Dynamic changes of immunoglobulin concentrations in pig colostrum and serum around parturition

The aim of the study was the determination of IgA, IgM and IgG concentrations in porcine serum and colostrum, in order to evaluate their variations in the perinatal period, as well as to clarify whether there is a correlation between colostrum intake, initial level of immunoglobulins (Ig) in piglet serum and development of their own immunity. The mean IgA, IgM and IgG concentrations in sow serum 10 days before parturition were 1.58, 6.12 and 39.56 mg/ml, respectively. Seven days later only the IgG level was insignificantly lower (34.94 mg/ml, p = 0.55), while concentrations of IgA and IgM increased to 2.25 and 7.25 mg/ml, respectively (p = 0.23 and 0.62, respectively). The mean initial IgG concentration in colostrum at farrowing was 118.5 mg/ml and differed between sows. The average value of IgA in colostrum at birth was 23.8 mg/ml and decreased to 7.85 mg/ml at 6 hours (h) and to 4.59 mg/ml at 24 h after the onset of farrowing. IgM concentration at birth was 12.1 mg/ml and decreased to 4.23 mg/ml at 24 h postpartum. Positive relationships were found between concentrations of IgM and IgA in serum of piglets at 14 and 56 days of life (r = 0.41 and 0.80, respectively, p < or = 0.05) as well as for IgG concentration in the piglets serum at 7 days and 56 days of age (r = 0.48, p < or = 0.05). The above observations suggest that there is a correlation between the level of Ig in piglet serum in the first days of life and improvement of their own immunity.     

IgA, igG1, IgG2, IgM, and BSA in serum and mammary secretion throughout lactation

Bovine IgG1, IgG2, IgA, and IgM were measured in the serum and lacteal secretions of six cows from 10 days prepartum to 240 days of lactation. Immunoglobulins in lacteal secretions were expressed in units of concentration (mg/ml) as well as in total daily output. All isotypes were selectively accumulated during colostrum formation. The rate of IgG1 accumulation decreased rapidly after calving; this decrease corresponded to a return to normal serum levels of this immunoglobulin. Selective accumulation of IgA > IgM > IgG1 was maintained throughout lactation, but IgG2 showed no selective accumulation beyond 5 days postpartum. In serum, IgA and IgM levels were elevated at parturition and showed a significant decrease postpartum. Increases in serum IgA levels 60 days postpartum corresponded to a rise in lacteal concentration. The concentration of all immunoglobulins increased during late lactation, coincident with a major reduction in milk yield. Six strains of mastitis-causing organisms were cultured during the period of the experiment; however, none resulted in clinical mastitis or showed an effect on immunoglobulin secretion.     

Distribution of antibodies to rotavirus in serum and lacteal secretions of naturally infected swine and their suckling pigs

Rotavirus antibodies were demonstrated in lacteal secretions and sera of 20 parturient sows and in sera of their newborn by an enzyme-linked immunosorbent assay blocking technique, using bovine rotavirus cell culture antigen and monospecific antibody to bovine rotavirus. Antibodies to rotavirus occur in the 3 immunoglobulin (Ig) classes IgM, IgA, and IgG in lacteal secretions. High and long-persisting antibody activity was mainly associated with the IgA class. The IgM and IgG decreased to undetectable concentrations in most sows during the 14-day investigation period. Serum antibodies of newborn pigs nursing their dams also decreased rapidly during this time. The heterologous enzyme-linked immunosorbent assay blocking technique was a reliable and rapid procedure for the demonstration of rotavirus antibodies.     

Quantitative Changes Associated with Calving in the Levels of Bovine Immunoglobulins in Selected Body Fluids I. Changes in the Levels of IgA, IgG1 and Total Protein

Levels of bovine IgA, IgG1 and total protein (TP) were determined in serum, saliva, tears and individual quarter lacteal secretions of six Holstein-Friesian cows sampled from six weeks before to four weeks after parturition. Hierarchal analyses of variance indicated significant variations among weeks, cows and quarters of the udder. A precipitous but non proportional drop in the levels of IgA and IgA1 in lacteal secretions occurred at calving. There was a concomitant increase in IgG1, and decrease in IgA, in serum. Correlation studies supported the concept of selective transport of IgG1 from serum to lacteal secretions in regulated amounts independent of serum IgG1 levels. Changes in the IgG1/TP ratio of serum and lacteal secretions supported the idea of a decrease in the selective transport mechanism. Correlation studies and estimations of secretory IgA (SIgA) in serum suggest that serum IgA is derived from IgA synthesized in secretory tissues. Highly significant correlations between IgA and IgG1 levels in all secretions postpartum suggest that local IgA synthesis and either IgG1 transport or local IgG1 synthesis are initiated by the same stimuli. Although some of the variation in the level reported for IgA and IgG1 in secretions resulted from protein dilution, much of the variation represents physiological differences between individual animals and tissues in the same animal. An IgG2/IgG1 ratio approaching that of serum occurred in a mastitic quarter of one cow. IgA was the principal immunoglobulin in saliva and tears, comprised a greater proportion of the immunoglobulin in milk whey than in prepartum lacteal secretions and was a minor immunoglobulin in bovine serum.     

Studies on immunoglobulins and trypsin inhibitor in colostrum and milk from sows and in serum of their piglets.

The concentrations of IgG, IgM, IgA and the specific sow colostrum trypsin inhibitor (SCTI) were measured by radial immunodiffusion in colostrum and milk samples from sows and in serum samples from their offspring during the suckling period. A clear time dependence was found for all the measured variates in both whey and serum. Statistically significant positive correlations were found between, on the one hand, concentrations of IgG and IgA, but not IgM, in sera from 39 suckling piglets 1 and 3 days old, and, on the other hand, concentrations of the same immunoglobulins and of the trypsin inhibitor in maternal colostrum (n = 7). Multiple regression analyses showed that at day 1 and day 3 the levels of both IgG and IgA in serum samples from the suckling piglets were positively influenced by both the SCTI and the IgG or IgA contents in maternal colostrum.     

The influence of age and breed on the concentrations of serum IgG, IgA and IgM in sows throughout the reproductive cycle

The influence of age and breed on the concentrations of IgG, IgA and IgM in the sera of sows throughout the reproductive cycle was investigated in 4137 sows which had had 0 – 20 gestations and representing three breeds: Swedish Landrace, German Landrace and L-12 (=Swedish Landrace × Large White). Data revealed an increase in total immunoglobulins (Ig), IgM and IgG serum levels with increasing gestation number; the latter contributed > 80% to total Ig levels. IgG was significantly increased up to the fourth gestation, whereas IgM showed a significant increase only to the third gestation. IgA showed only minor differences. Age-dependent increases in serum IgM were ascribed to the incraased probability of antigenic exposure during suckling, while failure to observe this change in serum IgA was ascribed to its role as a local Ig. Breed differences were observed to be significant for all three Ig's. It is concluded that establishment of group norms for serum Ig's should consider age and breed difference as well as stage of gestation or lactation.     

Immunoglobulins in nasal secretions of dog puppies from birth to six weeks of age

In order to investigate local immune defence mechanisms in the dog, the concentration of immunoglobulins (Ig) G, A and M in nasal secretions (NS) and serum of 42 healthy, neonatal Rottweiler puppies was determined. Ig were measured with a commercially available, dog-specific ELISA during the first six weeks of life. On average, IgG was the predominant Ig isotype during the first three days of life. The IgA:IgG ratio changed between weeks 1 and 3 due to markedly decreasing IgG concentrations. Between the fourth and sixth week, IgG predominated again. During the first week, only 21-39% of puppies had measurable amounts of IgM in NS, in week 2, this percentage increased to 69%. Marked differences between litters and between individual puppies within litters were found. No puppy diseased during the observation period and all developed normally.     

Persistence of passively transferred antibodies in porcine Taenia solium cysticercosis. Cysticercosis Working Group in Peru.

We evaluated the presence and persistence of anticysticercal antibodies in piglets born to Taenia solium infected sows. Infected sows from a disease-endemic area of Peru were transported to a nondisease-endemic area and impregnated. Serum samples were collected from sows and piglets on Day 2 through Week 35 after birth. Using an immunoblot specific for cysticercosis, Ig isotypes to 7 cyst antigens were measured and quantified. Serum samples from the piglets contained detectable antibodies from Week 1 through Week 35 (27 weeks after weaning). The primary Ig isotype present in both sows and piglets was IgG. Antibodies did not appear in piglet serum samples until after suckling, demonstrating that anti-cysticercal antibodies are transferred solely via colostrum. Our data have shown that maternally transferred antibodies to cyst antigens may persist through much of a pig's life. Therefore, the presence of passively transferred antibodies must be considered in studies that examine the prevalence of cysticercosis in pigs. Furthermore, when designing control strategies for cysticercosis, careful evaluation and selection of sentinel pigs becomes a crucial component of sentinel selection.     

Quantitation of the immunoglobulins in reproductive tract secretions of the mare

IgG, IgA, IgM and albumin concentrations were measured in serum, follicular fluid and oviductal, uterine and intestinal secretions of the horse. Follicular protein concentrations were found to be dependent on serum concentration and molecular size. Of the immunoglobulins only IgG was detectable in oviductal secretions, but IgG:albumin ratios did not differ significantly from those in serum. IgG, IgA and IgM were measured in uterine secretions, with IgG predominant. Serum transudation into uterine secretions was minimal. In intestinal secretions, IgA levels were slightly higher than IgG, with albumin and IgM at low levels. In five mares with histories of chronic metritis, IgG, IgA and albumin concentrations were significantly elevated in uterine secretions.     

Fetal infections and antibody profiles in pigs naturally infected with porcine circovirus type 2 (PCV2)

The aim of this study was to describe early infections with porcine circovirus type 2 (PCV2) in naturally infected piglets and the piglets' serologic profiles. A total of 20 sows (15 PCV2-vaccinated and 5 unvaccinated) and 100 newborn piglets were studied. Colostrum and serum of the sows and serum of the presuckling piglets were obtained on the day of parturition. Milk samples were collected on day 20 postpartum. Blood samples were taken and the piglets weighed on days 1, 20, 42, 63, and 84 postpartum. Colostrum and milk were evaluated for infectious PCV2 and for PCV2 total antibody (TA), neutralizing antibody (NA), and IgA. Serum samples were evaluated for PCV2 TA, NA, IgA, IgM, and DNA. The sows had high levels of TA and NA in serum and colostrum; however, 11 and 5, respectively, of the 20 colostrum and milk samples contained infectious PCV2. In the serum, PCV2 DNA and IgM were detected in 17 and 5, respectively, of the 20 sows. Nine piglets were born with PCV2 antibodies, which indicates in utero transmission of PCV2 after the period of immunocompetence (> 70 d of gestation). On day 1 postpartum, PCV2 DNA was detected in 29 of the 100 serum samples from the piglets. There was no difference between the weights of viremic and nonviremic piglets throughout the study. In conclusion, even on farms with sows that have high PCV2 antibody titers, vertical transmission of PCV2 may occur, resulting in piglet infection.     

Immunoglobulin concentrations in serum and nasal secretions of calves at the onset of pneumonia

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)     

Changes in serum immunoglobulin values in kittens after ingestion of colostrum.

Immunoglobulin values were determined in fetal and kitten sera. In the fetal and precolostral kitten sera, only IgG was detected, except in 1 case in which IgM was detected. The IgG, IgA, and IgM were transferred to the kittens through colostrum ingestion with some selectivity. Concentration of the transferred IgG, IgA, and IgM decreased significantly with half-lives of 4.15 +/- 1.29 days, 2.03 +/- 0.33 days, and 2.2 +/- 1.2 days, respectively. As a result of this decrease and increase of de novo immunoglobulin synthesis, IgG, IgA, and IgM were at their lowest values when kittens were 20 to 25 days, 14 to 20 days, and 8 to 10 days old, respectively. After their nadir was reached, IgG values increased gradually, IgA slowly, and IgM rapidly, as a result of de novo immunoglobulin synthesis. When the kittens were 90 days old, their immunoglobulin values were 80% (IgG), 7% (IgA), and 100% (IgM), compared with those of adult cats. These findings suggest that kittens that receive inadequate colostrum from their mothers will be particularly susceptible to infection after they are 5 weeks old.     

Intestinal and serum antibody response in gnotobiotic piglets to oral immunization with Escherichia coli

The local and systemic immune response to a formolized E. coli oral vaccine was investigated in 13 gnotobiotic piglets. Beginning at ten days of age animals received a daily dose of 10¹⁰ or 10¹¹ bacteria, on ten consecutive days. Intestinal loop tests with one animal of each group on day 26 showed protection which was more pronounced in the animal dosed 10¹⁰ bacteria compared with the other immunized piglet. Immunoglobulin class-specific antibodies to O and K antigens were determined by ELISA technique. In serum no IgG or IgA antibodies were found, whereas IgM-anti O149 antibodies in both immunized groups reached their highest level at day 4 of dosing and decreased thereafter. IgM-anti K88 antibodies were first detected at day 10 of dosing. Both immunized groups had comparable serum levels at days 20 and 30. Also in gut secretion the IgM antibody response was predominant, and higher levels were found in the 10¹⁰ group than in the 10¹¹ group. IgG and IgA antibody response were also detected in secretion.     

芪英汤和子甘汤中药复方促进母猪繁殖性能和断奶仔猪生长性能的临床研究

母猪产死胎、弱胎和断奶仔猪腹泻是兽医临床养猪业亟待解决的问题。为了响应国家在养殖业中执行的“减抗替抗”政策,本文基于中医辩证论治,探讨中草药复方芪英汤、子甘汤分别对母猪繁殖性能和断奶仔猪生长性能的影响。对同期发情的母猪(35头)和同期断奶仔猪(140头)进行中药方剂预混饲料的饲养方式,分别持续饲养至分娩结束、30 d,同时记录母猪分娩数据包括窝均出生仔猪数、窝均重、窝均死胎数、死胎率等,仔猪生长数据包括初重、末重、料肉比和腹泻率,通过酶联免疫吸附方法(ELISA)、荧光定量PCR(RT-PCR)检测母猪血清中IL-6、IL-1β、TNF-α、IgG、IgA、IgM和断奶仔猪血清中IgA的分泌情况以及母猪圆环病毒2型、伪狂犬病病毒、猪繁殖与呼吸综合征病毒及抗体来确定母猪免疫力情况。结果表明,芪英汤可以显著降低妊娠母猪炎性因子IL-6、TNF-α分泌水平,降低低胎次母猪生产新生仔猪死胎率、弱胎率、死亡率,分别下降1.96%、5.83%、8.25%,提高母猪的繁殖性能。子甘汤和芪英汤联用能够显著提高仔猪断奶后期IgA水平,降低腹泻率和料肉比, 提高生长性能,降低断奶仔猪血液中白细胞水平,红细胞恢复到正常水平。综上,中药复方芪英汤和子甘汤有助于提高母猪繁殖性能和恢复断奶仔猪生长性能。     

Helicobacter pylori-specific immunoglobulin synthesis in gnotobiotic piglets: evidence for the induction of mucosal immunity in the stomach

Short term tissue biopsy cultures and paired, sera, bile and gastric and intestinal contents from Helicobacter pylori-infected gnotobiotic piglets were tested for the synthesis of H. pylori-specific immunoglobulin (Ig) isotype production by antigen-specific ELISA from post-infection days (PIDs) 2-28. Serum antibody levels in all three Ig isotypes were elevated from baseline values by PID 14, serum IgM levels reached peak levels on PID 14 and by PID 28 bile was strongly positive for IgA and IgG.Intestinal, but not gastric contents from infected piglets, contained IgA-specific antibody from PID 14 onward. Gastric mucosal epithelia adjacent to areas of inflammation in infected but not uninfected control piglets produced readily detectable amounts of porcine secretory component (SC); IgA-positive plasma cells were identified in gastric submucosa and lamina propria in these areas. Culture fluid supernatants, collected from explanted gastric cardia and antra and intestinal ilea of H. pylori-infected piglets had trace amounts of IgA as early as PID 2 in some animals, and strong IgA reactivity in all by PID 28. Supernatants also contained H. pylori-specific IgG by PID 14. A strong gastric lymph node IgA response contrasted with moderate IgA production in mesenteric lymph nodes and spleen. Mucosal biopsy production of H. pylori-specific IgG was more evenly distributed throughout the lymphoid system. These data support the contention that the Ig response to H. pylori is initiated within the gastric compartment and matures over time to a generalized IgA-dominated mucosal and IgG-dominated nonmucosal humoral immune response.     

Effect of the sow vaccination regimen on the decay rate of maternally derived foot-and-mouth disease antibodies in piglets

Three pairs of sows were vaccinated against foot-and-mouth disease (FMD) at various intervals before farrowing and samples of blood were collected from their piglets periodically for 70 days after birth. When the sows were vaccinated 12 to 13 days before farrowing the predominating FMD neutralising antibody at time of parturition was IgM and the observed half lives of the maternally derived antibodies in the piglets were short (four to eight days). However, when sows were last vaccinated 30 to 32 days before farrowing, the maternally derived FMD neutralising antibodies in the piglets were predominantly IgG and the observed half lives were seven to 21 days. These observed half lives for IgG were shown to be closely related to the period over which the maternally derived antibodies could be demonstrated and to the rate of increase of the piglet's blood volume over the same period. If corrections were made for increase in blood volume the decay rate of IgM antibodies in piglets was seven to 18 days while the decay rate for IgG was greater than 408 days. This result suggested that there was little or no IgG catabolism or excretion during the first 70 days of the piglet's life.     

Hepatitis E virus infection dynamics and organic distribution in naturally infected pigs in a farrow-to-finish farm

The objective of the present study was to determine the pattern of Hepatitis E virus (HEV) infection in a naturally infected, farrow-to-finish herd. For that purpose, a prospective study was conducted in randomly selected 19 sows and 45 piglets. Blood samples were collected from sows at 1 week post-farrowing and from piglets at 1, 3, 6, 9, 12, 15, 18 and 22 weeks of age. Furthermore 3 or 5 animals were necropsied at each bleeding day (but at 1 week of age), and serum, bile, liver, mesenteric lymph nodes and faeces taken. HEV IgG, IgM and IgA antibodies were determined in serum and viral RNA was analysed in all collected samples by semi-nested RT-PCR. Histopathological examination of mesenteric lymph nodes and liver was also conducted. From 13 analysed sows, 10 (76.9%) were positive to IgG, one to IgA (7.7%) and two to IgM (15.4%) antibodies specific to HEV. In piglets, IgG and IgA maternal antibodies lasted until 9 and 3 weeks of age, respectively. IgG seroconversion occurred by 15 weeks of age while IgM and IgA at 12. On individual basis, IgG was detectable until the end of the study while IgM and IgA antibody duration was of 4-7 weeks. HEV RNA was detected in serum at all analysed ages with the highest prevalence at 15 weeks of age. HEV was detected in faeces and lymph nodes for the first time at 9 weeks of age and peaked at 12 and 15 weeks of age. This peak coincided with the occurrence of hepatitis as well as with HEV detection in bile, liver, mesenteric lymph nodes and faeces, and also with highest IgG and IgM OD values at 15 weeks. Finally, different HEV sequences from this farm were obtained, which they clustered within 3 different groups, together with other Spanish sequences, all of them of genotype 3. Moreover, the present study also indicates that the same pig can be infected with at least two different strains of HEV during its productive life. This is the first study characterizing HEV infection in naturally infected pigs with chronological virus detection and its relationship with tissue lesions throughout the productive life of the animals.     

Studies on maternally derived antibodies to Aujeszky's disease virus in piglets born to naturally or experimentally infected sows

The concentration of maternally derived antibodies to Aujeszky's disease virus was compared in 10 litters born to infected sows. Four sows had been naturally infected and six were experimentally infected. Both IgG and IgM were present in piglet sera during the first days of life. IgM antibodies went rapidly to undetectable levels; IgG persisted much longer. The duration was dependent upon the original concentration. There was a clear relationship between the clinical disease experienced by the sow and the titre of antibodies in serum and colostrum; sows which had been naturally infected or experimentally infected with a highly virulent strain passed onto their litters a high amount of specific antibodies while sows which after experimental infection presented only mild clinical signs had very low titres of neutralizing antibodies and their litters were virtually devoid of specific antibodies at 3 weeks after birth. A return to detectable levels of IgM was noticed in some litters at around 9 weeks postcolostrum intake suggesting a development of a specific immune response.     

Immunoglobulins in piglets from sows heat-stressed prepartum

Sows were subjected to moderate heat stress in a chamber (32 C) from d 100 of pregnancy until less than 8 h before delivery of first piglet, while control sows were in a thermoneutral chamber (21 C) or farrowing house (22 C). Blood serum and colostrum at parturition of heat-stressed sows and their piglets' serum at birth had elevated cortisol concentrations. Total protein, globulin and immunoglobulin G (IgG) concentrations in sow serum tended to decrease as parturition time was approached; albumin did not change. Total protein and IgG concentrations in colostrum at parturition and in milk 24 and 48 h later tended to be lower in heat-stressed sows. Concentrations of these four protein fractions (total, globulin, IgG and albumin) in piglet serum at birth did not differ among treatment groups, but soon after colostrum ingestion they increased markedly in all groups. Therefore, in all groups total protein remained constant while globulin and IgG decreased. Globulin concentration on d 1 was lowest in piglets from heat-stressed sows, but its rate of decrease after d 1 was not affected by sow treatment. Immunoglobulin G concentration was 11 mg/ml lower, but its rate of decrease through postnatal d 20 was slower in piglets from heat-stressed sows than in those from control sows; a 10-mg/ml difference in IgG concentration on postnatal d 1 has been associated with increased preweaning mortality in piglets. Higher cortisol concentration in serum and lower IgG in colostrum of sows under heat stress was associated in their piglets with higher serum cortisol at birth and lower serum IgG for the first 20 d postnatum.