Search Results

You are looking at 101 - 110 of 369 items for :

  • "colostrum" x
  • Refine by Access: All Content x
Clear All

Summary:

Four dairy cows that had been successfully rebred following fetal Neospora infection and abortion were identified from 2 drylot dairies. All 4 cows had uncomplicated pregnancies with the birth of 5 full-term calves. The calves all had high precolostral serum IgG antibodies. The precolostral antibodies to Neospora sp as determined by indirect fluorescent antibody test ranged from 5,120 to 20,480, compared with maternal serum and colostral antibody titers from 320 to 1,280. Two calves had mild neurologic limb deficits. Three calves had mild nonsuppurative encephalomyelitis and Neospora organisms were found in the CNS of 3 calves. Findings indicate that repeat transplacental Neospora infections occur in cows. Additionally, calves born from cows with a history of Neospora fetal infection and abortion may have congenital Neospora infections and/or neurologic dysfunctions at birth. The Neospora indirect fluorescent antibody test appears to be a useful antemortem test for detection of calves exposed in utero to Neospora organisms.

Free access
in Journal of the American Veterinary Medical Association

Summary

A retrospective study of the results of 12,549 agar gel immunodiffusion tests for bovine leukemia virus, conducted on 1,296 dairy bulls over an 8-year period, was performed to estimate the sensitivity and specificity of the test. The number of tests performed on each bull ranged from 5 to 35, with a mean of 9.7 tests per bull.

Bulls were categorized by their agar gel immunodiffusion test responses; 1,069 (82.5%) were non-infected and 227 (17.5%) were infected. Eighteen false-positive results were reported from the noninfected bulls. Test specificity was estimated to be 99.8%. Thirty-one false-negative results were reported from the infected bulls. Test sensitivity was estimated to be 98.5%.

Fifty-six bulls had 1 or more positive responses when < 6 months old. In 26 (46%), these results were thought to be attributable to colostral immunity.

Free access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To compare the efficacy of a Salmonella bacterin and a modified live Salmonella ser. Choleraesuis vaccine on a commercial dairy.

Animals—450 cows in late gestation and 80 calves.

Procedure—Group-1 cows (n = 150) were vaccinated once with a modified live S Choleraesuis (serogroup C1) strain 54 (SC54) vaccine, group-2 cows (150) were vaccinated on enrollment and 30 days later with a Salmonella ser. Montevideo (serogroup C1) bacterin, and group-3 cows (150) served as unvaccinated controls. One gallon of colostrum harvested from the first 80 cows to calve was fed to each calf. Outcome assessments included fecal shedding of Salmonella spp for the first 10 days after parturition (cows) or birth (calves), milk production, involuntary culling rate, mastitis incidence, antimicrobial use, and mortality rate.

Results—Salmonellae were isolated from 306 of 309 (99%) cows and 64 of 74 (86.5%) calves. Shedding frequency was less in SC54-vaccinated cows and calves that received colostrum from those cows, compared with the other groups, and vaccination was specifically associated with less shedding of serogroup C1 salmonellae. Production data were similar among groups.

Conclusions and Clinical Relevance—Vaccination of pregnant cows with an autogenous Salmonella bacterin had no effect on fecal shedding of salmonellae, whereas vaccination with a modified live S Choleraesuis vaccine reduced the frequency of fecal shedding of serogroup C1 salmonellae during the peripartum period. A commercial S Choleraesuis vaccine licensed for use in swine may be more efficacious than autogenous Salmonella bacterins on dairies infected with serogroup C1 salmonellae. (Am J Vet Res 2001;62:1897–1902)

Full access
in American Journal of Veterinary Research

Abstract

Objective—To determine the effect of maternally derived antibodies on induction of protective immune responses against bovine viral diarrhea virus (BVDV) type II in young calves vaccinated with a modified-live bovine viral diarrhea virus (BVDV) type I vaccine.

Design—Blinded controlled challenge study.

Animals—24 neonatal Holstein and Holstein-cross calves that were deprived of maternal colostrum and fed pooled colostrum that contained a high concentration of (n = 6) or no (18) antibodies to BVDV.

Procedure—At 10 to 14 days of age, 6 seropositive and 6 seronegative calves were given a combination vaccine containing modified-live BVDV type I. All calves were kept in isolation for 4.5 months. Six calves of the remaining 12 untreated calves were vaccinated with the same combination vaccine at approximately 4 months of age. Three weeks later, all calves were challenged intranasally with a virulent BVDV type II.

Results—Seronegative unvaccinated calves and seropositive calves that were vaccinated at 2 weeks of age developed severe disease, and 4 calves in each of these groups required euthanasia. Seronegative calves that were vaccinated at 2 weeks or 4 months of age developed only mild or no clinical signs of disease.

Conclusions and Clinical Relevance—Results indicate that a single dose of a modified-live BVDV type-I vaccine given at 10 to 14 days of age can protect susceptible young calves from virulent BVDV type II infection for at least 4 months, but high concentrations of BVDV-specific maternally derived antibodies can block the induction of the response. (J Am Vet Med Assoc 2001;219:351–356)

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective

To determine insulin-like growth factor-I (IGF-I) concentrations in canine mammary secretions and serum during lactation and to compare them between small and giant breeds of dogs.

Animals

7 gestating Beagles and 4 gestating Great Danes.

Procedure

Dogs were fed a common nutritionally complete and adequate gestation and lactation diet. Milk samples were collected at postpartum hour 12 and postpartum days 3, 7, 14, 21, and 28 after IV oxytocin administration. Two puppies/litter were identified at whelping for collection of blood samples corresponding to the days of milk sample collection plus days 35 and 42. Maternal blood samples were obtained on days 1, 7, and 42 from Beagles and days 1, 7, and 28 from Great Danes and were acid/ethanol extracted and analyzed by use of a radioimmunoassay.

Results

Maternal serum IGF-I concentration was greater in Great Danes at all sample collection times. Similarly, colostrum from Great Danes contained more IGF-I, compared with that of Beagles (70 ng/ml vs 40 ng/ml, respectively). These values decreased to approximately 10 ng/ml by day 3 in both breeds and remained between 10 and 20 ng/ml for the duration of lactation. Growth rate and serum IGF-I concentration were greater in Great Dane puppies at birth to day 42.

Conclusions and Clinical Relevance

High IGF-I concentration in colostrum may be biologically important for newborn puppies. Body mass and serum IGF-I concentration are directly correlated in growing Beagle and Great Dane puppies. Serum IGF-I concentration may be an indicator of growth potential in dogs. (Am J Vet Res 1999;60:1088-1091)

Free access
in American Journal of Veterinary Research

Abstract

Objectives

To determine whether high PaCO2 reduced apparent efficiency of IgG absorption (AEA) in calves and whether assisted ventilation of calves with high PaCO2 increased AEA.

Animals

48 Holstein calves.

Procedures

Arterial and venous blood samples were collected 1, 13, and 25 hours after birth; an additional venous sample was collected at 37 hours after birth. Arterial samples were analyzed for PaCO2 , PaO2 , pH, and bicarbonate and base excess concentrations; venous samples were analyzed for plasma IgG concentrations. On the basis of 1-hour PaCO2 , calves were assigned to nonrespiratory acidosis (PaCO2 < 50 mm Hg; n = 19) or respiratory acidosis (PaCO2 ≥ 50 mm Hg; 29) groups. Calves in the respiratory acidosis group were assigned randomly to receive no further treatment (n = 17) or to be given 5 minutes of assisted ventilation (12). All calves received between 1.8 and 2 L of colostrum 2, 14, 26, and 38 hours after birth. Plasma volume and AEA were determined 25 hours after birth.

Results

1-hour PaCO2 had no effect on AEA or on plasma IgG concentrations determined 13, 25, or 37 hours after birth. Artificial ventilation had no effect on plasma IgG concentration or AEA.

Conclusions and Clinical Relevance

Lack of effect of 1-hour PaCO2 on AEA and IgG concentration indicated that calves compensated for moderate acidbase imbalances associated with birth. Calves born with high PaCO2 achieved adequate plasma IgG concentrations if fed an adequate amount of high-quality colostrum early in life. The effect of artificial ventilation on PaCO2 was temporary and did not increase AEA. (Am J Vet Res 1999;60:609–614)

Free access
in American Journal of Veterinary Research

Abstract

Objective

To determine the ability of porcine respiratory coronavirus (PRCV) infections to induce passive immunity in suckling pigs to transmissible gastroenteritis virus (TGEV) challenge exposure.

Design and Animals

4 TGEV seronegative sows and their litters (group A) served as controls, whereas 2 other groups (B and C) of sows (also TGEV seronegative) were oronasally inoculated with live PRCV during 1 or 2 subsequent pregnancies, respectively.

Procedure

Effectiveness of passive immunity provided to pigs via colostrum and milk was assessed after TGEV challenge exposure, and TGEV antibody responses in colostrum and milk were analyzed.

Results

Mortality in the 3 groups of young pigs correlated with severity of clinical signs of TGEV infection and was highest in control litters (86% in group-A pigs) and lowest in litters of sows inoculated with PRCV in 2 subsequent pregnancies (14% in group-C pigs). Virus-neutralization and IgA and IgG TGEV antibody titers of milk collected from sows at challenge exposure had significant positive correlation with litter survival. Significantly higher numbers of TGEV-specific IgA and IgG antibody-secreting cells were found in group-A pigs than in group-C pigs, suggesting that high titer of maternal antibodies (induced in group-C sows multiply exposed to PRCV) may interfere with active antibody responses.

Conclusions and Clinical Relevance

Results suggest that, in PRCV-infected pig herds, multiple exposures of pregnant sows are associated with higher IgA and IgG antibody titers to TGEV in milk, and these titers contribute to protection against TGEV infection. (Am J Vet Res 1996; 57:664–671)

Free access
in American Journal of Veterinary Research

SUMMARY

In an attempt to identify important predictors of failure of passive immunoglobulin transfer (< 800 mg of IgG/dl), identify calves with failure of passive immunoglobulin transfer, and determine the effects of a colostrum supplement, blood samples were collected from 263 calves at postpartum hours 10 and 24. Calves of dams diagnosed with mastitis had lower mean plasma protein and IgG concentrations at 10 (P < 0.05) and 24 (P < 0.01) hours. Plasma protein and IgG concentrations were similar for single and twin calves at 10 hours, but IgG concentration at 24 hours was higher (P < 0.01) in twin calves. Calves born to dams that had dystocia had numerically lower mean plasma protein and IgG concentrations than did calves born to dams that had normal delivery. However, observed differences were small and, after adjustment for other important factors, these differences were not significant. Age of dam was associated with plasma protein (P < 0.05) and IgG (P < 0.10) concentrations at 10 hours, but had no effect at 24 hours. Plasma protein and IgG concentrations decreased as calves were born later in the calving season, although the association of birth date with IgG concentration at 24 hours was marginal (P = 0.07). Calf sex, dam body condition score, and birth weight were not related to plasma protein or IgG values. The sensitivity and specificity of a cutoff value of 4.8 g of protein/dl of plasma, measured at 10 hours, for diagnosing failure of passive immunoglobulin transfer at 10 hours were 78 and 94%, and for diagnosing failure of passive immunoglobulin transfer at 24 hours were 88 and 73%, respectively. A colostrum supplement administered to calves with low plasma protein concentration at 10 hours had no effect on plasma protein or IgG values at 24 hours or on pre-weaning morbidity and mortality.

Free access
in American Journal of Veterinary Research

SUMMARY

The ability of pigs to respond immunologically to ingestion of bovine parvovirus (bpv) was tested by feeding 4 cesarean-derived, colostrum-deprived (cdcd) pigs a live virus-contaminated, liquid diet for the first 4 weeks of life. Virus-neutralizing (vn) antibodies were detected in the serum of 2 of the 4 pigs when they were 4 weeks old. Antibody titer remained at about the same level for several weeks, then decreased during the remainder of the 29-week interval of testing. The relative reactivity of these sera based on results of indirect immunofluorescence paralleled the corresponding vn titer. Neither of the other 2 pigs exposed to bpv had any appreciable immune response. The potential for passive acquisition of antibody from the diet was tested by feeding 4 other cdcd pigs bovine colostrum containing antibodies to bpv and bovine viral diarrhea virus (bvdv) for the first 2 days of life. All had serum vn antibodies for both viruses when they were tested at 2 days of age. The decay rate of the heterologous, passively acquired antibody was approximately linear; however, antibody half-life was relatively short, about 3.5 days, and titers were no longer detectable when pigs were 4 weeks (bpv) and 6 weeks (bvdv) old. An additional 4 cdcd pigs fed a liquid diet without virus or antibody remained free of any appreciable serum reactivity for either bpv or bvdv. Results supported the hypothesis that antibodies for bpv previously detected in the serum of pigs and people may reflect ingestion of virus-contaminated bovine milk or milk products.

Free access
in American Journal of Veterinary Research

model could increase skills scores for individuals without previous laparoscopic experience. See page 1079 Stored equine colostrum for treatment of foals at risk for failure of transfer of passive immunity Results of a new study indicate

Full access
in Journal of the American Veterinary Medical Association