Introduction: Thyroid hormones affect protein turnover, and in the case of hypothyroidism a decrease in protein synthesis and reduced release of certain amino acids from skeletal muscles are observed. Changes in the amino acid system of skeletal muscles may be responsible for the occurrence of muscle disorders. Material and Methods: The study measured the content of selected amino acids in the gastrocnemius muscle of Wistar rats during experimental hypothyroidism induced by oral administration of methimazole at a concentration of 0.05% in drinking water for 90 d. The rats were divided into four groups: E1 (n = 6) - experimental males, E2 (n = 6) - experimental females, C1 (n = 6) - control males, and C2 (n = 6) control females. Results: A statistically significant reduction occurred in leucine, isoleucine, and 1-methylhistidine levels in males, and 1-methylhistidine in females, in comparison to the control groups. Conclusion: The hypothyroidism-induced changes in amino acid content may be responsible for the occurrence of skeletal muscle function disorders.

Introduction: Porcine pleuropneumonia inflicts important economic losses on most commercial herds. Detection of subclinical or chronic infection in animals still remains a challenge, as isolation and identification of A. pleuropneumoniae serotypes is difficult and quantification of the bacteria on agar plates is often almost impossible. The aim of the study was to develop and evaluate a serotype-specific quantitative TaqMan probe-based PCR for detection of serotype 2 in pig lungs, tonsils, and nasal swabs.Material and Methods: The primers were designed from the capsular polysaccharide biosynthesis genes of A. pleuropneumoniae serotype 2. PCR specificity and sensitivity were evaluated using reference strains and several other bacterial species commonly isolated from pigs.Results: The real-time qPCR for detection of A. pleuropneumoniae serotype 2 was highly specific and gave no false positives with other serotypes or different bacterial species of pig origin. The detection limit for pure culture was 1.2 × 10⁴ CFU/mL, for lung tissue and nasal swabs it was 1.2 × 10⁵ CFU/mL, and for tonsils - 1.2 × 10⁵ CFU/mL.Conclusion: The method can be used to serotype A. pleuropneumoniae isolates obtained during cultivation and to detect and identify A. pleuropneumoniae serotype 2 directly in nasal swabs and tonsil scrapings obtained from live pigs or lung tissue and tonsils collected post-mortem.

Introduction: The current study was designed to detect Mycoplasma agalactiae (Ma), Mycoplasma mycoides subsp. capri (Mmc), Mycoplasma capricolum subsp. capricolum (Mcc) and Mycoplasma putrefaciens (Mp) in sheep and goats with clinical signs consistent with contagious agalactia.Material and Methods: A total of 299 samples were collected from 55 mixed herds in Azarbaijan-e-Sharghi province, Iran. Samples were examined using PCR and culture methods.Results: The findings showed that in 40 herds at least one sample was positive by PCR or culture method. Moreover, out of 274 sheep samples, 101 were proved to be positive using the PCR technique and 76 were found positive using the culture method. Out of 25 goat samples, 10 were found positive using PCR and 9 were positive through the culture method. Less than 20% of isolated mycoplasmas were Ma. Ma was detected from almost all studied regions in the province while Mmc, Mcc, and Mp were detected only in a very limited area that was deemed by the research group the mixed infection zone.Conclusion: In vaccination or eradication projects, it would be more economical to focus on mixed infection zones. Further investigation on mixed infection zones could facilitate better understanding of contagious agalactia epidemiology.

Introduction: This article presents the analysis of the correlation between the category and health status of calves and the results of their rearing and levels of selected blood parameters.Material and Methods: The study included 105 Polish Holstein-Friesian and beef (Limousine, Charolaise and Hereford) crossbred calves. Young bulls were purchased at the age of two to four weeks. The animals underwent quarantine, were dehorned, and 46 young bulls were castrated. The germ horns were removed by burning out. Castration was carried out with a bloodless method using a rubber band. The calves were kept in groups and fed a milk replacer administered via teats from automated milk-feeding stations. After the period of milk feeding, the calves were fed grass silage ad libitum and a concentrate at 2.5 kg/animal/day. The calves were weighed every two weeks. Blood for analyses was sampled at 43 d of age.Results: After the rearing period finished at the age of six months, young bulls and steers had similar body weights (176.17 and 176.55 kg) and approximate average daily weight gains from birth (0.756 and 0.767 g/day). The healthy calves at six months of age weighed 180.47 kg, whereas the animals which at least once suffered from some diseases during rearing were lighter by approx. 30 kg (P ≤ 0.01). A statistically significant (P ≤ 0.01) difference was found for the count of red blood cells and white blood cells. In comparison with healthy individuals, the diseased animals had less RBC (8.33 and 9.42 10¹²/L respectively) and more WBC (27.03 and 12.26 10⁹/L respectively).Conclusion: Castration of young bulls did not have any impact on the results of rearing and health status of the calves. The magnitude of the analysed parameters depended on the health status of the calves. Thus RBC and WBC parameters may be used to predict the health status of calves during rearing.

The aim of this article was to evaluate the influence and effects of chosen bioaccumulative substances i.e. heavy metals, pesticides, and polychlorinated biphenyls (PCBs) on fish, as well as provide information on time trends and potential threat to human health. Chemical substances which pollute water may affect living organisms in two ways. First of all, large amounts of chemical substances may cause sudden death of a significant part of the population of farmed fish, without symptoms (i.e. during breakdown of factories or industrial sewage leaks). However, more frequently, chemical substances accumulate in tissues of living organisms affecting them chronically. Heavy metals, pesticides, and polychlorinated biphenyls are persistent substances with a long-lasting biodegradation process. In a water environment they usually accumulate in sediments, which makes them resistant to biodegradation processes induced by, e.g., the UV light. These substances enter the fish through direct consumption of contaminated water or by contact with skin and gills. Symptoms of intoxication with heavy metals, pesticides, and PCBs may vary and depend on the concentration and bioavailability of these substances, physicochemical parameters of water, and the fish itself.

Introduction: Avian pathogenic Escherichia coli (APEC) is a leading cause of extraintestinal infection and heavy economic losses. Imparting immunity after vaccination with live attenuated strain vaccination is an ideal strategy for infection control. This study considers an FtsK knockout mutant strain as a candidate. Material and Methods: An FtsK knockout mutant of APEC strain E058 was constructed and the pathogenicity of the mutant and wild-type strains was further evaluated in chickens. Results: The 50% lethal doses of each strain for one-day-old specific-pathogen-free (SPF) chickens challenged experimentally via trachea were 10⁵.⁵ and 10⁷.⁰ colony-forming units (CFU) respectively. Chickens challenged with the wild-type strain exhibited typical signs and lesions of avian colibacillosis, while those inoculated with the mutant strain showed mild pericarditis and pulmonary congestion. The growth rate of the FtsK mutant strain was much slower than the wild-type strain in the heart, spleen, liver, and lung of infected chickens. Conclusion: These results indicated that the APEC FtsK mutant can be attenuated for chickens, and that this mutant has the potential for the development of an APEC vaccine.

Introduction: The objective of the study was immunophenotypic and cytogenetic analysis of mesenchymal stem cells from equine bone marrow and foal umbilical cords during in vitro culture.Material and Methods: The mesenchymal stem cells were obtained from equine bone marrow of three horses and from foal umbilical cords of six foals. The cells were cultured in CO₂ incubators by standard procedure. Quantitative abnormalities of chromosomes, i.e. aneuploidy and polyploidy, and structural aberrations, i.e. breaks in chromosomes and chromatid, were taken into account during the study.Results: The results of cytogenetic analysis of equine bone marrow mesenchymal stem cells at the third and fourth passages indicated that the level of karyotype variability of these cells corresponded to the spontaneous level of karyotype variability typical of the peripheral blood lymphocytes of this species. Equine bone marrow contained several clones of stem cells that differed in the expression of specific nuclear markers characteristic of proliferating cells.Conclusion: Mesenchymal stem cells from foal umbilical cords during in vitro cultivation are characterised by quantitative abnormalities of the chromosomal apparatus.

Immunohistochemical studies have become an indispensable element of establishing the correct histopathological diagnosis of poorly differentiated lesions, proving particularly suitable, and occasionally indispensable, for diagnosis of poorly differentiated neoplastic tumours. Knowledge of the mechanism of action and normal reaction of individual proteins is required in selection of the antibody pattern for a given tissue and in evaluation of the obtained results. This paper aims to promote the application of immunohistochemical techniques in routine diagnosis, especially in cases of poorly differentiated or undifferentiated tumours.

Introduction: The aim of this study was to carry out a genetic analysis of Babesia canis isolates detected in dogs in eastern Poland and to study the correlation of the protozoa variant with a specific geographical region. Material and Methods: PCR was used to identify strains of B. canis from naturally infected animals (240 dogs from four provinces: Mazowieckie, Lublin, Podlasie, and Podkarpacie) by amplifying and sequencing a fragment of the 18S rRNA gene. Results: Sequencing the PCR products led to the identification of four variants of B. canis. Two previously described protozoa variants (18S rRNA-A and 18S rRNA-B) were observed in all provinces. Additionally, in the Mazowieckie and Lublin provinces a B. canis variant which contributed to the development of acute or atypical babesiosis was observed. The fourth variant of B. canis was detected only in dogs from the Lublin province, and the course of the disease was subclinical in all dogs infected with this variant. Conclusion: These results indicate the appearance of a new fourth B. canis genotype in Poland and confirm that it is still necessary to study the relationships between the genetic structure of protozoa, geographical distribution of the parasites, and clinical course of the disease.

Introduction: The aim of the study was to investigate the occurrence of goose haemorrhagic polyomavirus (GHPV) in wild birds inhabiting Poland.Material and Methods: Samples from 508 birds of different species were obtained between 2010 and 2015. The internal organ sections were homogenised and then total cellular DNA was isolated. The study was performed by means of PCR assay using primers complementary to the VP1 gene of the GHPV.Results: The presence of genetic material of GHPV was detected in 22 (4.33%) samples.Conclusion: It was the first such study in Poland to emphasise the role of wild birds as a potential source of GHPV infection for farmed geese.