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The aim of the paper was to evaluate the possible interaction between the presence of swine infectious diseases and low levels of mycotoxins in swine feed. The material for this research included the samples from three swine farms, where health disorders in different swine categories were detected. The applied research methods included: epidemiological and clinical evaluation, pathological examination, bacteriological and virological laboratory testing and microbiological feed testing, in order to examine the presence of fungi and mycotoxins by the method of thin layer chromatography. Beside this, the molecular diagnostic method, reverse transcripton-polymerase chain reaction (RT-PCR) and viral isolation was included. The obtained results support the existance of positive interaction between the mycotoxins and causative agents of bacterial and viral swine infective diseases.

An experimental study was conducted to investigate the course of classical swine fever (CSF) infection in piglets originating from sows vaccinated with China strain vaccine. The experiment was carried out on 24 piglets (age 28, 35, 44 and 54 days) from vaccinated sows and on 11 non vaccinated piglets, originated from non CSF vaccinated sows. Two piglets from the each age group originating from vaccinated sows were challenged by intramuscular injection with CSF virus. Four piglets of the same age from vaccinated sows, and two piglets derived from unvaccinated sows were added to the challenged group to determine contact (horizontal) infection. After challenge, clinical examination and blood sampling from every animal was carried out on day 0, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27 and 29. Blood samples were examined for CSF virus specific antibodies by ELISA test, and for viral antigen i. e. viral RNA by RT-PCR techique. After death or sacrifice pathomorphological changes, presence and distribution of CSF virus antigen were detected in piglet tissue samples by ELISA test. On the basis of the obtained results it can be concluded that not all piglets born to vaccinated sows have maternal antibodies at a detectable level, and the issue of the efficiency of passive immunization needs to be evaluated in the future. [ABSTRACT FROM AUTHOR]

Klasična kuga svinja (KKS) predstavlja zarazno oboljenje domaćih i divljih svinja. Cilj ovih ispitivanja bio je utvrđivanje prisustva virusa KKS u uzorcima limfatičnog tkiva i mozga prasadi, poreklom od vakcinisanih i nevakcinisanih krmača, i praćenje intenziteta patoloških promena pri različitom imunološkom statusu. Ispitivanja su izvršena na 20 prasadi oba pola, starosti 45 dana, koja su podeljena u tri grupe (G1, G2 i G3). Prasad G1 grupe poticala su od krmača koje su vakcinisane atenuiranom vakcinom C-soja virusa KKS. Prasad G2 i G3 grupe poticala su od nevakcinisanih krmača. Prasad G3 grupe predstavljala su kontrolnu grupu. Virus KKS inokulisan je intramuskularno prasadima G1 i G2 grupe (“Baker” soj, 2×105 TCDI/50). Sva prasad su uginula najdalje do 22. dana od momenta inokulacije. Imunohistohemijska metoda je korišćena za dokazivanje E2 (gp55) antigena u uzorcima tonzila, mandibularnih limfnih čvorova, ileocekalnih tonzila i mozga, kod svih prasadi u ogledu. Utvrđena je razlika u intenzitetu patoloških promena u limfatičnom tkivu i mozgu prasadi G1 i G2 grupe. Kolostralna antitela protiv virusa KKS nisu uspela da zaštite prasad od fatalnog ishoda bolesti. Između ostalog, ovi rezultati mogu imati značaj za program vakcinacije u budućnosti. Naime, vakcinacija svinja protiv KKS, atenuiranim K sojem virusa i dalje je obavezna zakonska mera u Srbiji. Uskoro će se program prestanka vakcinacije uskladiti sa EU direktivama.

Reproductive failure in swine is often a difficult diagnostic problem. If diagnoses of infectious disease or management related problems are not obtained, feed quality and safety may be questioned. Mycotoxins are often present in swine feed in the amount that can have detrimental impact on production and reproduction. Problems are expressed only as alterations of the reproductive cycle, reduced feed intake, slow growth or impaired feed efficiency. In Serbia, generally speaking, high concentrations of mycotoxins were noticed, especially mycotoxin zearalenone. High presence of zearalenone in swine feed is probably due to climatic influence and should be monitored constantly. This paper includes field observations regarding the influence of moldy feed containing mycotoxin zearalenone on the occurrence of the reproductive failure in swine breeding categories (sows, gilts and boars). The material for this research was obtained from four swine farms where certain reproductive disorders and health problems in breeding animals were detected. Depending on the specificity of each evaluated case and available material, the applied research methods included: anamnestic and clinical evaluation, pathomorphological examination, standard laboratory testing for detection of aerobic and anaerobic bacteria, and microbiological feed testing, in order to examine the presence of fungi and mycotoxins by applying the method of thin layer chromatography. On the basis of the obtained results, it could be concluded that mycotoxin zearalenone was detected in all examined feed samples. The presence of mycotoxin in feed was directly related to the reproductive failures in the examined swine categories (vulvovaginitis, endometritis, rebreeding, infertility). Swine reproduction represents the base for intensive swine production. The presence of mycotoxins in swine feed have influence on the reproduction and health status of pigs and under certain conditions may significantly disturb the production process. [Projekat Ministarstva nauke Republike Srbije, br. TR 31084: Wild animal health monitoring and introduction of new biotechnology procedures in detection of infectious and zoonotic agents - risk analysis for human health, domestic and wild animal health and for environmental contamination]

Mycotoxins are secondary metabolites of fungi that can contaminate animal feeds at all stages of food production chain. Consumption of feed contaminated with mycotoxins may result in immunosuppression, which represents a predisposing factor for occurence of infectious diseases in livestock. The influence on immune system is of special interest in swine industry. The technology on swine farms demands frequent vaccinations, which may be a problem in the case of immunocompromised animals. The aim of this paper was evaluation of mycotoxin influence on swine farms, as secondary factors for destabilization of animals’ immunological system. Material for this research included the samples from five swine farms, where health disorders, i.e. clinical and patomorphological signs resembling the problem with infectious diseases in different swine categories, were detected. The applied research methods included: epidemiological and clinical evaluation, pathomorphological examination, laboratory testing of bacteriological and virusological tissue originating from dead animals, and microbiological feed testing in order to examine the presence of fungi and mycotoxins. The obtained results indicated the existence of positive interaction between mycotoxins and causative agents of swine infective diseases. Despite continual pharmaco- and immunoprophylaxis in swine, the health problems of bacterial ethiology (colibacilosis, enteroxemia, dysentery, pneumonia, endometritis) were detected. From an epidemiological point of view, the presence of mycotoxins in animal feed may induce a breakdown of active immunity and occurrence of disease even in properly vaccinated animals.

The issue of mycotoxins and mycotoxicosis in veterinary medicine is directly connected to the usage of mouldy and/or adversely stored grains (corn, wheat, barley) used in animal feed. In swine production, in our geographical region, the most common are mycotoxicosis caused by zearalenon (F-2 toxin), but aflatoxins, ochratoxin and trichothecenes can also be found. For the known mycotoxins of clinical importance, the response is usually subacute or chronic and the presenting clinical signs are often vague. Mostly the problems are expressed only as alterations of the reproductive cycle, reduced feed intake and slow growth. However, if we consider the clinical signs and pathomorphological picture of mycotoxicosis in different swine categories (breeding animals, suckling and weaned piglets, fatteners), the age dependent changes can be found. Some mycotoxins have hepatotoxic, nephrotoxic and immunosuppressive effects, which further complicate the clinical and pathomorphological picture and diagnosis of mycotoxicosis in swine. The material for this research included the samples provided from ten swine farms. In different swine categories health disorders, resembling to the problem with mycotoxins were detected. The applied research methods included clinical evaluation and pathomorphological examination and laboratory microbiological feed testing, in order to examine the presence of fungi and some mycotoxins (aflatoxins, zearalenon, ochratoxin A and trichothecenes). On the basis of the obtained results, it may be concluded that the most frequently detected mycotoxin in the examined feed samples was zearalenon. The presence of mycotoxin in feed was directly connected to the reproductive failures and diagnosed health disorders in the examined swine categories (vulvovaginitis, skin necrosis, pneumonia, gastroenteritis).

Intrauterine infection of the fetus occurs if a pregnant non-vaccinated sow is infected with the virus of classical swine plague (CSF). The infection of the fetus results in the occurrence of viremia and the distribution of the virus in fetal tissue is similar to the distribution which is established in post-natal infected swine. The objective of these investigations was to determine intrauterine (transplacental) infection in the event of the appearance of CSF in different periods of pregnancy in non-vaccinated and vaccinated sows. The examined material were organs and tissue of fetuses within two examined cases of CSF in non-immune pregnant sows. In the third examined case of CSF, the material comprised the blood of piglets before suckling the colostrum, animals originating from vaccinated sows, at a farm in which CSF had been diagnosed. Samples of tissue and blood of the piglets were examined for the presence of antigens and specific antibodies against the CSF virus using the immunoenzyme technique (ELISA). Even though the investigations were performed on a small number of samples, the obtained results raise the question of the possibility of the occurrence of intrauterine infection with a CSF field virus in sows vaccinated with the C-strain of CSF. The syndrome of a carrier sow and persistent infections are the chief problem factors that need to be considered within the programme of curbing and eradicating classical swine plague.

The program of curbing and outrooting classical swine fever (CSF) in our country has for years been based on the vaccination of all categories of swine with the Kina (K) strain of the CSF virus, and, after the establishment of the source of infection, with the non-harmful removal of the infected swine herd, as well as on the implementation of all measures prescribed by the valid regulations. However, in spite of the implementation of all the listed measures, CSF still occurs continually. The epizootiological situation in our country in the course of 2005 was extremely unfavorable from the aspect of the number of identified CSF crisis spots, and it can be pointed out at this time that the disease was diagnosed clinically, pathomorphologically and using laboratory methods in 51 farms in a single examined epizootiological district. Under conditions when CSF appears continually throughout the year, vaccination using a modified live vaccine must continue being the basic measure in preventing the appearance, spreading, curbing, and eradication of CSF. With the objective of securing a concept of the most efficient further strategy for control and curbing of this disease, the paper presents the most important aspects regarding efficacy, safety, as well as field experience in applying vaccines which are based on the K strain of the CSF virus. .

The pathomorphological changes established following infection with the virus of classical swine plague in non-immune individuals are well known. However, piglets present a problem from the clinical-pathological aspect, in which this virus can be multiplied in spite of established colostral antibodies, but without the exhibiting of the clinical symptoms characteristic for the disease. The question of the characteristics of the pathomorphological finding is raised in the event of the breakdown of the colostral immunity of the piglets. With the objective of determining the influence of colostral antibodies on the development of pathomorphological changes in classical swine plague, piglets aged 28, 35, 44, and 54 days, originating from sows that had received a vaccine of the K-strain of the classical swine plague virus, were experimentally infected with a virulent variety of this virus (Becker strain). The control group comprised non-vaccinated animals originating from non-vaccinated sows. Following the death and/or sacrificing of the piglets in the experiment, a pathomorphological examination was performed of all organic systems and the presence of classical swine plague virus antigens was established in organs and tissues of piglets using the immunoenzyme (ELISA) test. Even though clinical signs characteristic for this disease were not found in all animals following artificial infection, the pathomorphological findings following death and/or sacrificing indicated a successful experimental infection and was typical for the acute course of classical swine plague. Bleeding was established in most organs and serous membranes (haemorrhagic diathesis). However, certain variations were also established regarding the expression and distribution of the pathomorphological changes in certain animals.

Aujeszky’s disease (Morbus Aujeszky) is an acute viral contagious disease occurring in a large number of domestic and wild animals. This epizootiological disease has been present in our country for quite some time now, and it has been increasingly frequently diagnosed in carnivora in the recent years. The objective of the investigations was to determine and establish the pathways for the transfer and the manner of spreading of the MA virus to carnivora. Epizootiological data on the appearance of MA, collected in the field, as well as an epizootiological report by the Serbian Ministry of Agriculture and of the Federal Ministry for Agriculture were used as material. Detailed epizootiological, clinical, pathomorphological, and laboratory analyses were performed in five critical spots for MA registered in the territory of Vojvodina province. We established the following pathways for the spread of the MA viral infection to carnivora: the consumption of thermally unprocessed swine carcasses, the consumption of thermally unprocessed pork originating from butcher shops or from regular slaughter on private farms, the consumption of viscera from emergency slaughtered sheep, cohabitation and contact with infected swine, and vaccination using a live vaccine contaminated with the MA virus.

The basic disorder in acute gastroenteritis is the disrupted transport of water and electrolytes, to a different degree. The objective of these investigations was to evaluate the efficacy of two oral rehydration solutions (ORS) in the treatment of acute gastroenteritis in suckling piglets. Fifty piglets, 20 with acute gastroenteritis and 30 healthy controls aged 10 days were chosen at random upon the incidence of diarrhea, for one of two ORS treatments (ORS-1 and ORS-2). The piglets with diarrhea were administered a probiotic per os on the first day and an antibiotic parenterally, until the diarrhea disappeared. All the piglets were followed clinically from days 1-6 of the investigations. Faeces samples were taken for bacteriological culture on the first day. Clinical signs of hydration were better, as well as the difference in body mass of piglets with diarrhea under the ORS-2 treatment which was significantly higher (p=0.036) in comparison with the difference in piglets under the ORS-1 treatment. All piglets with diarrhea had normally formed faeces on the sixth day. Escherichia coli was isolated from faeces of 48 piglets. Piglets with acute gastroenteritis, treated with ORS with a higher osmolarity and which contained instead of citrate, bicarbonates in higher concentrations, with less potassium, more sodium and more chlorine had a better state of hydration, with a significantly bigger difference in body mass, and the results of their control group were not significantly different against those of piglets treated with ORS of a different composition.

Different diseases in domestic animals require the application of different methods of immunological protection, depending on the type of vaccine manner of application and type of adjuvant. The objective of the work was to consider general principles and the basic requirements for efficient vaccination. It points out existing faults in practice which lead to the occurrence of mistakes made during vaccination and the appearance of resulting undesired consequences. There are many reasons why vaccination cannot achieve adequate protection of immunity in the organism. In most cases, this occurs due to the inadequate manner of application of the vaccine or subdosage. Mistakes can occur due to inadequate storage conditions which is an essential factor for maintaining vaccine viability. A special problem is vaccination of pregnant animals and young animals, the vaccination of immunodeficient animals. Risks which follow the implementation of vaccines are existing residual virrulence and toxicity the occurrence of hypersensitivity reactions which tend to appear when inactivated vaccines are applied, the occurrence of diseases in immunodeficient animals. Under certain conditions, vaccines can activate an autoimmune response, but the precise pathogenesis of this syndrome is unclear.

The main characteristic of swine herds in the territory of the Republic of Serbia is an unsatisfactory health status accompanied by increased incidence of contagious parasitic, genetic and other disorders. All this is a consequence of long-term unfavorable production conditions (maintenance of animals, diet, treatment, prevention, etc), which to a large extent altered the course and outcome of the mentioned diseases, and which had direct impact on the parameters which determine the health status of animals in a population. The health status of swine populations in our country are mostly determined by the presence of swine plague, but also diseases of pluricausal character, such as coli in fections, actinobđcillosis, atrophic rhinitis dysentery, and others. One must also not forget the presence of diseases which can be maintained in herds for a long time as enzootic diseases (Aujeszkyi, leptospirosis, tuberculosis, etc). Among parasitic diseases trichinellosis deserves special attention since it endangers the health of humans more and more every day. Most of the mentioned diseases are exhibited in very different clinical forms, so that their timely detection is very difficult and their control complex. That is why swine production in our country is characterized by a low percentage of fertilization, small number of live and large number of still-born piglets, and a high level of mortality in all categories. A logical consequence of this is a small number of produced porkers per sow, mostly of poor quality. In conditions where there are many diseases of different etiology, their control is complex and consequences always connected to a reduction or complete annulment of the expected benefits from an animal of high genetic potential veterinary-medical protection must cede its place to health protection as a technology which is based on a policy of disease prevention. This implies the establishment and maintenance of a high health status in swine herds with a clear definition of special criteria for elite, reproductive and production herds. The mentioned concept requires a well-prepared, organized and equipped veterinary service, in which relations are adequately coordinated and tasks are well distributed among experts on farms, in specialized institutions, faculties, and inspection services.

Piglets infected with the conventional swine plague virus as a result of secondary bacterial infections sometimes show an insufficiently clear clinical and pathoanatomical picture, which is why the very procedure of diagnosis is complex and the final diagnosis unreliable. That is why these investigations were aimed at examining the presence of bacterial microflora in diseased and dead pilgets which were found to have the viral antigen for CSP using the fluorescent antibody technique, in cases where the pathomorphological finding was not characteristic for conventional swine plague. Autopsies of dead piglets most often showed changes in the digestive tract and lungs, with resulting technopathy and diseases of infective nature. Such findings on knowledge of a present bacterial microflora are especially important in cases when conventional swine plague is controlled on farms and an announcement that the disease has been contained is in the offing.

Intensive cattle breeding implies the implementation of contemporary technological - organizational principles and the use of specialized genotypes of cattle with high production potential. The objective of our investigations was to determine, through epizootiological analysis of quarantine facilities for imported breeding pigs and internal sales of pigs the faults which lead to economic damages or even the spread of contagious diseases. Epizootiological investigations were carried out in four quarantine facilities for imported breeding pigs. Epizootiological investigations were conducted also in eight cases of internal sales. The following factors were considered during the epizootiological investigations: epizootiological observations of quarantine conditions minute records of epizootiologies and minute records of the republican veterinary inspector.

Viral infections hold an important place among factors which can cause disorders in swine reproduction. Infections with the porcine parvovirus (PPV) are present in all herds. In the past four years, 70-77% seropositive animals have been registered in herds of the industrial type. There are increasing reports about disorders in swine reproduction, both from individual breeders and mini farmers, caused by parvoviral infections. The objective of this work is to demonstrate the latest knowledge on epizootiology, pathogenesis, diagnostics, and prophylaxis of this diseases.

In this paper we examined the effects of certain pathological conditions on the sterility of breeding sows. Pathomorphological investigations were performed on 185 reproductive organs. We analyzed the reasons for elimination from local records. The biggest number of sows with pathological changes on reproductive organs were in the group of barren sows, 48.68% followed by anestric sows, 30.26%, and the smallest number in sows with failed fertilizations, 21.05%. Cysts in ovaries, ovarian tubes, oviducts and the mesosalpinx were found in 23.77% of the examined sows. Lutein cysts were found in a significantly higher percentage in sows which fail to be fertilized than in barren or anestric animals. Small granular degeneration of the ovaries was determined in barren sows and those which cannot be fertilized, while it was not determined in anestric sows. Cysts on uterus ligaments and ovaries and on ovarian tubes and oviducts were found in significantly higher numbers in sows which fail be fertilized than in barren or anestric sows. Their presence can be connected to obstructions in the transport process of spermatozoa, eggs, and the fertilization process in sows which fail to be fertilized, especially in cases of cysts located on the very serosa of ovarian tubes which we found in these sows. We determined small granular degeneration of the ovaries in barren sows and those which fail to fertilized, but not in anestric sows. Ovarian insufficiency was mostly connected to anestric sows. Vaginitis, endometritis, periometritis and oocytis present an important factor in the occurrence of sterility primarily in sows which are barren or which fail to be fertilized.

Recent variants of porcine circovirus type 2 (PCV2) were obtained from tissues of domestic pigs with porcine circovirus associated disease and from randomly selected wild boar samples from Serbia and Slovenia. A 450-base-pair nucleotide sequence was obtained by PCR from the ORF2. The derived nucleotide and amino acid sequences were aligned and compared to the corresponding region of closely related PCV2 sequences determined in previous years and retrieved from the GenBank. The 30 Serbian and 17 Slovenian PCV2 sequences clustered into three previously determined genotypes (PCV2a: 7), (PCV2b: 38) and (PCV2d: 2). Three major variable regions, concerning 29 amino acid position substitutions within the ORF2, were observed, which further supports the segregation of the detected strains into three separate genotypes. This study indicates that PCV2b is the predominant genotype in Serbia and Slovenia and the detected PCV2 strains are closely related to those previously described in Europe and in other parts of the world.