Journal of Veterinary Research
Year:2019 | Volume:74 | Issue:1 |Papers Count:19

BACKGROUND: Among infectious diseases, Newcastle disease, due to being highly contagious and its rapid spread among poultry and other bird species, is a deadly viral disease and is considered a global threat to the poultry industry. Objectives: To determine the occurrence of Newcastle disease in poultry broiler farms reported to the Iranian veterinary organization during the study period. Methods: This is a cross-sectional study from September 2013 to March 2015. During this study, from 185 farms and a total of 3700 bird sera, cloacal and tracheal swabs were sampled and tested using a haemagglutination inhibition test and reverse transcriptase polymerase chain reaction respectively. Results: In this study, of a total of 185 farms reported to the Iranian Veterinary Organization, 115 farms (62. 16%, 95%CI: 55. 17-69. 14) were positive for Newcastle disease viruses and then using specific primers, 69 farms (37. 3%, 95%CI: 30. 33-44. 26) had vaccinal pathotype (non-acute) and 46 farms (25%, 95%CI: 18. 76-31. 23) had acute pathotype (field virus). The mean± SD age of infected poultry was 24. 63± 5. 38 days and antibodies titer against Newcastle disease virus was 5. 97± 1. 21. The highest mortality rates were observed in the spring (32. 34%) and winter (26. 9%), respectively. Mazandaran (37%) and Isfahan (22%) province had the highest percentage of farms with Newcastle disease. Conclusions: The findings of this study suggested virulent Newcastle virus strains are circulating in the Iranian commercial broiler farms in the mentioned time and with high occurrence. Therefore, the relevant authorities need to make correct decisions to reduce the risk of Newcastle disease in the Iranian poultry industry and its control.

BACKGROUND: Colony Collapse Disorder is a mysterious phenomenon in which worker bees abruptly disappear from a beehive. Objectives: The aim of this study was to estimate the prevalence of CCD and its relation to climate and Nosema spp infections. Methods: This Cross sectional study was done from April to September 2016. With respect to different climatic zones of the country, a total of 183 apiaries were selected. In each apiary, 5 percent of the colonies were randomly sampled. Adult bee samples were then examined for the presence of Nosema infections using PCR. Data were analyzed by Chi-square using SPSS version 21. 0. Results: The results showed the prevalence of colony collapse disorder in the studied apiaries at 26. 8%. The CCD prevalence was 20. 5% in humid, 16. 1% in semi humid, 22. 7% in very humid, 38. 2% in arid, 43. 8% in semi-arid and 16% in Mediterranean conditions. Comparing CCD phenomenon in different climatic regions, there were significant differences (P<0. 05). The prevalence of Nosema ceranae infection was 85 (46. 4%), however, infection with Nosema apis was not observed in the samples either in pure form or as associated infection. There was no statistical significant difference between symptomatic and asymptomatic apiaries with colony collapse disorder in terms of presence or absence of N. ceranea (P>0. 05). Conclusions: The results suggest that climate could influence the prevalence of Colony Collapse Disorder. It may be due to different foraging resources in under studied area. According to findings of this study it seems that N. ceranea alone cannot be the cause for CCD. Further studies are needed to clarify the interactions between climate and other possible causes.

BACKGROUND: Toxoplasma gondii is an obligate intracellular protozoon with worldwide distribution that infects human and a wide spectrum of warm-blooded animals. OBJECTIVES: The aim of the study is to survey the prevalence of T. gondii antibody in slaughtered livestock in slaughterhouse with modified agglutination test in Sanandaj in 2015. Methods: Totally 343 serum samples were collected from 130 cows, 111 sheep and 102 goats from May to July 2015 in Sanandaj slaughterhouse. Sera were examined with modified agglutination test (MAT) for T. gondii antibody and 1. 40 titer antibody and above was considered as positive. Results: Antibodies of T. gondii were found in sera of 51 out of 343 (15. 45%) samples. From 51 seropositive sera, 13 cows (23. 84), 13 goats (12. 74%) and 9 sheep (8. 1%) were infected. The differences among species were statistically significant (P≥ . 002). Conclusions: Results indicate that T. gondii in sheep, goats and especially cows is prevalent, so consumption of undercooked meats should be avoided, also the prevention methods of infection should be taught to the people and due to the possibility of limitations in the results of serological tests, repetition of the study using molecular techniques is recommended

BACKGROUND: Dicrocoeliasis is one of the commonest parasitic diseases of the bile ducts and gallbladder in a wide range of mammals including ruminants and sometimes human being. The disease is really important in medicine, economy, and veterinary medicine. Annually, slaughter house loses a huge amount because of losing a great deal of valuable proteins in people daily diets. In order to bring the disease under control, morphological and molecular analysis of parasite in endemic districts is essential. OBJECTIVES: The present study was conducted to determine the morphological as well as molecular characterization of cattle, sheep and goats isolated from Dicrocoelium by applying ND1 genetic marker in the Markazi province, Iran. METHODS: In this cross-sectional study 480 fresh adult worms were collected from livers of 120 cattle, sheep and goats slaughtered in abattoirs in Markazi province. To diagnose the species of parasite, morphometric indices of mature worms were calculated based on standard parameters. Then DNA of 60 isolates with different morphometric characteristics was extracted and PCR reaction was performed for a part of ND1 (mtDNA). PCR was purified and its sequence was defined, the percentage of genetic similarity was compared to cases registered by GenBank and the exact species of parasite was recognized. RESULTS: The morphometric analysis in all isolates was as follows: testicles were sequential, the length and the width of the worm for all cattle, sheep and goat isolates were 7994± 967µ m, 6844± 100µ m, 6570± 110µ m (P<0. 0001) and 1649± 339µ m, 1490± 221µ m and 1430± 252µ m (P<0. 0001) respectively. The proportion of the length to the width was 4. 87± 0. 641, 4. 58± 0. 625, and 4. 64± 0. 622 respectively. All the results mentioned above confirmed Dicrocoelium dendriticum in the hosts of the district under investigation. The analysis of the gel electrophoresis in all isolates showed the existence of band 200pb. The percentage of genetic similarity to the registered items, cases were determined by the Gen bank between 97 and 99 percent. CONCLUSIONS: Molecular identification and morphometric assays clearly showed that D. dendriticum is the only agent of Dicrocoeliasis among cattle, sheep and goats in the Marakazi province, Iran. Molecular diagnosis of parasite by applying genetic marker of the nucleus is recommended.

BACKGROUND: Enzymes are organic catalysts that trigger and/or accelerate chemical reactions. OBJECTIVES: This research was done to compare the separate and combined levels of commercial multienzymes on feeding efficiency and carcass chemical composition of common carp (Cyprinus carpio). METHODS: Total number of 96 common carp fingerlings weighing 13. 06± 2. 56g were distributed in six treatments including control (without multienzyme), 1 g/kg Combo, 1. 5 g/kg Combo, 1 g/kg Natuzyme Plus, 1. 5 g/kg Natuzyme Plus and mixture of 1g/kg Combo+1 g/kg Natuzyme Plus in two replicates for 8 weeks. RESULTS: Growth indices such as the final weight, percentage of body weight increase, specific growth rate, food conversion ratio and average daily growth in treatment 1g/kg Natuzyme Plus showed significant differences compared to other experimental treatments (P<0. 05). Also, all experimental treatments had better condition in comparison with the control. The highest condition factor was seen in fish fed 1. 5 g/kg Natuzyme Plus which showed significant difference with 1. 5 g/kg Combo (P<0. 05). Common carp fingerlings fed mixture of Combo+Natuzyme Plus recorded a slight increase in protein content of carcass compared to other dietary treatments. Fish fed multienzymes had less (P>0. 05) lipid content of carcass in comparison with the control. There was no significant difference in ash and moisture contents of carcass (P>0. 05). CONCLUSIONS: According to results, it can be stated that Natuzyme Plus at the level of 1. 5 g/kg can be effective in improvement of growth performance and feed efficiency in farmed common carp fingerlings.

BACKGROUND: Probiotics and prebiotics are the most important bioactive compounds for aquatic health. OBJECTIVES: In this study, the effects of prebiotic (immunowall) and probiotic (primalac) were assessed on growth performance, survival, body composition, and blood biochemical parameters in the Caspian Sea common carp Cyprinus carpio fingerlings. METHODS: Juveniles (n = 100 per tank, 21 tanks) were distributed in four inclusion levels (each in three treatments) of 0, 0. 05, 0. 1 and 0. 15% of immunowall and primalac inclusions for a period of 56 days. Growth, body composition, and hematological parameters have been evaluated in different inclusion levels at the end of culture period. RESULTS: The increment of body weight, specific growth rate, and feed conversion ratio in fish fed with diets containing 0. 15% prebiotic and 0. 1% probiotic improved considerably compared to other treatments. The survival rate of the juveniles was not significant between treatments, and the group fed with the pre-and probiotics revealed higher survivals. Protein content in the group fed with the pre-and probiotic showed significantly higher contents compared to the control group, and lipid content showed increasing trend in different inclusions. The red blood cells contents showed no differences between treatments; but the white blood cells contents revealed higher performances in the fish-fed probiotics compared to prebiotic and control groups. CONCLUSIONS: These results recommend the addition of 0. 1 % immunowall and 0. 15 % primalac in the diets of the juveniles in terms of growth, feeding, and hematological indicators in the Caspian carp.

BACKGROUND: Based on previous studies, aquaculture systems affect on flesh quality in cultured species. In biofloc system, as a modern and new aquaculture system, animals use microbial flocs as feed and it seem such flocs affect on bodycomposition. OBJECTIVES: The aim of this study was to evaluate growth and chemical, microbiological and sensory properties of common carp meat cultured in Biofloc system. METHODS: Three hundred healthy fingerlings were randomly distributed in 12 tanks (70 L) at a density of 8. 3 kg m-3 and fed experimental treatments: commercial diet as a control and three biofloc treatments including sugar beet molasses biofloc (SBM+BFT), sugar biofloc (S+BFT) and corn starch biofloc (CS+BFT). Fish in BFT treatments were fed at 75% of the daily feeding rate of control. At the end of experiment, growth performance and survival investigated. In addition to evaluate cultured fish meat quality, sensory properties of raw fish (day 0), rigor mortis (3, 6 and 24 h after catch), bacterial count, pH, expressible moisture and TVN were also assessed during 16 days, (every 4 days). RESULTS: The results indicated that the lowest food conversion ratio (FCR) and highest condition factor was observed in fish fed BC which differed significantly from control (P<0. 05). No significant difference among treatments was observed in rigor mortis and bacterial count (P>0. 05). pH in carp flesh increased gradually during storage time (P<0. 05), but at the end of the storage period no significant difference was found between the treatments (P>0. 05). The lowest primary TVN was seen in BS treatment (9. 0 ± 0. 2 mg N/100g flesh) but in other treatments TVN was higher than 20 mg/ 100g flesh (P<0. 05). CONCLUSIONS: Overall, based on the results of this study, biofloc cultured fish flesh had acceptable quality in comparison with control fish.

BACKGROUND: Staphylococcus aureus is one of the most important pathogenic bacteria for human that is easily transferred during slaughtering, processing, packaging, storage and handling of meat and meat products as a result of poor hygienic principles, and causes staphylococcal food poisoning. Objectives: The objective of this study was to evaluate the contamination of raw and cooked ground beef in retail shops of Mazandaran to S. aureus and also detection of enterotoxin-producing genes in the isolates. Methods: One-hundred fifty ground beef samples (95 raw and 65 cooked) were collected randomly from retail shops, 21 May-21 July 2017. S. aureus was counted via culturing on Baird Parker Agar medium. Detection of enterotoxins A-E and G, H, I and J producing genes was conducted applying real-time PCR technique. Results: 68% of samples showed S. aureus contamination. The average count in raw and cooked ground beef samples was 3. 1×105 cfu/g and 5. 7×103 cfu/g, respectively. From 92 S. aureus isolates, 23 isolates (25%) were carrying enterotoxin coding genes; amongst them 15 isolates (65. 2%) were carrying just a single gene and the rest more than one gene. Two isolates carrying SEA+ SEC, two isolates SEA+SEE, one isolate SEA+SEG, one isolate SEC+SEI, one isolate SEA+SEC+SEG and one isolate SEE+SEG. Conclusions: These results show that enterotoxigenic S. aureus strains are present on considerable numbers in retail ground meat in Mazandaran.

BACKGROUND: Considering the progressing tendency of administration of nanomaterials products in the world and their entrance to aquatic ecosystems, their toxicity assessment on the aquatic environment and proposing the biocompatible solutions in their production seems indispensable. OBJECTIVES: In this study, the toxicity of silver nanoparticles (AgNPs), chemical and biosynthetic forms were evaluated using the biomarker, artemia nauplii (Artemia fransiscana). METHODS: For toxicity assessment, the OECD standard method was used. The artemia nauplii were exposed to additive serial concentration of biosynthetic and chemical silver nanoparticles. For biosynthesis of silver nanoparticles, aqueous extracts of two species of marine macroalgae Ulva flexuosa (green algae) and Sargassum boveanum (brown algae) were used. Artemia nauplii mortality in the times of 12, 24, 36 and 48 hours after exposure to silver nanoparticles were recorded and analyzed via Probit software. RESULTS: Survey findings showed that not only the toxicity of these three types of silver nanoparticles on artemia nauplii increased in a dose-dependent manner, but also their toxicity increased along with duration of exposure time. The toxicity of these nanoparticles were significantly different (P<0. 05). The 48 h LC50 value of chemical AgNPs in the artemia nauplii was 31. 8 mg/l, while 48 h LC50 for biosynthesis AgNPs produced by U. flexuosa, and S. boveanum were 366. 96 and 141. 16 mg/l respectively. CONCLUSIONS: Comparison of the toxicity of these three types of AgNPs on artemia nauplii showed that, the chemical form of AgNPs was more toxic (up to 10 times) than a biosynthetic form of AgNPs. Moreover, the source of biosynthesis of silver nanoparticles had a considerable impact on toxicity of final production, because a biosynthetic form of AgNPs produced by U. flexuosa was less toxic than the same form prepared from S. boveanum.

BACKGROUND: Probiotics have more functional effects on shrimp immunological parameters but there is less information on comparative effects of Commercial and Indigenous probiotics on post-larvae and larval stage of shrimp life. OBJECTIVES: This 60 day study was conducted to determine the effect of probiotic bacterium commercial and allochthonous (Bacillus subtilis and Bacillus licheniformis) on some of immune parameters and serum enzymes in the whiteleg shrimp (Litopenaeus vannamei). METHODS: Three experimental diets were supplemented with similar concentration of 1. 5×106 Cfu/g by bacteria, commercial and allochthonous supplementation. Control (without probiotic supplementation), D1 (commercial probiotic), D2 (commercial+allochthonous probiotic) and D3 (allochthonous probiotic) were used for the experiment. At the end of trial, to evaluate immune parameters, Shrimp hemolymph was collected by syringe into the ventral sinus of L. vannamei, transferred to a tube and allowed to anticoagulant. To investigate serum enzymes level, body shrimp were homogenized and extracts were analyzed biochemically. RESULTS: Total haemocyte count (THC), large granular cells (LGC), semi granular cells (SGC) and hyaline cells (HC) treated with commercial probiotics increased in comparison with control and significant difference was observed (P<0. 05). Enzyme alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were significantly decreased in the experimental groups compared with control (P<0. 05). However, post-larvae enzyme alkaline phosphatase was not found to be significantly affected by probiotic supplementation (P>0. 05). CONCLUSIONS: The probiotic Bacillus influenced the increase of the immune parameters haemolyph and decreased serum enzymes level and it is appropriate for supplementation in the diet of whiteleg shrimp post-larvae.

BACKGROUND: The consumption of probiotics in aquaculture is constantly growing due to the numerous benefits conferred on the fish health. Degradation of probiotics in gastrointestinal tract is one of the most important challenges in probiotic efficacy. Encapsulating of probiotics within a physical barrier has been found to increase probiotic viability in fish gastrointestinal tract. Objectives: In this study the effect of encapsulation of Lactobacillus plantarum with alginate/chitosan nano particles in in vitro situation and their effects in Huso huso were evaluated. Methods: Firstly, in vitro probiotic potential including: pH and bile resistance, gastrointestinal juice tolerance was evaluated. Then effects of encapsulated probiotic were evaluated in Huso huso. 480 juvenile H. huso were randomly divided into four treatments in triplicates. Fish in T1 were fed with alginate/chitosan enriched free probiotic diet, T2 received encapsulated Lactobacillus plantarum, T3 received bacteria without any encapsulation and T4 received basic diet as a control group. All treatments were fed with experimental diets for 60 days and study lasted for 15 days with control diet in all fish. Fish samples were taken on days 30, 60 and 75 and bio chemically compared among the treatments. Results: Results of first phase of study showed that mostly all probiotic properties of encapsulated bacteria were more appropriate than control treatment (P<0. 05). Encapsulation of bacteria in both procedures enhanced almost all immunological parameters compared to control treatment (P<0. 05). Higher Ca and Mg of plasma were observed in fish fed with Lactobacillus plantarum nano/microencapsulated and alginate/chitosan at day 30 and 60, whereas decreased TRI of plasma was observed in fish fed with Lactobacillus plantarum nano/microencapsulated at day 30. Conclusions: It can be concluded that nano encapsulation of Lactobacillus plantarum with alginate/chitosan not only improved in vitro probiotic effects of L. plantarum, but also it can increase Biochemical parameters of H. huso and could improve the positive performance of probiotics activity.

BACKGROUND: Alveolar pattern of the lung field is usually caused by several lung involvements such as edema, hemorrhage and pneumonia, but differentiation using radiography is usually impossible. Objectives: Evaluation of HU and lung pattern of pneumonia in dogs using CT-scan technique and confirmation by CT assisted FNA as a safe diagnostic procedure. Methods: In this study, 10 dogs with respiratory distress suspected for pneumonia were selected and radiography and CBC were used for evaluation of lung pattern and cytology. Before and after contrast medium injection, CT-scans of the lung field were achieved. Finally, in transverse CT sections, FNA of involved lung lobes was taken for cytologic evaluation. After the confirmation of pneumonia, CT scans were reevaluated with more attention and pulmonary pattern was described and HU of involved regions was measured. Results: In all of the patients, ventral region of the lungs, especially cranial and middle lung lobes were involved and the involvement of the left lungs was prominent. The mean HU of the unhealthy lung parenchyma before contrast medium study was between 31 and 39, and after contrast study was between 46 and 70. It means the HU has been significantly increased. Also, the contrast of the involved lung regions was increased which helped to differentiate the unhealthy lung tissue from the adjacent soft tissues. Hematology tests in all of the patients were representative of infection. Conclusions: Both CT-scan and CT assisted FNA from the lung are beneficial and practical methods for the diagnosis of pulmonary disorders such as pneumonia

BACKGROUND: The sources of fish oil for use in aquaculture is limited and different oil sources vary in fatty acid composition. OBJECTIVES: The main objective of this experiment was to determine the effects of plant oil sources such as soybean and canola oils with or without L-carnitine supplement on some blood biochemical parameters and growth performance of fingerlings rainbow trout. METHODS: In 3×2 factorial experimental design, 180 rainbow trout with 28± 2 g initial body weight were randomly divided into six groups with three replicates and fed two times a day at ad libitum by dietary treatments during 10 weeks. The experimental diets contained three dietary oil sources such as fish, soybean and canola oil; and two supplemental dietaries L-carnitine levels (0 and 1 g. kg-1). Feed conversion ratio, specific growth rate, feed intake, body weight gain and blood biochemical parameters of fish such as albumin, total protein, triglyceride, cholesterol and high-density lipoprotein (HDL) were measured at the end of the experiment. RESULTS: Replacement of fish oil by soybean and canola oil had no significant effect on growth performance such as body weight gain, feed intake, feed conversion ratio, specific growth rate, hepatosomatic index, carcass weight and condition factor of fish. L-carnitine supplement significantly improved weight gain and feed conversion ratio and increased condition factor of fish (P<0. 05). Soybean oil significantly increased cholesterol and triglyceride level, and canola oil decreased HDL and globulin level in blood serum of fish (P<0. 05). CONCLUSIONS: Results of this study showed that fish oil could be wholly replaced by soybean or canola oil in the diet of rainbow trout and also physiological responses and growth performance of fish to carnitine supplement were affected by dietary oil sources.

BACKGROUND: Extensive effort is focused on identifying genomic conserved antigens in development of effective vaccine against Enterotoxigenic Escherichia coli. Antigen 43 is one of the members of a large secreted protein family named autotransporters in the E. coli and other gram negative bacteria. Autotransporter proteins have a similar conserved structure. Some of them are recognized during both experimental and naturally occurring ETEC infections. Antigen 43 is represented as a potential target in vaccine development because of its virulence functions such as cell aggregation, biofi lm formation and its presence in convalescent sera from human patients with ETEC diarrhea. OBJECTIVES: In this study, we carefully investigate antigenic structure and immunogenicity of the Antigen 43 protein of strain 510 E. coli isolated from calves by experimental methods and immunoinformatics tools. METHODS: Amino acid sequence, physico-chemical parameters, stability, secondary and tertiary protein structure, the ability of induction the B and T cell immune responses by having the effective epitopes and also the allergenicity assessment were analyzed. RESULTS: In this study, we identified 15 peptide sequences that can potentially induce B and T cell immune responses and finally, 9 of them were introduced as antigens. CONCLUSIONS: The results of in-silico analysis on this protein suggested that it can be used in bovine colibacillosis vaccine development.

BACKGROUND: The mechanism of pathogenesis and the role of virulence factors of avian pathogenic E. coli is still ill-defined. The ostrich industry is expanding, resulting in the interaction between poultry and ostrich. It is reported that the investigation of iss and bor virulence genes together, due to their structural and functional similarities, is valuable. Objectives: The investigation and comparison of presence of two genes involved in serum resistance, iss and bor, in E. coli isolated from apparently healthy ostriches and poultry with colibacillosis. Methods: As a cross-sectional study, E. coli was recovered from fecal samples of apparently healthy ostriches and poultry with colibacillosis, and iss and bor genes were screened and compared via PCR in E. coli isolates. Results: iss frequencies, with no statistical difference, were 50% and 64. 4% in E. coli isolated from apparently healthy ostriches and poultry with colibacillosis, respectively (P>0. 05). 31. 8% and 15. 6% of E. coli isolated from apparently healthy ostriches and poultry with colibacillosis were positive for bor, respectively, with no statistical difference (P>0. 05). 11. 1% of isolates from colibacillosis and 18. 2% of isolates from apparently healthy ostriches feces, with no statistical difference, were positive for both genes (P>0. 05). Conclusions: Equal statistical distribution of both genes, bor and iss, between apparently healthy ostriches and poultry with colibacillosis and the health level of studied ostriches indicated that E. coli isolated from ostrich, probably employs other virulence factors instead of bor and iss to establish a disease. This hypothesis needs to examine more virulence genes in ostrich-origin E. coli. In addition, the ostrich feces could be introduced as a source of iss and bor genes.