• View in gallery

    Figure 1—Plot of serial dilutions of a standard bovine IgG and the resulting diameter of the zone of precipitation. Linear regression analysis revealed a high correlation (R2 = 0.98). Equation for the linear regression was as follows: IgG concentration = 0.0209 + (0.0039 × [zone diameter]2).

  • View in gallery

    Histogram of the relative frequency of various IgG concentrations in serum samples obtained from 170 Holstein dairy calves prior to ingestion of colostrum.

  • 1.

    Larson BL, Heary JR, Devery JE. Immunoglobulin production and transport by the mammary gland. J Dairy Sci 1979;63:655671.

  • 2.

    Arthur GH. The development of the conceptus. In: Arthur GH,Noakes DE,Pearson H,et al, eds. Pregnancy and parturition in veterinary reproduction and obstetrics. 2nd ed. Philadelphia: WB Saunders, 1999;51109.

    • Search Google Scholar
    • Export Citation
  • 3.

    Besser TE, Gay CC. The importance of colostrum to the health of the neonatal calf. Vet Clin North Am Food Anim Pract 1994;10:107115.

  • 4.

    Drewry JJ, Quigley JD III, Geiser DR, et al. Effect of high arterial carbon dioxide tension on efficiency of immunoglobulin G absorption in calves. Am J Vet Res 1999;60:609613.

    • Search Google Scholar
    • Export Citation
  • 5.

    Sawyer M, Osburn BI, Knight HD, et al. A quantitative serologic assay for diagnosing congenital infections in cattle. Am J Vet Res 1973;34:12811284.

    • Search Google Scholar
    • Export Citation
  • 6.

    Stott GH, Marx DB, Menefee BE, et al. Colostral immunoglobulin transfer in calves. III. Amount of absorption. J Dairy Sci 1979;62:19021907.

    • Search Google Scholar
    • Export Citation
  • 7.

    Tyler JW, Steevens BJ, Hostetler DE, et al. Colostral immunoglobulin concentrations in Holstein and Guernsey cows. Am J Vet Res 1999;60:11361139.

    • Search Google Scholar
    • Export Citation
  • 8.

    Hostetler D, Douglas VL, Tyler JW, et al. Immunoglobulin G concentrations in temporal fractions of first milking colostrums. J Appl Res Vet Med 2003;1:168171.

    • Search Google Scholar
    • Export Citation
  • 9.

    Deregt D, Smithson S, Kozub GC. A short incubation serum neutralization test for bovine viral diarrhea virus. Can J Vet Res 1992;56:161164.

    • Search Google Scholar
    • Export Citation
  • 10.

    Baszler TV, Adams S, Vander-Schalie J, et al. Validation of a commercially available monoclonal antibody-based competitive-inhibition enzyme-linked immunosorbent assay for detection of serum antibodies to Neospora caninum in cattle. J Clin Microbiol 2001;39:38513857.

    • Search Google Scholar
    • Export Citation
  • 11.

    Smith RD. Risk assessment and prevention. In: Smith RD, ed. Veterinary clinical epidemiology. 2nd ed. New York: CRC Press, 1995;91109.

    • Search Google Scholar
    • Export Citation
  • 12.

    Dohoo I, Martin W, Stryhn H. Measures of association. In: Veterinary epidemiologic research. Charlottetown, PEI, Canada: AVC Inc, 2003;121149.

    • Search Google Scholar
    • Export Citation
  • 13.

    Hall CA, Reichel MP, Ellis JT. Neospora abortions in dairy cattle: diagnosis, mode of transmission and control. Vet Parasitol 2004;128:231241.

    • Search Google Scholar
    • Export Citation
  • 14.

    Nielsen SS, Grohn YT, Quass RL, et al. Paratuberculosis in dairy cattle: variation of the antibody response in offspring attributable to the dam. J Dairy Sci 2002;85:406412.

    • Search Google Scholar
    • Export Citation
  • 15.

    Evermann JF, DiGiacomo RF, Hopkins SG. Bovine leukosis: understanding viral transmission and the methods of control. Vet Med (Praha) 1987;10:10511058.

    • Search Google Scholar
    • Export Citation
  • 16.

    Dean HJ, Hunsaker BD, Bailey OD, et al. Prevention of persistent infection in calves by vaccination of dams with noncytopathic type-1 modified-live bovine viral diarrhea virus prior to breeding. Am J Vet Res 2003;64:530537.

    • Search Google Scholar
    • Export Citation
  • 17.

    Lawrence WE. Congenital infection with Mycobacterium johnei in cattle. Vet Rec 1956;68:312314.

  • 18.

    Doyle TM. Foetal infection in Johne's disease. Vet Rec 1958;70:238.

  • 19.

    Seitz SE, Heider LE, Heuston WD, et al. Bovine fetal infection with Mycobacterium paratuberculosis. J Am Vet Med Assoc 1989;194:14231426.

    • Search Google Scholar
    • Export Citation
  • 20.

    Sweeney RW, Whitlock RH, Rosenberger AE. Mycobacterium paratuberculosis isolated from fetuses of infected cows not manifesting signs of the disease. Am J Vet Res 1992;53:477480.

    • Search Google Scholar
    • Export Citation
  • 21.

    Jacobsen KL, Bull RW, Miller JM, et al. Transmission of bovine leukemia virus: prevalence of antibodies in precolostral calves. Prev Vet Med 1982;1:265272.

    • Search Google Scholar
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    Thurmond MC, Carter DM, Puhr MJ, et al. An epidemiological study of natural in utero infection with bovine leukemia virus. Can J Comp Med 1983;47:316319.

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    Lassauzet MLG, Thurmond MC, Johnson WO, et al. Factors associated with in utero or periparturient transmission of bovine leukemia virus in calves on a California dairy. Can J Vet Res 1991;55:264268.

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    Nagy DW, Tyler JW, Kleiboeker SB, et al. Use of a polymerase chain reaction assay to detect bovine leukosis virus in dairy cattle. J Am Vet Med Assoc 2003;222:983985.

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  • 25.

    Nagy DW, Tyler JW, Kleiboeker SB. Decreased periparturient transmission of bovine leukosis virus in colostrum. J Vet Intern Med 2007;21:11041107.

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  • 26.

    Dubey JP. Neosporosis in cattle. Vet Clin North Am Food Anim Pract 2005;21:473483.

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    Staubli D, Sager H, Haerdi C, et al. Precolostral serology in calves born from Neospora-seropositive mothers. Parasitol Res 2006;99:398404.

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  • 28.

    Dubey JP, Buxton D, Wouda W. Pathogenesis of bovine neosporosis. J Comp Pathol 2006;134:267289.

  • 29.

    Guy CS, Williams DJL, Kelly DF, et al. Neospora caninum in persistently infected, pregnant cows: spontaneous transplacental infection is associated with an acute increase in maternal antibody. Vet Rec 2001;149:443449.

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  • 30.

    Osburn BI, MacLachlan NJ, Terrell TG. Ontogeny of the immune system. J Am Vet Med Assoc 1982;181:10491052.

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Frequency of detectable serum IgG concentrations in precolostral calves

Munashe Chigerwe BVSc1, Jeff W. Tyler DVM, PhD2, Dusty W. Nagy DVM, PhD3, and John R. Middleton DVM, PhD4
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  • 1 Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211
  • | 2 Department of Veterinary Medicine and Surgery and Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211
  • | 3 Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211
  • | 4 Department of Veterinary Medicine and Surgery and Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211.

Abstract

Objective—To determine the prevalence of detectable serum IgG concentrations in calves prior to ingestion of colostrum and to assess whether a detectable IgG concentration was related to dam parity, calf birth weight, calf sex, season of calving, or infectious agents that can be transmitted transplacentally.

Animals—170 Holstein dairy calves.

Procedures—Serum samples were obtained from calves prior to ingestion of colostrum, and serologic testing for bovine viral diarrhea virus (BVDV) and Neospora caninum was performed. Relative risk, attributable risk, population attributable risk, and population attributable fraction for calves with a detectable serum IgG concentration attributable to positive results for N caninum and BVDV serologic testing were calculated. Logistic regression analysis was used to determine whether dam parity, calf sex, season of calving, and calf weight were associated with precolostral IgG concentration.

Results—90 (52.9%) calves had a detectable total serum IgG concentration (IgG ≥ 16 mg/dL). Relative risk, attributable risk, population attributable risk, and population attributable fraction for calves with a detectable serum IgG concentration attributable to positive results for N caninum serologic testing were 1.66, 0.34, 0.014, and 0.03, respectively. Calf sex, calf birth weight, and season of calving were not significant predictors for detection of serum IgG in precolostral samples.

Conclusions and Clinical Relevance—Prevalence of IgG concentrations in precolostral serum samples was higher than reported elsewhere. There was no apparent link between serum antibodies against common infectious agents that can be transmitted transplacentally and detection of measurable serum IgG concentrations.

Abstract

Objective—To determine the prevalence of detectable serum IgG concentrations in calves prior to ingestion of colostrum and to assess whether a detectable IgG concentration was related to dam parity, calf birth weight, calf sex, season of calving, or infectious agents that can be transmitted transplacentally.

Animals—170 Holstein dairy calves.

Procedures—Serum samples were obtained from calves prior to ingestion of colostrum, and serologic testing for bovine viral diarrhea virus (BVDV) and Neospora caninum was performed. Relative risk, attributable risk, population attributable risk, and population attributable fraction for calves with a detectable serum IgG concentration attributable to positive results for N caninum and BVDV serologic testing were calculated. Logistic regression analysis was used to determine whether dam parity, calf sex, season of calving, and calf weight were associated with precolostral IgG concentration.

Results—90 (52.9%) calves had a detectable total serum IgG concentration (IgG ≥ 16 mg/dL). Relative risk, attributable risk, population attributable risk, and population attributable fraction for calves with a detectable serum IgG concentration attributable to positive results for N caninum serologic testing were 1.66, 0.34, 0.014, and 0.03, respectively. Calf sex, calf birth weight, and season of calving were not significant predictors for detection of serum IgG in precolostral samples.

Conclusions and Clinical Relevance—Prevalence of IgG concentrations in precolostral serum samples was higher than reported elsewhere. There was no apparent link between serum antibodies against common infectious agents that can be transmitted transplacentally and detection of measurable serum IgG concentrations.

In primates, birds, carnivores, and rodents, there is transfer of maternal immunoglobulins to the fetus in utero across the placenta or yolk sac membrane.1 In ruminants, the maternal and fetal blood supply is separated by a syncytium formed by the syndesmochorial placenta, which prevents transplacental transfer of maternal immunoglobulins to the fetus.2 Consequently, calves are hypogammaglobulinemic at birth.3,4

Precolostral immunoglobulin concentration for specific pathogens can be assessed as a component of a diagnostic investigation in cows that abort.5 In these circumstances, detection of an appreciable IgG concentration is deemed suggestive of in utero exposure to pathogens.

Detection of low serum concentrations of IgG, IgM, and IgA in calves at birth has been reported.5,6 In one of those studies,6 37% of calves had detectable immunoglobulin concentrations in samples obtained before ingestion of colostrum; however, the lower limit for the detection of immunoglobulins was not indicated. The purpose of the study reported here was to determine the prevalence of a detectable serum IgG concentration in dairy calves prior to ingestion of colostrum and to assess whether the prevalence of a detectable precolostral IgG concentration was related to dam parity, calf birth weight, calf sex, season of calving, or fetal serologic recognition of common infectious agents that can be transmitted transplacentally.

Materials and Methods

Animals—One hundred seventy Holstein dairy calves (68 heifer calves and 102 bull calves) born sequentially from cows of various parities with confirmed breeding dates were selected from the University of Missouri Foremost Teaching and Research Dairy for use in the study. This herd used artificial insemination exclusively and recorded all estrus and breeding events. Pregnancy diagnosis was performed on all cows within 45 days after breeding. Consequently, accurate calving dates were available for all cows. Adult cows were vaccinated annually with a multivalent vaccine (infectious bovine rhinotracheitis virus, BVDV types 1 and 2, parainfluenza-3 virus, bovine respiratory syncytial virus, Campylobacter fetus, and Leptospira spp [serovars Canicola, Grippotyphosa, Hardjo, Pomona, and Icterohemorrhagiae]).a Additionally, cows were vaccinated with an Escherichia colib bacterin at the end of lactation, 1 month before parturition, and at parturition. Calves were vaccinated with a multivalent vaccine (infectious bovine rhinotracheitis virus, BVDV type 1 and 2, parainfluenza-3 virus, and bovine respiratory syncytial virus)c at 2, 4, 6, and 12 months of age. The study was approved by the University of Missouri, Columbia, Animal Care and Use Committee.

Sample collection—Only calves whose births were observed were enrolled in the study. After parturition, each calf was immediately separated from its dam, weighed, and assigned a unique identification number. Heifer and bull calves were enrolled in the study. Serum samples were obtained from all calves within 1 hour after birth but before calves were provided colostrum. Samples were stored at −20°C until processed for serum immunoglobulin determinations and serologic testing to detect antibodies against BVDV and Neospora caninum.

Serum IgG determination—Total serum IgG concentrations were determined by adaptation of a radial immunodiffusion technique described elsewhere.7,8 Radial immunodiffusion plates for measuring IgG were prepared by dissolving 1% agarosed in a sodium barbital buffere containing 0.1% sodium azide.f Rabbit–anti-bovine IgGg (1%) was added to thawed agarose solution. Eleven milliliters of the agarose solution was added to 10-cm Petri dishes. After the agarose solidified, 3-mm wells were cut in the agar. Serum samples were diluted 1:2 with barbital buffer, and 5 μL was inoculated in each well. Plates were incubated for 72 hours at 23°C, and diameter of the zone of precipitation was then recorded. Sample IgG concentrations were determined by comparing the diameter of zones of precipitation with a standard curve generated by use of serial dilutions of a bovine IgG standard.h The regression equation generated for this technique can accurately predict inoculum IgG concentration. Lower detection limit of the radial immunodiffussion assay was 16 mg/dL.

Serologic testing—A serum neutralization test for BVDV type 1 was performed. Serologic titers against BVDV were determined by adaptation of a technique reported elsewhere.9 Briefly, titers were determined for heat-inactivated (56°C) serum samples (in duplicate), starting at a dilution of 1:4. The serum-virus mixture was incubated for 1 hour at 37°C. Trypsinized MadinDarby bovine kidney cells (0.05 mL of cell suspension) in medium were added to microtiter plates containing growth media (2mM L-glutamine and Earle's buffered saline solution containing 1.5 g of sodium bicarbonate/L, 0.1mM nonessential amino acids, 1.0mM sodium pyruvate, and 10% horse serum). Microtiter plates were incubated for 48 to 72 hours at 37°C in a humid, 5% carbon dioxide environment. Test sample wells were assessed for cytopathic effect at 48 to 72 hours by use of an inverted ocular of a light microscope. Endpoint antibody titer was defined as the highest dilution of serum at which virus neutralization was detected.

A commercial competitive ELISAi for detecting antibody against N caninum also was performed on all serum samples from calves, as described elsewhere.10 Diagnostic sensitivity and specificity of the competitive ELISA were 97.6% and 98.6%, respectively, by use of a cutoff value of 30% inhibition.10

Data analysis—The proportion of calves with a detectable serum IgG concentration and the mean ± SEM serum IgG concentration in calves with a detectable IgG concentration were calculated. The RR, AR, PAR, and PAF for calves that had a detectable serum IgG concentration attributable to a positive result for serologic testing to detect N caninum or BVDV also were calculated.11,12 Logistic regression was used to determine whether dam parity, calf sex, calf weight, and season of calving were associated with detection of precolostral IgG concentrations (dependent variable).j Detection or nondetection of an IgG concentration was treated as a binomial variable (0, serum IgG was not detectable; 1, detectable serum IgG concentration). Dam parity was treated as a categoric independent variable (first lactation, second lactation, and ≥ 3 lactations). Calf sex was treated as an independent binomial variable (0, male; 1, female). Calf weight was treated as a continuous independent variable. Season of calving was treated as an independent categoric variable and was divided into 4 seasons (winter [December, January, and February], spring [March, April, and May], summer [June, July, and August], and autumn [September, October, and November]). Variables were considered for inclusion in a stepwise logistic regression model when the value to enter was P < 0.05 by use of the Wald-C statistic.j The variable with the smallest P value to enter was added to the model at each step. The goodness-of-fit of the final model was estimated through the Hosmer-Lemeshow χ2-test statistic.j

Results

The regression equation generated by comparing the diameter of zones of precipitation with a standard curve generated by use of serial dilutions of a bovine IgG standard accurately predicted IgG concentrations (R2 = 0.98; Figure 1). Ninety (52.9%) calves had a detectable serum IgG concentration (IgG ≥ 16 mg/dL). Mean ± SEM serum IgG concentration for calves that had a detectable IgG concentration was 63.9 ± 4.9 mg/dL. The range of serum IgG concentrations in calves with a detectable serum IgG concentration prior to ingestion of colostrum was 16 to 234 mg/dL. The distribution of serum IgG concentrations in calves was determined (Figure 2).

Figure 1—
Figure 1—

Figure 1—Plot of serial dilutions of a standard bovine IgG and the resulting diameter of the zone of precipitation. Linear regression analysis revealed a high correlation (R2 = 0.98). Equation for the linear regression was as follows: IgG concentration = 0.0209 + (0.0039 × [zone diameter]2).

Citation: American Journal of Veterinary Research 69, 6; 10.2460/ajvr.69.6.791

Figure 2—
Figure 2—

Histogram of the relative frequency of various IgG concentrations in serum samples obtained from 170 Holstein dairy calves prior to ingestion of colostrum.

Citation: American Journal of Veterinary Research 69, 6; 10.2460/ajvr.69.6.791

One of 170 (0.6%) calves had positive results for a serum neutralization test (serum neutralization titer of 1:4) to detect BVDV type 1. Seven of 170 (4.1%) calves had positive results when serologically tested for N caninum. All serum samples that had positive results for BVDV type 1 or N caninum, except for 1 (positive result for N caninum), had a detectable serum IgG concentration. The RR, AR, PAR, and PAF for calves that had a detectable serum IgG concentration attributable to a positive result for N caninum were 1.66, 0.34, 0.014, and 0.03, respectively. The RR, AR, PAR, and PAF for calves that had a detectable serum IgG concentration attributable to a positive result for BVDV were not reported because only 1 calf had a positive result for BVDV for the serum neutralization test.

A logistic regression equation for the probability that a precolostral calf would have a detectable IgG concentration was generated: PIgG = 1/(1 + exp[0.1457 − {0.7996 × second parity}]), where PIgG is the probability of a detectable IgG concentration and exp is the exponential function. The probability that a precolostral calf from a second-lactation cow would have a detectable IgG concentration was 0.66, whereas the probability that a precolostral calf from a first-lactation cow or a cow in her third or greater lactation would have a detectable IgG concentration was 0.46. Thus, precolostral calves from second-lactation cows were 1.4 times as likely to have a detectable IgG concentration (RR = 0.66/0.46 = 1.4) as were precolostral calves from a firstlactation cow or a cow in her third or greater lactation. Calf sex, calf birth weight, and season of calving were not significant predictors of a detectable precolostral serum IgG concentration.

Discussion

A detectable serum IgG concentration in calves before ingestion of colostrum indicates transplacental transfer, de novo IgG production by the fetus after transplacental exposure or transcervical exposure, or an invalid assay for measurement of serum IgG concentrations. The linear regression equation for predicting IgG concentration in serum samples was generated by use of a broad range of standard concentrations of bovine IgG. Results clearly indicated a linear dose-response relationship and lack of systematic error at IgG concentrations as low as 16 mg/dL (Figure 1). Hence, transplacental transfer of IgG or production of IgG by the fetus appears to be more likely. Possible reasons for the wide range of IgG concentrations include the type of antigen, duration of exposure, and age of the fetus at the time of exposure to the antigen. An increase in IgG and IgM concentrations has been detected in serum samples obtained from precolostral calves naturally or experimentally infected with BVDV, Coxiella burnetii, Campylobacter fetus, Chlamydia organisms, and blue tongue virus, compared with immunoglobulin concentrations for control bovine fetuses and uninfected precolostral calves.5 It should be mentioned that only serum IgG was determined in the study reported here, whereas serum IgM and IgA concentrations were determined in the aforementioned study.5 Additionally, IgG subclassification was not performed. To further evaluate potential causes of precolostral serum IgG concentrations, infectious agents that can be transmitted transplacentally were considered. Common infectious agents that can be transmitted in utero in cattle include N caninum,13 MAP,14 BLV,15 and BVDV.16

The study herd consisted of 200 lactating dairy cows. The seroprevalence of MAP for the study herd was 6%, as determined on the basis of results for an ELISA.k Reported rates of transplacental MAP transmission range from 21% to 37% in cows with clinical signs of paratuberculosis.17,18,19 However, a low prevalence (8.6%) of fetal infections has been detected in calves born to cows without clinical signs of paratuberculosis.20 Consequently, MAP transmission and de novo serologic responses are unlikely causes of common detectable serum IgG concentrations in precolostral calves. Reported rates of transplacental BLV transmission range from 3% to 20%,15 with lower estimates reported more often.21,22,23 Accepting that there was an in utero transmission rate of 10%, as well as a reported BLV prevalence of 80% in this herd,24 it would appear that BLV infection was an unlikely cause of serum IgG concentrations in precolostral calves because only 8% of calves would have been infected at birth. In addition, another study25 that involved this herd revealed a transplacental transmission rate of 0% in 32 cows. It is important to mention that serologic tests used in the study reported here were qualitative. Thus, it is possible that the serologic tests may have required a higher IgG concentration than was detected in our study to be considered serologically positive. Consequently, precolostral IgG concentrations against the agents tested may have existed but not been detected by the serologic assays used in the study; thus, the number of calves with IgG attributable to each of the agents may have been underestimated.

Cattle in the study herd were annually vaccinated against BVDV by use of a multivalent modifiedlive vaccine that contained both type 1 and type 2.a All cattle, regardless of pregnancy status, were vaccinated. Only 1 (0.6%) calf had positive results when tested to detect antibodies against BVDV type 1. If a positive serologic result was attributable to transfer of immunoglobulins from dam to calf in utero as a result of vaccination, all calves should have had positive results for BVDV type 1. Vaccination with BVDV type 1 protects a fetus from infection with heterologous virulent strains.16 Results for that single calf suggest that in utero BVDV infection and subsequent response to the infection in utero by fetuses is an uncommon event in this herd.

Seroprevalence for N caninum varies with country, region, and type of serologic test used.26,27 Historical prevalence of N caninum on the farm for the study reported here was 50%, as determined on the basis of whole-herd serologic testing performed before study samples were acquired. Hence, 85 precolostral calves typically would have been expected to be seropositive. However, detected rates of vertical transmission vary,28 and infection can be transmitted intermittently.29 For any 100 calves in the herd, only 2 calves had detectable serum IgG concentrations attributable to positive results for N caninum serologic testing (PAR = 0.014). Consequently, N caninum was considered an unlikely cause of the high prevalence of detectable precolostral serum IgG concentrations.

The time at which a bovine fetus becomes immunocompetent ranges from 145 to 200 days of gestation.16,30 Results of the study reported here suggested that a significant proportion of calves are gammaglobulinemic at birth prior to ingestion of colostrum. Calves from second-lactation cows were 1.4 times as likely to have a detectable precolostral IgG concentration as were calves from first-lactation cows or cows in their third or greater lactation. The cause for this result remains unknown. It should be mentioned that another study6 as well as the study reported here were performed in single herds. Variation among herds with regard to prevalence of precolostral IgG concentrations may exist. On the basis of our results, it appeared that in utero production of detectable concentrations of IgG was more common than has been reported. Serologic testing was unable to identify correlations with any agents that are believed to be commonly transmitted transplacentally in cattle. Consequently, fetal production of IgG was associated with transplacental infection of a specific undetermined pathogen or, alternatively, should be considered a common event associated with in utero exposure and response to a broad range of antigens.

ABBREVIATIONS

AR

Attributable risk

BLV

Bovine leukosis virus

BVDV

Bovine viral diarrhea virus

MAP

Mycobacterium avium subsp paratuberculosis

PAF

Population attributable fraction

PAR

Population attributable risk

RR

Relative risk

a.

Bovi-shield Gold FP VL5, Pfizer Animal Health, Exton, Pa.

b.

Escherichia coli J-5 strain, Boehringer Ingelheim, St Joseph, Mo.

c.

Bovi-shield Gold 5, Pfizer Animal Health, Exton, Pa.

d.

Agarose, Sigma-Aldrich Co, St Louis, Mo.

e.

Barbital buffer, Sigma-Aldrich Co, St Louis, Mo.

f.

Sodium azide, Sigma-Aldrich Co, St Louis, Mo.

g.

Anti-bovine IgG (whole molecule) developed in rabbit IgG fraction of anti-serum, Sigma-Aldrich Co, St Louis, Mo.

h.

Bovine IgG (lyophilized), Sigma-Aldrich Co, St Louis, Mo.

i.

Neospora caninum antibody test kit, cELISA, VMRD, Pullman, Wash.

j.

PROC LOGISTIC, SAS for Windows, version 9.13, SAS Institute Inc, Cary, NC.

k.

CSL Veterinary/Biocur Animal Health, Omaha, Neb.

References

  • 1.

    Larson BL, Heary JR, Devery JE. Immunoglobulin production and transport by the mammary gland. J Dairy Sci 1979;63:655671.

  • 2.

    Arthur GH. The development of the conceptus. In: Arthur GH,Noakes DE,Pearson H,et al, eds. Pregnancy and parturition in veterinary reproduction and obstetrics. 2nd ed. Philadelphia: WB Saunders, 1999;51109.

    • Search Google Scholar
    • Export Citation
  • 3.

    Besser TE, Gay CC. The importance of colostrum to the health of the neonatal calf. Vet Clin North Am Food Anim Pract 1994;10:107115.

  • 4.

    Drewry JJ, Quigley JD III, Geiser DR, et al. Effect of high arterial carbon dioxide tension on efficiency of immunoglobulin G absorption in calves. Am J Vet Res 1999;60:609613.

    • Search Google Scholar
    • Export Citation
  • 5.

    Sawyer M, Osburn BI, Knight HD, et al. A quantitative serologic assay for diagnosing congenital infections in cattle. Am J Vet Res 1973;34:12811284.

    • Search Google Scholar
    • Export Citation
  • 6.

    Stott GH, Marx DB, Menefee BE, et al. Colostral immunoglobulin transfer in calves. III. Amount of absorption. J Dairy Sci 1979;62:19021907.

    • Search Google Scholar
    • Export Citation
  • 7.

    Tyler JW, Steevens BJ, Hostetler DE, et al. Colostral immunoglobulin concentrations in Holstein and Guernsey cows. Am J Vet Res 1999;60:11361139.

    • Search Google Scholar
    • Export Citation
  • 8.

    Hostetler D, Douglas VL, Tyler JW, et al. Immunoglobulin G concentrations in temporal fractions of first milking colostrums. J Appl Res Vet Med 2003;1:168171.

    • Search Google Scholar
    • Export Citation
  • 9.

    Deregt D, Smithson S, Kozub GC. A short incubation serum neutralization test for bovine viral diarrhea virus. Can J Vet Res 1992;56:161164.

    • Search Google Scholar
    • Export Citation
  • 10.

    Baszler TV, Adams S, Vander-Schalie J, et al. Validation of a commercially available monoclonal antibody-based competitive-inhibition enzyme-linked immunosorbent assay for detection of serum antibodies to Neospora caninum in cattle. J Clin Microbiol 2001;39:38513857.

    • Search Google Scholar
    • Export Citation
  • 11.

    Smith RD. Risk assessment and prevention. In: Smith RD, ed. Veterinary clinical epidemiology. 2nd ed. New York: CRC Press, 1995;91109.

    • Search Google Scholar
    • Export Citation
  • 12.

    Dohoo I, Martin W, Stryhn H. Measures of association. In: Veterinary epidemiologic research. Charlottetown, PEI, Canada: AVC Inc, 2003;121149.

    • Search Google Scholar
    • Export Citation
  • 13.

    Hall CA, Reichel MP, Ellis JT. Neospora abortions in dairy cattle: diagnosis, mode of transmission and control. Vet Parasitol 2004;128:231241.

    • Search Google Scholar
    • Export Citation
  • 14.

    Nielsen SS, Grohn YT, Quass RL, et al. Paratuberculosis in dairy cattle: variation of the antibody response in offspring attributable to the dam. J Dairy Sci 2002;85:406412.

    • Search Google Scholar
    • Export Citation
  • 15.

    Evermann JF, DiGiacomo RF, Hopkins SG. Bovine leukosis: understanding viral transmission and the methods of control. Vet Med (Praha) 1987;10:10511058.

    • Search Google Scholar
    • Export Citation
  • 16.

    Dean HJ, Hunsaker BD, Bailey OD, et al. Prevention of persistent infection in calves by vaccination of dams with noncytopathic type-1 modified-live bovine viral diarrhea virus prior to breeding. Am J Vet Res 2003;64:530537.

    • Search Google Scholar
    • Export Citation
  • 17.

    Lawrence WE. Congenital infection with Mycobacterium johnei in cattle. Vet Rec 1956;68:312314.

  • 18.

    Doyle TM. Foetal infection in Johne's disease. Vet Rec 1958;70:238.

  • 19.

    Seitz SE, Heider LE, Heuston WD, et al. Bovine fetal infection with Mycobacterium paratuberculosis. J Am Vet Med Assoc 1989;194:14231426.

    • Search Google Scholar
    • Export Citation
  • 20.

    Sweeney RW, Whitlock RH, Rosenberger AE. Mycobacterium paratuberculosis isolated from fetuses of infected cows not manifesting signs of the disease. Am J Vet Res 1992;53:477480.

    • Search Google Scholar
    • Export Citation
  • 21.

    Jacobsen KL, Bull RW, Miller JM, et al. Transmission of bovine leukemia virus: prevalence of antibodies in precolostral calves. Prev Vet Med 1982;1:265272.

    • Search Google Scholar
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Contributor Notes

Supported in part by US Agricultural Experiment Station Funds, USDA Formula Funds, and University of Missouri Departmental Committee on Research Funds.

The authors thank John Denbigh and Eric Adkins for technical assistance.

Address correspondence to Dr. Chigerwe.