2 share a common FcR. Further, bovine pmn are capable of gene activation and are responsive to changes in their environment, thus being amenable to modulation for effective pathogen destruction.

Free access
in American Journal of Veterinary Research