Humoral immune response of water buffalo monitored with three different antigens of Toxocara vitulorum

Humoral immune response of water buffalo naturally infected with Toxocara vitulorum was monitored using three different antigens of this parasite in serum and colostrum of buffalo cows and calves. Soluble extract (Ex) and excretory/secretory (ES) larval antigens and perienteric fluid antigen (Pe) of adult T. vitulorum were used to measure the antibody levels by an indirect ELISA. Serum of 7-12 buffalo cows for the first 365 days and colostrum of the same number of buffalo cows for the first 60 days of parturition, and serum of 8-10 buffalo calves for the first 365 days after birth were assayed. The ELISA detected antibodies against all three T. vitulorum antigens in the colostrum and serum of 100% of buffalo cows and calves examined. The highest antibody levels against Ex, ES and Pe antigens were detected in the buffalo cow sera during the perinatal period and were maintained at high levels through 300 days after parturition. On the other hand, colostrum antibody concentrations of all three antigens were highest on the first day post-parturition, but decreased sharply during the first 15 days. Concomitantly to the monitoring of immune response, the parasitic status of the calves was also evaluated. In calves, antibodies passively acquired were at the highest concentrations 24 h after birth and remained at high levels until 45 days coincidentally with the peak of T. vitulorum infection. The rejection of the worms by the calves occurred simultaneously with the decline of antibody levels, which reached their lowest levels between 76 and 150 days. Thereafter, probably because of the presence of adults/larvae stimulation, the calves acquired active immunity and the antibodies started to increase slightly in the serum and plateaued between the days 211 and 365. All three antigens were detected by the serum antibodies of buffalo calves; however, the concentration of anti-Pe antibody was higher than anti-EX and anti-ES, particularly after 90 days of age. By conclusion, the buffalo cows develop immunity and keep high levels of antibodies against T. vitulorum-Ex, ES and Pe antigens and these antibodies are transferred to their calves through the colostrum. This passively acquired immunity does not protect the calves against the acquisition of the infection, but these antibodies, passively or actively acquired, may have an important role during worm rejection by the calves and prevention of intestinal reinfection.     

An enzyme-linked immunosorbent assay (ELISA) for detection of antibodies against Toxocara vitulorum in water buffaloes

Toxocara vitulorum, a parasite of the small intestine of cattle and water buffaloes, is mainly acquired by calves via the colostrum/milk from infected cows. To understand the development of immune responses in calves, antibody levels to a soluble extract antigen (Ex) from T. vitulorum infective larvae were measured by an indirect ELISA with sera of 15 buffalo calves, which were sampled every 15 days for the first 180 days after birth and 9 buffalo cows during the perinatal period. From all serum samples examined during the first 180 days, antibody level was lowest and highest in calves at 1 day of age before and after suckling colostrum, respectively, suggesting that the origin of antibodies was the colostrum. Immediately after birth, antibody levels in suckled calves remained at high levels until day 15, began to decrease to lower levels between 15 and 30 days and remained relatively stable until 120 days. By comparing the immune responses of these animals with their parasitological status it was considered possible to determine if passively acquired or actively produced antibodies provided protection against the infection. High numbers of T. vitulorum eggs in the feces between 30 and 60 days indicated that passively acquired antibodies did not provide protection against the infection, at least during these first days, and the maximum fecal egg counts during 30-45 days were coincident with decreased antibody levels. Between 60 and 120 days, when serum antibodies were detected at reduced, but stable levels, adult nematodes were expelled from the intestines and no more T. vitulorum eggs were found, suggesting development of acquired resistance. However, the potential and functional protective role of the antibodies against T. vitulorum infection and the process of self-cure requires further investigation.     

Mast cell and eosinophils in the wall of the gut and eosinophils in the blood stream during Toxocara vitulorum infection of the water buffalo calves (Bubalus bubalis)

Toxocara vitulorum is a pathogenic nematode from the small intestine of very young buffalo calves. To understand the development of the inflammatory responses in the wall of the gut, samples of tissues were removed from the duodenum, jejunum and ileum of buffalo calves naturally infected with T. vitulorum during the beginning of the infection, at the peak of egg output, as well as during the periods of rejection of the worms and post-rejection. Two additional control groups of uninfected calves (by anti-helminthic therapy of their mothers and after the birth) were also necropsied on days 30 and 50 after birth. Blood samples were fortnightly collected from birth to 174 days post-birth. Blood smears were prepared and stained with Giemsa for eosinophils. The parasitological status of buffalo calves was evaluated through weekly fecal egg counts (EPG) from 1 to 106 days after birth, which revealed that T. vitulorum egg shedding started on day 11, reached the peak of the infection on day 49 and finally expelled the parasites between days 50 and 85 after birth. In the infected buffalo calves, the mast cell population increased significantly, by two-fold in the mucosa (villus-crypt unit (VCU)) of the duodenum and four-fold in the proximal jejunum; but these increases were statistically significant only at the peak of the infection. Although mast cell numbers increased in the mucosa of the ileum as well as in both the submucosal and muscle tissues of the duodenum, proximal jejunum and ileum, the data was not significantly different from the controls. Eosinophil numbers increased in the mucosa of the duodenum (two-five times higher than the control) and proximal jejunum (three-five-fold) during the period of the infection (beginning, peak and rejection). The relative numbers of eosinophils increased in the blood stream from the second to the seventh week. In conclusion, T. vitulorum infection elicited mastocytosis and tissue eosinophilia in the duodenum and proximal jejunum, as well as eosinophilia in the blood stream, during the beginning, at the peak and during the rejection of the worm. After the rejection of the worms, the numbers of these cells returned to normal levels suggesting that these cells may have a role in the process of rejection of T. vitulorum by the host.     

Colostral Transfer of Rinderpest Neutralizing Antibody to Offspring of Våccinated Dams

The transfer of maternal antibodies to Friesian and buffalo calves born of dams vaccinated against rinderpest was through colostrum only. Colostral antibody titers at the time of parturition were higher than the serum titer. Two hours after suckling, a high level of rinderpest neutralizing antibodies was detected in the sera of newborn animals. The half-life of maternal antibodies in buffalo and Friesian calves was found to be approximately 33 and 29 days respectively. By the age of 7-8 months, 60 per cent of buffalo calves and 80 per cent of Friesian calves had no detectable levels of rinderpest neutralizing antibody.     

Toxocara vitulorum in the milk of buffalo (Bubalus bubalis) cows

The duration of excretion of Toxocara vitulorum larvae in the milk of buffalo cows determines the optimum time for treating calves. Studies on 10 cows showed that a few larvae occur in the colostrum of some cows before the calf has suckled, but most are present from the day after calving and for a further five days. From day 9 onwards, very few larvae were found in the milk. The total number of larvae found was comparable with the number of adult parasites collected from the calves of cows with similar histories. The larvae were 1254 +/- 60 microns long and 36 +/- 6.7 microns in diameter at the ventriculus, figures which are substantially different from some published results.     

Vaccination of pregnant cows with K99 antigen of enterotoxigenic Escherichia coli and protection by colostrum in newborn calves

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.     

Neospora caninum infection and congenital transmission: serological and parasitological study of cows up to the fourth gestation

In this paper, a parasitological and serological study performed in three cows up to the fourth gestation is reported in order to clarify the extent of vertical propagation and, secondly, in which period of gestation the recrudescence of previous infection occurs. The cows selected for the study delivered healthy but congenitally infected calves in first pregnancy. The parasite was found, by biological tests in Swiss mice, in all the placentas of the three cows examined, during the three subsequent gestations, at calving. The parasite was found, at slaughtering, in the brains of all nine calves born clinically healthy from the three cows as well. The serological profile, performed at monthly intervals on serum of the cows, showed that IgG and IgM increased in the third trimester of gestation; this rise of antibodies was constantly observed during the three gestations and in all three cows. In the calves, the IgG titres increase after colostrum consumption and an IgM peak at birth, were indicative of a late infection. These findings, along with negative results obtained by a serological study conducted simultaneously on 38 cows housed in the same stable as the experimental animals and the negative results obtained in isolating parasite or antibodies from farm dogs, suggest that N. caninum infection can be maintained over several bovine generations and that recrudescing persistent infection, rather than a new infection, explains the Neospora infection of calves.     

Toxocara vitulorum in suckling calves in The Netherlands

A Dutch farmer with beef cattle and suckling calves noticed one of the calves suffering from diarrhoea and observed large white worms near the perineum. In the faeces of this calf, eggs of Toxocara vitulorum were found. The majority of the cows in the herd were of the Piemontese breed previously imported from southern France. Treatment with albendazole was successful. Two other calves had positive faecal egg counts. One month after treatment of these calves with doramectin, no eggs were found. To prevent further infections on the farm and dissemination of this uncommon infection to other farms, the farmer decided to have all his cattle slaughtered.     

Passive immunity and serological immune response in dairy calves associated with natural Giardia duodenalis infections

In a previous study, Giardia infection patterns were studied in newborn dairy calves over a 4-month period. Chronic Giardia infections were observed in all calves with initial cyst excretion occurring at approximately 1 month of age. In the work presented here, the passive immunity and serological immune response associated with these Giardia infections were examined. Colostrum and milk samples were collected from the dams of these calves, and monthly serum samples were collected from each calf. The colostrum, milk and sera samples were analyzed by ELISA and Western blot for the presence of anti-Giardia IgG antibodies. In addition, the in vitro anti-Giardia activity of milk and colostrum was examined using a miniculture adherence assay. When examined by ELISA, mean anti-Giardia antibody titres were found to be significantly higher in colostrum compared to milk. The monthly mean serum antibody titres in the calves were not found to differ significantly at any time point during the study. Western blot analysis revealed that colostrum from the dams reacted strongly with many different Giardia antigens between 205 and 7.5kDa, while milk reacted with few antigens in the same size range. Sera collected from the calves when 30 and 60 days of age reacted with few Giardia antigens, but as the calves aged, IgG antibodies in their sera began to react with antigens of 21, 50, 65, 73 and 79kDa. The miniculture adherence assay demonstrated that colostrum had significantly more anti-Giardia activity in vitro compared to milk. These results suggest that the calves in this dairy did not mount a significant humoral immune response against Giardia following infection. However, colostrum contained a high level of anti-Giardia antibodies and exhibited anti-Giardia activity in vitro. Therefore, colostrum may have the potential to provide initial protection against Giardia infections in calves, but the lack of a strong, specific humoral immune response by these calves could account for the high prevalence and chronic duration of the infections.     

Passive transfer of antibodies to Shiga toxin-producing Escherichia coli O26, O111 and O157 antigens in neonatal calves by feeding colostrum

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.     

安格斯母牛初乳产量与质量测定及其新生犊牛被动免疫效果评价

【目的】 新生犊牛被动免疫转移失败（failure of passive transfer,FPT）会导致犊牛发病率和死亡率显著增高,影响后期生长发育。本试验针对国外引进的安格斯母牛初乳产量和质量进行测定,并对其新生犊牛被动免疫效果进行评估,以期为新生犊牛初乳管理措施制定提供科学依据。【方法】 随机选择健康安格斯初产母牛（24月龄）和经产母牛（36~48月龄）各15头,待母牛产犊后立即进行人工挤奶测定初乳产量、营养成分及免疫球蛋白浓度。选取初产和经产新生犊牛各15头,测定其初生重,分别采集犊牛出生后未食初乳（0 h）和食初乳后（24~36 h）血样,测定其血清总蛋白含量及各生理生化指标。【结果】 初产母牛平均初乳产量极显著低于经产母牛,但其初乳中乳蛋白、非脂乳固体、乳糖、灰分含量,以及密度和电导率均极显著高于经产母牛（P<0.01）。初产母牛和经产母牛初乳中免疫球蛋白浓度分别为28.72%和26.24%,合格率分别为93.33%和91.67%,差异均不显著（P>0.05）;初产和经产新生犊牛被动免疫失败率分别为33.3%和25.0%;初产新生犊牛平均初生重极显著低于经产新生犊牛（P<0.01）;被动免疫成功犊牛平均初生重和球蛋白含量均极显著高于被动免疫失败犊牛（P<0.01）。【结论】 新疆安格斯犊牛FPT的主要原因可能是母牛初乳产量低导致新生犊牛初乳摄入不足,初生重较低的犊牛FPT的风险性较高。本研究为制定切实可行的新生安格斯犊牛初乳补饲计划提供了科学基础。     

Effects of colostral antibody on susceptibility of calves to Cryptosporidium parvum infection

Effects of colostral antibody on susceptibility of calves to Cryptosporidium parvum infection were examined. Six calves were fed pooled colostrum that contained C parvum antibody, 6 times daily (at 4-hour intervals) for 7 days and then milk replacer for 7 days. Colostrum was obtained from healthy cows or cows inoculated parenterally with C parvum oocysts before parturition. Antibody content was determined in serum and colostrum whey, using an ELISA for anticryptosporidia immunoglobulin. Six calves were fed colostrum from healthy cows 1 time, and then milk replacer 6 times daily for 14 days. On day 1, all calves were challenge exposed with C parvum, PO, and were monitored daily for diarrhea and oocyst shedding. Bovine colostrum containing specific antibody to C parvum, at ELISA titers up to 10,240, was not effective in protecting calves against challenge exposure to C parvum.     

Lysozyme in the colostrum and blood of calves and dairy cows

During examination of lysozyme concentration we have found out that 90.3% of calf sera had the lysozyme concentration to 0.5 microgram . ml-1, 5.7% of sera showed zero values and only 4.0% of sera values from 0.5 to 1.4 microgram . ml-1. A higher lysozyme content was recorded in sera of calves up to the age of ten days in comparison with sera of calves after the second week post natum. The lysozyme concentration showed in calves a two-phase increase in the age dynamics up to the seventh to eighth week of life with a peak in second and fifth to eighth week of age. The increase rate in the first phase and the time onset of increase in the second phase were in negative, and/or positive relation to the level of immunity obtained through colostrum. The lysozyme concentration in serum of dairy cows was on fourth day post partum as much as ten times higher than in serum of their progenies 48 hours after parturition. In first colostrum the lysozyme concentration fluctuated within the range of 0.15 to 0.65 microgram X ml-1, with an average of 0.30 microgram X ml-1. The concentration of lysozyme and immunoglobulins of the IgG and IgM class in colostrum showed a contrary trend in first and second milk yield, with a tendency towards increase for lysozyme and towards decrease for immunoglobulins.     

Detection of bovine antibodies to the outer membrane of ruminal Bacteroides succinogenes by enzyme-linked immunosorbent assay (ELISA)

The enzyme-linked immunosorbent assay (ELISA) was used to detect bovine serum antibodies directed to the outer membrane antigen of a ruminal bacteria, Bacteroides succinogenes. The outer membrane antigen of B. succinogenes was highly reactive against homologous antiserum, compared with rabbit sera raised against B. ruminicola subsp. ruminicola, B. ruminicola subsp. brevis and Selenomonas ruminantium. The titers of sera from colostrum-deprived calves were negligible level, while those of sera from colostrum-fed calves were relatively high. The mean titer of sera from 10 day-old calves was significantly (p less than 0.01) higher than that of 40 day-old calves, and was significantly (p less than 0.01) lower than that of adult cattle. The mean titer of sera from dairy cows which fed high-roughage diet was higher than that of feedlot cattle which fed high-concentrate diet. These results suggest that the antibodies against the outer membrane antigen of B. succinogenes transfer to calves via the colostrum, and that the titers of cows are affected by the way of feed management.     

Identification of immunoreactive polypeptides of Babesia equi parasite during immunization

This study was carried out to identify immunoreactive polypeptides in Babesia equi merozoite antigen. Three fractions of killed B. equi merozoite antigen viz.; whole merozoite (WM), cell membrane (CM) and high speed supernatant (HSS) antigens were prepared from the parasite infected erythrocytes. These antigenic preparations along with ghost antigen from non-infected erythrocytes were fractionated on 12% sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotted with sera showing high antibody titres. On SDS-PAGE, 16 polypeptides with molecular weight (Mr) in the range of 112-17kDa were obtained from the WM and CM antigens. But only six polypeptides were detected (96.5-28kDa) in the HSS antigen. On immunoblotting with high titred serum collected from donkeys following two immunizations with a killed B. equi merozoite immunogen, 11 polypeptides were observed in the WM and CM antigens (Mr 112-18kDa). Of these, four polypeptides (Mr 112, 45, 33 and 18kDa) were identified as most immunoreactive. Besides these, a 28kDa was observed as strong immunoreactive protein in WM and CM antigens. The HSS antigen showed only six polypeptides and one peptide (28kDa) was identified as immunoreactive. When high titred serum collected from immunized donkeys following challenge with B. equi infected blood and was used for immunoblotting, the protein profile of WM and CM antigens remained the same. However, three additional polypeptides (Mr 81, 54.5 and 39kDa) were detected in HSS antigen.     

Managing the production, storage, and delivery of colostrum.

Provision of an adequate immunoglobulin mass to dairy calves is an essential component for survival, health, and future productivity. To prevent FPT of immunity due to suckling of the dam, newborn dairy calves should be removed from the calving area within 30 minutes of birth. First and later lactation cows are suitable colostrum donors, provided they are healthy, well-vaccinated, have had optimal transition management, and an appropriate dry-period length. Early colostrum collection yields an adequate immunoglobulin mass provided that 3 to 4 L of colostrum is fed to the newborn calf. Regular testing for the adequacy of the dairy's colostrum feeding program is an excellent way to prevent calf health problems and identify potential need for CSs or replacement products.     

Passive protection of calves against experimental infection with Salmonella typhimurium

Cows were vaccinated with formalin-killed Salmonella typhimurium approximately seven weeks and two weeks before parturition to investigate whether passive immunity could protect their calves against experimental S typhimurium infection. After birth the calves were left with their dam for 48 hours and then separated and fed cold, stored colostrum from their own dam for a further eight days. Oral challenge five days after birth with 10(8) S typhimurium did not result in the death of these calves even when they had absorbed little colostrum. Mortality was reduced to 22 per cent in calves which sucked from vaccinated dams and were then fed colostrum from unvaccinated cows and to 50 per cent in calves born to unvaccinated cows and later fed colostrum from vaccinated animals. Calves which sucked from a vaccinated dam and then received stored colostrum from the same cow excreted salmonellas for significantly shorter periods after challenge and were less often infected at necropsy 28 days after inoculation. Protection was not correlated with the levels of O or H agglutinating antibodies in serum, which were at a maximum 24 hours after sucking and then slowly declined. There was no evidence of an active antibody response in the serum. Measurement of the O and H response of cows after vaccination indicated that the vaccination schedule could be improved. The highest levels of agglutinating antibody were measured between two and three weeks after the first vaccination and there was only a minimal response to the second vaccination before parturition.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effect of subclinical ketosis in dry cows on the composition of the colostrum and on health indicators in newborn calves

Subclinical ketosis of dry cows was studied as to its effect on the composition of colostrum and on the health condition and selected clinico-biochemical parameters in the new-born calves of these cows. The experimental group consisted of eight cows with ketonuria and their calves. The control group consisted of six cows without ketonuria and their new-born calves. Calves of both groups were reared in similar conditions. Colostrum samples were taken from the first milking and then from the milking 24 hours after parturition. The blood of the calves was sampled before the intake of colostrum and 24 hours after birth. The concentration of ketone bodies, particularly beta-hydroxybutyrate, was much higher in the colostrum of both groups of cows than in the blood (62.6 mg total ketone bodies per 1 litre of the first colostrum of the cows of the experimental group). The concentration of ketone bodies slightly increased after parturition. The cows with ketonuria secreted into colostrum a larger amount of oxidated ketone bodies. Colostrum quality was good in both groups. Decreased viability was not recorded during the clinical examination of the calves after birth. The level of total ketone bodies in the blood of pre-colostral calves in the experimental group was 10.4 mg per litre (a much lower concentration than in blood of their dams), and exhibited no appreciable change after taking in the colostrum. The blood of calves born to cows with ketonuria contained significantly higher amounts of oxidated ketone bodies. No correlation was demonstrated between the contents of ketone bodies in the blood of cows, in the blood of calves, and in the colostrum. The calves of the experimental group were found to have a significantly higher AST activity in plasma, as compared with the control group. Twenty-four hours after birth, the quantity of immunoglobulins in the blood serum was significantly lower in the calves of the experimental group. Thanks to good attendance and hygiene, the morbidity did not increase and no losses occurred.     

Colostrum quality,IgG absorption and daily weight gain of calves in small-scale dairy production systems in Southern Vietnam

Dairy production is expanding rapidly in Vietnam, but still, the smallholder farms are most common. The aim of this study was therefore to get improved knowledge about colostrum quality in dairy cows, immunoglobulin G (IgG) absorption, daily weight gain in dairy calves and calf management in small-scale dairy production systems in Southern Vietnam. A field survey was conducted on 40 farms, with two calves on each farm being intensively studied. It was observed that newborn calves were separated from their dams immediately after birth and offered 2–4 L first colostrum within 4 h by bucket feeding. The first colostrum IgG level, fat and protein content were on average 35.6, 4.8 and 21.4%, respectively, and 91% of the cows produced colostrum of good quality (Brix value >22%). The IgG level in serum of calves, measured as Brix value, was on average 9.3%. Colostrum in the samples studied was of quite high quality and on-farm observations showed that colostrum was offered on the first day of calf life, so passive transfer of immunity to the calves was high. In total, 10% of the calves had a Brix value for IgG in serum lower than 8.3%, indicating that those calves had suffered from failure of passive immune transfer (FPT). The daily weight gain of female and male calves was 0.75 and 0.54 kg, respectively. Serum IgG was positively correlated with colostrum protein (P = 0.002). Daily weight gain and diarrhoea was negatively correlated (P = 0.001).