BACKGROUND: Today, the fight against the bacteria causing foodborne diseases is of particular importance in the packaging of seafood. It is therefore vital to find new compounds with antibacterial properties.OBJECTIVES: In the present study, antibacterial properties of synthetic nanocomposite zinc chromite-zinc aluminate (ZnCr2O4-ZnAl2O4) on E. coli and Pseudomonas aeruginosa were studied.METHODS: After synthesis of nanocomposite, antibacterial activity of nanocomposite zinc chromite-zinc aluminate was evaluated via disk diffusion method, Minimum Inhibition Concentration (MIC), and Minimum Bactericidal Concentration (MBC) using the microdilution method.RESULTS: The results of this study revealed a higher sensitivity reaction of Pseudomonas aeruginosa (18.6±1.2 mm) compared to E. coli (12.7 ± 1.4 mm). No significant differences were observed between Gentamicin antibiotic and synthetic nanocomposite against Pseudomonas aeruginosa (P<0.05). The minimum MIC and MBC concentrations were seen in Pseudomonas aeruginosa (1.66 mg/ml) and the maximum concentration of MIC belonged to E. coli (5 mg/ml).CONCLUSIONS: In this study, the effects of nanoparticles on these gram-negative bacteria could be attributed to the small diameter of the ions, and hence the greater penetrability of these nanoparticles despite the wall's resistance. Based on the results, zinc chromite-zinc aluminate nanocomposite showed a better performance compared with gram-negative bacteria, specifically Pseudomonas aeruginosa resistant bacteria, and could be used for further studies in fisheries product packaging.

BACKGROUND: Fresh sausages are classified as one of the most perishable meat products due to the lack of using chemical preservatives.OBJECTIVES: The present study aimed to increase the refrigeration time of fresh sausages using Zataria multiflora Boiss. essential oil.METHODS: In this study, samples of fresh sausages, containing different concentrations of Zataria multiflora Boiss. essential oil (0, 0.05, 0.1, and 0.2 %), were prepared and stored under the refrigerated condition for 17 days. Subsequently, they were evaluated for microbial, chemical, and sensory properties at six time intervals (days 0, 2, 4, 6, 10, and 17).RESULTS: Based on the results of the study, by adding Zataria multiflora Boiss. essential oil to fresh sausages, the microbial count in the treatments containing high concentrations of essential oil (0.1 and 0.2 %) was significantly different from that in the control group (P<0.05). The amount of volatile nitrogen bases at the beginning of the study was 14 mg/ 100 g and after six days, in the control group, it reached 32.1 mg/ 100 g. Meanwhile, in the treated samples, it was less than 25 mg/ 100 g up to day 10. Moreover, at the end of the study, the level of TBARS in the control group reached 1.48 mg malondialdehyde /kg while this level was less than 0.78 mg malondialdehyde / kg for the groups treated with Zataria multiflora Boiss. essential oil. The results of this study also showed that the addition of essential oil has a non-significant effect (P>0.05) on sensory properties.CONCLUSIONS: Zataria multiflora Boiss. essential oil was found to have the potential to increase the shelf life of fresh sausages without adverse sensory effects.

BACKGROUND: Sex determination is an essential issue in certain fish species, like sturgeons. During the rearing management, distinguishing between male and female fish is an important process for producing meat or caviar.OBJECTIVES: The current study aimed to find the feasibility of electric organ discharge (EOD) frequency ‎generating to introduce a novel method of sex determination in three freshwater species, namely the ‎black ghost knife fish (Aptronotus albifrons), goldfish (Carassius auratus), and the Sterlet ‎sturgeon (Acipenser ruthenus), as non-electric fishes.METHODS: In this regard, following sex detection, EOD frequency ‎of fishes were recorded via an oscilloscope. In addition, knife fish was used as a reference sample on which a lot of work has been done to evaluate the accuracy of the method and the use of the oscilloscope. Furthermore, the EOD frequency of male and female ‎Sterlet sturgeons was recorded and reported for the first time in this study.RESULTS: The frequency ‎magnitude was significantly different in genders of Sterlet (P<0.05) with higher EOD frequency in males ‎than in females. There was no recorded frequency in goldfish ‎male and female. EOD frequencies, which were recorded in male and female of black ghost fish, ‎represented significant differences compared with the other studies (P<0.05).CONCLUSIONS: The results achieved ‎in this study revealed that sex differences are one of the effective parameters in terms of EOD ‎frequency inequality; this non-invasive method can be utilized for sex identification of valuable ‎species, like sturgeon. However, it is required to gather advanced equipment and conduct further ‎research in physiology and biology of reproduction for accurate recording of electrical frequencies ‎and detection of their origins.

BACKGROUND: Neosporosis is a disease caused by the protozoan Neospora caninum, which is characterized by abortion in cattle and neuromuscular paralysis of various organs, particularly the hind limbs of dogs. The diagnosis of neosporosis is often made by serological molecular tests.OBJECTIVES: This study was conducted to investigate the presence of N. caninum oocysts in the feces of dogs. METHODS: A total of 100 fecal samples were collected from indoor and outdoor dogs during 2018-2019 around Tabriz. Information about age, location, and history of antiparasitic treatment of the dogs were recorded in a questionnaire. Primarily, fecal samples were examined microscopically for Neospora ocysts. After breaking the collected oocysts through freeze-thaw and sonication, DNA contents of the oocysts were extracted and analyzed via PCR.RESULTS: In a light microscopic study, oocysts were observed in 45 (45 %) of the fecal samples. In the PCR study, 21 of the 45 cases tested positive for Neospora infection (21 %). All the positive cases of infection were observed in molecular examination in dogs older than one year. The positive cases were observed in 2 % of the domestic dogs, 8 % of the stray dogs, 6 % of the kennel dogs, and 5 % of the rural dogs. Furthermore, 19 % of the infected dogs had no history of antiparasitic treatment; only 2% had a history of antiparasitic treatment. The results of statistical analysis showed that the rate of infection in dogs around Tabriz with Neospora caninum was significantly (P<0.05) related to the animal's living environment and history of antiparasitic treatment. However, this rate was found to have no significant relationships with the age of the animals.CONCLUSIONS: Due to the high rate of infection with Neospora caninum in dogs in Tabriz, it is necessary to apply preventive methods in traditional and industrial farms around this city and use rapid diagnosis methods in them.

BACKGROUND: Omega-3 fatty acids can be conducive toreducing the harmful effects of physiological stress through reducing the stimulatory activity of glutamatergic neurons.OBJECTIVES: The aim of this study was to investigate the effects of omega-3 fatty acids on performance, blood parameters, and the profile of fatty acids in the egg yolks of laying hen under stress.METHODS: This study was performed using 96 LSL-Lite laying hens in a 2 × 3 factorial experiment with 2 factors, namely stress (no dexamethasone and 1.5 mg/kg of diet dexamethasone) and omega-3 fatty acids (the levels of 0, 0.24 and 0.48 % of diet), in a completely randomized design for 70 days from 35 to 44 weeks of age.RESULTS: Physiological stress reduced the feed intake, the percentage of egg production, and egg mass in laying hens (P<0.05). Omega-3 fatty acid supplements had no effects on these traits. The groups receiving 0.48 % of omega-3 fatty acids had the lowest heterophil:lymphocytes (P<0.05), and there was no difference between stressed and non-stressed groups. The ratio of omega-6 to omega-3 fatty acids was higher in birds previously affected by stress (P<0.05). Feeding with omega-3 fatty acids in birds increased omega-3 fatty acids in egg yolk and reduced the ratio of omega-6 fatty acids to omega-3 in laying hens (P<0.05).CONCLUSIONS: Based on the results of this experiment, physiological stress had a negative effect on performance traits, and the use of omega-3 fatty acids in laying hens under stress had no effect on performance traits. Physiological stress altered the profile of fatty acids and increased the proportion of omega-6 to omega-3 fatty acids in egg yolk. The use of omega-3 fatty acids reduced the negative effects of stress and improved the profile of fatty acids in egg yolk.

BACKGROUND: Trypanosomosis is a blood parasitic disease with veterinary and cosmopolitan importance due to Trypanosoma evansi (Kinetoplastida: Trypanosomatidae) type A in camels, cattle, buffaloes, and equine and type B in camels. OBJECTIVES: We conducted the present study to discriminate Trypanosoma evansi type A and B infection in one-humped camels (Camelus dromedarius) in Sistan-va-Baluchestan Province, south eastern Iran. METHODS: A total number of 369 blood samples were randomly taken from jugular vein of the examined one-humped camels from different parts of the region. Genomic DNA was extracted and polymerase chain reaction (PCR) was performed to amplify 205bp-fragment-length and 436bp-fragment-length of RoTat 1.2 VSG gene (T. evansi type A) and Minicircle gene (T. evansi type B), respectively. RESULTS: Molecular findings revealed that all the infected camels were affected by T. evansi type A. CONCLUSIONS: Based on the results of the current study, we could conclude that the cause of infection in the examined camels of the region, like other parts of the world, was T. evansi type A.

BACKGROUND: Yersiniosis is known as one of the most prevalent bacterial diseases in fish, which causes high mortality and economic losses in cultured fish farms every year. OBJECTIVES: The present study was conducted to investigate the changes in hematological indices and gut histopathology in Caspian roach (Rutilus caspicus) exposed to Yersinia ruckeri. METHODS: 60 Caspian roach broodstock with an average weight of 63.4 ± 2.1 g were divided into three groups (with two replicates for each group), including one treatment, one positive control, and one negative control groups. The treatment group was intraperitoneally injected with Yersinia ruckeri bacterium at a dosage of 3.8 × 107 cell/fish. The positive group just received normal saline (0.9 % NaCl) via intraperitoneal injection. No injection was performed in the negative control group. RESULTS: Symptoms appeared on the fourth day after exposure and 20 % of the fish in the treatment group died 5 days after the challenge. Cumulative mortality reached 53 % on day 9 after the challenge.  According to hematological analysis, the challenge with Yersinia ruckeri led to a significant increase in white blood cell counts (WBC) compared to the control groups. Moreover, 10 days following exposure, the treatment group experienced hypochromic macrocytic anemia. Gut histopathology was characterized with necrosis and detachment of intestinal epithelial cell and inflammatory cells infiltration in the treatment group. CONCLUSIONS: Based on the obtained results herein, Yersinia rackeri can cause acute disease in Caspian roach; therefore, preventing and controlling this disease is essential for these fish in infected regions.

BACKGROUND: Calf pneumonia is one of the most common diseases in dairy and beef herds. OBJECTIVES: To compare steroidal and non-steroidal anti-inflammatory drugs as adjunctive therapy in dairy calf pneumonia. METHODS: Forty calves less than six months of age diagnosed with calf pneumonia in dairy farms of Mashhad suburb were enrolled in this study based on the University of Wisconsin Calf Respiratory Scoring Chart. In this system, calves are scored based on factors such as nasal discharge, rectal temperature, cough, eye and ear staining. Calves should not have a history of any other disease. Moreover, factors such as age, sex, and severity of the disease were considered similar in distributing calves among different groups. These calves were divided into four treatment groups; all were treated with antibiotic florfenicol. The first group received dexamethasone, while dexaphenyl, phenylbutazone, distilled water were used in other groups. After 5 days, calves were examined and scored again and blood samples were taken. Complete blood count (CBC), fibrinogen, total protein, hapto-globulin and albumin measurements on blood samples before and after treatment were done. Repeated measurement ANOVA and Paired t-test were used for statistical analysis with the significance level of 0.05. RESULTS: The results showed that the degree of health, heart and respiratory rate, fibrinogen and total protein, Lymphocyte, N/L, TP-Fib/Fib ratio, MCV and MCHC significantly changed during the two sampling periods (p < /em>˂0.05), but there was no significant difference between the treatment groups (p < /em>˃0.05). Only the PCV factor and TP-Fib/Fib ratio was significant between groups (p < /em>˂0.05). CONCLUSIONS: Results indicate that in the treatment regimen of dairy calf pneumonia, the use of an anti-inflammatory drug, along with antibiotics and antibiotic treatment alone are not significantly different.

BACKGROUND: Peste des petitis (PPR) is a highly contagious viral disease with high incidence and mortality rate, which is endemic in the Middle East, Southwest Asia, and Africa. This disease has been causing economic losses in sheep and goat flocks in these areas. Studies have shown that environmental and host risk factors can influence the severity of PPR infection. OBJECTIVES: We conducted the present study to investigate the prevalence of PPR in small ruminants population of Garmsar city and its suburbs. Furthermore, the effect of host factors, including animal species, gender, and age, and environmental factors, such as sampling season, geographical area, and sampling location, were evaluated. METHODS: Blood samples of 180 sheep and goats were taken in spring, summer, and autumn and after centrifugation, serum samples were isolated. We measured antibody response using competitive enzyme linked immunosorbent assay (C-ELISA). RESULTS: The apparent and true prevalence of contamination in small ruminants of Garmsar and its suburbs ware 24.44 % and 23.91 %, respectively. The results revealed non significant relationships between animal species (p < /em>= 0.08), gender (p < /em>= 0.14), and age (p < /em>= 0.98) with PPR serum prevalence. Meanwhile, there was a significant relationship between season (p < /em>= 0.03), geographical area (p < /em>= 0.0004), and sampling location (p < /em>= 0.0001). In addition, the odds ratio of PPRV infection in autumn was 2.62 (95% CI: 0.06 – 6.02; p < /em>< 0.05) times more than that of other season and in the south-eastern of Garmsar, it was 6.71 (95% CI: 3.01-17.60; p < /em>< 0.05) times more than that of other geographical regions. The odds ratio of PPRV infection in the Mahmood Abad village was 63.63 (95 % CI: 12.14 – 132.93; p < /em>< 0.05) times higher than that of other villages. CONCLUSIONS: According to the obtained findings, PPR was proven to be an endemic disease in Garmsar and its suburbs and the environmental risk factors have a greater impact on the seroprevalence of disease than host risk factors. Therefore, in order to control the disease in endemic areas, further attention should be paid to environmental risk factors and minimizing the risk of epidemics through vaccination at sensitive timescales and areas before high-risk environment changes.

BACKGROUND: Plasma lipoprotein profile is one of the effective mechanisms in testicular tissue development and spermatogenesis process in roosters. OBJECTIVES: The present study was conducted to investigate the effect of dietary supplementation of l-carnitine during pre-pubertal period on testicular histology, spermatogenesis indexes and plasma lipoproteins of immature cockerels METHODS: A total of twelve Ross broiler breeder males (12 weeks) for 22 weeks in a completely randomized design with two treatments (0, and 250 mg/kg of L-carnitine in the diet) and six replications were used. Feeding program, and photoperiod regimen was performed based on ROSS 308 management handbook. To achieve the objectives of the study, at the age of 34 weeks, four birds were randomly selected from each treatment and after collecting blood samples from the veins under the wings, the birds were slaughtered. Finally, plasma cholesterol, LDL and HDL concentrations using a commercial kit and testicular parameters (number of seminiferous tubules, number of Sertoli cells, height of epithelium seminiferous tubules, seminiferous tubules diameter, spermatogenesis index, and tubular differentiation index) after preparation of 5-μm paraffin sections, were analyzed by SAS software. RESULTS: The results showed that the number of seminiferous tubules, and the number of Sertoli cells were significantly affected by l-carnitine (p < /em><0.05). L-carnitine supplementation in the diet of immature cockerels before sexual maturity significantly increased the spermatogenesis index (p < /em><0.003) and tubular differentiation index (p < /em><0.02). HDL levels were significantly affected by l-carnitine supplementation (p < /em><0.007). There was a significant tendency in LDL concentration (p < /em>=0.09) and LDL/HDL ratio (p < /em>=0.059) between treatments, but no significant differences were observed in cholesterol concentration between treatments. CONCLUSIONS: According to the results of this study, feeding immature cockerels before sexual maturity with 250 mg l-carnitine improves testicular tissue development and spermatogenesis process.