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Colostrum from ewes that had been repeatedly exposed to cestode infection, whether or not their immunity was boosted by vaccination with Taenia ovis, transferred a strong immunity to the lambs. Susceptible ewes, not recently exposed to tapeworm eggs, gave no protection to their lambs via the colostrum. There was no evidence that colostrum-deprived lambs were more susceptible to infection with T ovis than lambs that received colostrum from non-immune ewes. Colostrum from naturally immune vaccinated ewes gave good protection to lambs for up to six weeks but thereafter the effect was variable. The immunity that developed in susceptible ewes after vaccination with activated embryos was not passed on to the lambs via the colostrum.  相似文献   

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Abstract Extract Many farmers in New Zealand find it necessary to vaccinate their sheep flocks against certain of the clostridial diseases. Effective vaccines are available to protect sheep against the major scourges of blackleg, enterotoxaemia (pulpy kidney), malignant oedema, tetanus and black disease, but, to secure the full protective potential of each vaccine, it must be applied in the optimum fashion. This means using a potent vaccine, correctly administered to responsive sheep at such time before exposure that protection will have reached its peak when the challenge is encountered. It is generally accepted that such an ideal set of circumstances is only rarely achieved in the field.  相似文献   

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The importance of blood and colostrum/milk serum gamma-glutamyl transferase (gamma-GT) enzyme activity was evaluated to assess passive transfer status in healthy lambs. Thirty Akkaraman sheep (3-6 years old) were used which had normal pregnancy period and the same conditions, and the age of the lambs ranged between 0 and 15 days. Blood and colostrum/milk samples were collected from sheep and lambs after birth, before suckling (0) and after on 1st, 3rd, 7th and 15th days. Serum immunoglobulin G (IgG) concentration was determined by the use of Single Radial Immunodiffusion method. Serum gamma-GT activity was measured, using a commercially available kit in blood and colostrum/milk samples. Correlations were carried out between immunoglobulin and gamma-GT levels. Regression models (simple and multiple) were calculated with significant data. Linear correlation was determined between colostrum/milk gamma-GT activity and IgG concentrations and between serum gamma-GT activity and IgG concentrations in lambs on the 0 day. (r: 0.607, P: 0.001), 1st (r: 0.768, P: 0.001) and the 3rd (r: 0.603, P: 0.001) days and on the 1st (r: 0.637, P: 0.001) and 3rd (r: 0.478, P: 0.012) days in the experiment, respectively. Multivariate regression models were developed to estimate sample IgG concentration. Serum and colostrum/milk IgG concentration could be predicted using the formula: lamb serum IgG = 825 + 0.688 (lamb gamma-GT) + 52 (days); colostrum/milk IgG = 832 + 0.505 (colostrum/milk gamma-GT) - 167 (days). The regression models were moderately accurate in predicting serum IgG concentration (R2 = 0.51) and colostrum/milk IgG concentration (R2 = 0.55). Test sensitivity and positive predictive values for serum gamma-GT enzyme activity were found to be 96 and 100% and for colostrum/milk gamma-GT enzyme activity were found to be 100 and 68% to prediction IgG concentration. Serum and colostrum/milk gamma-GT activity can be used to assess passive transfer status of lambs. Along with this, regression models used to calculate serum and colostrum/milk gamma-GT activities found to be useful to estimate sample IgG concentration. The use of serum and colostrum/milk gamma-GT enzyme activity was found useful especially after birth on the 0, 1st and 3rd days.  相似文献   

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Newborn lambs (n = 45) at the Agricultural Research Institute of Northern Ireland were fed either 50 grams of commercial lamb milk replacer or 50 grams of commercial colostrum replacer (bovine origin) in 200 ml of water four times during the first 24 hours of life or were given ad libitum access to the ewe. Total plasma protein at 24 hours of age was highest in lambs allowed to suckle the ewe (76.9 g/L). However, by 14 days of age, there were no differences in plasma protein levels among the three treatments. Bovine IgG was measured in lambs fed colostrum replacer and ovine IgG was measured in other lambs. Mean plasma IgG concentrations at 24 hours of age were 0.7 (milk replacer), 18.0 (colostrum replacer), and 26.6 (dam's milk) g/L. Bovine IgG administered orally to newborn lambs was adequately absorbed, and circulating IgG concentrations were sufficiently maintained throughout this study.  相似文献   

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Previous studies demonstrated that the anaemia encountered in lambs reared on bovine colostrum and a milk substitute was associated with the presence of immune complexes on lamb erythrocytes. In the present study the usefulness of a panel of 20 sheep sera for the detection of "anti-sheep" factors in bovine colostrum by double immunodiffusion in agarose was investigated. Utilising this method, 353 batches of bovine colostrum have been examined, 132 of which were declared safe for use in the rearing of lambs. When fed to lambs, only 2 samples (1.5%) caused anaemia as compared with up to 20% before this test was introduced. Experiments designed to determine whether the bovine colostra, declared anaemia-prone, would indeed cause anaemia when fed to lambs, showed our method to fully discriminate between safe and unsafe colostra for the rearing of lambs. In a follow-up collaborative study, set up to cover most of the Netherlands, the general validity of the test system described was demonstrated, using 114 batches of safe colostrum to feed 723 lambs. Further experiments are needed to determine the exact nature of the factor(s) involved in this phenomenon.  相似文献   

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The purpose of this study was to clarify whether cats have a colostral and milk phase of lactation differentiated by concentrations of immunoglobulins, and whether colostrum ingestion by newborn kittens is essential for optimal transfer of passive immunity. Milk from specific pathogen-free queens was analyzed for IgG and IgA concentrations from parturition through 6 weeks of lactation. Serum IgG and IgA concentrations from birth through 8 weeks of age were determined for colostrum-fed kittens, colostrum-deprived kittens that were fed a milk replacer, and colostrum-deprived kittens that were fostered onto queens in the milk phase of lactation. The total IgG and IgA concentrations in milk were significantly higher on the day of parturition than on day 7 of lactation, indicating cats do have a colostral phase of lactation. The predominant immunoglobulin in both colostrum and milk was IgG. The serum IgG concentrations in colostrum-deprived kittens fostered on queens in the milk phase of lactation were similar to colostrum-deprived kittens fed a milk replacer, and the concentrations were significantly lower than in colostrum-fed kittens for the first 4 weeks of life. The serum IgA concentrations in both colostrum-deprived groups were significantly lower than colostrum-fed kittens on day 2 after parturition, but were similar thereafter. Colostrum-deprived kittens fostered onto queens in the milk phase of lactation had failure of passive transfer of maternal antibodies. Protective concentrations of immunoglobulins can be restored in kittens with failure of passive transfer of immunity by parenteral administration of adult cat serum, but not by fostering on queens in mid-lactation.  相似文献   

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The immune response to the K99 was tested in 45 pregnant cows, subcutaneously vaccinated, for protecting the newborn calves. Serological tests were performed in the blood sera of all animals and in the milk and colostrum sera; hemogram, inhibition of the adhesion to the brush border and histological tests were performed. The calves from vaccinated cows survived the experimental infection after the suction of colostrum in spite of the fact that the calves from control dams died with diarrhea.  相似文献   

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To determine whether consumption of colostrum with high levels of serum neutralizing antibody to bovine herpesvirus 1 would protect neonatal calves from the frequently fatal multisystemic form of infectious bovine rhinotracheitis, Holstein calves were fed for 48 h after birth with either pooled colostrum from seropositive vaccinated cows or colostrum from seronegative unvaccinated cows. The serum neutralizing antibody achieved in the former calves was between 64 and 256 and the titer in the latter calves was below 8. At 48 h of age the calves were challenged by aerosolization with bovine herpesvirus 1. All five seronegative calves died or were euthanized in a moribund state between days 5 and 7 of the trial, whereas all five seropositive animals remained healthy throughout the study. Twice daily clinical examination revealed significantly lower scores in the seronegative group from 60 h postinfection. Relative lung weights were greater in the seronegative group, associated with a severe acute necrotizing bronchiolitis with fibrin exudation. The seronegative group of calves also demonstrated an acute necrotizing rumenitis, pharyngitis, glossitis, esophagitis, laryngitis and tracheitis. The seropositive animals had only small areas of subacute necrotizing fibrinopurulent rhinitis. Bovine herpesvirus 1 virus was isolated from all nasal passages of all calves but isolation of virus in the seronegative calves was made from the trachea (5/5), lung (4/5), bronchial lymph nodes (4/5), spleen (4/5), thymus (3/5), liver (2/5), rumen (2/5) and brain (1/5).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

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Streptococcus uberis is an important environmental mastitis pathogen that causes subclinical and clinical mastitis in lactating and nonlactating cows and heifers throughout the world. Previous work from our laboratory suggests that S. uberis adhesion molecule (SUAM) is involved in S. uberis pathogenesis and may be an excellent target for vaccine development. The objective of this study was to evaluate the antibody response of cattle vaccinated with recombinant SUAM (rSUAM). Uninfected primiparous dairy cows (n=30) in late lactation were divided randomly into three groups of 10 cows each: control, 200 μg rSUAM, and 400 μg rSUAM. Cows in groups vaccinated with 200 μg and 400 μg rSUAM received an emulsion containing adjuvant, phosphate-buffered saline (PBS) and affinity purified rSUAM. Cows in the control group received an emulsion containing adjuvant and PBS. Cows were vaccinated subcutaneously in the neck region at drying off (D-0), 28 d after drying off (D+28) and within 7 d after calving. Serum was collected at D-0, D+28, at calving (C-0), calving vaccination (CV), and during early lactation (CV+14). Serum antibody responses were measured by an ELISA against rSUAM. Following the first vaccination a significant increase in anti-rSUAM antibodies was detected at D+28 in cows from groups vaccinated with 200 μg and 400 μg rSUAM when compared to the control group. This increase in anti-rSUAM antibodies continued following the second immunization at D+28; reaching the highest levels in the post-parturient sampling period (C0), after which antibodies appeared to plateau. S. uberis UT888 pretreated with several dilutions of heat-inactivated serum from cows vaccinated with rSUAM, affinity purified antibodies against rSUAM, and to a 17 amino acid long peptide from the N terminus of SUAM (pep-SUAM) were co-cultured with bovine mammary epithelial cells and adherence to and internalization of S. uberis into epithelial cells was measured. Compared to untreated controls, opsonization of two strains of S. uberis with sera from cows vaccinated with rSUAM, with affinity purified rSUAM antibodies, or with affinity purified pep-SUAM antibodies significantly reduced adherence to and internalization of this pathogen into bovine mammary epithelial cells. In conclusion, subcutaneous vaccination of dairy cows with rSUAM during physiological transitions of the mammary gland either from or to a state of active milk synthesis induced antibodies in serum and milk and these antibodies reduced adherence to and internalization of S. uberis into mammary epithelial cells under in vitro conditions. SUAM appears to be an excellent candidate for vaccine development.  相似文献   

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To study whether or not passive immunity of neonatal calves against Shiga toxin-producing Escherichia coli (STEC) O26, O111, and O157 was obtained by colostrum administration, serum antibodies in calves after the feeding were determined by enzyme-linked immunosorbent assay (ELISA) in comparison with antibodies in colostrum and sera from donor dams. The highest antibody titers to STEC in colostrum from dams were detected soon after parturition. The antibody titers were found to be elevated in sera of neonatal calves (4-9 hr after birth) orally administered with colostrum with high antibody titers, suggesting that passive immunity of neonatal calves to STEC infection may be obtained by feeding colostrum. These results suggest that colostrum administration to neonatal calves may play an important role in elevating serum antibodies against STEC in neonatal calves.  相似文献   

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A new immunodiffusion (ID) test for antibodies to bovine leukemia virus (BLV) antigens was established. This test, refered to as the tannic acid enhanced, indirect, double immunodiffusion (IID-T) test, includes the following steps: (a) double micro-immunodiffusion using diluted references reagents, (b) treatment of the gel plate with antiglobulin serum, (c) treatment of the gel plate with 1% tannic acid. The IID-T test has proved to be eight times more sensitive than the double immunodiffusion test (ID) commonly used for anti-BLV. Diagnostic efficiency at individual levels of the IID-T test for anti-gpBLV is higher than this parameter of the ID test for anti-gpBLV and radioimmunoassay (RIA) for anti-p24BLV. The IID-T test is simple, reproducible, and more economic than the ID test in the amount of the reference reagents required. The IID-T test is more reliable than the ID test especially when weak, low titer sera are tested. Thus, the IID-T test seems to be suitable for large scale serodiagnosis of BLV infection in cattle.  相似文献   

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