rss_2.0Acta Veterinaria FeedSciendo RSS Feed for Acta Veterinaria Veterinaria Feed and Meat Quality Alterations Connected with Wooden Breast in Broiler Chickens of Different Genotypes and Slaughter Ages<abstract> <title style='display:none'>Abstract</title> <p>This study examined pathomorphological changes and meat quality alterations associated with Wooden Breast Myopathy (WB) in total of 192 broiler chickens divided into Ross 308 (n=96) and Cobb 500 (n=96) heavy hybrids at ages 42, 60, and 70 days. WB occurrence remained consistently high (&gt;73%) across periods, peaking on day 70 (83% for Ross, 90% for Cobb). Cobb broilers had better production results and carcass traits parameters after day 42 and day 60 of the experiment (p≤0.05). Genotype did not affect WB occurrence or severity, while slaughter age influenced severe cases WB occurrence, increasing from 11.67% on day 42 to 36.67% on day 70 (p=0.003). The presence of WB was associated with higher ultimate pH, lightness (L*), redness (a*), and yellowness (b*) of the muscle (p&lt;0.0001), except on day 70. Physicochemical and color parameters were also influenced by slaughter age (p&lt;0.0001). On day 42, drip loss (p&lt;0.0001), cooking loss (p≤0.05) and shear force (p&lt;0.0001) were affected by genotype. On days 60 and 70, the differences in water retention capacity were observed only between normal and severely affected breasts (p&lt;0.0001). For each slaughter age severely affected WB had higher shear force compared to normal breasts (p&lt;0.0001). Additionally, with the increasing slaughter age of broilers, drip loss, cooking loss, and shear force of the breast meat were increased (p&lt;0.0001). The results obtained regarding the occurrence and severity of WB and its consequent meat quality alterations suggest that extended fattening is not recommended for poultry production.</p> </abstract>ARTICLEtrue of the 1L-5-6L MGF110 Genes Influence on the Biological Properties of the African Swine Fever Virus () “Volgograd/14c”<abstract> <title style='display:none'>Abstract</title> <p>African swine fever continues to pose a global agricultural problem due to the absence of vaccine prevention and the high cost of anti-epizootic measures. This study examines the functional role of the African swine fever virus (ASFV) 1L-5-6L multigene family 110 genes <italic>in vivo</italic>. Four clinically healthy Large White pigs were used in this study. Two groups of animals were inoculated with either the parental strain or the deletion variant, respectively. For subsequent challenge infection, the homologous virulent strain “Stavropol 01/08” was used. Blood samples were collected at specific time intervals. The ASFV infectious activity was determined by titration in porcine blood-derived macrophages. Virus-specific antibodies to the ASFV p30 protein were detected using an enzyme-linked immunosorbent assay (ELISA).</p> <p>The results of real-time polymerase chain reaction (PCR) showed a significant difference in Ct values between samples from the two groups of animals. The determination of ASFV infectious activity in blood samples demonstrated the presence of the virus in animals immunized with the parental strain. The virus was not detected in samples from animals immunized with the deletion strain. The ELISA method demonstrated the presence of p30 protein antibodies in serum samples from 10 to 14 days after immunization with the parental strain, while no antibodies were detected in serum samples from animals immunized with the deletion strain.</p> <p>The properties of the ASFV recombinant strain “Volgograd/D(1L-5-6L) MGF110” were studied in an <italic>in vivo</italic> experiment. It was found that the deletion strain does not reproduce in animals, unlike the parental strain.</p> </abstract>ARTICLEtrue Markers in Canine Mammary Tumors<abstract> <title style='display:none'>Abstract</title> <p>Canine mammary tumors (CMTs) are one of the most common neoplasms in female dogs. Unfortunately, the current diagnosis often occurs in later stages, and there is a pressing need for more comprehensive data on treatment options to improve overall prognosis. Consequently, the early detection of these tumors is critical for improving treatment outcomes and survival rates. As such, biomarkers are essential for improving the diagnosis, treatment, and prognosis of CMT, the reason for which further research is required to enhance our understanding of the disease. The most studied biomarkers for CMT are evaluated from serum and tissue samples using different molecular approaches and relate to proliferation and cell cycle. Several biomarkers were also described regarding cell damage, autophagy and apoptotic-related pathways, hypoxia, angiogenesis, EMT, invasion, metastasis or cancer stem features. Overall, biomarkers have shown the potential to be used as a tool for the early detection of mammary tumors in dogs. However, more research is needed to validate these biomarkers and to develop sensitive and specific diagnostic tests. In this regard, we aimed to review known biomarkers and their role in CMT comprehensively. We also encouraged further investigations of reliable biomarkers that could improve treatment outcomes and survival rates for dogs with this disease.</p> </abstract>ARTICLEtrue Postmortem Finding of a Colloid Goiter in an American Black Bear ()<abstract> <title style='display:none'>Abstract</title> <p>The present case report aims to describe a postmortem finding of a colloid goiter, without obvious clinical signs of endocrine disease in a 30-year-old American black bear (<italic>Ursus americanus</italic>) from the “Zoo” in the city of Sofia, Bulgaria. A clinical examination due to a bad general condition was performed under anesthesia and a computed tomography was conducted. After the established irreversible spondylarthrosis changes the bear was euthanized. Postmortem, the thyroid gland was pathologically examined and typical findings for a colloid goiter were observed. Hibernating mammals such as the American black bear have been shown to enter a state of physiological hypothyroidism during hibernation. Hormonal signals from the thyroid gland have been suggested to be a key mediator of hibernation. From the presented case could be assumed that the captive life conditions and the prolonged life of the zoo bears may affect the function of their thyroid gland.</p> </abstract>ARTICLEtrue Hepatic Fibrosis in an Aborted Holstein-Friesian Fetus<abstract> <title style='display:none'>Abstract</title> <p>Congenital hepatic fibrosis (CHF) is a rare condition characterized by abnormal accumulation of fibrous tissue in the liver, leading to liver dysfunction. While CHF has been documented in various animal species, it has rarely been reported in cattle. This report presents a case of CHF in an aborted Holstein-Friesian fetus. During the necropsy, the most notable macroscopic findings included an enlarged liver with an irregular “cobblestone appearance” on the surface and firm parenchyma, as well as moderate ascites. Histopathological examination revealed extensive hepatic fibrosis in the portal areas, accompanied by bridging fibrosis extending between portal tracts and bile duct proliferation within the fibrous tissue. Screening for infectious agents as the cause of abortion or liver lesions was unremarkable. The necropsy and histopathological findings confirmed CHF, constituting the first case described in Holstein-Friesian calves in Serbia. Further research is required to determine whether this condition has a genetic basis or is influenced by yet to be identified factors in Holstein-Friesian cattle.</p> </abstract>ARTICLEtrue Resistance Profile of subsp. Isolated from Dog and Human Samples in Türkiye: The Case of Kastamonu<abstract> <title style='display:none'>Abstract</title> <p>Salmonellosis is of great importance for humans and animals. Companion animals, particularly dogs, can be asymptomatic carriers of <italic>Salmonella,</italic> and thus have been ignored as a source of salmonellosis. They can also spread multidrug resistant <italic>Salmonella</italic> strains via dog feces, causing inconvenience in the treatment of human salmonellosis. The purpose of this study was to investigate the presence of <italic>Salmonella enterica</italic> subsp. <italic>enterica</italic> isolates from collected dog feces belonging to dogs residing at the Municipal Dog Shelter, Anatolian Shepherd Dog Farm, and from blood, stool, and joint fluid samples from humans with symptoms of gasroenteritis, abdominal, and joint pain. In addition to this, the antibiotic resistance profiles of <italic>Salmonella enterica</italic> subsp. <italic>enterica</italic> isolates were examined. A total of 45 human and 11 dog <italic>Salmonella enterica</italic> subsp. <italic>enterica</italic> isolates were obtained. The 11 <italic>Salmonella enterica</italic> subsp. <italic>enterica</italic> recovered from dogs were identified as <italic>S.</italic> Infantis, <italic>S.</italic> Enteritidis, and <italic>S.</italic> Typhimurium, which correspond to serovars priotorized for human health. Almost all human isolates (42/45) and all dog <italic>Salmonella</italic> isolates (11/11) were found to be resistant to one or five, and one or four of the tested antibiotics, respectively, but not for CFZ, CAZ, CST in human and CFZ, CAZ, CST, ETP in dog <italic>Salmonella</italic> isolates. Common resistance profiles in dog and human origin <italic>Salmonella</italic> isolates were GEN/AMK, AMP/GEN/CIP/SXT, AMP/CIP, SXT. Exhibition of the common resistance profiles against antibiotics recommended in the treatment of human salmonellosis should not be ignored. Companion animals should be monitored for carrying <italic>Salmonella</italic> and spreading antibiotic resistant bacteria.</p> </abstract>ARTICLEtrue Pancreatic Ultrasonography and Vcheck cPL Rapid Test in Dogs with Suspected Acute Pancreatitis<abstract> <title style='display:none'>Abstract</title> <p>The aim of this study was to evaluate the importance of quantitative ultrasonography in the diagnosis of acute pancreatitis in dogs, as well as to examine the correlation between the results of ultrasound examination and the Vcheck cPL rapid test in dogs with suspected acute pancreatitis. A total of 37 dogs were included to the study – 15 healthy dogs and 22 dogs with gastrointestinal clinical signs which had at least 1 out of 3 criteria (vomiting, cranial abdominal pain and jaundice). Serum was collected to evaluate cPL level by Vcheck cPL rapid test. A score 0 implied the Vcheck cPL Rapid test result was less than 200 ng/ml. A score 1 implied Vcheck cPL Rapid test result between 200 and 400 ng/ml, and a score 2 more than 400 ng/ml. Ultrasound was performed in all dogs in order to investigate the pancreatic lesions within 48 hours and evaluate the level of pancreatitis by score from 0 to 2. The criteria for pancreatitis on ultrasonograms included enlargement or irregularity of the pancreas, hypoechoic areas of the pancreas and hyperechoic mesentery surrounding the pancreas. An ultrasound assessment of pancreatitis implied: score 0 when none of the criteria was present. Score 1 when 1–2 from 3 criteria were present, and score 2 when all of the 3 criteria were present. Correlation between Vcheck cPL Rapid test and pancreatic ultrasonography was examined. The results indicate that agreement of Vcheck cPL Rapid test and pancreatic ultrasonography had kappa values of 0.71 which are in the “moderate” agreement range. This means that both Vcheck cPL Rapid test and ultrasonography should be used in the diagnostics of acute pancreatitis in daily clinical practice. Additionally, quantitative ultrasound assessment can be helpful in distinguishing acute pancreatitis from normal pancreas.</p> </abstract>ARTICLEtrue Detection of Candidate Genes for Body Weight in Indonesian Cattle Breeds with Genome-Wide Association Study (GWAS)<abstract> <title style='display:none'>Abstract</title> <p>Genome-wide association study (GWAS) was used to detect candidate genes affecting economic traits in livestock. GWAS can detect single nucleotide polymorphisms (SNPs) in all chromosome regions. This study aimed to determine the genetic markers for body weight by GWAS in native cattle breeds of Indonesia. The Illumina Bovine 50K BeadChip was used to determine the candidate genes in three mixed-sex Indonesian cattle breeds of Bali (16 animals), Madura (16 animals), and Ongole grade (13 animals). All animals were raised at the Pasuruan Regency, East Java, Indonesia breeding station. The GWAS was performed in pooled sample of animals (45 animals) with the general linear model (GLM) method using SNP markers with minimum allele frequency (MAF) values more than 0.05 by TASSEL 5.0. software. Therefore, the body weight of cattle at 1 to 3 years of age was collected for each animal for computing Manhattan plot graphics. This research found that <italic>SUGT1</italic>, <italic>SF3A3</italic>, and <italic>DSCAM</italic> genes were detected as potential genetic markers for body weight in cattle breeds of Indonesia. The <italic>SUGT1</italic> and <italic>DSCAM</italic> genes were monomorphic in Bali cattle (<italic>Bos javanicus</italic>). In addition, both genes were significantly associated (<italic>P</italic>&lt;0.05) with the body weight of Ongole-grade cattle (<italic>Bos indicus</italic>) at three years of age. However, the <italic>SF3A3</italic> gene was significantly (<italic>P</italic>&lt;0.05) associated with body weight of Madura cattle (<italic>Bos indicus</italic>) at 2 and 3 years of age. In conclusion, the GWAS of pool animals reveals three candidate genes significantly associated with body weight in many cattle breeds of Indonesia. Further study to detect SNPs in candidate genes with sequencing method is essential to apply these findings practically.</p> </abstract>ARTICLEtrue of Combined Hypothyroidism and Selenium Deficiency on Selenoenzyme Glutathione Peroxidase Activity in Rats<abstract> <title style='display:none'>Abstract</title> <p>The effects of propylthiouracil (PTU) treatment and selenium-deficient diet on selenium and thyroid status of Wistar male rats were examined in this study. Wistar male rats (n =128) were divided into four groups: (1) control group – selenium-adequate rats fed a diet supplemented with 0.334 mg Na selenite/kg feed and received regular drinking water (Se+PTU-); (2) selenium adequate rats fed a diet supplemented with 0.334 mg Na selenite/kg feed and received a dose of 150 mg/L of PTU in drinking water, (Se+PTU+); (3) selenium-deficient rats fed a diet containing 0.031 mg Na selenite/ kg and received regular drinking water (Se-PTU-); (4) selenium deficient rats fed a diet containing 0.031 mg Na selenite/kg and received 150 mg/L of PTU in drinking water (Se-PTU+). After three and seven weeks of treatment, all Se – animals had significantly lower whole blood Se concentrations and GPx1 and GPx3 activities. PTU induced a significant decrease in T4 and T3 plasma concentrations after three weeks of treatment in both PTU+ groups. Furthermore, after seven weeks, the T3 level was close to its detection limit in Se – animals. A negative correlation was spotted between GPx activity and concentration of T3 after three and seven weeks. It could indicate an inhibitory influence of thyroid hormones on the expression and/or activities of GPx enzymes related to the available Se in conditions of systemic decrease of T4 concentration. This effect was particularly pronounced in Se – animals.</p> </abstract>ARTICLEtrue Use of Long-Term GnRH Agonist in Prepubertal Bitches: Effect on P4, E2 and Melatonin Serum Concentration before and During First Estrus<abstract> <title style='display:none'>Abstract</title> <p>The aim of this study was to determine the length of the contraceptive period after the application of deslorelin implant (4.7 mg) in juvenile, prepubertal bitches and assess the effects on the hormonal status (P4, E2 and melatonin), as well as on the occurrence of normal physiological estrus. Twelve crossbred prepubertal female dogs (4 months of age) were divided into the two groups, the treated group (DESLO) and control (placebo) group (C). Hormone assays, vaginal microbiological and cytological smears and the measurements of electrical resistance of cervical mucus were performed once in 3 weeks until the first signs of proestrus, and every day during estrus. GnRH implant significantly postponed time of onset of estrus (633 ± 30,38 days vs. 143.80 ± 52,30 days, P&lt;0.001). In estrus, DESLO group showed statistically higher E2 (34.58 pg/mL vs. 20.59 pg/mL, P&lt;0.001) and melatonin serum concentration (45.86 pg/mL vs. 18.85 pg/mL, P&lt;0.001) compared to the control group. The average P4 serum concentration had no statistically significant differences between groups. In conclusion, deslorelin implants do not cause “flare up” effect in perpubertal bitches, however, increase of E2 and especially melatonin serum concentrations show the need to explore the consequences and mutual influence of melatonin and deslorelin implants in the future.</p> </abstract>ARTICLEtrue Follow-Up of Tumors in Young Dogs in the Republic of Serbia<abstract> <title style='display:none'>Abstract</title> <p>Although the incidence of neoplasms increases with age, some tumors occur more commonly in younger dogs. Still, little information is available on the occurrence of neoplasms in dogs up to the age of 24 months. This study is a retrospective review of histopathological diagnoses of neoplasia at our laboratory during the last seven years (2017–2023) in two groups of dogs: group up to the age of 12 months and group from 13 to 24 months. In a total of 3704 neoplasms found in different dog tissues, 74 (2.00%) were identified in dogs up to 12 months and 135 (3.64%) in dogs aged 13 to 24 months. Canine cutaneous histiocytoma was the most frequent in both groups:41 cases (54.41%) in dogs up to 12 months, followed by 39 cases (28.89%) in those up to 24 months. In the present analysis of the group up to 12 months, 82.43% of tumors (n = 61) were benign, and 17.57% (n=13) were malignant, followed by 68.15% (n=92) benign neoplasms, and 31.85% (n=43) malignant in dogs aged from 13 to 24 months. French bulldogs and mixed-breed dogs were the most frequently affected. These data provide valuable epidemiological information on neoplasms in young dogs in the Republic of Serbia.</p> </abstract>ARTICLEtrue and Cross-Sectional Studies to Evaluate Changes in Cow Milk Microbiota Over the Lactation Stages<abstract> <title style='display:none'>Abstract</title> <p>To clarify the changes in milk microbiota by lactation stage, i.e., d ays in milk (DIM) for Fresh of 0 to 21, Early (DIM of 22 to 80), Middle (DIM of 81 to 200), and Late (DIM 201 or more) lactation stages in dairy cows, we performed longitudinal (12 sampling at each stage, total 48 samples) and cross-sectional sampling (Fresh [n = 7], Early [n = 12], Middle [n = 11], and Late [n = 11] stages, total of 41 samples) to comprehensively analyze the microbiota in milk samples by 16S rRNA amplicon sequencing. Although the relative abundance of bacteria of the phylum Actinobacteria increased significantly in the Late lactation stage in the longitudinal study, no significant changes were observed in the cross-sectional study. While no changes were observed in the milk microbiota during the lactation stages, environmental factors appeared to have a comparatively larger impact than interindividual diversity on the composition of the milk microbiota. Furthermore, the findings illustrated the importance of selecting appropriate study designs to clarify changes in milk microbiota throughout the lactation period. The findings obtained in this study not only provide useful information for interpreting previous research results, but also provide knowledge that could be helpful when designing new studies.</p> </abstract>ARTICLEtrue Isolated From Diarrheic Calves and their Phenotypic Resistance Pattern<abstract><title style='display:none'>Abstract</title> <p>Diarrhea is a prevalent and economically impactful ailment in cattle herds, resulting in substantial losses attributed to mortality, treatment expenses, and impaired calf growth. The aim of this study was to establish data about the occurrence of the main bacterial agents involved in diarrhea in dairy calves in the state of Maranhão, as well as to determine the most effective and/or resistant antibiotics, establishing a foundation for treatment and prevention protocols. The samples were collected with rectal swabs and initially cultivated on sheep blood agar (5%) and MacConkey agar and later on <italic>Salmonella-Shigella</italic> agar and eosin-methylene blue agar. Gram staining, biochemical tests, and antibiograms were performed on the obtained colonies. Ten municipalities were studied, with 230 calves evaluated from ten dairy farms. A total of 21 animals exhibited clinical signs of diarrhea, representing a frequency of 9.13%. The frequency of positive farms was 35%, and in 50% of municipalities. Bacteria isolated belonged to the <italic>Enterobacteriaceae</italic> family, with 71.4% <italic>Escherichia coli</italic>, 14.3% <italic>Enterobacter</italic> sp., 9.5% <italic>Proteus </italic>sp. and 4.8% <italic>Klebsiella</italic> sp. On the antibiogram, the bacteria that showed the highest resistance levels were those of the <italic>Proteus</italic> genus, followed by <italic>Enterobacter</italic> sp. and <italic>E. coli</italic>. The bacteria found are relevant for both animal and human health due to their zoonotic potential and serve as a public health alert since the isolates in this study showed in vitro resistance to several antibiotics, which predisposes them to the emergence of multidrug-resistant bacteria.</p> </abstract>ARTICLEtrue Plateau Angle Measurement in Dogs – Comparison of Three Different Methods<abstract><title style='display:none'>Abstract</title> <p>The aim of this study was to establish two new methods for measuring the tibial plateau angle (TPA): proximal tibial circle (PTC) as well as full tibial circle (FTC) method, and to test their reliability in comparison to the classical method (CM). Three radiologists implemented each method, and measurements were repeated three times.</p> <p>The results of consecutive measurements obtained by two observers had excellent reliability with an interclass correlation coefficient (ICC) greater than 0.9 for all methods, while measurements obtained by the third observer had good reliability for the CM (ICC=0.885) and PTC method (ICC=0.851).</p> <p>The results obtained by the three observers for all methods indicate good reliability for the PTC and FTC methods (ICC=0.848 and 0.880, respectively) and excellent reliability for CM (ICC = 0.909); the results of the different observers for each method were not significantly different.</p> <p>The significant difference resulting from the applied measurement method (ICC = 0.447 and P&lt;0.01) was confirmed. Statistically significant differences were not found between the CM and PTC method (P&gt;0.05), while differences between the PTC and FTC, as well as CM and FTC methods, were statistically significant (P&lt;0.01).</p> <p>New methods for TPA measurements based on shorter tibial axes may be an alternative to a method based on the full-length axis. A high correlation between the methods indicates the precision of each of them. Newly established methods can be used when the tarsal joint is not included in radiographs or is affected by degenerative changes, making use of the classical method not possible.</p> </abstract>ARTICLEtrue Hormones in Raw and Retail Cow’s Milk and Possible Risk for Consumers<abstract><title style='display:none'>Abstract</title> <p>The study aimed to determine the concentration of energy-related hormones in cow’s milk and to consider them from a public health perspective. Fourteen Holstein cows were subjected to milk and blood sampling on the following days in lactation (DIL): 10, 30, 60, 90, 150, 180, 210, 250 and 280 to determine milk hormones, fat and protein content and blood biochemical parameters. For the same purpose, bulk-tank milk was sampled and samples of retail m ilk with 1.5% (CM<sub>1.5</sub>) and 3.2% (CM<sub>3.2</sub>) fat was purchased. Milk insulin-like growth factor-1 (IGF-1) values were significantly lower at 90, 150, 180, 210 and 250 and significantly higher at 10, 30 and 60 DIL than lactation average (LA). Milk insulin concentrations were significantly lower at 30, 60 and 90 and higher at 210, 250 and 280 DIL than LA. Free thyroxine (fT<sub>4</sub>) level in the milk was higher at 250 DIL, while milk free triiodothyronine (fT<sub>3</sub>) concentrations were lower at 30, 60, 90 and 280 DIL, and significantly higher at 10 and 180 DIL than respective LA. Milk cortisol levels were lower at 60 and 280 DIL than LA. All measured milk hormones were significantly lower in CM<sub>1.5</sub> compared to CM<sub>3.2</sub>, bulk-tank milk and LA. An exception was the LA of IGF-1, which was significantly lower than the IGF-1 content in CM<sub>1.5</sub>. Blood biochemical parameters fluctuated evenly during lactation and were within the reference range. Hormone concentrations in cow’s milk fluctuate during lactation, giving milk an important role in the context of public health.</p> </abstract>ARTICLEtrue Prevalence of and Genеs in Coagulasе-Positive Staphylococci Isolated From Dogs with Dermatitis and Otitis in Belgrade, Serbia: A One Year Study<abstract><title style='display:none'>Abstract</title> <p>The escalating global concern of antimicrobial resistance in human and veterinary medicine is exacerbated by the inappropriate prescription of antibiotics for bacterial infections in companion animals. This study aimed to determine the distribution of coagulase-positive staphylococci causing clinical skin and ear infections in dogs and to determine methicillin-resistant isolates. A total of 78 staphylococcal strains were isolated from clinical samples taken from patients at the Dermatology Clinic at the Faculty of Veterinary Medicine in Belgrade, Serbia. Multiplex PCR was used for species-specific identification, and <italic>mecA</italic> and <italic>mecC</italic> genes were used to determine methicillin resistance, in addition to phenotypic determination, MIC values and detection of PBP2a. Out of the 78 samples analyzed, 65.8% were identified as <italic>Staphylococcus pseudintermedius</italic>, 22.4% as <italic>S. aureus</italic>, 7.9% as <italic>S. coagulans</italic>, and 3.9% as <italic>S. intermedius</italic>. Four <italic>S. aureus</italic> isolates exhibited methicillin resistance confirmed by cefoxitin disk diffusion, while five were confirmed with MIC testing and latex agglutination. <italic>MecA</italic> gene was detected in 29.4% of <italic>S. aureus</italic> and 30% of <italic>S. pseudintermedius</italic> isolates. These isolates were classified as methicillin-resistant <italic>S. aureus</italic> (MRSA) and methicillin-resistant <italic>S. pseudintermedius</italic> (MRSP), respectively. No isolates carried the <italic>mecC</italic> gene. This study provides insights into the prevalence of CoPS species and methicillin resistance in isolates from dogs. Continued surveillance is essential to monitor and understand the emergence and dissemination of antimicrobial resistance in veterinary medicine and the results of this study accent the need for establishment of a continuous antimicrobial resistance surveillance program in the Republic of Serbia.</p> </abstract>ARTICLEtrue of Antioxidative Activity of Broiler Muscles after Dietary Modulation with Selenium and Methionine<abstract><title style='display:none'>Abstract</title> <p>The objective of the study was to compare the antioxidative capacity of broiler chicken breast and leg muscles after dietary modulation with selenium (Se) and methionine (Met). Free radical scavenging (ABTS, DPPH) and iron reduction (FRAP) activities were determined as the total antioxidative potential (TEAC), as well the enzyme activity of catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx), in relation to concentrations of lipid peroxidation end products (TBARS). Analyses were performed on breast m. <italic>pectoralis superficialis</italic> and <italic>profundus </italic>individually and together. The studied leg muscles included <italic>biceps femoris, gastrocnemicus, iliotiobialis, peroneus longus, sartorius, semimembranosus, semitendinosus</italic> and all leg muscles together. Flex broiler chickens were fed diets supplemented with 6.7, 8.2, 9.7 and 11.2 g DL-methionine/kg feed and Se as sodium selenite and selenized yeast at 0.26, 0.38 and 0.50 mg Se/kg. Greater TEAC and enzyme activities were observed in leg than in breast muscles. Selenium did not change TEAC in muscles sets, but improved antiradical capacity in the <italic>pectoralis major</italic> and <italic>minor, sartorius</italic> and <italic>biceps femoris</italic>. The highest level of methionine increased TEAC in individual leg muscles. Selenium and methionine at the highest concentrations increased SOD activity in the entire group and individual muscles, while Se raised GPx activity. In conclusion, the diet supplementation with selenium and high concentrations of methionine had a greater impact on the antioxidative potential of individual than the whole set of chicken breast and leg muscles. The positive effect of the studied diet modulation could raise the quality and extend the shelf-life of fresh chicken meat.</p> </abstract>ARTICLEtrue Investigation Related to Gastrointestinal Helminth Resistance and Performance in Cattle<abstract> <title style='display:none'>Abstract</title> <p>The objective was to characterize a herd of 73 Nellore heifers, identifying resistant, resilient, and susceptible animals to gastrointestinal helminths, relating the global methylation of the DNA of these animals with the degree of helminthiasis and factors that interfere with performance. Individual count of eggs per gram of feces (EPG), fecal culture for gender identification, weighing and blood sampling were carried out to determine PCV, STP, EOS, IgG, followed by DNA extraction and methylation analysis. The results were: 47% resistant animals, 34% resilient, and 19% susceptible to gastrointestinal helminth infections, with EPG counts of 53, 216, and 841, respectively, showing a statistical difference between all groups. The quantification of DNA methylation was 0.311, 0.245 and 0.178, respectively, for resistant, resilient, and susceptible animals, with a correlation being found between resistance to gastrointestinal helminths and overall DNA methylation. For weight gain, resistant and resilient animals showed higher values than susceptible ones, with a correlation between weight gain and EPG. The same was observed for VG; however, there was no statistical difference to the EOS, PPT, and IgG values. A significant correlation was found between PCV and EPG; quantifications of PCV and methylated DNA, STP and EPG; VG and STP. Therefore, the methodologies used made it possible to identify the animals regarding the degree of infection by gastrointestinal nematodes, making it possible to correlate the resistance of cattle to helminths with the amount of global DNA methylation and its performance.</p> </abstract>ARTICLEtrue of Frequent Phlebothomy on Blood Iron Concentration, Haematological, Metabolic and Endocrine Parameters in Rams<abstract><title style='display:none'>Abstract</title> <p>Frequent phlebotomies, even when only a small volume of blood is taken for diagnostic purposes, can lead to the development of iron deficiency with hematological and metabolic changes. The study aimed to determine the influence of frequent blood loss by phlebotomy on blood iron concentration (Fe), hematology, metabolic and endocrine parameters and their relationships. Blood samples were collected from 30 blood donor rams for 6 consecutive weeks, with approximately 10% of blood collected weekly. Such chronic blood loss resulted in a decrease in Fe. Indicators of iron transport in the bloodstream changed, so the value of total iron-binding capacity (TIBC) and unsaturated iron-binding capacity (UIBC) increased, while the value of transferrin saturation percentage (TS%) decreased. Hematological changes included a decrease in red blood cells, hemoglobin, mean red blood cell volume and hematocrit and a tendency for reticulocyte count and red cell distribution width to increase. Chronic blood loss resulted in a specific metabolic response that included the increase in glucose, cholesterol, triglycerides, aspartate-aminotransferase, and insulin resistance, while thyroxine, triiodothyronine and cortisol decreased and there was a tendency for lactate to increase and BHB to decrease. The mentioned blood parameters correlated with Fe and additionally showed greater changes when Fe was extrapolated to the level of clinical deficit (Fe=9μmol/L). These correlations suggest the need to monitor the metabolic and endocrine status during chronic blood loss, in addition to Fe and erythrocyte indices. Compared with previous results in other animal species, Fe may have a direct influence on metabolic processes in rams.</p> </abstract>ARTICLEtrue of Molecular Tests in Diagnosing Ovine Brucellosis Caused by<abstract><title style='display:none'>Abstract</title> <p><italic>Brucella ovis</italic> infects sheep and causes a clinical or subclinical disease characterized by genital lesions and reduced fertility in rams, placentitis and abortions in ewes, and increased perinatal mortality in lambs. As part of this study, analyses were conducted on a sheep farm near Belgrade (Serbia). Of the serological tests, indirect ELISA was performed. A total of 94 blood sera were analyzed, 33 from rams and 61 from ewes. The results showed 23 (69.7%) positive findings in rams and 2 (3.3%) positive findings in ewes, with an overall prevalence of 25.4% bounded by a 95% confidence interval. Bruce-ladder multiplex PCR and Real time PCR were performed on 19 serologically positive rams and two serologically positive ewes. The results indicate a slightly higher sensitivity of Real time PCR compared to conventional PCR in diagnosing <italic>B. ovis</italic> from the reproductive tissues of rams. However, the differences in sensitivity between different nucleic acid extraction protocols were not significant. Most rams showed a positive PCR result in only one sample of reproductive tissue, suggesting the recommendation to take multiple samples from each animal. Further research is needed to bring the sensitivity of molecular tests in diagnosing ram epididymitis closer to the sensitivity of serological tests.</p> </abstract>ARTICLEtrue