Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “SWINE”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,423 records · Page 79Linked to original sources

The use of immunofluorescence techniques for the laboratory diagnosis of transmissible gastroenteritis of swine.

Over a four year period, 74 of 250 field outbreaks of enteric disease (30%) and 110 of 440 swine (25%) were positive for transmissible gastroenteritis by immunofluorescence procedures. Of 141 swine from herds positive for transmissible gastroenteritis 110 (78%) were positive by fluorescent antibody techniques. The fastest, easiest to perform and most effective procedure was the examination of frozen sections of the jejunum from acutely ill animals by the fluorescent antibody tissue section technique. Only two herds were found to be positive by the fluorescent antibody tissue culture technique which were negative by fluorescent antibody tissue section technique. A considerable number of outbreaks, 21 of 74 (28%), of transmissible gastroenteritis were detected by immunofluorescence in swine over two weeks of age. The majority of outbreaks of transmissible gastroenteritis, 50 of 74 (68%), occurred in Missouri during the months of January through April and 63 of 74 (85%) during the months of December through May. The recurrence of the disease in a number of counties over a four-year period suggest the possibility of endemic foci.

Animals↗

Distribution and biology of Ornithodoros erraticus in parts of Spain affected by African swine fever.

Ornithodoros erraticus was found in 30.7 per cent, 35.0 per cent and 71.0 per cent of the pig-pens sampled in the provinces of Salamanca, Badajoz and Huelva in which African swine fever is a problem in the rearing of Iberian pigs. Between 38 and 65 per cent of the pig-pens in these areas are now abandoned and their populations of O erraticus are extinct or becoming so because they can no longer feed on pigs, which in Spain are their main hosts. The abandonment of pig-pens has resulted in the elimination of most soft ticks infected with the virus of African swine fever, and means that the distribution of ticks is now irregular and focal. Another factor affecting their distribution is the kind of soil on which the pig-pens are located. In abandoned pig-pens, the adults and large nymphs survive for about five years or longer when animals occasionally enter them. Hungry tick populations may transmit African swine fever when feeding in winter, whereas the populations that have continuous access to pigs do not feed until the pig-pens reach a temperature of 13 to 15 degrees C. In the latter populations, each stage exhibits a single annual peak of activity, which implies that the development from larva to adult takes two to three years. Pigs may die as a result of the bites, but on no occasion were 100 per cent of the fasting ticks seen to feed, even though they had the opportunity of doing so. This may hinder the eradication of this soft tick from infested pig-pens.

African Swine Fever↗

Factors affecting patency of venous allografts in miniature swine.

In immunologically defined National Institutes of Health miniswine, a segment of internal jugular vein was anastomosed to the carotid artery as an interposition graft. Patency of swine major histocompatibility complex matched, one haplotype mismatched, and complete mismatched veins was 9.8, 6.3, and 3.0 weeks respectively (p = 0.009). More than 90% of mismatched and 20% of matched allografts developed a positive crossmatch before occlusion (p = 0.006). The mixed lymphocyte response did not predict graft occlusion. Treatment of 10 swine with cyclosporine (10 mg/kg/day) did not significantly improve patency for one haplotype mismatched grafts. In haplotype mismatched veins, cryopreserved grafts occluded more rapidly than noncryopreserved grafts: mean 2.4 versus 6.3 weeks, respectively (p = 0.002). In all cryopreserved vein grafts, alloantibody appeared at or after graft occlusion rather than before occlusion as seen with fresh allografts (p = 0.046). The mean patency of cryopreserved versus fresh autografts was 3.3 and greater than 32 weeks, respectively (p = 0.004). In summary, these results indicate that (1) allograft patency is related to the degree of swine major histocompatibility complex match and development of cytotoxic alloantibodies; (2) moderate-dose cyclosporine does not prolong allograft patency nor suppress development of antibody; (3) cryopreservation may accelerate graft occlusion through nonimmunologic mechanisms.

Animals↗

Association of uveal melanocyte destruction in melanoma-bearing swine with large granular lymphocyte cells.

Sinclair strain miniature swine spontaneously develop and regress malignant melanoma lesions, with uveitis and vitiligo occurring subsequent to tumor regression. Peripheral blood lymphocytes (PBL) of Sinclair swine undergoing tumor regression and melanocyte destruction demonstrated significant lytic activity against K562, porcine semiallogeneic uveal melanocytes, and melanoma cells in 4-h chromium release assays. The ability of porcine PBL to lyse these target cells appears to be an age-associated immune response, as evidenced by the relative inability of PBL of pigs less than 4 weeks old to lyse target cells. In young adult pigs, however, PBL cytotoxic activity significantly increases; piglets 6 weeks old and older demonstrate efficient killing of all three targets. Conjugate formation assays demonstrate that a lymphoid effector cell possessing large granular lymphocyte (LGL) morphology may be involved in melanocyte destruction. These findings suggest that a LGL subpopulation may participate in melanoma and melanocyte destruction which can induce a uveitic syndrome in Sinclair swine with melanoma.

Aging↗

Analysis of Haemophilus parasuis isolates from southern Ontario swine by restriction endonuclease fingerprinting.

To study the occurrence and distribution of various strains of Haemophilus parasuis in southern Ontario swine, organisms isolated from healthy swine, from specific pathogen-free and conventional herds, and from disease cases were examined using restriction endonuclease fingerprinting analysis. In most herds, several strains of H. parasuis could be detected although one or two strains usually predominated. Individual animals were colonized by a single or limited number of strains. In several cases, the same strains were isolated from more than one specific pathogen-free herd. Conventional herds carried a more heterogeneous population of H. parasuis. Only one strain was isolated which was common to more than one conventional herd. No strains were isolated which were common to both specific pathogen-free and conventional herds. None of the strains isolated from disease cases were found in healthy conventional or specific pathogen-free swine examined in this study.

Animals↗

Goitrogenic effects in offspring of swine fed sulfadimethoxine and ormetoprim in late gestation.

Effects of feeding sulfadimethoxine and ormetoprim to sows and gilts in late gestation were evaluated. One sow and 2 gilts were randomly selected and were fed 1 of 3 rations: (1) a gestation ration from farm A, where congenital goiter in newborn pigs was a problem, (2) gestation ration from farm A containing 275 g of sulfadimethoxine and 55 g of ormetoprim/100 kg of ration, or (3) standard swine gestation ration containing 275 g of sulfadimethoxine and 55 g of ormetoprim/100 kg of ration. Sows and gilts were fed the appropriate ration for 22 to 58 days before farrowing. The numbers of stillborn or weak pigs did not increase in any group. However, congenital goiter was detected in all pigs from swine fed medicated rations 2 and 3. Congenital goiter was not present in pigs from swine given gestation ration 1.

Animal Feed↗

Aflatoxicosis in Iowa swine: eight cases (1983-1985).

During 1983, 1984, and 1985, aflatoxicosis was diagnosed in 8 Iowa swine herds after the herds were fed corn from the 1983 corn crop. As a result of the diagnosis, the associated environmental conditions, clinical signs of aflatoxicosis, macroscopic and microscopic lesions, aflatoxin concentrations detected in feeds, and management of affected swine were reviewed. Concentrations of aflatoxin in shelled corn and complete feed were as high as 2,020 ng and 1,200 ng of aflatoxin (B1 and B2)/g of feed, respectively. Clinical signs of aflatoxicosis included decreased feed consumption and weight loss. Some pigs died acutely, but death often was preceded by a period of clinical disease. Greater morbidity and mortality were observed in swine herds that consumed greater concentrations of aflatoxin.

Aflatoxins↗

Efficacy of injectable ivermectin against natural infections of Stephanurus dentatus in swine.

Ivermectin (300 micrograms/kg of body weight) was given to swine subcutaneously in the neck to test its efficacy against the kidney worm, Stephanurus dentatus. Two separate field trials were conducted using 146 swine (40 males and 106 females). Urine was obtained before and after treatment and was examined for presence of S dentatus eggs. Stephanurus dentatus eggs were quantitated in positive samples. All treated swine positive for S dentatus eggs in the pretreatment urine samples (n = 54) were negative by 14 to 21 days after treatment with ivermectin. Adverse reactions caused by ivermectin injection were not noticed.

Animals↗

Bone marrow transplantation in miniature swine. II. Effect of selective genetic differences on marrow engraftment and recipient survival.

In order to study the effect of defined genetic differences on bone marrow transplantation in miniature swine, five different combinations of major histocompatibility complex (MHC)-matched and mismatched bone marrow transplants were performed. Eight of nine fully MHC-mismatched allogeneic bone marrow transplants failed to reconstitute, and one animal reconstituted briefly but then died quickly thereafter. Five of six class I-matched/class II-mismatched (g----c) bone marrow transplants engrafted, showed a skin rash typical of graft-versus-host (GVH) reaction, and died 3 weeks after the marrow transplantation. None of five class II-matched/class I-mismatched (g----d) transplants engrafted. Parental marrow transplants into F1 hosts engrafted and caused GVH skin rash, with survivals from 1 to 9 months (n = 5). Serologic typing of the F1 recipients of parental marrow showed only donor-type peripheral blood lymphocytes (PBL), suggesting complete marrow replacement. Conversely, F1 into parental marrow transplants showed no engraftment (n = 6). These results indicate that resistance to MHC-mismatched allogeneic bone marrow engraftment in swine represents a host response recognizing donor class I MHC differences. This response appears to interfere with engraftment of donor bone marrow cells despite host preparation with 900-1100 rads total-body irradiation. In the absence of donor MHC class I differences, engraftment was seen despite the existence of multiple non-MHC differences, and even in the presence of class II differences. Such engraftment also led to GVH, varying in intensity according to the strength of genetic disparity (i.e., worst in parent----F1 combination). These results suggest that miniature swine should provide an effective model for study of both GVH elimination (in the parent----F1 combination) and problems of engraftment (in the F1----parent combination), the two most important obstacles to clinical allogeneic transplantation.

Animals↗

[Practical aerogenic immunization of swine against plague].

A total of 3,500 pigs were immunized against hog cholera (swine fever) using an aerosol lapinized vaccine strain K, immediately after weaning the animals in the fattening sectors of two cooperative swine-breeding farms. Ordinary premises for pigs were used as chambers where the vaccine was dispersed at the rate of 10 ml per cu. m with the aid of the Soviet-made apparatuses DAG-2. This type of immunization proved effective, being well tolerated, causing troubles whatever in the treated animals. The immunity produced protected them from swine fever in the course of at least ten months, which was sufficient for the pigs in the fattening sector. This positive result is obtainable at a single aerosol treatment both for pigs of sows that have not been immunized and for pigs of sows that have regularly been immunized against hog cholera.

Aerosols↗

[Experimental studies on a decrease in hypotrophy in newborn piglets in commercial swine raising].

The birth of hypotrophic piglets with 2-3 times lower live weight than the normally born ones, which die till the 40th hour, because of the abruptly decreased vitality is described. Their percent is 7 for the reproductive bases and 10 for a commodity swine breeding complex. Studies were carried out on 402 pregnant pigs, treated with protein hydrolysate and glucose (injected) together with vitamin-mineral additions to the forage. For a control were used 395 pregnant pigs under the same conditions, but not treated with the above mentioned medicines. A two fold decrease of the birth of hypotrophic piglets was achieved. The rest of the pigs are with a higher live weight and vitality which is the reason of their suffering from coli bacteriosis and other diseases of the conditions at a considerably lower extent. It is supposed that the irreplaceable (limited) amino acids are at the base of that biological phenomena for the prophylaxis of the hypotrophy in the pathology of the hybrid industrial swine breeding. That model scheme as a method can be realized in reproductive and nuclear bases for hybrid swine breeding because of its undeniably great and economic effect.

Animal Feed↗

[Epizootiology, prevention and control of salmonellosis in swine].

Microbiologic studies were carried out in 1981-1985 with a total of 25,561 samples--12,878 were cadavers and viscera, 574 were fetuses, 6,208 were swabs of rectal samples. 844 were feces, 4,096 were washings, 493--feed samples, etc. A number of prophylaxis and control programmes were tested under productional conditions with the use of drugs and vaccinations with a live and a killed autovaccine. Salmonella organisms were isolated as follows: 9.05% from cadavers, 2.5% from fecal samples, 1.35% from rectal swabs, 1.2% from washings from the environment, 0.6% from feed samples--all belonging to 19 serologic types. Greatest importance was shown to have S. cholerae suis, which was epizootically specific for swine, however, the part played by var. america also grew as compared to var. kunzendorf. With the exception of several sporadic cases all other serologic types of Salmonellae were isolated from carriers, rectal and fecal samples, and others. In the event of swine salmonellosis under productional conditions better results were obtained with the use of drugs. Both morbidity and mortality rate dropped twice as low with animals treated with a live vaccine once, and with a killed autovaccine four times. Suggested is a prophylactic and control program, following a definite pattern in dealing with swine salmonellosis in enzootic foci, with the use of complex measures.

Animals↗

Field evaluation of the enzyme-linked immunosorbent assay for swine trichinosis: efficacy of the excretory-secretory antigen.

A field evaluation of an enzyme-linked immunosorbent assay (ELISA) for swine trichinosis was done with sera obtained from 5 herds experiencing ongoing transmission of Trichinella spiralis. Epizootiologic studies conducted on these herds offered an opportunity to evaluate the accuracy of an ELISA, using larval T spiralis excretory-secretory antigens. Sera from 162 infected pigs and 143 serum samples from noninfected pigs originating from the same farms were tested. The infection status of the pigs was determined by digestion of diaphragm or tongue muscle samples. Two criteria were established to classify the ELISA optical density (OD) readings: Criterion I stated that an OD greater than or equal to 5 times the mean OD of several normal swine sera pools was positive; criterion II stated that a OD greater than or equal to 4 times the normal sera values was positive. The results obtained did not reveal obvious serologic variations among infected herds located in the 4 states involved. Overall, the test detected 93% (criterion I) and 96% (criterion II) of infected pigs. The majority of false-negative sera was from hogs that had less than 5 larvae/g of muscle; 1 hog had 73.8 larvae/g of diaphragm muscle. The false-positive rates were 8% for criterion I and 9% for criterion II. The actual rate for these false-positive samples may have been overestimated, because generally, only small tissue samples (0.4 to 10 g) were digested; larger sample sizes might have altered the results. The relevance of this qualification is that these pigs originated from herds with prevalence rates greater than 50%. Other factors that may account for occasional false-positive sera or false-negative sera in the swine trichinosis ELISA are discussed.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Effects of eight weeks of physical conditioning on atherosclerotic plaque in swine.

Effects of individually prescribed exercise on the regression or interference with deposition of atherosclerotic plaque were studied. Twenty miniature swine allotted, by litter, to a control-diet group (groups CE and CS) and an atherogenic diet group (groups AE and AS). All pigs were subjected to injury (balloon catheter) of the aortic endothelium. They were fed for 8 weeks and after an initial graded exercise test was done, then each group was suballotted to an exercising group (groups CE and AE) or a sedentary group (groups CS and AS). Groups CE and AE (exercised) were given 8 weeks of training. Groups CS and AS (sedentary) were sham exercised during this period. A second graded exercise test was administered to the swine (all groups) before they were euthanatized. Aortas were analyzed for the percentage of area involved and for atherosclerotic plaque density. Samples of blood from the swine after they were fasted were obtained before the start of the project (base line) and once every 2 weeks thereafter. These were analyzed for triglycerides, high- and low-density lipoprotein, and total cholesterol concentration. Comparison of results of blood lipid analyses from weeks 1, 9, and 15 did not show significant differences within diet groups between exercise and sedentary. Significant differences at weeks 9 and 15 were observed between diet groups (ie, the pigs fed the atherosclerotic diet had higher blood lipids). Plaque formation was not found in the pigs fed the control diet (groups CE and CS). Plaque formation was evident in all pigs fed the atherosclerotic diet (groups AE and AS) with no significant differences between exercised and sedentary groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Preliminary study of the pharmacokinetics and toxicopathy of deoxynivalenol (vomitoxin) in swine.

Study was made of the pharmacokinetics and toxicopathy of deoxynivalenol (DON, vomitoxin) given IV to swine. In the 24 hours after swine were given DON, clinical signs of vomiting, diarrhea, muscular weakness, tremors, and twilight coma were similar to those observed with other 12,13-epoxytrichothecenes. Hypoglycemia and pancreatic islet cell lesions were observed which indicated that DON-induced changes in intermediary metabolism may be an insidious aspect of DON intoxication. Histopathologic examination of all organ systems revealed pancreatic acinar and islet cell necrosis and mild lympholysis of the mesenteric lymph nodes. The renal excretion of DON was altered by IV infusion of saline solution. Pharmacokinetic findings may indicate that DON was both secreted and reabsorbed by the renal tubules. The half-life of DON ranged from 2.08 to 3.65 hours. Residues of DON were not found in skeletal muscle of swine at 24 hours after dosing.

Animal Feed↗

Research needs and priorities for swine internal parasites in the United States.

The swine industry in the United States is increasing in the Southeast. The proportion of pigs raised in confinement has increased to 25% and the trend is expected to continue. Changes in geographic origin and in management have affected the swine parasite fauna. A few parasites have almost disappeared and others have gained new prominence. Prevention and control of parasites are accomplished by feed additives and routine therapeutic treatments. Knowledge of the epizootiologic factors governing parasite transmission, in relation to climate and management systems, may lead to improvements in the prevention and control of swine parasites. Opportunities exist for developing biological, chemical, and managerial practices that can be integrated economically into management systems to control parasites and improve performance through decreases in mortality and morbidity and increases in daily gain and feed conversion efficiency.

Animal Husbandry↗

Social stress and resistance of chicken and swine to Staphylococcus aureus challenge infections.

The purpose of this research was to determine the effect of social stress on the susceptibility of chickens and swine to Staphylococcus aureus infection. Chickens were housed under four levels of social stress. Weaned pigs remained with their litter or were housed separately. One day after some birds were placed in the high stressed environments all were challenged intravenously with S. aureus. Susceptibility was characterized by joint infection in swine and reduced weight gain in chickens. Chickens which were moved into the high stressed environments before challenge lost weight while the controls gained weight (P less than 0.001). During the three days postchallenge the most severely stressed chickens lost less than half as much body weight as did the least stressed (P less than 0.001). During the post-challenge period chickens selected for high corticosterone response in a high social stress gained weight while chickens selected for a low corticosterone response in a low stress environment lost weight (P less than 0.0001). Swine housed under a reduced level of stress (social) were more susceptible to S. aureus than those kept under higher levels of stress (P = 0.0001).

Animals↗

Miniature swine as an animal model in photodermatology: factors influencing sunburn cell formation.

Swine have played an important role as animal models in dermatological research. In order to evaluate the usefulness of pig skin in photodermatology, sunburn cell (SBC) formation in the epidermis of miniature swine and erythema production were studied. SBCs were readily formed in the epidermis of the swine by ultraviolet radiation. Suberythemal doses of broad-band UVB radiation were effective in producing SBCs, and there was a dose-response relationship between SBC formation and ultraviolet radiation. When SBC formation was related to ultraviolet radiation in terms of biological dose (i.e. minimal erythema dose) neither the spectral characteristics of the sources nor the degree of pigmentation in the skin affected the response. When SBC formation was related to physical dose (J/m2) the protection value of tanning was evident. These results, when coupled with the morphological and physiological similarities between human and porcine skin, demonstrate the usefulness of this animal model in photodermatology.

Animals↗