A serosurvey of swine and free-living species on Iowa farms for antibodies against encephalomyocarditis virus

Swine and free-living nonporcine species from 20 Iowa swine farms were surveyed for antibodies against encephalomyocarditis virus (EMCV). The microtitration serum neutralization test was used, and antibody titers ≥ 1:8 were considered positive. The overall prevalence in 267 sows in various groups was 37.8% (range 20-86%). The prevalence in sows maintained in total confinement was significantly lower than in sows not maintained in total confinement (p = 0.01). Prevalence in sows was not associated with other herd characteristics or with abundance estimates of rats and/or mice.

Free-living animals tested included 74 domestic cats (Felis domestica), 203 house mice (Mus musculus), 15 mice of the genus Peromyscus, nine Norway rats (Rattus norvegicus), 34 opossums (Didelphis virginiana), 14 raccoons (Procyon lotor), and seven striped skunks (Mephitis mephitis). Of these, the only seropositive animals were two domestic cats.

The results of this study failed to implicate the free-living species surveyed as important reservoirs of EMCV for swine, and suggested that swine themselves and/or some species not included in this survey are the main reservoir of EMCV for swine in Iowa.

     

Effects of cooled floor pads combined with chilled drinking water on behavior and performance of lactating sows under heat stress

This study was conducted to evaluate whether cooled floor pads combined with chilled drinking water could alleviate negative impacts of heat stress on lactating sows. Thirty sows (Landrace × Yorkshire, Parity = 1 to 6) were housed in individual farrowing stalls in two rooms with temperatures being controlled at 29.4°C (0700–1900 hours) and 23.9°C (1900–0700 hours). Sows in one room (Cool), but not in the other room (Control) were provided cooled floor pads (21–22°C) and chilled drinking water (13–15°C). Behavior of sows (15 sows/treatment) was video recorded during farrowing, and days 1, 3, 7, 14, and 21 after farrowing. Videos were viewed continuously to register the birth time of each piglet, from which total farrowing duration and birth intervals were calculated. The number of drinking bouts and the duration of each drinking bout were registered for each sow through viewing videos continuously for 2 h (1530–1730 hours) each video-recording day. Postures (lying laterally, lying ventrally, sitting, and standing) were recorded by scanning video recordings at 5-min intervals for 24 h each video-recording day, and time budget for each posture was calculated. Rectal temperature and respiration rate were measured for all sows the day before and after farrowing, and then once weekly. Sow and litter performance was recorded. Data were analyzed using the Glimmix procedure of SAS. The cooling treatment did not affect sow behavior or litter performance. Sows in the Cool room had lower rectal temperature (P = 0.03) and lower respiration rate (P < 0.001), consumed more feed (P = 0.03), tended to have reduced weight loss (P = 0.07), and backfat loss (P = 0.07) during lactation than sows in the Control room. As lactation progressed, sows increased drinking frequency (P < 0.001) and time spent lying ventrally (P < 0.0001), standing (P < 0.001), and sitting (P < 0.0001), and decreased time spent lying laterally (P < 0.0001) in both Cool and Control rooms. While cooled floor pads combined with chilled drinking water did not affect sow behavior, they did alleviate heat stress partially, as indicated by decreased rectal temperature, respiration rate, weight, and backfat loss, and increased feed intake in lactating sows.     

Actinobacillus suis septicemia in mature swine: two outbreaks resembling erysipelas

In the winter of 1987/88 a previously unrecognized septicemic disease syndrome — actinobacillosis in mature sows and gilts — was diagnosed in two minimal-disease swine herds in southwestern Ontario. In herd 1, 34 sows, 2 boars, 13 feeder pigs, and 30 suckling pigs were affected; 11 sows, 2 feeders, and 18 suckling pigs died. In herd 2, 13 sows and 1 feeder pig were affected; 1 sow and 1 feeder pig died. The disease was manifested by moderate fever (39-40.5°C), round or rhomboid erythematous skin lesions, and inappetence. Sudden deaths without previous clinical signs were frequent. Histologically, coccobacillary thromboemboli in superficial and deep dermal vessels were associated with infarcted dermal and epidermal tissues. The causative organism, Actinobacillus suis, was isolated from the affected pigs. Treatment with commonly used antibacterial drugs was effective.

In many respects, the disease resembled acute swine erysipelas and presented diagnostic problems for this reason.

     

Streptococcal infection as a cause of reproductive tract problems of swine

This study determined that streptococci were the etiological agents responsible for a high percentage of breeding sows experiencing infertility and abortions.No isolations of virus were obtained from fetuses, or placentae. There was no positive serology obtained from sows that aborted when tested for evidence of virus, leptospira, brucella, and eperythrozoon antibodies. Streptococci were the predominant isolates obtained from the genito-urinary tract of sows and boars. Cultures were taken from 75 sows and 46 (61%) yielded hemolytic streptococci; 27 of these streptococci belonged to a specific serogroup. Of the 75 sows studied, 46 were infected, and of these, nine aborted, 14 were infertile, and 23 farrowed normally. There was a significantly (P < 0.02) higher number of sows that had abortions or were infertile in the infected group. A random sample of 18 sows given penicilin therapy indicated a significant benefit from treatment (P < 0.02) in the reproductive performance of infected animals.Twelve out of 16 boars yielded hemolytic streptococci with seven isolated being of a specific serogroup.The percentage distribution of all streptococci isolates belonging to a specific serogroup was 63.4% group C, 22% group D, and 7.3% each fooup A and G.     

Some Observations on the Diagnosis and Epidemiology of Leptospirosis in Swine

The results of combined epidemiological, clinical, serological, bacteriological and histopathological studies following an outbreak of disease caused by L. pomona on a farm stocked with cattle, sheep, pigs, goats and horses maintained for experimental purposes, are reported.

The incidence of infection was high in horses, cattle and pigs. A few low titres were seen in sheep. The goats were not infected. Apart from a single bovine abortion all the clinical symptoms observed occurred in pregnant sows. Seven of these aborted or gave birth to stillborn pigs within a six week period.

Fifteen species of wildlife were trapped or shot on the farm during the year following the outbreak. L. pomona was isolated from four skunks and a porcupine. Epidemiological studies indicated that wildlife reservoir hosts were the primary source of infection for the domestic livestock.

Leptospiruria and the serological response were studied in a group of eight infected sows. Microscopic agglutination titres of 10² or less could not be associated with leptospiruria and the duration of leptospiruria was found to range from a few weeks to over two years in individual sows. Direct dark-field examination of urine proved superior to guinea-pig inoculation as a method of detecting leptospiruria and it is suggested that the former technique could be adopted with advantage as a routine aid to diagnosis.

     

Validating the effectiveness of alternative euthanasia techniques using penetrating captive bolt guns in mature swine (Sus scrofa domesticus)

Euthanasia of mature swine is challenging. Temporal and behind-the-ear locations are two sites that have been identified as alternatives to the more commonly used frontal placement. In stage one, the effectiveness of two penetrating captive bolt gun styles (cylinder or pistol) was evaluated using frontal, temporal, and behind-the-ear placement in anesthetized mature swine (n = 36; weight: 267 ± 41 kg). For stage one, when evaluating treatment efficacy by sex, the cylinder-style equipment was 100% effective in achieving death when applied to all cranial locations (frontal, temporal, and behind-the-ear) for sows; however, the pistol-style equipment was only 100% effective when applied at the behind-the-ear location for sows. For boars, the cylinder-style equipment was 100% effective when applied to the frontal and behind-the-ear location, but the pistol-style equipment was not effective for any cranial location in boars. Therefore, the pistol–frontal, pistol–temporal, pistol–behind-the-ear, and cylinder–temporal were not included for boars, and pistol–frontal and pistol–temporal were not included for sows in stage two. In stage two, commercial, mixed-breed, mature swine (n = 42; weight: 292 +/− 56 kg) were randomly assigned to one of four treatments based on the inclusion criteria described in stage one. A three-point traumatic brain injury (TBI) score (0 = normal; 1 = some abnormalities; 2 = grossly abnormal, unrecognizable) was used to evaluate six neuroanatomical structures (cerebral cortex, cerebellum, hypothalamus, thalamus, pons, and brain stem), and the presence of hemorrhage was also noted. All treatments were 100% effective in stage two. A significant interaction between gun style and placement was determined on predicting total TBI as the cylinder style produced a higher total TBI score compared with the pistol type of the magnitude of +2.8 (P < 0.01). The cylinder style tended to produce a greater TBI score than the pistol in the temporal location (+1.2; P = 0.08). No difference was noted for TBI score behind-the-ear between the cylinder- and pistol-style gun (P > 0.05). TBI tended to be less in boars compared with sows (−0.6; P = 0.08). Hemorrhage was observed in frontal, parietal, occipital, and temporal lobes. This study demonstrated that the cylinder-style captive bolt gun more effectively resulted in brain trauma and death compared with a pistol-style gun and the behind-the-ear and temporal placement showed promise as an alternative placement site for euthanizing mature pigs on-farm.     

Within-herd Use of Boar Semen at 5°C, with a Note on Electronic Monitoring of Oestrus

A system was designed to allow a small swine farm in a northern latitude to use its own boars for artificial insemination (AI) conveniently. Semen was collected twice weekly for 3 day use (days 0, 1 and 2), extended in an egg yolk extender and stored at 5°C. Farm personnel were trained to manage the entire AI programme. For simplicity all semen collected was used for insemination. In the first test 47 gilts and 15 sows were inseminated with semen from four boars. One boar was subfertile with a farrowing rate of 36%. The averages for the other boars ranged from 71 to 100%. Then semen was collected from seven boars and all was used to inseminate 70 gilts and 55 sows with 3 × 10⁹ or more sperm. Overall 63% farrowed an average of 10.1 piglets per litter. Litter size for sows was 1.5 piglets larger than for gilts. There was no difference in farrowing rate when more than 3 × 10⁹ sperm were inseminated. The feasibility of initiating a complete AI programme within a small herd using herd boars was established. However, selection of the boars, use of only high quality semen, and experience with detecting oestrus was required to increase the farrowing rate. The use of various agents to protect sperm against cold shock below 15°C is worthy of further investigation. A new type of electronic probe, which measures the conductivity of cervical mucus, could be helpful if a boar is not available for conventional detection of oestrus.     

Immunity to Escherichia coli in pigs: Serum Gamma Globulin Levels, Indirect Hemagglutinating Antibody Titres and Bactericidal Activity Against E. coli in pigs up to five Weeks of Age

Serum gamma globulin levels, indirect hemagglutinating antibody titres and bactericidal activity against the 0149:K91;K88ac:H10 Serotype of Escherichia coli were determined in pigs up to five weeks of age from vaccinated and non-vaccinated sows.

Gamma globulin levels at two days of age were approximately twice adult levels, by three weeks of age they were one quarter of adult levels and remained so until five weeks of age. Indirect hemagglutinating antibody activity was highest at two days of age, fell until three weeks of age and then rose. Little or no indirect hemagglutinating antibody activity was detected in sera taken at two days of age from pigs from non-vaccinated sows. Only three of 26 two day old pigs had demonstrable bactericidal activity; by three weeks of age 16 of 26 had bactericidal activity. Serum from piglets of vaccinated sows had no more bactericidal activity than did sera from non-vaccinated sows.

     

Effect of housing system and boar exposure on estrus expression in weaned sows

Reproductive efficiency depends on detection of estrus, which may be influenced by housing and boar exposure. This experiment investigated the effects of housing system and boar contact on measures of estrus in weaned sows. Mixed-parity sows were randomly assigned to be weaned into gestation crates away from boars (AWC, n = 45), into pens away from boars (AWP, n = 42), or into pens adjacent to a mature boar (ADJ, n = 46). Estrus detection was initiated at approximately 0700 (0 h) and again at 0.25-, 0.5-, 1-, 2-, 4-, and 8-h intervals beginning on d 4 and continuing through d 7 following weaning. Estrus detection involved observation of the standing response after application of nose-to-nose boar exposure, backpressure, and side rubbing. For the AWC sows, a mature boar was moved to the front of the crates for a 10-min period and then removed. Sows housed in AWP were moved approximately 15 m to an empty pen adjacent to a mature boar for a 10-min period, and then returned to their pen. Sows housed ADJ were not moved and estrus detection was performed in their home pen for a 10-min period. The proportion of sows expressing estrus within 7 d from weaning was lowest for ADJ (80%, 37/46) compared with AWP (98%, 41/42) and AWC (96%, 43/45; P < 0.05). There was an effect of interval from weaning to estrus on the percentage of sows expressing estrus, but there was no interaction with treatment. Sows in AWC and AWP (4.7 d) had decreased (P = 0.01) intervals from weaning to estrus compared with ADJ (5.2 d). The duration of estrus was also shorter (P < 0.001) for ADJ (45 h) compared with AWC (58 h) or AWP (62 h). There was a treatment x interval x day of estrus effect for the percentage of sows expressing estrus. After detection of the first standing response on the first day of estrus, only 62 to 82% of sows were detected standing over the next 2 h for all treatments. However, at 4 to 8 h, this increased to 85 to 98% for the AWC and AWP sows, but <73% of the ADJ sows were detected during this period. On the second day of estrus, estrus expression was not influenced by interval for the AWC and AWP sows and was between 90 to 100% during the 8-h period, whereas ADJ sow detection rates were between 68 to 88%. These data suggest that housing sows adjacent to boars negatively affects estrus expression and detection. In addition, refractory behavior occurs in approximately 30 to 40% of sows and is influenced by housing relative to the boar, day of estrus, and interval from last boar exposure.     

Distribution and persistence of atypical porcine pestivirus in experimentally inoculated pigs

Atypical porcine pestivirus (APPV) is a cause of congenital tremors (CTs) in piglets and has been found in swine populations around the globe. Although systemic distribution of the virus has been reported, there is limited information regarding viral localization at the cellular level and distribution at the tissue level. We collected multiple tissues from 2-d-old piglets (n = 36) born to sows inoculated at 45 or 62 d of gestation with APPV via 3 simultaneous routes: intravenous, intranasal, and directly in amniotic vesicles. In addition, 2 boars from APPV-inoculated sows with CT were raised and euthanized when 11 mo old. In situ hybridization performed on tissue samples from piglets demonstrated a broad and systemic distribution of viral RNA including endothelial cells, fibroblasts, and smooth muscle. Labeling in tissues was more pronounced in piglet tissues compared to boars, with the notable exception of diffuse labeling of the cerebellum in boars. Presence of APPV in boar tissues well after resolution of clinical signs suggests persistence of APPV similar to other pestiviruses.     

Intra-uterine insemination with low numbers of frozen–thawed boar spermatozoa in spontaneous and induced ovulating sows under field conditions

The present study was conducted to evaluate non-return rate (NR), farrowing rate (FR), and number of total pigs born/litter (TB) of weaned sows after intra-uterine insemination (IUI) using low numbers of frozen–thawed (FT) spermatozoa. Semen from 6 boars was cryopreserved individually in a 0.5-ml straw, at a concentration of 1 × 10⁹ spermatozoa/ml. A total of 40 multiparous sows with weaning-to-estrus interval of 3 to 7 days were included. The sows were detected for standing estrus twice daily and randomly assigned to two groups: I) spontaneous ovulation (n = 20) and II) induced ovulation (n = 20) which the sows were given 750 IU human chorionic gonadotrophin (hCG) i.m. immediately at estrus detection. Ovulation was determined every 12 h using transrectal ultrasonography. FT semen containing 1 × 10⁹ motile spermatozoa/dose was used to IUI. In group I, the sows were inseminated at 24 h after the detection of estrus and repeated every 12 h until ovulation. In group II, the sows were inseminated at 36, 42 and/or 48 h after hCG treatment. The results showed that the interval from standing estrus to ovulation (EOI) differed significantly between group I (40.2 h) and group II (35.6 h; P = 0.01). Variation of EOI among sows within each group seemed to be lower in group II (4.5 h SD) than in group I (5.5 h SD; P = 0.5). The number of IUI per sow was 2.9 ± 0.6 times in group I and was 2.4 ± 0.5 times in group II. There were no significant differences (P > 0.05) in the NR (80 vs 85%), FR (60 vs 65%) and the TB (8.0 ± 2.8 vs 9.4 ± 3.7 piglets/litter) between the groups. These results indicated that multiple doses of IUI with a low number of FT boar spermatozoa provided a fairly good NR, and reasonable FR and TB both in spontaneous and induced ovulating sows. The number of inseminations required for attaining acceptable fertility tended to be lower in the weaned sows with induced ovulation.     

Inhibited development of Ostertagia spp. and Cooperia spp. in naturally acquired infections in calves

Abstract

Aujeszky? disease is predominantly a nervous disease of piglets, weaners, and fatteners in which the mortality may vary from 540%. Respiratory disease is also a feature of infection with certain strains of the virus. Infection of pregnant sows may cause abortion, stillbirths, and mummification, and infertility may result in both boars and sows. Traditionally the serum neutralisation test has been used as an indicator of past infection with Aujeszky s's disease virus (ADV). However, cell-mediated immunity has recently been shown to play an important role in recovery and protection from infection with ADV and antibody-dependent cell-mediated cytotoxicity can be used as an alternative diagnostic test for detection of antibody. A number of inactivated, and live, avirulent vaccines are now available for control of the disease but their use is contraindicated in countries such as New Zealand which have a low prevalence of infection. Where possible early eradication is the best policy to follow.     

Vaccination of pregnant sows against transmissible gastroenteritis with two attenuated virus strains and different inoculation routes

Summary

Two attenuated transmissible gastro‐enteritis (T. G. E.) virus strains were used for vaccination experiments in sows.

Four different experiments were carried out (see Table 1). In each experiment, 9 sows were vaccinated during pregnancy and 3 sows served as controls. They were kept together in one farrowing house. The sows were due to farrow at about the same time. The sows and their litters were challenged shortly after farrowing by exposing 3 piglets of 2 control litters to virulent TGE virus.

The following vaccination schedules were used (see Table 1): twice intramuscularly with TGE‐vac (a commercially available TGE‐vaccine), one oral administration followed by an intramuscular vaccination with an attenuated TGE Purdue (Pu) strain, twice orally with Pu strain in enteric coated capsules, and one direct intra intestinal administration followed by 2 intramuscular vaccinations or 3 intramuscular vaccinations with the Pu strain.

All sows, except most of those treated with enteric coated capsules, seroconverted demonstrably (Table 2). The geometric mean seroneutralization (SN) titer log 2 varied from 4.1 to 7.5 after the first vaccination and from 7.6 to 10 after the second vaccination.

None of the vaccination schedules resulted in an effective lactogenic immunity. The morbidity in the piglets was 100% within 3 to 5 days after challenge. The mortality rate varied from 44 to 80% in litters from vaccinated sows and from 71 to 100% in litters from control sows (see Table 3). Clinical signs were observed in 33,3% of the control sows and in 36% of the vaccinated sows.

No correlation was found between the titer of SN antibodies in the sera of the piglets and their survival rate (Table 4).

A rapid decrease in antibody concentration was observed, during the first week of lactation in milk samples collected from 4 orally and intramuscularly vaccinated sows (Table 5).     

Dynamics of sperm DNA fragmentation in raw boar semen and fertility

The aims were to evaluate sperm DNA fragmentation (SDF) in boars through the dispersion of their chromatin in raw semen samples, quantifying the extent of SDF, and to assess dynamic aspects of sperm DNA damage after incubation to obtain the rate of sperm DNA fragmentation (rSDF) under thermal conditions similar to the uterus (37°C) over a period of up to 24 hr and to correlate the reproductive outcome of the sows with the SDF of the boars at ejaculation. The study was performed on a pig‐breeding farm in southern Uruguay. Sixty‐one ejaculates from five of the most frequently used hybrid boars were evaluated. Semen was collected weekly from each of the boars, using the gloved‐hand technique and discarding the jelly‐like fraction of the ejaculate. Fresh semen was kept in a water bath at 37°C and protected from light, and was thereafter processed with Sperm‐Sus‐Halomax^® to evaluate SDF. The smears for time 0 (T0) were made on farm, and thereafter smears were made at the laboratory at 4 hr of obtaining the semen (T4), then every 2 hr (T6, T8, T10, T12) and a final fixation at 24 hr (T24). Differences in SDF were observed among exposure times for all boars (p < .05), but not between T10 and T12 (p = .7751) nor T4 and T24 (p = .9113). In none of the T24 samples, sperm heads could be seen with chromatin dispersion halos. Furthermore, there were differences among boars when comparing sperm rSDF (p < .05). Farrowing rate was not affected by SDF at T0 (r = .38, p = .75), nor was litter size (r = .16, p = .70). With the present experimental conditions, we have not been able to show a relationship between sperm DNA fragmentation at ejaculation and reproductive performance. However, this could be a result of the low number of ejaculates and boars used.     

Leptospiral antibodies in cattle in alberta and evidence of an emerging serovar

Antibodies to Leptospira interrogans serovars hardjo and pomona were present in 8.3% and 0.5% of sera respectively, from adult female cattle in Alberta surveyed in 1984-85. Criterion for a positive serum sample was 50% agglutination at 1/100 dilution in the microscopic agglutination test. A positive herd contained one or more cows with positive serum. Prevalences were calculated on sample sizes that would give 80-95% reliability. Hardjo antibody prevalences and hardjo-positive herd prevalences were 0-53.9% and 0-83.3%, respectively, among 65 municipalities surveyed. Pomona prevalences by comparison were 0-3.4% and 0-11.7% respectively. Hardjo had increased significantly since 1980-82, and antibodies were found throughout the province. Pomona occurred mainly in southeastern Alberta, where it was isolated from cattle, swine and skunks. Hardjo was isolated only from cattle and it was found in many areas. Antibodies to icterohaemorrhagiae were present in 0.4% of sera from parts of Alberta surveyed in 1980; evidence of the presence of leptospires related to this serovar in bovine and porcine urinary tracts was obtained by immunofluorescence.     

Disease risks associated with free-ranging wild boar in Saskatchewan

This study investigated the disease status of Saskatchewan’s feral wild boar population. Whole carcasses, tissue samples, and/or serum from 81 hunter-killed boars from Saskatchewan were submitted to the Canadian Wildlife Health Cooperative (CWHC) between 2009 and 2014. Serological tests were negative for PRRS, H1N1, and H3N2 swine influenza, PCV-2, and TGE/PRCV in 22/22 boars and for Toxoplasma gondii and Mycoplasma hyopneumoniae in 20/20 boars. Of 20 boars whose sera were tested 20 were positive for Actinobacillus pleuropneumoniae, with 7 positive for, among other strains, serotype 14; 16 were positive for Lawsonia intracellularis, 1 was positive and 6 were suspicious for Salmonella spp. Polymerase chain reaction tests were negative for PRRS and PCV2 in 58/58 boars and positive for Torque teno virus in 1/8 boars. Digestion assays were negative for Trichinella spp. in 22/22 boars. The high seroprevalence of A. pleuropneumoniae serotype 14 is noteworthy as this serotype has not been previously reported in North America.     

种公猪精液伪狂犬病野毒的筛查

本文基于1 100头基础母猪的规模化场进行公猪精液伪狂犬病病毒筛查,农业部规定伪狂犬病病原学检测方法是通过ELSIA方法检测猪伪狂犬病gE野毒抗体。由于抗体检测具有滞后性,导致正在发生感染的猪群g E抗体检测往往呈阴性,但此时通过病原学检测精液已经正在排毒。本文互补了ELSIA抗体检测方法与荧光定性PCR检测病原的优劣,成功实现种公猪精液伪狂犬病病毒的筛查。     

Disease patterns and immune responses in the offspring to sows with high or low antibody levels to Actinobacillus pleuropneumoniae serotype 2

The serum antibody responses to Actinobacillus pleuropneumoniae and the secondary invader Pasteurella multocida were monitored from birth until slaughter in the offspring to sows with high or low levels of serum antibodies to A. pleuropneumoniae.Serum antibody concentrations to A. pleuropneumoniae were higher from birth to the age of 9 weeks in piglets delivered by high responding sows. In contrast, antibody levels to P. multocida were similar in both groups during this period. From the age of 20 and 15 weeks, antibody levels to A. pleuropneumoniae and P. multocida, respectively, were higher in the offspring to high responding sows.This implies that the offspring to sows with high levels of antibodies may be better protected during the first period of life because of a higher level of passively derived immunity. These piglets will also mount a higher antibody response when later infected, indicating a heritability of the humoral immune response.     

A comparative examination of swine sera for antibody to Aujeszky virus with the conventional and a modified virus-serum neutralization test and a modified direct complement fixation test.

Sera of pigs from élite breeding herds, of boars and sows collected at slaughter-houses, and of pigs from herds known to be infected, were examined for antibody to Aujeszky virus. The conventional and a modified virus-neutralizing antibody (VNA) test and a modified direct complement fixation (CF) test were employed. In simultaneous titrations of positive sera the modified VNA test gave titers approx. 4 log2 units above the titers obtained by the conventional test. The conventional VNA test was found insufficiently sensitive. Unspecific neutralization in the modified VNA test was infrequent in serum dilution 1/2 and rare in dilution 1/4. The GF tests on sera of slaughter sows and animals from known infected herds showed a remarkable consistency with the VNA tests. Inconsistent results were obtained with but few sera. Abt. 5 % of the sera could not be examined because of complement fixation with control antigen.     

Effects of oral caffeine administration to sows with induced parturition on hypoxia in piglets

To counteract the effects of perinatal hypoxia in piglets, the oral administration of caffeine to sows with induced parturition was evaluated. On day 113 of gestation 9 sows received 27 mg/kg body weight (BW) of caffeine mixed with 200 g of standard diet. The same amount of feed without the addition of caffeine was administered to 9 control sows. Additionally, on day 113 of gestation, all sows were treated by two injections in the perianal area of 1 mg of alfaprostol (at 8:00 am and 14:00 pm), and on the morning of farrowing by 14 IU of oxytocin in the perianal area. Caffeine did not affect BW of piglets and size of litters; however piglets from treated sows showed a higher capacity to adapt to extra-uterine life. Particularly, they showed a greater thermoregulatory ability (P<0.001) and a higher percentage of viability score≥7 compared to piglets from control sows (92% vs. 75%, respectively; P=0.030). Caffeine furthermore reduced the frequency of high serum biopterin values (>80 nmol/L) in piglets born from treated sows (P=0.001). In conclusion, the caffeine orally administered to sows with induced parturition showed a protective effect on the consequences of neonatal hypoxia in tissue ischemia–reperfusion injury in piglets.