فصلنامه دامپزشکی ایران
سال نهم شماره 41 (زمستان 1392)

The aim of this study was determining the prevalence rate, serotyping and sensitivity to antibiotics of Salmonella isolated from slaughtered broiler chickens of Guilan province. Two hundred carcasses were randomly selected out of 20 slaughtered broiler flocks and then 1000 samples were collected from different parts of carcasses (skin, meat, gallbladder, liver and intestine). All samples were cultured in different media, and the isolated Salmonella serotypes were identified. Sensitivity and resistance of isolated Salmonella were determined to 15 antibiotics. Three flocks (15%) and in 8 cases (0.8%) were positive to the Salmonella. Two serotypes were identified, including 6 samples (75%) of Salmonella enteritidis and 2 samples (25%) of Salmonella thompson. Salmonella was isolated from 4 samples of liver (50%), 2 samples of skin (25%) and 2 samples of caecum (25%). In this study, no salmonella was isolated from poultry meat. The results of sensitivity and resistance of Salmonella to antibiotics indicated that, 100% of isolates were resistant to cefazolin, streptomycin, kanamycin, tetracycline, nalidixic acid and sulfonamide + trimetoprim. There were three resistance patterns among the isolates, 100% of isolates were resistant at least to seven antibiotics and 25% were resistant to eight antibiotics from fifteen antibiotics. It is concluded that, the prevalence rate of Salmonella infection was lower than to the other studies, the dominant serotype was Salmonella entritidis and 100% of isolates were sensitive to ceftriaxone, gentamicin and chloramphenicol.

Pulmonary lesions of sheep are particularly important because this animal serves as one of the most acceptable source of red meat and respiratory system plays a critical role in performance of other systems. The aim of this study was to provide a regional picture of sheep lung lesions and determination of their causes as possible. For this purpose, from November 2008 to April 2009, lungs of 4592 sheep in Ahvaz slaughterhouse were examined carefully and 100 affected ones (2.18%) were found and transferred to laboratory for further investigation. Histopathological, bacteriological and parasitological studies were performed routinely on the lungs. Interstitial pneumonia, hydatid cyst, verminous pneumonia, ovine pulmonary adenocarcinoma and bronchopneumonia were the most frequent lesions (relative frequency rates were about 1.31, 1.07, 0.65, 0.5 and 0.44 percent respectively). Viruses, air pollution resulting from industrial activities and intermittent dust storm in the region must be considered as possible causes of interstitial pneumonia in sheep. Corynebacterium pseudotuberculosis was the most isolated bacteria from suppurative lesions. The most isolated nematodes were Cystocaulus ocreatus and Dyctiocaulus filaria that are different from reported species from other parts of the country.

The goal of this study was to compare the effect of different forms of L. casei as a probiotic bacterium on the growth and immunity of rainbow trout. For this purpose, four hundred and eighty rainbow trout (50±6.5 g initial weight) were prepared and acclimatized to the laboratory conditions for 10 days and then the fish randomly divided into four groups. One group selected as control and fed with a commercial diet without any supplementation. Other groups received commercial supplemented diet with live, lyophilized and heat killed forms of L. casei at concentration of 5×108 CFU/gr, respectively. Duration of the study was 45 days and sampling for biometry and humeral immunity (serum lysozyme activity, alternative complement activity and total antibody) were conducted at the day of 0, 15, 30 and 45. Results showed that the amount of final weight, weight gain percentage and specific growth rate statistically (P<0.05) were higher at the fish fed with live (fresh culture and lyophilized) and heat killed form of L. casei than the control. Also, the amounts of these parameters were higher at the fish fed lyophilized form of bacteria than other treatments. Immune assay showed serum lysozyme activity, alternative complement pathway and the level of serum total antibody increased at days 15 and 30 after receiving the different forms of L. case. The elevation of these parameters were significant (P<0.05) in fish fed with the lyophilized form of bacteria than the control. Also, results showed that the activity of lysozyme, alternative complement pathway and serum total antibody decreased in fish fed different forms of bacteria on day 45 (15 days after feeding withdrawal). Based on obtained results, it is concluded that addition of lyophilized form of L. casei into the rainbow trout diet could improve growth parameters and enhanced immunity in this fish.

Somatotropical genes are as transcription factors that have crucial role in chicken growth. Pit1 gene is a pituitary specific transcription factor that has major roles on the differentiation of anterior pituitary and the regulation of the prolactin, growth hormone and thyroid-stimulating hormone-β genes. Pit1 gene is regarded as a key candidate gene for productive traits of chickens. This study was conducted to determine the polymorphism of Pit1 gene exon 6 of west Azerbaijan native chickens using Polymerase chain reaction - Single-strand conformation polymorphism. Blood samples were randomly collected from 100 birds and DNA was extracted from the blood samples. Exon 6 of Pit1 gene encompassing 179 bp was amplified. The PCR products were electrophoresed in 10% polyacrylamide gel and stained with silver nitrate. Based on SSCP analyze of PCR products, three genotypes including AA, AB and BB were identified. The genotypes in this locus deviated from Hardy-Weinberg equilibrium. Shanon index, Nie index and observed heterozygosity were 0.59, 1.67 and 0.32 respectively. On the basis of obtained results it was revealed that the Pit1 gene had high degree of polymorphism which can be considered for future breeding programs.

This study was conducted to evaluate the effect of acetic acid and diet energy on productive performance and intestinal microflora in 216 day-old broiler chicks. Chicks were divided to 2 parts and each part was split into 9 groups (12 birds) after six days. The first and second parts of chicks were fed by control (N) and high energy (H) diet, respectively. Each of the amounts of 0 (A0), 0.7(A0.7) and 1.4 (A1.4) acetic acid were added to diets of three groups of both parts in 3 replicates. A bird of each group in the day 18, 28 and 38 was slaughtered and its ileosecal contents were picked. CFU/g of Coliforms, E. coli and lactobacillus of samples were determined. The results showed that the lowest feed conversion ratio was achieved by 1.4% acetic acid (P<0.05). There was intraction effect of time and acetic acid on CFU/g of Coliforms and E. coli (P<0.05). On day 38, CFU/g of Coliforms obtained by 0.7 and 1.4 % acetic acid was lower than 0% acetic acid (P<0.05). CFU/g of E. coli with 0.7 % acetic acid, achieved on day 28 was higher than on day 38 (P<0.05). The lowest CFU/g of lactobacillus was obtained with 0% acetic acid (P<0.05). Conclusion, the addition of acetic acid up to 1.4% to diet of broilers can improve feed conversion ratio, enhance the growth of lactobacilli and prevent the growth of Coliforms and E. coli in the digestive contents.

The isoflavones genistein and daidzein are phytoestrogens which are found at high levels in soy products. These isoflavones are currently of growing interest owing to their beneficial effects on many disorders, including cancer, cardiovascular diseases and osteoporosis. However, there is little information on the antimicrobial effects of these isoflavones. The purpose of the present study was to compare the antimicrobial effects of genistein and daidzein against seven important foodborne pathogens, namely E. coli O157:H7, Listeria monocytogenes, Bacillus cereus, Staphylococcus aureus, Vibrio parahaemolyticus, Salmonella typhimurium, and Cronobacter sakazaki. To achieve this purpose, the effect of different concentrations of genistein or daidzein on the lag phase duration of growing bacteria was evaluated by measuring the optical density of the samples during 24 h at 35 ºC. According to the results of the present study, the lag phase duration of E. coli O157:H7 was not altered significantly in the presence of up to 1000 µM of both the isoflavones (p>0.05). However a significant increase in the lag phase duration of B. cereus, S. aureus and S. typhimurium was observed in the presence of 500 µM of genistein or 1000 µM of daidzein (p<0.05). Furthermore, both isoflavones made a significant increase in the lag phase duration of L. monocytogenes and V. parahaemolyticus in the concentration of 125 µM and also in the lag phase duration of C. sakazakii in the concentration of 1000 µM (p<0.05). In conclusion, in the presence of 1000 µM of genistein and daidzein, the lag phase duration of all the tested bacteria were significantly increased except for E. coli O157:H7.

This study was done on the skin of 5 of 15 normal and mature female soleid fish with average weight of 790.4±170.41gr in reproductive season (September) from khoor Musa area. The fish were cached with gill net from mouse creek. In order to conduct a microscopical study, 0.5 cm thick samples were taken from different parts of the skin, including dorsal, lateral (on lateral line), ventral, head and tail. The samples were fixed in Bouin’s solution and 5-6 µm thick sections were made using routine paraffin embedding method and were stained by H&E, Alcian blue (AB) pH 2.5 and PAS. The histochemical results showed that there are 2 types of mucous secreting cells (acidic and neutral) in epidermis of Soleid fish. The acidic mucous secreting cells were stained blue in AB staining and neutral mucous secreting cells were stained purple in PAS staining and they were recogonized from other cells easly. Histometrical results showed that the number and distribution of acidic mucous cells varied in different regions of skin, so that these cells were more in ventral region than dorsal and head (P<0.05) but there were no significant differences between the number of neutral cells in different regions of skin (P>0.05).

Due to the effects of some pollutants on the thyroid gland function and to assess the effects of hypothyroidism on some blood biochemical parameters of common carps, this study was conducted. Fishes were divided into four groups of 30 each. The groups were treated by zero (control group), 3, 9 and 27 mg/L of propylthiouracil in water for one month. After 1 month, blood was taken from 15 fishes from each group and their weight, serum thyroid hormones, triglycerides, total cholesterol, HDL-c, LDL-c, glucose and serum urea urea were measured. For the reminder, the drug application was discontinued and the other halves of the fish were examined one month later, in the similar manner to the previous stage. In stage 1 (after one month) in comparison between different groups, thyroid hormones did not show significant difference (p>0.05), but in the second stage, T4 level was lower in the treatment groups in comparison with the control (p<0.05). T3 level in 3 and 9 mg/l groups were higher than 27 mg/L group and the control (p<0.05). The triglycerides level was higher in 3 and 9 mg/L groups compared to control group (p<0.05). HDL-c in the second stage in 3 mg/L group was higher than the control group and 27mg/L group (p<0.05). Glucose in the second stage was significantly lower in 9 mg/l group in comparaison with the control group (p<0.05). Urea also increased in the treated groups in comparison with the control (p<0.05). Accordingly, it is concluded that thyroid hormones had responded to the treatment with delay and their changes have affected the studied variables dependently.

The success of a horse in competitions, largely depends on cardiovascular, respiratory and musco-skeletal system capacities which are basically determined by genetic characteristics and training procedur. It seems that the evaluation of parameters like vital signs, electrocardiogram and hematologic changes following intense physical activity provide data which may help in predicting the athletic capacity of horse in real racing conditions. In this study, the red blood cell changes and different related indices and leukograms were determined before and after intense physical activity in eight, 4-10 years old Arabian horses. The blood samples were collected at 1 h before, just after, 3 hours and 24 hours after running with maximum speed in a 1250-meters course and were analyzed using an automatic counter machine. The results showed that most of the measured parameters (including RBC count, hematocrit, MCV and WBC count) were significantly increased just after running. It seems that factors like stress induced by racing conditions and sweating increase the measured parameters. The changes occurred in different kinds of white blood cells showed different patterns.

The aim of the present study was to evaluate the effect of purslane on performance and carcass characteristic of broiler chickens. Broiler chicks were allocated randomly in 3 groups with 4 replicates and 12 chick per replicates to receive diets supplemented with 0 (control), 1 and 2 % of dried purslane for 42 days. Body weight gain (BWG) and feed intake (FI) were measured at the end of every week and calculated for starter (1-21 days) and grower (22-42 days) periods. Four male and four female chicks from each treatment were chosen randomly and killed by cervical dislocation on day 42 and carcass components weights were measured. The results of this experiment indicated that purslane did not affect FI, BWG and feed conversion ratio (FCR) of broilers in starter period. However BWG and FI increased significantly with inclusion of dried purslane in grower and throughout the experimental period (P<0.05), but FCR didn’t changed significantly. Dried purslane did not have a significant effect on carcass component. Therefore, it was concluded that supplementation of diet with dried purslane can increase weight gain and feed intake of broiler chicks without changes in feed conversion ratio.

This study was conducted to evaluate the effect of two gonadotropins, eCG and FSH, separately or together on reproductive parameters of Zandi ewes. The ewes (n=135), during breeding season, were synchronized using CIDR and randomly assigned to 8 treatment groups. The control group (n=36) received no treatment. The ewes in eCG group (n=20) recieved an im injection of 400 IU eCG at the time of CIDR removal. In addition to eCG injection at CIDR removal, the groups eCG+FSH/0h (n=15), eCG+FSH/12h (n=10) and eCG+FSH/24h (n=14) ewes were injected 10 mg of FSH at 0, 12 and 24 h after CIDR removal, respectively. The ewes in group FSH/0h (n=15), FSH/12h (n=10) and FSH/24h administrated one dose of FSH at the time of CIDR removal 0, 12 and 24 h after CIDR removal, respectively. All ewes were artificially inseminated using fresh semen of Zandi ram in 48 h following CIDR removal. After parturition, the reproductive parameters of ewes and birth weight were recorded. The reproductive parameters were analysed using the ProcGenmod and the data of birth weight analysed by ProcGLM in SAS 9.1. The highest lambing rate was obtained in the group FSH/24 (80%) which it was not significantly different (P > 0.05) with control (52.8%) and eCG (55%) groups. Moreover, the highest fecundity rate was achieved in FSH/24 group (86%), which was higher (P <0.05) than control (52.8%) and eCG (55%) groups. The highest litter size occurred in eCG+FSH/24h group (1.4%), which was not significantly different (P > 0.05) compared to other groups. The data of birth weight also didn’t show significant differences (P > 0.05) between the treatment groups. The result of current research showed that an injection of FSH at 24 h after CIDR removal can be more effective on the reproductive parameters of Zandi ewes during breeding season.

Although the Aloe vera plant is well known for its anti-inflammatory, anti-viral, anti-bacterial and immunostimulant properties, but it is more known because this herb has a role in wound healing and freshness in human skin. However, Aloe­ vera has not been used for wound healing in aquaculture. This study was carried out to evaluate the healing effect of Aloe vera on the surgical wounds in fish skin. For this purpose, 150 common carps (120-150 g) were divided into following 5 groups. Fish were anesthetized with MS222 (Tricaine methane sulfonate) and then skin wounds with 5mm diameter and full thickness and circular shape were created by surgical punch biopsy on the left side of each fish. In order to study the healing effect of Aloe vera extract following treatments were applied: group 1 received no treatment (control group), group 2 received a permanent floating in 3% Aloe vera extract, group 3 received oral treatment, through diet containing 5% Aloe vera extract, group 4 received a short time bath containing 10% Aloe vera extract (10±1 min) and group 5 received a permanent floating in 0.5 mg/lit malachite green. Tissue samples were taken from the skin wounds at day 7th, 14th and 21st from six fish in each time, fixed in 10% formalin and then processed through routine histological methods.The results showed that epithelialization, regeneration of injured subepidermal compartment, formation of granulation tissue, angiogenesis and formation of scales were better in group 4 than the other groups. In day 21st, formation of normal epidermis, dermis and scale were more completed in group 4 compared to the others. On the basis of these results, it can be concluded that short time bath with Aloe vera has positive effects on the wound healing in fish. However, permanent floating of fish in Aloe vera may alter water quality and food intake and indirectly has negative effects on wound healing. In order to obtain a more solid results further research is recommended.