مجله تحقیقات دامپزشکی
سال شصت و نهم شماره 4 (پاییز 1393)

Bovine viral diarrhea virus (BVDV) causes significant economic and health effects in cattle farms. Because of the relative inefficiency of BVDV eradication programs، in recent years، numerous strategies such as anti-viral gene therapy has been used extensively to fight it. One of the ways to evaluate the quality of these anti-viral strategies is the study of their efficacy in the specific cell lines expressing those viral genes through the induction of gene expression by transfection of plasmids or infection of viral vectors. This study was performed for preparation of a cell line expressing some portions of BVDV genome to evaluate the efficacy of preventive and therapeutic strategies against this virus. After the culture of BVDV NADL، vRNA was extracted and proliferation of 5''UTR and NS3-coding genes and cloning of these gene segments was performed in the upstream of GFP gene in pWPI-linker B lentivirus plasmid. After confirmation of cloning، lentiviral vector containing BVDV-NS3 and BVDV-5''UTR were generated in 293T cells using third-generation packaging system. Then MDBK cells persistently express 5''UTR and NS3 were generated by the infection with lentiviral vectors containing BVDV-NS3 and BVDV-5''UTR. The efficacy of infection with lentiviral vectors carrying transgenes، examined by fluorescence microscopy، Western blotting and RT-PCR tests، were compared with control groups and the presence and expression of the above mentioned genes were confirmed. The results indicate that the successful production of a MDBK cell line expressing both genes of BVDV and lentiviral vectors are preferred to the others for their persistent and long-term gene expression in several cell generations and the ability to infect many different cell lines.

Bovine mastitis is the most costly disease in dairy cows and causes significant decrease in milk production. This disease is one of the main reasons of antibiotic therapy in dairy cows. Staphylococcus aureus is counted as a major pathogen associated with the outbreaks of mastitis in dairy herds. Therefore, the purpose of the present study is to examine the antibacterial activity of nanosilver against Staphylococcus aureus isolated from subacute mastitis in cow. The MIC was calculated by a broth microdilution method, and the MBC was measured by subculturing the bacteria from the wells that showed no apparent growth onto Mueller-Hinton agar. For the in vivo experiment of the current investigation we injected 25 µg/mL of nanosilver for 5 days treat mice contaminated with Staphylococcus aureusisolated from subacute mastitis. The results showed that the MIC and MBC of nanosilver for Staphylococcus aureusisolated from subacute mastitis was 5µg/mL. In addition, the results of the present study demonstrated that the time of the antimicrobial action of nanosilver against Staphylococcus aureus is 7 minutes after adding nanoparticles of silver. Also 5 days treatment with 25 of nanosilver treated contaminated mice with Staphylococcus aureus isolated from subacute mastitis. These in vitro and in vivo results clearly indicate that the nanosilver might have a good antibacterial activity against Staphylococcus aureus.

Boophilus tick is responsible for the transmission of some pathogens (types of germs) and the reduction of fertility in Cattles. Tropomyosin protein plays an important role in regulating actin function, immune and allergic reactions and vaccine production. Accurate identification of antigenic determinants (epitopes) is difficult, time consuming and not economic, thus we focused on development of rapid methods such as prediction based on sequence and structure of protein. A wide array of Immunoinformatics softwares and tools were used for the analysis of antigenicity, frequency in protein secondary structure and domains, physic-chemical factors related to region of linear epitopes, B cell epitopes, and binding peptide segments to MHC II alleles in cattle. Protein analysis with different algorithms and evaluated accuracy of our result with different profiles of protein results in 3 selected epitopes (AA62-80(NH2-EQLSQANSKLEEKDKALQA-COOH), AA170-185(NH2-AMVEADLERAEERAETG-COOH) and AA200-218 (NH2-VGNNLKSLEVSEEKALQKEET-COOH)) for B cell and a epitope AA192-207(NH2-LEEELRVVGNNLKSL-COOH) for T cell. For desirable stimulation of immune system, only some segments of protein (epitopes) are enough. Selecting efficient epitopes causes concentration immune responses, preparation suitable vaccine and reduces allergic and adverse responses.

Colibacillosis in poultry, reduces growth and performance, increases mortality and causes economic losses. An experiment was conducted to study the effect of egg yolk powder and antibody (IgY) on intestinal morphology and reduction of bacterial colonization in broilers infected with E. coli. Ten laying hens were immunized with E. coli O2: K1. The eggs were collected for providing IgY antibody and egg yolk powder with freeze dryer. In the second experiment,180 day-old broilers were randomly divided into 6 treatment groups with 3 replicates of 10 birds per replicate including: (1) positive control (challenged with E.coli but did not receive antibody); (2) negative control (did not challenge with E.coli and did not receive antibody); (3) the group was challenged with E.coli and received 0.4% yolk powder; (4) the group received specific antibody in drinking water and challenged with E. coli; (5) the group received specific antibody in drinking water; (6) the group received 0.4% yolk powder in diet. All groups received the same dietary energy and protein. FI, WG and FCR were measured on weekly basis. On days 21 and 42, one bird per pen was euthanized, samples of jejunum were collected for histo-morphological examination and samples of ileal contents were collected for E. coli O2: K1 enumeration. The results indicated that number of E. coli in positive group was significantly higher than other groups. Number of E. coli in ileum of the birds which received antibody in drinking water or fed with diet supplemented with egg yolk powder was significantly lower than the other infected groups (p|£|0.05). Using specific antibody improved intestinal health compared to positive control group. According to results of this experiment it can be concluded that using E. coli specific antibody in food or water of chickens reduces intestinal colonization of this bacterium.

Toxocara canis is one of the most frequent small intestinal helminths of dogs with zoonotic importance through which the soil is contaminated with the eggs through the fecal excretion. This study was carried out to determine T. canis infection in dogs and soil of public parks of Piranshahr city using fecal examination. In the present study, a total of 150 feces and 150 soil samples were randomly collected from Piranshahr city in the period April 2012 to April 2013. The specimens were subjected for floation using Clayton-lane method. The average rate of infection in examined dogs and soil was respectively 31.3% and 8%. The infection in stray dogs, sheepdogs and watchdogs were respectively 32.14%, 25.7%, 33.89%. The infection had significant difference between age groups of <1 year-old (54.54%) and >1 years-old (22.44%) (p<0.05). The infection rate in male dogs (38.46%) was significantly higher than female dogs (25%) (p<0.05). The highest infection rate was in spring (42.1%) and the least in fall (24.32%) (p<0.05). The average egg number per gram of feces (EPG) and soil were 2195.7±983.7 and 5±3.6, respectively. The EPG had significant difference with examined animals. Of 150 examined soil samples, 12(8%) were positive for eggs of T. canis. The highest infection rate was found to be from soils of slaughterhouse area (16%, EPG 5±3.6) (p<0.05). The highest infection rate was in spring (13.15%) which had significant difference with other seasons (p<0.05). The results showed that T. canis was parasite in dogs and soil of different areas of Piranshahr city in which it could be of public health concern in the region.

The purpose of dehorning in cattles is to decrease injuries and increase security in farms. Besides breeding managements, different chemical and physical methods are used for dehorning of livestock, depending on their age, each of which has advantages and disadvantages. This study was performed to evaluate the effects of clove oil on disbudding new born calves following injection under horn bud. 12 five-day-old healthy calves from both sexes were divided randomly into 3 equal groups. In group 1 (T) 0.5 mL of clove oil, in group 2 (Control / C) 0.5 mL of dimethylsulfoxide (DMSO) and in group 3 (N) 0.5 mL of normal saline was injected under left horn bud. Right horn bud in all calves was considered as control group 4 (B) to ensure that all calves are horned. During the study, the rate of horn growth and clinical parameters (Temperature/Pulse/ Respiratory rate) in calves was evaluated in determined time intervals between groups. In the current study, injection of the clove oil stopped horn growth but there were no significant differences in horn growth rate between groups C, N, and B. Injection of clove oil, DMSO and normal saline had no significant effects on clinical parameters, significantly. According to the results of this study, injection of clove oil under horn bud can be an effective method to stop horn growth without any undesirable effects on clinical parameters.

Searching for factors that reduce the adverse effect of heat stress (HS) on broiler performance has particular importance. The present study was designed to investigate the influence of dietary melatonin, gamma-amino butyric acid (GABA) and dark period on growth performance, carcass characteristics and blood parameters of broiler under heat stress condition. A total of 143 one-day-old chickens (broiler line Arian) were used in an unbalanced completely randomized form with 4 treatment, 13 experimental units and 11 birds per experimental unit. The treatment consists of 40 mg of melatonin/kg diet from the age of 30 to 40 days, 100 mg (GABA)/kg diet from the age of 10 to 40 days, dark of period from 10 to 40 days of age and control. All treatments were kept a circular HS (40±1°C) for 6 h from 35 to 40 post hatch. Weekly growth performance of chickens was determined and blood samples were taken, on days 10, 30 and 40 of age for measurement of glucose, cholesterol, triglyceride, HDL and LDL parameters. On days 35 and 38 of age T3, Thiobar Butyric Acid Reacting Substances (TBARS) and corticosterone parameters were measured. Data were analyzed by using of GLM procedure of SAS. The diet supplementation of GABA increased feed intake in the second (p<0.01) and third (p<0.05) weeks of age. Dark period reduced body weight in the third weeks of age (p<0.05). The treatment of GABA in the fourth week increased body weight compared to the control group (p<0.01) and a significant decrease for FCR was observed in the fourth weeks (p<0.01). Addition of GABA in diet increased serum glucose at 30 days of age (p<0.01), in the both melatonin and GABA treatment groups serum HDL was increased at 40-day-old (p<0.01). Control chickens showed significantly (p<0.01) higher TBARS compared to the experimental group birds at 38-day-old. The results demonstrated that dietary GABA had the most beneficial effects in reducing the adverse effects of heat stress on the broiler chicken.

In recent years, immunocompromised patients are at high risk for the development of invasive aspergillosis. Due to the increase of antimicrobial resistance, natural agents with medicinal and immunomodulatory effects has gained more attention. Honey is a natural substance with documented antimicrobial, anti-inflamatory and wound healing effects. The purpose of this study was to evaluate the effect of three Iranian kinds of honey on Killing Power and Nitric Oxide Production in Peritoneal Macrophage in BALB/c mice. Male BALB/c mice were gavaged with three different kinds of honey for a 10-day period. Then the mice were euthanized and their peritoneal macrophages were cultured. Macrophage killing and nitric oxide production was evaluated. Our results showed that honey could significantly increase the killing power of macrophage which was significantly higher than in control group (p<0.05). Nitric oxide production in groups treated by northern and central honey was lower than the control group, whereas in groups treated by southern and mixed honey nitric oxide production was significantly higher than control group (p<0.05). LPS stimuli had no significant effect on neither macrophage killing nor nitric oxide production (p>0.05). In conclusion, honey could act as an immunomodulator during Aspergillus fumigatus infections.

Shell is one of the most important by-products of shrimp processing methods which can potentially pollute the environment, whereas shrimp shell contain large amounts of chitin and chitosan and can be used as immune and growth stimulator in aquaculture. The purpose of present study was to investigate the effect of oral administration of chitosan extracted from Litopenaeus vannamei's shell on some hematological and growth factors of common carp. Shrimp shells were collected from shrimp processing plants and chitosan was extracted. Then 300 common carp were divided into 4 equal groups in 3 trirepcats (12 aquarium totally). Fish were fed with basal food supplemented with 0% (as control group), 0.25% (G2.5), 0.5% (G5) and 1% chitosan (G10) for 60 days. Blood samples were taken every 20 days from each group during the experiment. Samples were used for hematological parameters include: WBC, RBC, PCV, Hb, leukocyte differential count and globular indices (MCV, MCH and MCHC). At the end of study growth indices include: Specific Growth Rate, percentage weight gain and Food Conversion Rate were calculated. The results showed that oral administration of chitosan in different dose didnt affect hematological parameters of Common carp (p>0.05). Meanwhile results indicate that all growth indices improved in G10 compare to control (p<0.05). FCR and SGR in G10 treatment were 2.98±0.64 and 0.60±0.09, versus 3.82±0.30 and 0.44±0.04 in control group, respectively. Lower concentration of chitosan (0.25% and 0.5%) induced no significant change in growth indices of fish (p>0.05). Although Chitosan extracted from white leg shrimp in concentration of 1% improved growth indices of common carp, no significant impact were seen in hematological parameters. Therefore, 1% chitosan can be used as a growth stimulant in Common carp.

The loop pattern of the small intestine is of considerable importance in categorizing them and the intestine length of the two sex is different. In this respect there is no research performed on pheasant family as guinea fowl. In this research histomorphology of guinea fowl's small intestine was studied. For this study 20 adult male and female guinea fowls were selected and their small intestines were studied morphologically. For each guinea Fowl, a tissue sample was obtained and prepared using Haematoxylin and Eosin Stain Kit. Macroscopic results suggest that they are basically much akin to other poultry with this difference that in guinea Fowl there are less loop patterns in Jejunum. From the microscopic point of view, guinea fowl's small intestine mucosa membrane does not include internal Plicae circulars, but there are villi (made of mucus) instead. The outer edge of the villus is formed of simple columnar epithelium with a few Goblet cells. In the Ileum goblet cells are reduced as we reach the end of it. CONCLUTIONS: Intestines in both sex have the same length and structure and loop patterns are straight and few in numbers.

The Persian Squirrel (Sciurus anomalus) is a member of the family Sciuridae in the Middle East and very little information is available about the anatomy of the different organs of this animal. In this study, histological and macro anatomical structures of penis were examined on 6 adult male Persian squirrels. Each animal was sacrificed after anesthesia with ketamine and xylazine then dissected openwith the penis exposed from its root. The penises were first grossly examined, and then root, body and free part of peniswere studied, using histological technics and staining H&E, TCM and Verhoeff. Grossly, the color of penis was bright pink andthemean length of that was 5.87 ± 0.68 cm. A caudo-ventral curvature separates the free part of the penis, i.e.the glans in the middle part and the nail in the head part, from the body part. Histologically, the ducts cooper are branched after entering in penile bulb and make a large glandular structure in the bulb, then as a single duct continue along the body of penis with urethra and below it continue up to the free part. Two corpora are confluent in the body and form a uniform and crescent of corpus cavernosum that surrounded by tunica albuginea and converted to os penis in the free part. Therefore, from a histological standpoint, the Persian squirrel penis belongs to the intermediatetype. These findings provide vital information on the penile anatomy of the Persian squirrel, which will serve as a basis for comparing penile morphology among thesuborder hystricomorpha and expand knowledge of the reproductive biology in this animal.

Tetraploid rainbow trout has a key role in producing infertile triploid fish by indirect method and introducing them in cultivation system. The purpose of the present study was to determine the optimal heat shock for tetraploidy induction in rainbow trout with emphasis on egg size. The efficiency of different shock temperatures: 28, 30 and 32 °C, durations: 1, 5 and 10 min and starting time: 45, 55, 65, 75 and 85 degree-hour post fertilization (dhPF) on two different egg size diameters (4.2 ± 0.12 and 5.5 ± 0.20 mm) for tetraploidy induction in rainbow trout were analyzed. Tetraploidy rates were determined using red blood cell sizes as well as number of nucleolar organizing regions (NORs) at swim up stage. Tetraploidy rates were in the range of 18-69 and 18-76 % for the groups of eggs over and less than 5 mm in diameter respectively. The statistical analysis showed that the highest tetraploidy efficiency (13%) for the larger egg size achieved by treating eggs at 28°C, for 10 min starting at 65dhPF. While for the smaller egg size, the highest efficacy (7%) was observed in group treated at 28°C, for 5 min starting at 75 dhPF. Although tetraploidy induction has been done previously in rainbow trout, for the first time, the results of this study showd that tetraploidy efficacy was affected by egg size as well as other shock related parameters.

Snow trout (Schizothorax pelzami) is an economically important species endemic in the north east of Iran. The purpose of the present study was to investigate the reproduction cycle, time and temperature range of spawning. The biometry of 243 fishes was measured and the ovarian development stages and plasma sex steroid hormones (testosterone, 17b- estradiol, progesterone and 17a-OH-progesterone) were measured during 12-months sampling. The (p<0.05) maximum significant gonadosomatic index (10.3 %) and ova diameter (1605.6 mm) were observed during April. The results showed that the concentration of sex hormones testosterone and 17b- estradiol began to increase significantly (p<0.05) during cortical alveoli stage (in September) and reached the maximum level (6.99 and 143.4 ng/mL, respectively) in February with the mean water temperature 13 oC at the end of vitelogenesis stage. The progesterone concentration began to increase at the end of vitellogenesis stage and reached (p<0.05) maximum significant level (3.49 ng/mL) in March. The concentration of 17a-OH-progesterone increased significantly (p<0.05) with a lag phase compared to progesterone in February. The results of present study showed that snow trout had a single-spawning strategy and sex steroid hormones testosterone and 17b- estradiol involved in the vitellogenesis stage and progesterone and 17a-OH-progesterone involved in the final ova maturation. The best spawning time was within March to April with temperature range 15.7-17.3 oC.