Immune and oxidative parameters were evaluated as indicators of the influence of stress on the occurrence of respiratory syndrome in feedlot calves. The study was carried out on 60 2 and a half-month-old Simmentaler calves transported at feedlot. Mean daily feed consumption, daily weight gain, and behavioural activity were evaluated. Blood was collected on days 1, 3, 7, 14, 21, and 28 of feedlot. Serum NO ions, lipid peroxidation, acute phase proteins, IgG, and IgM were determined. The calves showed a decrease in feed consumption during the first 7 d of the feedlot. Sporadic stereotypies were noted. NO concentration showed a significant (P < 0.05) increase on days 7 and 14. Concentration of thiobarbituric acid reactive substances (TBARS) increased (P < 0.05) on days 1 and 3. IgM concentration was found to be considerably lower on days 14 and 28. Serum haptoglobin level showed a significant increase in stressed calves on days 1, 3, 7, and 14 of the feedlot. Based on these results, it can be suggested that stressors associated with transport and adaptation to the feedlot induce a stress reaction in calves, resulting in behavioural disorders, reduced weight gain, suppression of the humoral immunity and increased morbidity during the first weeks. These parameters seem to be crucial in evaluating the animals' health and welfare.
The aim of the study was to evaluate the effect of flunixin and florfenicol administered in combination with vitamin E or C on selected leukocyte immune mechanisms and on the inflammatory process during the first few weeks in the feedlot. Fifty calves divided into 5 groups (n = 10) received florfenicol and flunixin with vitamin E or C. Blood was collected on the 1st, 3rd, 7th, 14th, 21st, and 28th d of the experiment. Intracellular metabolism (NBT), apoptosis, chemotaxis, susceptibility to M. haemolytica leukotoxin, and expression of β2-integrins were determined in leukocytes. The symptoms of respiratory tract infection were observed in 40% of calves in control group, while in the other groups the morbidity rate ranged from 10% to 20%. Leukocytes showed decreased NBT, and the mean values for apoptosis ranged from 14% to 24%. The lowest percentage of apoptotic cells was observed in the calves that received florfenicol with flunixin and vitamins E and C. The chemotactic activity confirmed the significant inhibitory effect of the preparations on migration of the cells. A significant decrease (P ≤ 0.05) in the susceptibility of leukocytes to leukotoxin was noted in the group that received florfenicol and flunixin with vitamin E. Expression of β2-integrin receptors was the lowest in calves receiving florfenicol with flunixin and vitamin E or C. The application of an antibiotic and a non-steroidal anti-inflammatory drug with antioxidants protected the leukocytes involved in defence against M. haemolytica virulence factors and effectively limited oxidative stress in the calves.
The study was performed on nasal swabs, tracheal samples, and sera obtained from young beef heifers aged between 6 and 12 months, from farms in eastern and south-eastern Poland. The samples were evaluated using bovine herpesvirus 1 (BHV-1) ELISA kits (ELISA BHV1 antibody and ELISA BHV1 antigen) and PCR. Among all the animals examined, 37 (32.2%) were positive in the ELISA BHV1 antigen test. The presence of BHV-1 was confirmed by PCR in 42 (36.5%) animals. In the ELISA BHV1 antibody test, 39 (33.9%) seropositive animals were identified. The presence of BHV-1 positive samples was observed in all the examined breeds of young cattle. There were no significant differences (P ≤ 0.05) in BHV-1 positive samples. The results indicate that the incidence of BHV-1 infections in feedlot cattle herds studied was 32.2%-36.5%, which suggests that preventive measures should be implemented in order to limit transmission of the virus.
Shedding time of bovine respiratory syncytial virus (BRSV) and bovine parainfluenza virus 3 (BPIV3) in calves vaccinated intranasally with modified live Rispoval RS-PI3 vaccine was determined. Blood and nasal swabs were collected on selected days before and after vaccination. Antibodies against BRSV and BPIV3 were tested by Respiratory ELISA Pentakit and the viral RNA was detected by RT-PCR. Twenty eight days after administration of the vaccine, a marked increase of specific antibody titres to BRSV and BPIV3 was detected in vaccinated calves. All animals were RT-PCR positive both for BRSV and BPIV3. Both viruses were excreted with nasal discharges within 8 d after vaccination but the course of shedding in individual calves was variable.
Introduction: The study sought to characterise antimicrobial resistance among coagulase-negative Staphylococcus (CNS) species recovered from broiler chickens and turkeys in Poland including the presence of 12 antimicrobial resistance genes and five classical genes of staphylococcal enterotoxins. Material and Methods: A panel of 11 antimicrobial disks evaluated the phenotypic sensitivity of the tested strains to antibiotics. Five multiplex PCR assays were performed using primer pairs for specific detection of antibiotic resistance genes and staphylococcal enterotoxin A to E genes. Results: Selected antimicrobial agent susceptibility testing revealed 100% of such in in vitro conditions to cefoxitin among strains of Staphylococcus sciuri and S. chromogenes. The blaZ (for ß-lactam) and mecA (for methicillin resistance) genes were in 58.3% and 27.5% of strains, respectively. Among genes resistant to tetracyclines, tetK was most frequent. Fewer (CNS) strains showed genes resistant to macrolides, lincosamides, and florfenicol/chloramphenicol. Multiplex PCR for classical enterotoxins (A-E) detected the see gene in two S. hominis strains, while the seb gene producing enterotoxin B was found in one strain of S. epidermidis. Conclusion: CNS strains of Staphylococcus isolated from poultry were either phenotypically or genotypically multidrug resistant. Testing for the presence of the five classical enterotoxin genes showed that CNS strains, as in the case of S. aureus strains, can be a source of food intoxications.
Sanitary conditions and diet are important elements determining the occurrence of pathogens in animals. The aim of the research was to assess the effect of an experimental diet with rye and xylanase for broiler chickens in cages and in a free-range system on the intestinal microbiome. The study was carried out in two experimental stages, the first on 224 1-d-old male Ross 308 chickens with an initial weight of 41 g, and the second on 2000 1-d-old male chickens with an initial weight of 42 g. All birds were reared to 42 d of age and fed crumbled starter (1 to 21 d) and pelleted grower–finisher (22 to 42 d) isonitrogenous and isoenergetic diets, supplemented with 20% rye and/or 200 mg/kg xylanase. Directly after slaughter, bacteria were isolated from the cloaca of birds and identified using classical microbiological methods and MALDI-TOF mass spectrometry. The antibiotic susceptibility of the bacteria was assessed by the disc diffusion method. The study showed the presence of abundant bacteria in the gut microbiome of chickens kept in both housing systems. The most frequently isolated bacteria were Escherichia coli, Enterococcus spp., Proteus spp., Campylobacter spp., and Staphylococcus spp. Antibiotic resistance was significantly higher in E. coli, Proteus spp., and Campylobacter spp. obtained from chickens from the free-range farm, but in the case of Enterococcus and Staphylococcus, resistance was higher in bacteria from caged birds. The high antibiotic resistance among pathogens of the gastrointestinal tract necessitates the search for means to control the microbiome in favour of beneficial bacteria. The significant influence of rye and xylanase on the bacterial content may be the basis for the introduction of this method to support the control of pathogens.