Immunization of Cattle Against Rabies Using Inactivated Cell Culture Vaccines

Twenty-one heads of cattle were vaccinated with Madibovin, 31 with Rabdomun and 127 with Rabisin on 4 different farms. Rabies neutralizing antibody titre (≥0.5 IU/ml) was detected in 80% of 163 animals tested about 1 month and in 42% of 133 animals tested about 1 year after primary vaccination. On 3 of the farms 86 animals received booster vaccination about 1 year after primary vaccination. All these animals had antibody titre (≥0.5 IU/ml) about 1 month after booster and antibody levels were higher than after the primary vaccination. Rabies antibody titres (≥0.5 IU/ml) were detected in 96% of 50 animals tested 1 year after the booster. No significant differences (p>0.05) in antibody levels were detected between animals vaccinated with Madibovin or Rabisin (farm C) respectively with Rabisin or Rabdomun (farm D) at any collection time. Responses to rabies vaccines varied considerably between the farms. After primary vaccination of the animals on 2 farms with the same batch of Rabisin, the antibody levels clearly differed (p<0.0001) between the farms.Our results indicate that booster is always necessary after primary vaccination to ensure that all animals are protected.     

Rabies Antibody Titres in Vaccinated Reindeer

One dose of inactivated, adjuvanted rabies vaccine of cell culture origin (Rabisin) induced good but short-duration immunity in close to 100% of the 50 semi-domesticated reindeer (Rangifer tarandus tarandus L.) vaccinated. Most of the animals (44) had rabies virus antibody titre ≥1.5 IU/ml at 38 days after vaccination. Five animals had titre 0.5 IU. Antibody titres were not, however, present 1 year after primary vaccination in most animals. About 1 year (360-413 days) after primary vaccination, 22 of the 39 reindeer that could be sampled had rabies virus antibody titre <0.5 IU/ml.     

Serosurveillance of rabies antibodies in dogs in Mumbai region by using indirect ELISA

Rabies is a highly fatal viral infection of the central nervous system affecting all warm-blooded animals including humans. To implement the preventive and control measures, it is important to decide the status of anti-rabies antibodies in dogs. Out of 120 serum samples, 47 (39.2 %) serum samples, showed an antibody titre equal to or above the cut off value of 0.5 IU/ml. The maximum number of dogs showed anti-rabies antibody titres equal to or above the cut-off value of 0.5 IU/ml after <1 month pre-exposure to the rabies vaccine. In 15 serum samples of pet dogs, we observed 13 (86.66 %) dogs with protective anti-rabies antibody titre. Statistical analysis suggests that the age of the animal had no significant effect on anti-rabies antibody titre in vaccinated pet dogs. The overall low seroprevalence of anti-rabies antibody in stray dogs indicates their susceptibility to rabies infection and thus posing a risk of rabies to other animals and humans.     

Factors associated with the success of rabies vaccination of dogs in Sweden

Background

United Kingdom, Ireland, Malta and Sweden maintain their national provisions for a transitional period regarding rules concerning rabies vaccination and individual serological test for rabies neutralizing antibodies. The purpose of vaccinating dogs against rabies is to establish pre-exposure immunity and protect individual animals from contracting rabies.The aim of the study was to investigate factors associated with reaching the internationally accepted threshold antibody titre of 0.5 IU/mL after rabies vaccination of dogs.

Methods

The study was a prospective single cohort study including 6,789 samples from Swedish dogs vaccinated with commercially available vaccines in Sweden, and the dog''s antibody responses were determined by the OIE approved FAVN test. Information on potential risk factors; breed, age, gender, date of vaccination, vaccine label and the number of vaccinations, was collected for each dog. Associations between the dependent variable, serological response ≥ 0.5 IU/mL or < 0.5 IU/mL and each of the potential risk factors were investigated using logistic regression analysis.

Results

Of 6,789 vaccinated dogs, 6,241 (91.9%) had an approved test result of ≥ 0.5 IU/mL. The results of the multivariable logistic regression analysis showed that vaccinating with vaccine B reduced the risk of having antibody titres of < 0.5 IU/mL by 0.2 times compared with vaccination using vaccine A. Breed size was found significant as an interaction with number of vaccinations and age at vaccination as an interaction with day of antibody testing after last vaccination. In summary, larger breeds were at higher risk of having antibody titres of < 0.5 IU/mL but if vaccinated twice this risk was reduced. Moreover, there were a increased risk for dogs < 6 months of age and > 5 years of age to have antibody titres of < 0.5 IU/mL, but this was affected by number of days from vaccination till testing.

Conclusions

The probability of success of rabies vaccinations of dogs depends on type of vaccine used, number of rabies vaccinations, the breed size of the dog, age at vaccination, and number of days after vaccination when the antibody titres are tested. The need for a booster vaccination regimen is recommended for larger breeds of dog.     

Walking the dog and moving the cat: rabies serology in the context of international pet travel schemes

Data of 13'469 blood samples from 10'999 dogs and 2'470 cats tested for rabies neutralizing antibodies within the framework of pet travel schemes were analysed for single and combined factors influencing antibody titres and failures. The time span between vaccination and drawing the blood sample was confirmed as a major source of failure in dogs with a proportion of 23 % at 4 months after primary vaccination (single dose). Failures in dogs and cats (titre < 0.5 IU) were significantly reduced after double primary vaccination (2 doses within 7 - 10 days), although failures reached comparable levels in dogs as early as 6 months after vaccination. In contrast, failure after vaccination was generally below 5 % in dogs and absent in cats after a booster applied at earliest 12 months after single primary vaccination. Statistically significant differences between the failures of the vaccine brands ?Rabisin? (1.5 %), ?Defensor? (6.7 %), ?Nobivac Rabies? (11.0 %) and ?Rabdomun? (18.2 %) were found in dogs but also between the titres induced in cats. Significant differences were found between different dog breeds with some small breeds showing a significantly higher responsiveness. Taken together, a new regimen for rabies vaccination consisting of double primary vaccination with a short interval of 7 - 10 days and a one-year booster appears to be highly recommended for dogs and cats.     

Rabies antibody titres in vaccinated dogs

In a field study, rabies virus neutralizing antibody titres were determined by the microtest modification of the rapid fluorescent focus inhibition test before and after primary vaccination in 30 puppies, and before and after booster vaccination in 59 previously vaccinated dogs. A commercial modified live virus vaccine was used. Three weeks after primary vaccination the mean antibody titre was 102 ± 90, but only 24 dogs presented for booster vaccination had detectable antibody levels (mean titre 12 ± 16). The antibody responses three weeks after booster vaccination (mean 380 ± 216) were significantly greater than the responses to primary vaccination. It was concluded that previously vaccinated dogs could have an anamnestic response to booster vaccination, even when antibodies were not detected in their sera before revaccination.     

Induction of oestrus by administering Inhibin antiserum along with equine chorionic gonadotropin in anoestrous bitches

As dogs experience oestrus only once or twice a year, it is necessary to establish an effective method of oestrous induction for efficient breeding. In the present study, we evaluated inhibin antiserum (IAS) on oestrous induction in anoestrous females. Bitches were administered 0.5 ml/kg IAS or a mixture of 50 IU/kg equine chorionic gonadotropin (eCG) and 0.5 ml/kg IAS and 500 IU human chorionic gonadotropin (hCG) administered 7 days after the mixture injection. As a control, bitches received 50 IU/kg eCG, with 500 IU hCG administered 7 days after eCG injection. Blood-tinged vaginal discharge, vulvar swelling, plasma progesterone concentrations and ovarian follicular development were assessed from day 0 to day 14. IAS alone injection did not induce oestrus in bitches at the anoestrous stage. Conversely, vulvar swelling, blood-tinged vaginal discharge and an estimated luteinizing hormone (LH) surge appeared on days 3–7, days 3–6 and days 7–9 after the IAS+eCG mixture injection, respectively, in all five bitches at the anoestrous stage. The average number of developing and ovulated follicles in bitches administered IAS+eCG was 8.8 and 9.6 respectively. A single eCG injection followed by hCG induced oestrous signs, with an average of 8.3 developing follicles and 4.5 ovulated follicles. This study revealed that IAS alone did not induce oestrus, but when IAS was used in combination with eCG, it induced oestrus and promoted a considerable number of ovulations in anoestrous dogs.     

Responses of female lambs to Rev-1 (brucellosis) vaccination

In order to investigate Rev-1 vaccination immunogenicity, 60 indigenous (Makuii) non-infected female lambs 3–4 months of age in northwestern Iran were systematically divided into two groups: 40 into a treatment (T) group and 20 into a control (C) group. Lambs in Group T received 1 ml of Rev-1 vaccine by s.c. injection and blood samples were collected from both groups at 15 days and 2, 4, 6, 8, 10, 12 and 14 months after vaccination. The seroagglutination test (SAT) and the 2-mercaptoethanol test (2-MET) were carried out on the sera. Control lambs were negative in all the examinations. The results of the SAT showed that the mean( ± SD) antibody titre of lambs in Group T was maximum (725 ± 112 IUml⁻¹) at Day 15, then declined gradually until the fourth month and was in the normal range (31 IU ml⁻¹) thereafter. The results of the 2-MET were negative in Group C but in Group T the antibody titre was at a maximum level (161.7 ± 46.6 IUml⁻¹) at Day 15, decreased to 1.2 ± 2.5IUml⁻¹ at 4 months post-vaccination and was negativ; thereafter. In the second part of the trial, 20 vaccinated and ten control lambs received 0.25 ml melitin by i.d. injection 10.5 months after vaccination. The control group showed no reaction but 13 (65%) of the vaccinated lambs showed an oedematous swelling at the site of injection within 48 h, which indicated that the delayed-type hypersensitivity test (DTHT) could be useful in the diagnosis of Brucella infection in lambs. In the third stage of the experiment, four vaccinated and three control lambs were injected with Brucella melitensis strain 16M at a rate of more than 123 × 10⁶ bacteria per lamb 14 months after vaccination. Rectal temperature (Tem), heart-rate (HR) and respiration rate (RR) were measured three times a day (at 08:00, 14:00 and 21:00 h) 3 days before until 9 days after injection. SAT was carried out on the day before injection and at the time of slaughter. The mean Tem, HR and RR did not significantly change but the mean( ± SD) SAT titre in the T lambs 9 days after injection was 47.5 ± 9.9 IU ml⁻¹ (vs. 8.66 ±6.1 IU ml⁻¹ in the control lambs) (P < 0.01). All lambs were slaughtered on the ninth day. Fewer bacterial cultures of samples taken from the uterus, spleen, liver and lymph nodes were positive in T lambs compared with the controls. The lower proportion of Brucella-positive lambs in the vaccinated group compared with the control group indicates that vaccination with Rev-1 improved the resistance of lambs to the experimental infection.     

Immune response to Japanese rabies vaccine in domestic dogs

To evaluate the immune response induced by Japanese rabies vaccine for veterinary use as international units (IU), we measured levels of rabies antibody in serum samples from dogs by the rapid fluorescent focus inhibition test (RFFIT). In dogs immunized with a reference vaccine (potency level of 3.1 IU/ml), prepared by the same method as that used to produce commercial vaccine, and its dilutions (1 : 2 or 1 : 4), neutralizing-antibody levels increased to 1.0-2.0 IU/ml over a period of 1 month and then decreased to 0.2-1.5 IU/ml over a period of 1 year after the first vaccination and showed a remarkable increase to 12-47 IU/ml after the second vaccination. Sixty-five (74.7%) of the 87 serum samples from domestic dogs that were tested were seropositive (> or =0.1 IU/ml). However, the seropositive rate in dogs less than 1-year old at the time of vaccination was low (57.1%), and the antibody levels in these dogs were not sufficiently high for the rabies antibody titre in serum to be maintained for 1-year. Levels of rabies antibody in all serum samples were also measured by the virus neutralizing test (VNT), and a strong correlation (r > 0.95) was found between the results of the RFFIT and those of the VNT.     

Antibody response to an anti-rabies vaccine in a dog population under field conditions in Bolivia

Rabies remains an important public health issue in Bolivia, South America. Public concern and fears are most focussed on dogs as the source of rabies. The objective of the present study was to assess immunity of an inactivated suckling mouse brain vaccine against canine rabies used for the official vaccination campaigns under field conditions in an endemic area of rabies in Bolivia. A total of 236 vaccinated and 44 unvaccinated dogs in Santa Cruz de la Sierra, selected using stratified random sampling, were investigated in order to obtain owned dog characteristics and antibody titres against rabies in April 2007. The proportion of vaccinated dogs with an antibody titre exceeded the protection threshold value of 0.5 EU/ml was 58% [95% confidence intervals (CI): 52-65], indicating that vaccination is likely to elicit an antibody response (odds ratio 6.3, 95% CI: 1.2-11.5). The range of geometric mean of antibody titre for vaccinated dogs (0.89 EU/ml; 95% CI: 0.75-1.04) was considered to meet the minimal acceptable level indicating an adequate immune response to the vaccine. However, the titre level was not satisfactory in comparison with the results from other field investigations with inactivated tissue culture vaccines. It is recommended for public health authorities to (1) consider modernizing their vaccine manufacturing method because the level of immunity induced by the current vaccine is comparably low, (2) conduct frequent vaccination campaigns to maintain high levels of vaccination coverage, and (3) actively manage the domestic dog population in the study area, which is largely responsible for rabies maintenance.     

Prevalence of rabies antibodies in street and household dogs in Chandigarh,India

The present study reports the first survey for the detection of antirabies antibodies in street and household dogs in India. We aimed to check the efficacy of control programs for the disease in the Union territory of Chandigarh. The serum samples were collected from 100 street and 50 household dogs and tested for the presence of antirabies antibodies by ELISA. As per WHO criteria, a titre of >0.5 IU/ml of antirabies antibody in serum samples was taken as the protective level. Protective antirabies antibody titre was found only in 1% of the street dogs and 16% of the pet dogs. The awareness among the pet dog owners about the antirabies vaccination schedule was low as 18% did not know the vaccination status of the dog and 66% had got the initial immunization done with only three doses and annual boosters were not given. A National Rabies Elimination Program needs to be launched as a collaborative venture by both medical and veterinary practitioners to curb this deadly disease. Also periodic surveys to test the status of antirabies IgG among dogs need to be carried out to ascertain the attainment of WHO protective levels     

Antibody response to Raboral VR-G® oral rabies vaccine in captive and free-ranging black-backed jackals (Canis mesomelas)

Rabies is a zoonotic disease that remains endemic in large parts of southern Africa because of its persistence in wildlife and domestic dog vectors. The black-backed jackals (Canis mesomelas) is primarily the wildlife vector responsible for rabies outbreaks in northern parts of South Africa. Two trials were carried out to investigate antibody responses to the oral rabies vaccine Raboral V-RG® in black-backed jackals under captive and free-ranging conditions. In captive jackals 10/12 (83%; 95% confidence interval [CI]: 52% – 98%), seroconverted after single oral vaccination. Nine captive jackals had protective antibody titres (> 0.5 IU/mL) at 4 weeks (median: 2.1 IU/mL; inter quartile range [IQR]: 0.6–5.7) and 10 jackals had at 12 weeks (median: 3.5 IU/mL; IQR: 1.5–8.3) and three maintained antibody titres for up to 48 weeks (median: 3.4 IU/mL; IQR: 2.0–6.3). Four sites were baited with Raboral V-RG® vaccine for wild jackals, using fishmeal polymer and chicken heads. Baits were distributed by hand or from vehicle at three sites in north-eastern South Africa, with an average baiting density of 4.4 baits/km² and at one site in central South Africa, at 0.12 baits/km². This resulted in protective antibody titres in 3/11 jackals (27%; 95% Cl: 6–61) trapped between 3 and 12 months after baiting in north-eastern South Africa, compared with 4/7 jackals (57%; 95% Cl: 18–90) trapped after 3–18 months in central South Africa. This study shows the potential utility of oral rabies vaccination for the control of wildlife-associated rabies in north-eastern and central South Africa, but extensive studies with wider distribution of bait are needed to assess its potential impact on rabies control in wild jackals.     

Serological responses of adult dogs to revaccination against distemper, parvovirus and rabies

Serum antibody titres to canine distemper virus (CDV), canine parvovirus (CPV) and rabies were measured in dogs that had not been revaccinated annually and compared with the titres in a control group of regularly vaccinated animals; 83 per cent (171 of 207) of the dogs vaccinated against CDV one or more years earlier had serum neutralising antibody titres equal to or greater than 16; 64 per cent (136 of 213) of the dogs vaccinated against CPV one or more years earlier had haemagglutination inhibiting titres equal to or greater than 80; and 59 per cent (46 of 78) of the dogs vaccinated against rabies two or more years earlier had serum neutralising antibody titres equal to or greater than 0.5 iu/ml. Three weeks after a single booster vaccination the dogs' antibody titres against CDV had increased above the threshold level in 94 per cent of the dogs, against CPV in 68 per cent, and against rabies in 100 per cent.     

Comparison of antibody responses after vaccination with two inactivated rabies vaccines

Thirty laboratory dogs were randomly assigned to two groups (A and B) of 15 dogs and subcutaneously vaccinated with a single dose of one of two commercially available monovalent inactivated rabies vaccines: RABISIN (Merial, France) (group A) and NOBIVAC Rabies (Intervet International) (group B). Rabies antibodies were measured over a period of 4 months using the fluorescent antibody virus neutralization (FAVN) test. The two vaccines performed differently in terms of magnitude and persistence of rabies antibodies titers in dogs. Two weeks after vaccination, average rabies antibody titers peaked at 2.53 IU/mL (range, 0.17-13.77 IU/mL) and 1.26 IU/mL (range, 0.50-4.56 IU/mL) in groups A and B dogs, respectively. The average FAVN antibody titres against rabies on D28, D56, D84, D112 and D120 were significantly higher in group A than in group B. Although all dogs from group B serologically responded to vaccination, the proportion of dogs with antibody titres >or=0.5 IU/mL dropped significantly after D28 and was statistically significantly lower on D56, D84 and D112 compared to group A dogs. In conclusion, in the context of international trade, the choice of the vaccine and the timing of blood tests are critical factors in achieving successful serological test results after rabies vaccination. RABISIN induces high and sustained antibody titres against rabies, increasing the flexibility for the time of blood sampling after primo-vaccination.     

Factors affecting the serological response of dogs and cats to rabies vaccination

After being vaccinated against rabies some cats and dogs fail to show an antibody titre adequate to meet the requirements of the UK Pet Travel Scheme. To investigate this problem, the data derived from 16,073 serum samples submitted to the Veterinary Laboratories Agency for serological testing between 1999 and 2002, 1002 samples submitted to BioBest during March and April 2001, and 1264 samples associated with one make of vaccine submitted to BioBest between June 2001 and January 2003, were analysed. The probability of antibody titre failing to reach at least 0.5 iu/ml was analysed by logistic regression as a function of the choice of vaccine, the interval between vaccination and sampling, the sex and age of the animal, and its country of origin. In dogs, all these factors, except sex, had highly significant (P < 0.001) effects on the test failure rate, and in cats all the factors had a significant effect (P < 0.05).     

Epidural anesthesia in dogs undergoing hindlimb orthopedic surgery: effects of two injection sites

This prospective clinical trial evaluated the effects of epidural anesthesia (EA) placed at the lumbosacral compared to the L5–L6 junction in dogs undergoing hindlimb orthopedic surgery. In all, 98 dogs were randomly assigned to receive injection at either L7–S1 (LS group) or L5–L6 (LL group) at the same local anesthetic regimen (1 mg/kg bupivacaine 0.5% and 0.1 mg/kg morphine 1%). Fentanyl (1 µg/kg) was the intraoperative rescue analgesia (iRA) administered if mean arterial pressure increased by 30% above pre-stimulation value. Procedural failure, iRA, hypotension, motor block resolution, and postoperative side effects were recorded. There were 7/47 (15%) epidural procedural failures in the LS group and 8/51 (16%) (P=1.00) in the LL group; iRA was administered in 21/40 (52%) LS group dogs and in 13/43 (30%) LL group dogs, respectively (P=0.047). The incidence of hypotension was 10/40 (25%) and 16/43 (37%) in the LS group and the LL group, respectively (P=0.25). Proprioceptive residual deficit at 8 hr after EA was recorded in 3/26 (12%) in group LS dogs and in 13/26 (50%) group LL dogs, respectively (P=0.01). The proprioceptive residual deficit at 24 hr in one dog (LL group) resolved within 36 hr. No episodes of postoperative urinary retention, pruritus or neurological damage were recorded. The L5–L6 EA decreased significantly iRA but delays the proprioceptive recovery time. Further studies are needed to determine whether a lower bupivacaine dose reduces the duration of the residual block retaining the same incidence of iRA.     

Inactivated suckling mouse brain rabies vaccine provides short-term immunity in capuchin monkeys (Cebus apella).

Eight capuchin monkeys (Cebus apella) were vaccinated against rabies with an inactivated suckling mouse brain vaccine (SMBV). Three 1-ml doses of 2% brain tissue suspension were given by i.m. injection at 0, 30, and 60 days. Blood samples were collected at 0, 30, 60, 90, 150, 210, 240, 300, and 365 days and were tested by simplified fluorescence inhibition to titer-neutralizing antibodies. All of the animals developed neutralizing antibodies with titers >0.5 IU/ml after vaccination, but the immune response persisted for only 122.3 +/- 32.6 days. The SMBV was able to induce immune response in the capuchin monkeys, but protection was short-lived.     

Putative protective antibody response following oral vaccination of multi-age free ranging helmeted guinea fowls (<Emphasis Type="Italic">Numida meleagris</Emphasis>) with Newcastle disease virus strain I-2 coated on oiled rice

On-farm study was conducted to determine the efficacy of thermostable Newcastle disease (ND) strain I-2 vaccine coated on oiled rice following oral vaccination of multi-age free ranging helmeted guinea fowls. The results from haemagglutination-inhibition assay showed that 7 days after the guinea fowls were orally vaccinated they seroconverted and attained the geometric mean antibody titre (GMT) of 4.9 log₂ (80%). This antibody titre was above the GMT of 3.0 log₂ which is regarded to be protective against field challenge of ND. Furthermore, the results revealed that 28 days after vaccination, the antibody levels reached GMT of 7.6 log₂ (100%). Moreover, all vaccinated guinea fowls survived the challenge of virulent ND virus whereas all unvaccinated chickens died of ND. The findings from the present study showed that the I-2 virus coated on the oiled rice is safe, immunogenic and provoked production of protective antibody response following oral vaccination of helmeted guinea fowls.     

Effect of hCG on Early Luteal Serum Progesterone Concentrations in PG600‐Treated Gilts

Gilt oestrus and ovulation responses to injection of a combination of equine chorionic gonadotrophin (eCG) and human chorionic gonadotrophin (hCG) (PG600) can be unpredictable, possibly reflecting inadequate circulating LH activity. The objective of this study was to determine the effect of PG600 followed by supplemental hCG on gilt ovarian responses. In experiment 1, 212 Hypor gilts (160 day of age) housed on two farms in Spain received intramuscular (i.m.) injections of PG600 (n = 47), or PG600 with an additional 200 IU hCG injected either concurrently (hCG‐0; n = 39), or at 24 h (hCG‐24; n = 41) or 48 h (hCG‐48; n = 45) after PG600. A further 40 gilts served as non‐injected controls. Ovulation responses were determined on the basis of initial blood progesterone concentrations being <1 ng/ml and achieving >5 ng / ml 10 d after the PG600 injection. The incidence of ovulating gilts having progesterone concentrations >30 ng/ml were recorded. During the study period, 10% of control gilts ovulated whereas 85–100% of hormone‐treated gilts ovulated. There were no significant differences among hormone groups for proportions of gilts ovulating. The proportions of gilts having circulating progesterone concentrations >30 ng/ml were increased (p ≤ 0.02) in all hCG treated groups compared with the PG600 group. In experiment 2, a total of 76 Hypor gilts at either 150 or 200 days of age were injected with PG600 (n = 18), 400 IU eCG followed by 200 IU hCG 24 h later (n = 20), PG600 followed by 100 IU hCG 24 h later (n = 17), or 400 IU eCG followed by 300 IU hCG 24 h later (n = 21). Blood samples were obtained 10 days later for progesterone assay. There were no effects of treatment or age on incidence of ovulation, but fewer 150‐day‐old gilts treated with PG600 or 400 IU eCG followed by 200 IU hCG had progesterone concentrations >30 ng / ml. We conclude that hCG treatment subsequent to PG600 treatment will generate a higher circulating progesterone concentration, although the effect is not evident in older, presumably peripubertal, gilts. The mechanism involved and implications for fertility remain to be determined.     

Mammary Secretion of IgG in Sows

The IgG-concentration was determined in serum of 3 pregnant sows before and after partus and in colostrum of 7 sows 0–6 days post partum. The IgG-concentration decreased in serum before partus and increased after partus. The lowest value (1.5 g/100 ml) was observed at partus. The results indicate that IgG is transmitted from serum to colostrum.The concentration of IgG in colostrum was found to be 2.1–10.4 g/100 ml at partus. The concentration decreased very fast during the first day post partum. During 3–6 days post partum the IgG concentration was rather constant (0.3–0.5 g/100 ml). The importance of the results for the passive immunization of piglets is discussed.