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1.
Serum anti-Ostertagia ostertagi and anti-Cooperia oncophora antibody responses were assessed in first season and second season calves grazing permanent paddocks. Calves without previous exposure to trichostrongyles were found to mount significant parasite-specific IgG1 antibody responses within two months of introduction to the pastures. A significant serum IgA response to O ostertagi and IgG2 responses to both O ostertagi and C oncophora antigens were also observed, but these responses were weaker. No consistent serum anti-trichostrongyle IgM responses were discernible in either age group. Second season grazing calves had significantly elevated IgG1, IgG2 and IgA antibody levels at turnout when compared to first season calves, but only IgA antibody levels against O ostertagi increased during the second grazing season. Comparison of serum antibody levels in first and second season calves grazed separately or together suggests that mixed grazing had no discernible effect on antigen priming.  相似文献   

2.
During previous work Schistosoma antibodies and circulating antigens were detected at birth in the serum from some calves born to Schistosoma mattheei infected mothers. The objectives of the present survey were: (1) to investigate the proportion of calves, born to cows infected with S. mattheei, which have specific antibodies and circulating schistosome antigens present in their serum at birth and (2) to investigate whether the presence or absence of these specific antibodies and/or circulating antigens at birth may affect the pattern of a natural S. mattheei infection in calves from 4 to 5 months of age, when the colostral antibodies are thought to be of negligible importance. A total of 28 calves born to infected mothers were randomly selected. Faeces, serum and colostrum samples were collected from the cows at calving, serum samples were collected from the calves at birth (day 0), after intake of colostrum (day 1) and monthly thereafter up to the age of 10 months. Both serum and colostrum samples were analysed for IgG(H+L) against SWAP mattheei and schistosome circulating anodic antigen (CAA) levels. The calves were exposed to a natural challenge from the age of 4-5 months. Faecal samples were collected from the calves monthly, starting at an age of 5 months up to 10 months, and were examined for faecal egg counts. Nine (group 1) out of the 28 calves were found to have specific antibodies in their serum at birth, in 5 of them CAA levels were also detected. In the other 19 calves (group 2) no IgG(H+L) or CAA were detected. At the end of the study faecal egg counts and CAA levels were significantly lower in calves from group 1 compared to group 2. Results confirm earlier work that specific antibodies and circulating antigens may be present in serum from calves at birth, and show that these calves have lower faecal egg counts and CAA levels after exposure to a natural challenge.  相似文献   

3.
OBJECTIVE: To determine whether serum IgG concentrations in neonatal calves are adversely affected by short-term frozen storage of colostrum. DESIGN: Prospective study. SAMPLE POPULATION: Experiment 1 consisted of 10 pairs of Holstein calves (n = 20) fed matched aliquots of either fresh (n = 10) or frozen and thawed (10) colostrum. In experiment 2, 26 Holstein calves were fed either fresh (n = 13) or frozen and thawed (n = 13) colostrum. PROCEDURE: Experiment 1 consisted of calves resulting from observed parturitions; calves were randomly assigned to treatment groups (fresh or frozen and thawed colostrum) in pairs. Calves were fed 4 L aliquots of colostrum via oroesophageal intubation at 3 hours of age. Serum IgG concentrations at 2 days of age were compared between the 2 groups by use of a paired t-test. Experiment 2 consisted of calves resulting from observed parturitions; calves were randomly assigned to treatment groups (fresh or frozen and thawed colostrum). Calves were fed 4 L aliquots of colostrum via oroesophageal intubation at 3 hours of age. Regression analysis was used to determine whether calf serum IgG concentration was a function of colostral IgG concentration and colostrum storage group. RESULTS: Significant differences were not observed between the 2 groups in experiment 1. No significant relationship was observed between colostrum storage group and serum IgG concentration in experiment 2. The model that best predicted serum IgG concentrations accounted for 20% of the variability in serum IgG concentration. CONCLUSION AND CLINICAL RELEVANCE: Frozen colostrum is an adequate source of IgG for calves.  相似文献   

4.
Background: Natural autoantibodies (N(a)ab) were found in every species tested so far, and are likely important in maintaining homeostasis.

Objectives: (1) To determine N(a)ab in Bos taurus calves, (2) evaluate effects of diet and age on N(a)ab binding repertoires in calves, and (3) delineate bovine liver cell lysate (BLL) antigens related with variation in rumen score and body weight.

Animals and methods: Effects of age and diet on staining of BLL fragments by IgM and IgG antibodies in serum samples collected at 20 or at 26 weeks of age from bull calves either fed a restricted or ad libitum diet were analyzed using quantitative Western blotting. Correlations between fragments stained and grouping of calves were done by Principal Component Analysis (PCA). Redundancy analysis (RDA) was done to relate rumen score and body weight variation at slaughter at 27 weeks of age with stained BLL fragments.

Results: In sera from all calves IgM and IgG antibodies binding BLL antigens were found. Corresponding fragments were stained, but quantitative differences in staining intensities were related to diet and age for both IgM and IgG. PCA revealed that age had a greater influence than diet on BLL fragment staining. RDA suggested that staining by IgM or IgG of specific BLL fragments was related with variation in rumen score and body weight.

Conclusions and clinical importance: Analyses of N(a)ab in serum could be a potential tool to estimate the health status of cattle, and be used to evaluate effects of husbandry practices.  相似文献   

5.
Bovine IgG2a has been implicated in protection against pyogenic infections, including those caused by Haemophilus somnus. To further investigate the role of IgG2a in defense against H. somnus, IgG1 and IgG2a antibodies were purified from antiserum against an immunodominant 40 kDa outer membrane protein (p40) of H. somnus, which was previously shown to passively protect calves against H. somnus pneumonia. The passive protective capacity of anti-p40 IgG1 or IgG2a was evaluated in vivo in calves. Purified anti-p40 IgG1 or IgG2a was incubated with H. somnus for 15 min before intrabronchial inoculation of calves. Bacteria incubated with anti-p40 IgG1 or IgG2a were inoculated into one caudal lung lobe and bacteria incubated with IgG1 or IgG2a from the respective preimmunization serum were inoculated into the contralateral lobe. The volumes of pneumonia in the right and left lungs were determined 24 h later. The difference in volume of pneumonia with H. somnus preincubated in IgG1 pre- and postimmunization anti p40 was less (16 cm3, P = 0.298) than the difference in volume of pneumonia with H. somnus preincubated in IgG2a pre- and postimmunization anti p40 (30 cm3, P = 0.146). Although the differences in lesion size between pre- and postimmunization serum were not statistically significant, the trend suggests IgG2a may be more protective than IgG1. To examine this further, the peptide specificity of these IgG1 and IgG2a antibodies to p40 was examined. After limited proteolysis of p40, IgG2a antibodies reacted with 2 peptides not recognized by IgG1 antibodies. Other peptides were recognized by both isotypes. Since these studies suggested that IgG2a may be important in protection against infection, we then investigated some aspects of the role of the 2 IgG2a allotypes, A1 and A2. In retrospective studies of age differences in expression of IgG2a allotypes, no heterozygotes were detected in calves of 60 d old or less, and fewer heterozygotes were detected in calves 61-120 d old than in cattle older than 270 d (P < 0.01). In a subsequent prospective study of the time course of allotype expression, Holstein calves shown to be heterozygotes expressed the IgG2aA1 allotype early but the IgG2aA2 allotype was not usually detected until 3 to 4 mo of age. Thus, both the retrospective and the prospective studies showed age related differences in expression of the IgG2aA1 and A2 allotypes. This could have implication in protection.  相似文献   

6.
Pasteurella multocida serotype B:2 is the causative agent of haemorrhagic septicaemia (HS), a fatal disease of cattle and buffaloes. As a step towards the identification of individual antigens that may protect against HS, proteins present in a sonicated cell extract (SCE) and outer-membrane protein (OMP) preparation of a wild-type P. multocida serotype B:2 were investigated by immunoblotting with sera from calves which had been protected against challenge with a virulent strain of P. multocida B:2 by vaccination with a live-attenuated aroA derivative of the challenge strain. Five proteins in SCE, of approximately 50, 37, 30, 26 and 16 kDa, were recognised by the sera. In an OMP preparation, two bands, at 37 and 50 kDa, were recognised as strongly immunogenic. Mass spectrometry analysis of proteins corresponding in size to those detected by immunoblotting identified the 37 kDa band as OmpA, but the band at 50 kDa was not identified with certainty. A major 30 kDa OMP, identified as OmpH, was not strongly immunogenic.  相似文献   

7.
Absorption and Synthesis of Immunoglobulins G in Newborn Calves   总被引：1，自引：0，他引：1  
Newborn calves (n=19) got 4.5 liters of pooled colostrum within three feedings in the first 14 hours post natum (p.n.). The immunoglobulin G1 (IgG1) and IgG2 concentrations in the colostrum pool were 54.9 mg/ml and 4.2 mg/ml. The precolostral serum IgG concentrations in calves were 0.15 mg/ml (IgG1; SD 0.24) and 0.06 mg/ml (IgG2; SD 0.14). The highest serum IgG levels p.n. were measured 12 hours after the first colostrum feeding (9.3 mg IgG1/ml (SD 4.0), 0.8 mg IgG1/ml (SD 1.0). Thereafter, the mean IgG1 level was reduced continuously to the significant lowest concentration of 4.9 mg/ml (SD 2.3) at day 28 p.n. and then increased continuously to the significant highest concentration of 9.0 mg/ml (SD 4.8) on day 77 p.n. The mean concentration of IgG2 was lowest on day 11 p.n. (0.5 mg/ml; SD 0.4) and highest on day 77 p.n. (1.2 mg/ml; SD 0.6).
In blood from 198 calves, housed in Germany and sampled between day 4 and 6 p.n., the IgG concentration averaged 4.9 mg/ml serum (SD 3.3). From 93 dams of these calves a sample of the first colostrum could be obtained showing a mean concentration of 22.0 mg IgG/ml (SD 11.0). IgG levels in the colostrum and in the serum showed a correlation of r=0.37.
In Kenia IgG levels of three week old calves from two farms were measured. The calves were always with mother for the first 24 hours. The mean serum IgG concentrations of the calves were 22.5 mg IgG/ml (n=7, SD 6.8) and 15.2 mg IgG/ml (n=15; SD 6.3). Comparing to the serum IgG levels found in calves of our studies in Germany there were significant differences.  相似文献   

8.
The effect of colostral maternal antibodies (Abs), acquired via colostrum, on passive protection and development of systemic and mucosal immune responses against rotavirus was evaluated in neonatal calves. Colostrum-deprived (CD) calves, or calves receiving one dose of pooled control colostrum (CC) or immune colostrum (IC), containing an IgG1 titer to bovine rotavirus (BRV) of 1:16,384 or 1:262,144, respectively, were orally inoculated with 105.5 FFU of IND (P[5]G6) BRV at 2 days of age. Calves were monitored daily for diarrhea, virus shedding and anti-BRV Abs in feces by ELISA. Anti-rotavirus Ab titers in serum were evaluated weekly by isotype-specific ELISA and virus neutralization (VN). At 21 days post-inoculation (dpi), all animals were euthanized and the number of anti-BRV antibody secreting cells (ASC) in intestinal and systemic lymphoid tissues were evaluated by ELISPOT. After colostrum intake, IC calves had significantly higher IgG1 serum titers (GMT=28,526) than CC (GMT=1195) or CD calves (GMT<4). After BRV inoculation, all animals became infected with a mean duration of virus shedding between 6 and 10 days. However, IC calves had significantly fewer days of diarrhea (0.8 days) compared to CD and CC calves (11 and 7 days, respectively). In both groups receiving colostrum there was a delay in the onset of diarrhea and virus shedding associated with IgG1 in feces. In serum and feces, CD and CC calves had peak anti-BRV IgM titers at 7 dpi, but IgA and IgG1 responses were significantly lower in CC calves. Antibody titers detected in serum and feces were associated with circulation of ASC of the same isotype in blood. The IC calves had only an IgM response in feces. At 21 dpi, anti-BRV ASC responses were observed in all analyzed tissues of the three groups, except bone marrow. The intestine was the main site of ASC response against BRV and highest IgA ASC numbers. There was an inverse relationship between passive IgG1 titers and magnitude of ASC responses, with fewer IgG1 ASC in CC calves and significantly lower ASC numbers of all isotypes in IC calves. Thus, passive anti-BRV IgG1 negatively affects active immune responses in a dose-dependent manner. In ileal Peyer's patches, IgM ASC predominated in calves receiving colostrum; IgG1 ASC predominated in CD calves. The presence in IC calves of IgG1 in feces in the absence of an IgG1 ASC response is consistent with the transfer of serum IgG1 back into the gut contributing to the protection of the intestinal mucosa.  相似文献   

9.
We examined the relationship between serum gamma glutamyltransferase (GGT) activity and serum gamma immunoglobulin G (IgG1) concentration in Holstein calves. Blood samples were collected from calves aged 1 to 3 days. A follow-up sample was obtained from each calf 2, 7, or 15 days after the initial sampling. Serum GGT activity and lgG1 concentration were measured. Regression models were used to predict lgG1 concentration as a function of age and serum GGT activity measured 2, 7, or 15 days later.
Serum GGT activity and calf age at the time of the second sample were directly related to serum IgG1 concentration in the initial sample in calves aged 3 to 17 days ( r = .54) and in calves aged 3 to 10 days ( r = .63). Models were used to estimate the serum GGT activity equivalent to a serum IgG1 concentration of 1,000 mg/dL. One-day-old calves should have serum GGT activities > 200 IU/L. Four-day-old calves should have serum GGT activities > 100 IU/L. One-week-old calves should have serum GGT activities > 75 IU/L. Calves with serum GGT activities < 50 IU/L should be classified as having failure of passive transfer.  相似文献   

10.
OBJECTIVE: To evaluate associations between neonatal serum IgG1 concentration and pre- and postweaning morbidity and mortality rates and average daily gains (ADGs) in beef calves and define a cutoff point for serum IgG1 concentration necessary for optimal health and performance of beef calves. DESIGN: Nonconcurrent cohort study. ANIMALS: 1,568 crossbred beef calves. PROCEDURE: Single radial immunodiffusion was used to quantitate IgG1 concentration in sera collected from calves between 24 and 72 hours after birth. Logistic regression, ANCOVA, and likelihood ratios were used to analyze data. RESULTS: In the preweaning period, lower perinatal IgG1 concentrations were significantly associated with higher morbidity rates, higher mortality rates, and lower ADGs. Calves with serum IgG1 concentration < 2,400 mg/dL were 1.6 times as likely to become ill before weaning and 2.7 times as likely to die before weaning as calves with higher serum IgG1 concentrations. Calves with serum IgG1 concentration of at least 2,700 mg/dL weighed an estimated 3.35 kg (7.38 lb) more at 205 days of age than calves with lower serum IgG1 concentration. No significant association of serum IgG1 concentration with feedlot morbidity, death, or ADG was identified. CONCLUSIONS AND CLINICAL RELEVANCE: By use of likelihood ratios, the threshold of serum IgG1 concentration for optimal health and performance of calves was higher than values reported previously. Implementation and maintenance of management and intervention strategies designed for early detection and treatment of calves at risk for failure of passive transfer will likely result in increases in preweaning health and performance parameters.  相似文献   

11.
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 >or= 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.  相似文献   

12.
OBJECTIVE: To evaluate effects of 2 commercially available colostrum replacement products on serum IgG and total protein concentrations in dairy calves. DESIGN: Prospective clinical trial. ANIMALS: 84 Holstein bull calves from a single dairy. PROCEDURES: Calves were randomly assigned to be given 4 quarts of colostrum (group 1; n = 21), 2 packages of a colostrum replacement product (product A; group 2; 21), 1 package of a different colostrum replacement product (product B; group 3; 21), or 2 packages of product B (group 4; 21). Treatments were given within 3 hours after birth, and blood samples were collected 24 hours later and submitted for determination of serum total protein and IgG concentrations. RESULTS: Group 1 calves had significantly higher serum total protein and IgG concentrations than did calves in the other 3 groups. However, the percentage of calves with adequate passive transfer (ie, serum IgG concentration > 1,000 mg/dL) was not significantly different among groups 1 (90%), 3 (81%), and 4 (95%). In contrast, only 10% of calves in group 2 had adequate passive transfer. It was predicted that calves fed product B that had serum total protein concentrations > 5.2 g/dL would have serum IgG concentrations > 1,000 mg/dL at least 90% of the time. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that product B could be considered as an alternative to colostrum in dairy calves, but product A failed to routinely provide adequate serum IgG concentrations when fed according to label directions.  相似文献   

13.
为研究探讨初乳饲喂次数对娟姗犊牛生产性能的影响,试验选取初生重接近的健康娟姗犊牛20 头,随机分为4 组,分别为对照组、试验I组、II组和III组,每组5 头犊牛,试验期为60 天。4 组犊牛出生当日饲喂两次初乳,首次初乳量按照体重的10.0%进行灌服,第2次初乳于出生后6~8 h按照体重的5.0%进行饲喂。4 组犊牛出生当日在产房饲养,2日龄时均转为室外犊牛岛单栏饲养。2日龄后,对照组每天上午06:00和下午16:00时各饲喂常乳1次,2~6日龄每次饲喂1.50 L,7~20日龄每次饲喂1.80 L,21~35日龄每次饲喂2.50 L,36~60日龄每次饲喂3.00 L,自7日龄开始犊牛自由采食颗粒料。试验Ⅰ组、Ⅱ组、Ⅲ组分别继续饲喂初乳至犊牛2日龄、4日龄、6日龄后再饲喂常乳,饲喂时间和饲喂量与对照组一致。结果表明:(1)在饲喂初乳后48 h、72 h、96 h,试验组与对照组犊牛血清免疫球蛋白g(IgG)均差异显著(p<0.05),120 h、144 h、168 h,试验Ⅰ组与对照组比较,犊牛血清IgG含量差异不显著(p>0.05),试验Ⅱ组、Ⅲ组血清IgG含量与对照组相比,差异极显著(p<0.01)。(2)随着初乳饲喂次数的增加,可有效降低犊牛20日龄内腹泻发生率,试验Ⅰ组、Ⅱ组、Ⅲ组较对照组比较犊牛腹泻发生率分别降低9.5%、22.5%、36.5%,治疗犊牛腹泻总成本较对照组分别下降12.0 元、43.2 元、76.8 元,3 组试验组犊牛成活率为100.0%。(3)初乳饲喂次数的增加,使0~60日龄娟姗犊牛平均日增重(ADG)升高,试验组与对照组相比较,日增重均差异极显著(p<0.01),分别增加16.7 g、33.3 g、80.0 g。试验Ⅱ组、Ⅲ组较试验Ⅰ组ADG差异也极显著(p<0.01)。综合考虑,建议娟姗犊牛饲喂初乳至6日龄,可降低犊牛腹泻发生率、减少治疗费用,提高犊牛成活率及ADG。  相似文献   

14.
This study examined the relationship between serum gamma-glutamyl-transferase (GGT) activity and passive transfer status in beef calves less than 18 days of age. Immunoglobulin G1 (IgG1) concentrations were measured in 69 commercial beef calves between the ages of 24 and 72 hours. GGT activities were then measured in these same calves at various ages between 3 and 18 days of age. Models were developed predicting serum IgG1 concentration as a function of calf age and serum GGT activity. Minimal association was present between initial serum IgG1 concentration and serum GGT activity when all calves less than 18 days of age were considered (r2 = 0.065). When the study population was restricted to calves less than 8 days of age, the fit of the developed model was greatly improved (r2 = 0.438). Serum GGT activity has no apparent advantage relative to other assay procedures for predicting passive transfer status in beef calves. If serum GGT activity is to be used to assess passive transfer status in beef calves, application of this procedure should be restricted to calves less than 8 days of age.  相似文献   

15.
Effect of colostrum intake on diarrhoea incidence in new-born calves   总被引：4，自引：0，他引：4  
In a survey which lasted one year and included data of 73 dairy cows with their calves, colostrum immunoglobulin G (IgG) of 22 primiparous cows and serum IgG of their calves were lower than the corresponding IgG levels of 51 multiparous cows and their calves. Serum IgG concentration was not correlated with diarrhoea incidence. Although there were no seasonal differences in the IgG concentration of colostrum and calf serum, neonatal diarrhoea incidence was higher in calves which were born in winter than in calves which were born in summer (P < 0.01). Thus the high diarrhoea incidence in winter was not a consequence of an insufficient IgG transfer to the calves. The 60 calves of the second study were fed colostrum on the first day of life. From the second to the tenth day 28 experimental calves received milk and 0.5 l of surplus colostrum of the first and second milking twice a day, whereas 32 control calves received milk only twice a day. Two of the 28 experimental and 11 of the 32 control calves suffered from diarrhoea during the first ten days of life (P < 0.05). These results show that the ingestion of surplus colostrum in addition to milk after the first day of life protects the new-born calf against infectious diarrhoea.  相似文献   

16.
本试验旨在研究断奶前后犊牛在不同固液比例饲喂模式下营养物质代谢及其瘤胃发酵的异同,从而探索基于不同饲喂模式下的犊牛断奶方式。试验选用7日龄荷斯坦公犊牛36头,随机分成3组,每组12头,各组采用相同原料组成、相同营养成分的代乳粉和颗粒料。在总干物质饲喂量保持一致的情况下,改变固液饲料饲喂比例,形成3种饲喂模式组:高液体饲料比例(HL)组,28~56日龄内,颗粒料∶代乳粉保持在1∶2,56日龄断奶;对照(LS)组28~56日龄内,颗粒料∶代乳粉从1∶2逐步降低到1∶1,56日龄断奶;高固体饲料比例(HS)组,28~42日龄内,颗粒料∶代乳粉从1∶2逐步降低至1∶0,并于42日龄断奶。试验期77 d。分别于犊牛28、42、56和84日龄采集瘤胃液,35和63日龄进行断奶前后消化代谢试验。结果表明:断奶前,与HS组相比,HL、LS组犊牛总能代谢率相对较高,但差异不显著(P0.05);断奶后,HS组消化能代谢率、氮利用率及氮的生物学价值较HL组显著提高(P0.05)。与HL组相比,HS组84日龄瘤胃液微生物蛋白含量显著提高(P0.05)。3组间瘤胃液氨态氮浓度无显著差异(P0.05)。84日龄时,HS组犊牛瘤胃液总挥发性脂肪酸浓度和丁酸比例显著高于HL组(P0.05),各组间丙酸、戊酸比例无显著差异(P0.05)。综上可得,适量增加固体饲料饲喂比例有助于改善断奶前后犊牛瘤胃发酵环境,促进瘤胃微生物蛋白的合成,提高断奶后犊牛饲粮能量代谢率、氮的生物学价值及氮利用率;采用高固体饲料饲喂模式,犊牛在42日龄固体饲料采食量达到1.0 kg/d时实施断奶具有一定优势。  相似文献   

17.
Immunoglobulin (Ig) concentrations in serum and in nasal secretions were correlated with pneumonia and diarrhea during the first 12 weeks of life in 56 calves. The peak onset of pneumonia occurred between 2 and 4 weeks of age when the calves' serum IgG1, IgG2, and IgA concentrations were lowest. As IgG2 concentrations increased, fewer calves developed pneumonia. Peak onset of pneumonia was also correlated with the lowest IgG and IgA concentrations in the calves' nasal secretions. Most calves developed pneumonia when serum concentrations of IgG1 were less than 1.5 g/dl, IgG2 less than 0.3 g/dl, IgA less than 0.1 g/dl, and IgM less than 0.2 g/dl and when the combined IgG and IgA values in nasal secretions were less than 0.2 mg of Ig/mg of protein. In study A, diarrhea preceded pneumonia in 63% of 56 calves. In study B, 38% of 23 calves had diarrhea and/or hemorrhagic feces before pneumonia. Seemingly, there was a relationship between diarrhea and pneumonia. Furthermore, pneumonia occurred at or just after the time when IgG1, IgG2, and IgA concentrations in serum and the combined IgG and IgA concentrations in nasal secretions were lowest. Pneumonia is a common disease of calves between 1 and 5 months of age, a period coinciding with the usual low point in serum immunoglobulin (Ig) concentrations due to catabolism of passively acquired antibodies. Calves that absorb less than adequate amounts of Ig may be susceptible to pneumonia at approximately 2 months of age, when serum Ig concentrations would be lowest.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

18.
Indirect enzyme-linked immunosorbent assays were applied to differentiate Chlamydia (C.) psittaci-specific IgG1 and IgG2 levels in 143 individual serum samples from cattle with naturally occurring chlamydial infections and in 190 sequential serum samples from 26 experimentally infected pregnant cows, calves, and a bull. The mean IgG1:IgG2 ratio of naturally infected cattle was 1:4 indicating a significant (p less than 0.001) IgG2 dominance. Similar ratios were detected in the experimentally infected cattle. The dominance of IgG2 was independent of breed, sex, and age. Twenty-nine cattle had significant immunoglobulin levels to both C. psittaci and Coxiella (C.) burnetii simultaneously. The predominance of C. psittaci-specific IgG2, in contrast to the predominance of C. burnetti-specific IgG1 detected in these same individual serum samples under identical conditions, indicates that the ability to preferentially produce either IgG1 or IgG2 was not limited in these individual cattle. A transient yet significant IgG1 response was also developed in cows following chlamydia-induced abortions (immunotype 1) or in cattle infected with the polyarthritis-serositis-encephalomyelitis agents (immunotype 2). IgG1 levels decreased faster than IgG2 levels. These findings have diagnostic implications and identify the need for determining the immunoglobulin classes and subclasses of the humoral immune responses of animals and man to chlamydial infections.  相似文献   

19.
Inadequate consumption of colostrum can negatively affect calf health and survival. The serum immunoglobulin G (IgG) concentrations of 935 beef calves from 152 herds in Alberta and Saskatchewan have been described, using radial immunodiffusion. The determinants and health effects of serum IgG concentrations were studied in 601 calves sampled between 2 and 8 days of age. Of these calves, 6% had failure of passive transfer and an additional 10% had marginal passive transfer. Serum IgG concentrations were lower in calves born to a heifer, as a twin, or experiencing dystocia. The odds of both calf death and treatment were increased in calves with serum IgG concentrations below 24 g/L; a threshold notably higher than the 16 g/L usually considered as providing adequate passive transfer. The finding of 1/3 of calves with serum IgG concentrations less than 24 g/L suggests that calfhood treatments and mortality could be decreased by ensuring that high risk calves consume colostrum.  相似文献   

20.
The dynamics of the humoral immune response of calves were analysed after primary infection and re-infection with the intestinal nematode Cooperia punctata. 12 male 5 month-old Holstein-Friesian calves were randomly divided into two groups A and B. At the beginning of the experiment Group A animals were each infected experimentally with a single oral dose of 130,000 infective third stage larvae (L3) of C. punctata. The animals of Group B were kept as non-infected controls. The two calves from Group A with the highest infections died of cooperiosis at 32 and 44 days after infection (DAI), respectively. On DAI 100 the calves were treated with the recommended dose of oxfendazole. On DAI 180 the remaining four calves of Group A and three animals of Group B (B1) were infected with 260,000 L3 of C. punctata, while the other three calves of Group B (B2) served as non-infected controls. Monitoring of the humoral immune response predominantly demonstrated an IgG1 response against both adult and L3 antigen of C. punctata. Moreover, re-infections increased the levels of these immunoglobulins. IgA levels were less increased than IgG1 and no significant increase was observed in IgG2 and IgM levels. Immunoblotting analysis showed that total IgG present in the serum of the primary infected animals mainly reacted against adult proteins of 12-14 and 17-20 kDa and against L3 proteins of 33 and 43 kDa. After re-infection total IgG reacted with the same adult proteins but also with an adult 29 kDa protein.  相似文献   

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