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in Journal of the American Veterinary Medical Association

Summary

The effects of alkalinizing agents, administered prior to feeding colostrum, on blood-gas and acid-base values and on absorption of IgGl were determined in 40 newborn Holstein calves. Two treatments, sodium bicarbonate (3 mEq/kg of body weight, IV) and doxapram HCl (2 mg/kg, IV), were evaluated, using a randomized complete-block experimental design. These treatments resulted in significant (P< 0.01) alteration of blood-gas and acid-base values, generally in the direction of normal values for adult cattle. Significant least squares mean effects were detected for sodium bicarbonate treatment on blood pH ( + 0.04 units, P < 0.01), Pco2( + 4.1 mm of Hg, P <0.01), and HCO3 concentration ( + 4.4 mEq/L, P < 0.01). Significant least squares mean effects were detected for doxapram HC1 treatment on blood pH ( + 0.06 pH units, P <0.01) and Pco2(–5.2 mm of Hg, P <0.01). Absorption of colostral IgGl was not affected by the treatments given or by the altered blood-gas and/or acid-base status.

Free access
in American Journal of Veterinary Research

Objective

To assees the relationship of WBC counts and partial oxygen tension in the portal vein and caudal vena cava with portal bacteremia, bacteria in the liver, and postoperative morbidity and mortality in dogs with portosystemic shunts.

Design

Prospective study.

Animals

12 clinically normal dogs and 15 dogs with single congenital portosystemic shunts.

Procedure

Blood was collected from the portal vein and caudal vena cava for aerobic and anaerobic bacterial culture, WBC count, and measurement of partial oxygen tension. Samples of liver tissue, indwelling catheters, and fluids administered IV were also obtained for bacterial culture.

Results

Bacteria were cultured from samples obtained from the portal vein and caudal vena cava of 1 dog with a shunt and from the caudal vena cava of 1 clinically normal dog; neither dog had postoperative complications. In dogs with shunts and in clinically normal dogs, partial oxygen tension in the portal vein was significantly greater than that in the caudal vena cava. Postoperative complications were identified in 33% of dogs with shunts. Partial oxygen tensions of dogs with shunts with postoperative complications did not significantly differ from those of all dogs with shunts or dogs with shunts without complications. Significant differences in WBC counts were not found when comparing dogs with shunts with and without complications. Anaerobic bacteria were not cultured from the liver of any dog.

Clinical Implications

Leukocytosis, portal bacteremia, and portal hypoxemia were not notable findings in dogs with shunts and were not correlated with postoperative morbidity or mortality. (J Am Vet Med Assoc 1997;211:715–718)

Free access
in Journal of the American Veterinary Medical Association

Summary

Absorption of colostral immunoglobulins by Holstein calves was studied in 3 herds in which 3 methods of colostrum feeding were used. Failure of passive transfer, as determined by calf serum immunoglobulin G1 (IgG1) concentration < 10 mg/ml at 48 hours of age, was diagnosed in 61.4% of calves from a dairy in which calves were nursed by their dams, 19.3% of calves from a dairy using nipple-bottle feeding, and 10.8% of calves from a dairy using tube feeding.

The management factor determined to have the greatest influence on the probability of failure of passive transfer in the herds using artificial methods of colostrum feeding (bottle feeding or tube feeding) was the volume of colostrum fed as it affected the amount of IgG1 received by the calf. In dairies that used artificial feeding methods, failure of passive transfer was infrequent in calves fed ≥ 100 g IgG1 in the first colostrum feeding. In the dairy that allowed calves to suckle, prevalence of failure of passive transfer was greater than 50% even among calves nursed by cows with above-average colostral IgG1 concentration. Analysis of the effect of other management factors on calf immunoglobulin absorption revealed small negative effects associated with the use of previously frozen colostrum and the use of colostrum from cows with long nonlactating intervals.

Free access
in Journal of the American Veterinary Medical Association

Summary

The effect of postnatal acid-base status on the absorption of colostral immunoglobulins by calves was examined in 2 field studies. In study 1, blood pH at 2 and 4 hours after birth was related to serum IgG1 concentration 12 hours after colostrum feeding (P < 0.05). Decreased IgG1 absorption from colostrum was associated with respiratory, rather than metabolic, acidosis, because blood PCO2 at 2 and 4 hours after birth was negatively related to IgG1 absorption (P < 0.05), whereas serum bicarbonate concentration was not significantly related to IgG1 absorption.

Acidosis was frequently observed in the 30 calves of study 1. At birth, all calves had venous PCO2 value ≥ 60 mm of Hg, 20 of the calves had blood pH < 7.20, and 8 of the calves had blood bicarbonate concentration < 24 mEq/L. Blood pH values were considerably improved by 4 hours after birth; only 7 calves had blood pH values < 7.20.

Calves lacking risk factors for acidosis were examined in study 2, and blood pH values at 4 hours after birth ranged from 7.25 to 7.39. Blood pH was unrelated to IgG1 absorption in the calves of study 2. However, blood PCO2 was again found to be negatively related to colostral IgG1 absorption (P < 0.005).

Results indicate that postnatal respiratory acidosis in calves can adversely affect colostral immunoglobulin absorption, despite adequate colostrum intake early in the absorptive period.

Free access
in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association

Objective

To examine the ability of several commonly used tests for evaluation of passive transfer of immunoglobulin to predict mortality in dairy replacement heifers.

Design

Prospective observational study.

Animals

246 dairy replacement heifers between 1 and 8 days of age.

Procedure

Using serum samples obtained from each calf, total serum protein concentration and results of zinc sulfate turbidity, sodium sulfite turbidity, radial immunodiffusion, and glutaraldehyde coagulation were determined. Calves were monitored for 100 days, and relative risks for death were calculated. Logistic regression models predicting death also were developed.

Results

None of the logistic regression models detected a significant association between test results and mortality. The greatest relative risks of mortality were observed in calves with serum protein concentrations < 4.5 g/dl, serum IgG, concentrations < 500 mg/dl, and sodium sulfite test scores < 1+.

Clinical Implications

Calves with lower passive transfer values had increased risk of death; however, failure of passive transfer is not an infallible predictor of mortality. (J Am Vet Med Assoc 1996;208:2047-2049)

Free access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To evaluate the association between maintaining joint hospital and maternity pens and persistence of multi–drug-resistant (MDR) Salmonella enterica serovar Newport on 2 dairy farms.

Design—Observational study.

Sample Population—Feces and environmental samples from 2 dairy herds.

Procedure—Herds were monitored for fecal shedding of S enterica Newport after outbreaks of clinical disease. Fecal and environmental samples were collected approximately monthly from pens housing sick cows and calving cows and from pens containing lactating cows. Cattle shedding the organism were tested serially on subsequent visits to determine carrier status. One farm was resampled after initiation of interventional procedures, including separation of hospital and maternity pens. Isolates were characterized via serotyping, determination of antimicrobial resistance phenotype, detection of the CMY-2 gene, and DNA fingerprinting.

Results—The prevalence (32.4% and 33.3% on farms A and B, respectively) of isolating Salmonella from samples from joint hospital-maternity pens was significantly higher than the prevalence in samples from pens housing preparturient cows (0.8%, both farms) and postparturient cows on Farm B (8.8%). Multi–drug-resistant Salmonella Newport was isolated in high numbers from bedding material, feed refusals, lagoon slurry, and milk filters. One cow excreted the organism for 190 days. Interventional procedures yielded significant reductions in the prevalences of isolating the organism from fecal and environmental samples. Most isolates were of the C2 serogroup and were resistant to third-generation cephalosporins.

Conclusions and Clinical Relevance—Management practices may be effective at reducing the persistence of MDR Salmonella spp in dairy herds, thus mitigating animal and public health risk.

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To describe geographic, farm-type, and animal-type factors associated with multiple antimicrobial resistance (MAR) in fecal Escherichia coli isolates from cattle.

Design—Cross-sectional field study.

Sample Population—1,736 fecal samples from cattle on 38 farms in California, Oregon, and Washington.

Procedures—Fecal samples were collected from preweaned calves (2 to 4 weeks old) and cows that recently calved on dairy and beef cow-calf farms, preweaned calves on calf ranches, and 1-year-old steers on feedlots. One fecal E coli isolate per sample was isolated, and antimicrobial susceptibility was tested. Escherichia coli isolates were initially clustered by antimicrobial resistance patterns and categorized by number of antimicrobial resistances. A generalized estimating equations cumulative logistic regression model was used to identify factors associated with an increase in MAR in fecal E coli isolates from cattle.

Results—MAR was higher in E coli isolates from cattle in California, compared with those from cattle in Washington or Oregon. Multiple antimicrobial resistance was highest in E coli isolates from calves on calf ranches and progressively lower in isolates from feedlot steers, dairy cattle, and beef cattle. Multiple antimicrobial resistance was higher in E coli isolates from calves than from adult cattle, in E coli isolates from cattle of conventional farms than of organic farms, and in isolates from beef cattle in intensive dairy farm regions than from beef cattle distant from dairy farm regions.

Conclusions and Clinical Relevance—MAR in fecal E coli isolates from cattle was influenced by factors not directly associated with the use of antimicrobials, including geographic region, animal age, and purpose (beef vs dairy).

Full access
in Journal of the American Veterinary Medical Association