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Porcine circovirus type 2 (PCV2) and hepatitis E virus (HEV) are the most recently recognized causes of infectious hepatitis of pigs and may or may not act independently in the development of the disease. Recently it has been suggested that swine torque teno viruses (TTVs), in co-infections with some swine viral pathogens, may potentiate the severity of disease. In order to search for virological cofactors associated with infectious hepatitis in pigs, we investigated the liver tissues, to determine the presence of TTVs, PCV2 and HEV of naturally infected pigs and analysed the prevalence of both genogroups of the TTVs in the hepatitis lesions. Histopathological techniques, nested-polymerase chain reactions (nPCRs), polymerase chain reaction (PCR) and one-step reverse transcriptase polymerase chain reaction (RT-PCR) were applied to detect hepatitis lesions, TTVs genogroups 1 and 2, PCV2 and HEV infection. Of the livers examined 58% (29/50) had mild to moderate hepatitis and 74% (37/50), 56% (28/50) and 26% (13/50) samples were nPCR, PCR and RT-PCR positive for TTVs PCV2 and HEV respectively. TTVs were detected in 84% (16/19) of the samples which were determined to be of mild severity while present in almost all (90% or 9/10) samples identified as having moderate hepatitis lesions. Additionally, the livers of 12 out of 21 (57%) pigs without the hepatitis lesions were positive for TTVs. These results demonstrate an association between TTVs and infectious hepatitis of pigs in concomitant infections with PCV2 and/or HEV and indicated that TTVs may play a role as a cofactor in the pathogenesis of disease.

The aim of this study was to assess the significance of body condition scoring and metabolic profile test for estimation of energy status of healthy high-yielding dairy cows. Twenty one healthy cows (primiparous and secundiparous) were divided into three groups: dry cows, early puerperal cows and early lactating cows. Cow's energy status was estimated by the analysis of blood samples for beta-hydroxybutirate (BHBA) and glucose. Additionally, urea, total bilirubine and total protein were measured in blood serum samples. According to body condition scores (BCS) results dry cows were overweight (4.03±0.29 points). Immediately after calving, cows lost their weight significantly, since BCS was 2.85±0.46 points at puerperal period and 3.12±0.33 points at day 60 of lactation (p<0.001 compared to dry period, respectively). Glucose concentration did not change significantly between dry and puerperal period, while BHBA increased significantly (0.46±0.14 mmol/l at dry period to 1.08±0.21 mmol/l at puerperal period; p<0.001). Urea concentration did not change significantly during examined period. Total bilirubin concentration significantly increased from dry (6.31±0.37 mmol/l) to puerperal period (7.63±2.52 mmol/l; p<0.001 compared to dry period) and remained high until day 60 of lactation (7.62±0.13 mmol/l; p<0.001 compared to dry period). Total protein concentration decreased from dry to puerperal period (69.59±6.14 g/l to 58.87±3.29 g/l; p<0.001). According to obtained results it can be concluded that cows were not in adequate energy status during transition period. Our results also indicate that, body condition scoring, BHBA and total bilirubin concentrations can be used as reliable indicators of cow's energy status even when there are not clinically visible health disorders.

The aim of this paper was to investigate the morphology, localization and typization of abomasal ulcers in high-yielding dairy cows, as a contribution to the existing knowledge on the subject. A total of ten high-yielding dairy cows which died during the period of early puerperium and two Holstein heifers which died in late pregnancy after transport to a new location were investigated in this study. Samples of altered abomasal tissue were taken at necropsy for further histopathology and mycology investigations. The disclosed ulcerations of the abomasums in twelve investigated animals differed among them not only as far as localization and morphology are concerned, but also in the degree of intramural penetration. Such differences distinguished them into four types. Ulcerations of type one and type two, recorded in two heifers and six cows, as well as in one cow with lymphoma of the abomasum. Perforating ulcer of type three, with circumscripted peritonitis was diagnosed in one cow in the corpus of the abomasum close to the curvatura major. An interesting finding was the simultaneous occurrence of type four perforating ulcer and ulcer-type one, which were located next to each other. Histopathological examination of the structure of the ulcerated abomasum dyed with the hematoxylin-eosin method showed that coagulation necrosis in the area of the ulceration revealed a moderate inflammatory infiltrate in the lamina propria. In the cow affected with lymphoma, a copious tumorous lymphoid infiltrate was concurrent. Mycotic ulcerative abomasitis was described in a cow seven days after calving. In these lesions Aspergillus fumigatus and Mucor spp. were isolated. Histopathological analysis of tissue samples dyed with the Grocott method, described septed and nonsepted hyphae in the blood vessels and surrounding tissue of the tunica mucosa and submucosa

Mycoplasma hyopneumoniae is a primary agent associated with mycoplasma pneumonia and the porcine respiratory disease complex (PRDC). Various reports have indicated that different strains of M. hyopneumoniae are circulating in the swine population. Lysates from lung swabs from naturally infected pigs of different ages were tested according to a new variable number of tandem repeats (VNTR) genetic typing method based on the polyserine repeat motif of the P146 lipoproteoadhesin, which can be applied directly on clinical material without isolation of M. hyopneumoniae. The aim was to determine the diversity of M. hyopneumoniae isolates from conventional farrow-to-finish pig farms located in different geographical areas of Serbia. PCR amplification was carried out using M. hyopneumoniae -specific designed, conserved primers (p146MH-L and p146MH-R) flanking the region encoding the repeat motif, followed by sequencing and cluster analysis. Five groups of M. hyopneumoniae with thirteen to twenty-four serine repeats were observed. Analysis of three samples from each farm indicated that the specific isolate is ubiquitous in pigs of different ages. Furthermore, seven clusters were observed within 27 tested samples. The results indicated a considerable diversity among M. hyopneumoniae field isolates in the swine population from conventional farrow-to-finish farms in Serbia and suggest close genetic relatedness of the corresponding isolates.