مجله تحقیقات دامپزشکی
سال شصت و هشتم شماره 3 (تابستان 1392)

The poultry red mite، Dermanyssus gallinae is the most important ectoparasite in domestic poultry. Some plant preparations have been shown to be an effective acaricide against it. The acaricidal effects of cinnamon، mint، and eucalyptus extracts were studied. Mites were counted in the monitoring traps for the first time in a layer house with a history of D. gallinae problem. Then، some rows of layer house were sprayed using a concentration of 27. 50 mg/Cm3 cinnamon، 28. 30 mg/Cm3 mint، 63 mg/Cm3 eucalyptus extracts and a similar row was used as an untreated control group. Red mite traps made of cardboard were used to assess the mite density during days 1 and 7 after treatment and removed after 24 h. The collected mites were counted and the efficacy against all mite stages (larvae، nymphs and adults) was calculated. Results showed that on day 1 and 7 after the administration of cinnamon extract، efficacy rate was 66. 97% and 12. 91%، respectively. Moreover، efficacy rate on day 1 and 7 was 80. 85% and 58. 14% when treatment was done with eucalyptus extract، 90. 19% and 40. 24% with mint extract. Also، statistical analyses showed significant differences between trapped mites during the first day after plant preparations treatment and control group. But this study did not show significant differences between trapped mites during the firts week after plant extracts treatment with the exception of eucalyptus. It can be concluded that plant preparations can be used for controlling poultry red mite.

Mass mortality of Caspian seal has occurred in recent years and canine distemper virus (CDV) has been identified as the main pathogenic agent in these events. Despite the repetition of this event and the presence of a large number of dead seals in the coastal region of the Caspian Sea، very little is known about the epidemiological role of these animals in canine distemper virus survival in this area. In this study the frequency of antibody against CDV in unvaccinated rural dogs in the southeast coastal region of the Caspian Sea (Iran) was evaluated by means of serum neutralization test. Serum samples (185) were randomly collected from rural dogs from 2008 to 2010. Totally the frequency of positive antibody reaction in animals against CDV was found to be 55. 6% (103/185) in 1/32 dilution (CI%95:47-61). In this study no significant difference in susceptibility was observed between males and females and among different age groups. Moreover، most of the positive cases were observed during the winter. These results indicate that this virus is present in the ecosystem. Furthermore، there is evidence of previous natural exposure to CDV. This high frequency of antibody in serum samples might be because of previous contact with CDV contaminated corpse of Caspian seal. Dogs'' population in rural areas is dense enough to maintain CDV in environment and rural dogs can be a reservoir of infection for urban dogs and wild carnivores.

Colibacillosis due to Escherichia coli is one of the most important infectious diseases in poultry. While the influence of E. coli virulence factor in birds may differ due to interactions with other influential factors، the sole presence of such factors in E. coli does not determine its pathogenicity. Therefore، it is necessary to test the pathogenic capability of E. coli isolates on susceptible birds. The purpose of this study was to determine the virulence of three E. coli isolates from colibacillosis and compare their effects on day-old chicks using a lethality test. Seventy 1-day-old chicks were divided into 3 treatment groups of 20 chicks and 2 control groups of 5 chicks. Each treatment group was assigned to one E. coli isolate and divided into 4 sub-groups of 5 chicks. The overnight broth culture of each E. coli isolate was washed with PBS three times and diluted. Then، 0. 5 ml of undiluted culture (~109 CFU/mL)، and the dilutions of 0. 1، 0. 01، and 0. 001 of each culture were injected subcutaneously to each of the 5 birds in each subgroup behind the neck. One group of 5 birds was injected by PBS while negative control group did not receive anything. The chicks were monitored every 12 hours for 6 days. The dead chicks during the course of the experiment and all survived ones were necropsied and samples were taken from hearts and livers for bacteriological culture. Virulence of each E. coli isolate was evaluated based on a scoring system developed on death time، gross pathological observations، and bacteriological findings. All E. coli isolates of this study were capable of causing mortalities and producing the lesions typical of colibacillosis. There were no significant differences among the three E. coli isolates in their in vivo virulence abilities but the difference between each of the three E. coli isolates and each of the two control groups was significant (p|||£|0. 05). This study determined that our E. coli isolates were able to cause mortalities in day-old chicks. These findings increased our knowledge on the virulence characteristics of three Iranian E. coli isolates originated from avian colibacillosis.

Anemia is a common disorder in domestic pet animals، usually encounter-ed in veterinary clinics. The objective of this study was to evaluate the hematological and serum biochemical parameters of the anemic dogs and to show practically the value of measuring the corrected reticulocyte percentage (CRP). A survey was conducted on 500 dogs which referred to small animal hospital of the faculty of veterinary medicine of Tehran university. From this population، a group of 139 anemic dogs was selected with PCV less than 37% and 20 healthy dogs as control group. They were examined for the hematological parameters (RBC، Hb، PCV، MCV، MCHC، RDW، WBC، PLT، Dif، reticulocyte percentage and corrected reticulocyte percentage) and serum biochemical factors (Fe، alanine amino transferase activity،creatinine، total protein and glucose). The anemic dogs were divided into 3 anemic groups based on MCV and MCHC: microcytic hypochromic (1. 44%)، microcytic normochromic (21. 59%) and normocytic normochromic (76. 97%). A comparison survey was conducted between the results of the 3 anemic and control groups by one way ANOVA and Tukey test. The measurement of hematological parameters indicated that RBC، Hb and PCV decreased significantly in all anemic dogs. The results showed that RDW of microcytic hypochromic group increased significantly compared to control. The reticulocyte percentage of all anemic groups was significantly different from control group، but calculation of CRP showed there was only significant difference between normocytic-normochromic and control groups. One way ANOVA indicated that serum Fe in microcytic-hypochromic group and serum creatinine in normocytic-normochromic group significantly decreased and increased، respectively. Total protein of all groups is significantly decreased compared to control group. There were no significant changes for the other parameters. Based on the result، it is suggested that CRP and biochemical parameters be measured such as: creatinine، total protein، ALT and glucose in addition to CBC، in all anemic dogs.

To improve the oxidative stability of meat products، the use of the dietary form of natural additives، especially those with plant origin is increasing. Aloe vera plant، the in vitro antioxidant effect of which has been previously discussed، is a potential candidate for this purpose. This study was designed to evaluate the effects of feed sup-plementation with Aloe vera gel extract on lipid peroxidation of broiler breast fillets during frozen storage. Fifty-four 1-day old broilers were allocated into three groups (basal diet as control، basal diet supplemented with 100 and 300 mg/kg methanol extract of Aloe vera gel) and fed for 6 weeks. In the term، chicks were slaughtered and their breast fillets were stored at -20°C for 9 months. Lipid peroxidation was assessed after 1، 3، 6 and 9 months of frozen storage using chemical (PV and TBARS) and sensory evaluations. Results indicated that incorporation of 300 mg/kg Aloe vera gel methanol extract in broiler diets caused the delay of lipid peroxidation in raw breast meat (with 9. 6 meq/kg، 92. 67 µg/kg and 6. 3 in PV، TBARS and Sensory evaluations، respectively) in comparison with control sample (with 15. 2 meq/kg، 139. 33 µg/kg and 3 in mentioned evaluations) at the last day of the experiment (p<0. 05). This study showed that methanol extract of Aloe vera gel can be considered as a dietary supplementation substance in chicken diet and can delay the oxidative spoilage of chicken breast fillets during frozen spoilage.

Essential oils (EO) are antimicrobial compounds، but may be beneficial under unfavorable nutritional and environmental conditions. Essential oils produced in Iran are of comparable quality to imported ones.

The aim of this study was to compare the effects of Orego-Stim (Essential oil based on Oregano; 0. 5 g/kg; imported) and Anti-Biophin (Essential oil based on Thyme; 1 g/kg; local) essential oils on performance and precaecal digestibility of nutrients in broiler chicks fed barley-corn based diets with and without b-glucanase (0. 05 g/kg).

At the beginning of the second week of rearing period، 192 chicks of mixed sex were allotted into six groups of four replicates with eight chicks per replicate according to a 2×3 factorial experiment arranged as a completely randomized design.

Inclusion of Orego-Stim or Anti-Biophin in barley based diets caused a significant (p<0. 05) improvement in total feed conversion، final body weight and nutrients digestibility، without a significant effect of b-glucanase addition to the diets. The type of essential oils (imported vs. local) did not affect the measured characteristics.

Feeding broiler chicks with barley based diets، supplemented with essential oils، decreased the anti-nutritional effects of barley grains in these diets and improved broiler performance، without the need to supplement the barley-based diets with b-glucanase. Because of the lack of any significant difference between the imported and locally-produced essential oils، and the higher cost and scarcity of the imported EO، domestic products such as Anti-Biophin at recommended levels can replace the imported ones.

Siamese fighting fish (Betta splendens، Regan، 1909) is a freshwater fish native to southeast Asia that has attracted considerable attention in Iran as an ornamental fish. The purpose of this research was karyotyping of this fish by in vivo method as well as its Ag-NOR chromosomal banding. Chromosomal spreads were obtained from hematopoietic (head kidney and spleen)، gill and testicular tissues by splash and squash (stamping) methods on cold slides، which were then stained by 25% Giemsa. In addition، sequential staining nucleolus organizer regions (NORs) were performed by Ag-NO3 staining. Chromosome number in diploid and haploid cells in this species were counted 2n=42 and n=21، respectively. Fundamental number was NF=68. 4 pairs of NORs which were found in methaphase plates. Chromosomal formula consisted of 1 pair of metacentric، 3 pairs of submetacentric، 9 pairs of subtelocentric (acrocentric) and 8 pairs of telocentric chromosomes. The chromosomal formula was similar in both sexes، however، comparing male and female karyotypes، the chromosome pair number 17 was heteromorphic. In this study، the number of chromosomes (2n) was similar but chromosomal formula and arm number (FN) were different from those in the previous studies. Metacentric chromosomes (pair 1) and presence of a pair of heteromorphic chromosomes in the two sexes (pair 17) are reported in this species for the first time. In the case that chromosomes pair 17 are sex chromosomes، a WZ sex determination system can be suggested for this species where females are heterogametic (WZ) and males are homogametic (ZZ) sexes.

Common carp (Cyprinus carpio) fishes during release into the rivers estuary of the Caspian southern basin are generally exposed to a broad spectrum of agri-cultural pesticides. The objective of this study was to investigate the effects of three agricultural pesticides including Malathion، Carbaryle and Glyphosate on C. carpio in lethal level by determining LC50 96h and sub-lethal levels via cholinesterase (ChE) activity. The median lethal concentration using a standard method which is called OECD No. 203 (1992)، was measured. About 300 fingerlings with average weight of 2. 0 ± 0. 4 g were randomly selected and were then exposed to each pesticide in three treatments (0. 1، 0. 2 LC50 96h and negative control) in three replications. 5، 10 and 15 days after the test period، sampling from the head and body of fishes was carried out. The ChE activity was assayed with biochemical method described by Ellman. The LC50 96h for three glyphosate، malathion and carbaryle pesticides were obtained as 6. 75، 1. 3 and 12. 67 mg/L، respectively. The mean values of ChE for both head and body under control conditions were found 1241. 356 and 723. 103 mU/min/mg protein، respectively. Therefore، the ChE activity of head was 1. 7 times more than the body. During the test period، inhibition activitiy of ChE was significantly observed in the fishes treated by any of three components in comparison with control (p<0. 05). The ChE inhibition potential by carbaryle and glyphosate was lower than malathion as compared with control. The exposure time concentration exhibited a significant effect compared to the fishes treated by the investigated pesticide types. The used pesticide concentrations for non-target species which were ineffective and permissible according to the lethality bioassay test can lead to their enzyme responses and bio-damages.

To determine histomorphological changes of ureter and kidney following experimental ureteral anastomosis. The aim of this study was to evaluate more details about complications arising from ureteral anastomosis in dogs. Five healthy mongrel dogs weighing between 15-30 kg were used. Anesthesia was induced by acepromazine and thiopenthal sodium and maintained by halothane in oxygen in a closed circuit. After midline celiotomy، left ureter near trigon area was incised and immediately end to end anastomosis was performed in simple interrupted pattern by using polydiaxanon 6/0. All animals were euthanized at day 90 after operation and the ureters and their related kidneys were evaluated both macroscopically and microscopically. The gross observations of the ureters showed obstruction (one case) and mild hydroureter (three cases). Microscopically، hyperplasia (in epithelial and muscularis layers)، fibrosis (lamina properia-submucosa and serosal layers) and different phases of inflammation and repair (in lamina properia-submucosa، muscularis and serosal layers) were observed in the ureters. Histological sections in the related kidneys revealed hydronephrosis in one case. Although ureteral anastomosis is technically difficult in small animals and has a high rate of postoperative obstruction، in case of transected or damaged ureter، ureteral reanastomosis is one of the options for veterinary surgeons. In the present study، in spite of some complications، the anastomosis has been performed successfully in 80 percent of animals and certainly meticulous surgery is mandatory to prevent ureteral obstruction.

Evaluation of clinical signs and pathological lesions could be very important for recognition of nervous system diseases in cattle and buffaloes. This study was carried out to understand the nature of pathological conditions affecting brain of cattle and buffaloes in an abattoir study. 46 samples out of 850 samples (37 cattle، 9 buffaloes) which showed various macroscopic lesions were collected for detailed examination. The specimens were ginned processed through routine method for paraffin embedding section (5-7micron)، stained by haematoxilyin and eosin method. Congestion and hemorrhage (8 cows، 9 buffaloes); pigmentation (4 cows); chromatolysis (4 cows، 2 buffaloes); gliosis (4 cows، 1 buffalo); vacuolization of the white matter (4 cows); necrosis (6 cattles، 2 buffaloes); cerebellum edema (3 cows); perivascular cuffing (4 cows، 3 buffaloes); blood vessels hyperplasia (3 cows); coenurus cerebralis (3 cows); encephalitis (9 cattle، 1 buffalo); mineralization (5 cows); meningeal hemorrhage and congestion (10 cows، 9 buffaloes); meningeal edema (2 cows); meningitis (7 cows); cerebral congestion and hemorrhage (1cow، 5 buffaloes); degeneration of molecular layer (2 cows); degeneration of granular layer (3 cows) Purkinje cells degeneration (cows 4، 1 buffalo). Multiple lesions in the central nervous system have been observed in apparently healthy animals without clinical signs. Considering the importance of ruminants encephalopathy and comparing these results can be a basis for further study.

Bovine viral diarrhea (BVD) and infectious bovine rhinotracheitis (IBR) are two of the most important diseases responsible for major economic losses in the Iranian dairy industry. Since there are not in-house vaccines، the evaluations of the effectiveness of imported commercial vaccines are imperative. The purpose of the present study was to assess the clinical effectiveness of commercial inactivated Bovine viral diarrhea virus (BVDV) and Bovine herpes virus type 1 (BHV-1) vaccines to reduce the occurrence of culling and diseases، as well as their impact on milk production and prevention of birth of calves persistently infected (PI) with BVDV. A blind randomized controlled trial was performed. Animals were assigned to treatment (n=342) and control (n=351) groups by systematic randomization. Animals in the treatment group were inoculated with inactivated BVDV and BHV-1 vaccines (Intervet-Schering Plough). One and seven months later، vaccination was repeated. Over a one-year period، the incidence of disease، death and culling، birth of PI calves and milk production were recorded and compared. All statistical analyses were done with IBM SPSS statistics 20 software. At the start of the study، the two groups showed no significant differences in the means of age (day)، parities، days in milk، milk production and preexisting antibodies of BVDV and BHV-1. In addition، significant difference was not observed between treatment and control groups during the period of study. Unlike previous years، there were no reports of BHV-1 respiratory disease and birth of PI calves in the herd as a whole. Although the efficacies of the mentioned vaccines were approved previously، effectiveness was not augmented in our study. Evidence-based Vaccinology in the developing countries should be performed by implementation of effectiveness studies.

Braxy vaccine، a culture of a suitable strain or strains of Clostridium septicum in a fluid medium، its filtrate or derivatives، will be inactivated so that it produces its immunogenic activity without toxicity. Production of C. septicum vaccine (Braxy vaccine) using enriched culture media in fermenter. Conventional and enriched culture media were used for growing C. septicum (CN913) vaccinal strain in both 10 liter glass bottle and fermenter، in a triplicate manner. All twelve experiments were inspected to ensure compliance with the requirements of the vaccine international standards for minimum lethal dose (MLD)، sterility، freedom of abnormal toxicity، safety and potency tests. Results showed that the culture of C. septicum in fermenter using enriched culture media is the best. Based on international standards، 2. 5IU/mL was determined for C. septicum alpha toxin potency test، but in this study 4IU/mL was obtained. Using enriched culture media in fermenter is suitable for braxy vaccine production.

Within a few consecutive days، 8 cases of lambs'' mortality were reported from the Golestan National Park area (Golestan province). According to the farmer''s claims، the disease has occurred only in less than one year old lambs whose major feeding was free grazing in the oak rich areas and also collected and manually feeding with new and fresh buds of this tree. Ascites، hydrothorax، hydropericarditis، intestine، abomasum and mesenteric subserosal accumulation of fluid، and swelling of the kidney with cortex hemorrhage was observed in necropsy. Microscopic pathology revealed tubular and glomerular nephritis with tubular hyaline casts and mucosal necrosis with submucosal and serosal edema of GI specimens. Based on available epidemiological data، macro and microscopic pathology، oak poisoning is the most likely cause of mortality in this flock. It seems the major cause of mortality is the high sensitivity of these young animals and furthermore، the farmers insistence on feeding them the fresh buds of this tree.