SCIENTIFIC-RESEARCH IRANIAN VETERINARY JOURNAL
Year:2012 | Volume:7 | Issue:4 (33)|Papers Count:12

The aim of this study was to evaluate the effect of ovariectomy and chronic treatement with estradiol valerate on histomorphometric properties of thyroid gland in female rabbits. Fifteen adult female rabbits of the New Zealand strain were divided into the sham operated control group (SO), or ovariectomized group (Ovx) and ovariectomized group treated with estradiol valerate (Ovx EV). Results showed that the glandular parenchyma in both peripheral and central thyroid zones, is composed of a mixture of large and small follicles. After Ovariectomy the pattern of morphological changes in peripheral and central zones was similar. In comparison with SO rabbits, in both peripheral and central thyroid zones, the relative volume densities of the follicles, epithelium, colloid and the epithelial height were significantly decreased and the volume density of the interstitium was significantly increased in Ovx rabbits (p<0.05). Chronic EV treatment of Ovx rabbits reversed these changes to the pre-ovariectomy state, so that none of the above mentioned morphometric parameters in the Ovx EV rabbits were significantly different from those in the SO controls (p<0.05).

Leptospirosis as an occupational hazard to butchers, fanners, and veterinarians is an important zoonosis. Leptospiral infection may be occurred in veterinary students by contact with farm, pet, and laboratory animals. The aim of this study was the seroprevalence survey of leptospiral infection in veterinary students in Shahid Chamran University of Ahvaz. Blood samples were taken from 187 students. The Sera were initially screened at serum dilution of 1: 100 against six live antigens of Leptospira interrogans sub species: pomona, canicola, hardjo, ballum, icterohemorrhagiae and grippotyphosa using the microscopic agglutination test (MAT). Antibodies against one or more serovars at dilution ³1: 100 were detected in 32 (17.1 %) student. Among the positive sera, antibodies were most frequent to serovar canicola (42.1%) followed by pomona (28.9%), grippotyphosa (18.4%), icterohemorrhagiae (7.9%) and hardjo (2.6%). There was no difference between the grades and sex of students with leptospiral infection.

Forty larvae from the first day to three weeks post hatch for investigating the development of pylorus and pyloric caecum in larval stages of Acipenser stellatus were prepared. The larvae were collected randomly and immediately were fixed in Buin's fluid. After providing the samples, some sections at 6 micrometers were prepared, stained with hematoxylin and eosin and studied microscopically.The results showed that in the first day after hatch the abdominal cavity was filled with yolk. In the first week, pylorus with a thick musculature is apparent. The luminal surface of pylorus was lined with a simple columnar epithelium devoid of any secretory cells. Pyloric caecum has some short villi with simple columnar epithelium possessing some cytoplasmic vacuoles. Until the second week, pyloric caecum is pyramidal and its mucosal epithelium is simple columnar with cytoplasmic vacuoles. Up to the end of third week, the pylorus possesses some mucosal plicae with simple columnar epithelium with the least cytoplasmic vacuoles. At this time the luminal surface of caecum shows tall leaf shape villi with a simple columnar epithelium in which a few secretory cells is observed gradually. In caecum as well as pylorus the cytoplasmic vacuoles decrease and then disappear.

This experiment was conducted for comparison the effects of prebiotic (contains mannanoligosaccharide and b-glucan), butyric acid and bacitracin as dietary growth promoter on histomorphometry of small intestine of broiler chickens. One hundred and ninety two day- old broiler chicks were divided into four groups and each treatment contained four replicates. Group 1 as Control (basal diet), group 2, basal diet and prebiotic, group 3, basal diet, organic acid and group 4 basal diet and bacitracin as growth promoter were feed for 42 days. For histomorphometrical evaluation, small intestine segments were sampled and routine histological laboratory methods were used. Sections stained with hematoxylin-eosin and the height and width of villi and depth of crypts were measured. The results of present study showed that prebiotic had significant (p<0.05) effect on improvement of feed conversion ratio in 22-42 days and total period compared with the control and organic acid-fed broilers. In addition, antibiotic treatment improved feed conversion ratio compared with the organic acid- fed broilers (p<0.05); while antibiotic and organic acid were not effected when compared with the control. The addition of prebiotic or antibiotic increased the villus height in duodenum (P<0.001). Prebiotic increased villus width of duodenum and ileum compared with other treatments and the duodenal crypt depth was increased by antibiotic and organic acid treatments compared with prebiotic treatment and control (P<0.01). The findings of this study shows that addition of prebiotic in broilers diet can increase the absorption surface of nutrients and performance, but butyric acid do not act as a growth promoter.

Avian Influenza Virus (AIV) is classified in the genus of influenza virus A within the Orthomyxoviridae family. The aim of this study was the cloning and expression of NSI gene belongs to an avian influenza virus isolate (AiChicken/Iran/AH-l/06), serotype H9N2 from a broiler chicken flock in Ahvaz, with respiratory signs and mortality. The NS 1 protein is used for the DIVA test (Differentiating Infected from Vaccinated Animals) in the form of an ELISA test. For this purpose several nucleotide sequence of the NS 1 coding region (from nucleotide 27 to 680) of avian influenza virus subtype H9N2 retrieved extracted from the Gene bank in order to design the required primers. The NS 1 gene was subsequently amplified by RT - PCR. The vector, pMAL-c2X and the amplified NSI gene, both were digested by EcoRI and Pstl restriction endonucleases and ligated by T4 DNA ligase. The construct was then transformed into BL strain of E. coli and finally the purified recombinant vector was used for expression of NS 1 protein. The 66.4 KDa protein was identified by both SDS-PAGE and Western blotting. Observation of expressed protein with the expected molecular weight in SDS-PAGE and a positive reaction with avian influenza virus H9N2 infected chicks sera by Western blotting revealed a successful expression of the segment ofNSl gene in Eicoli.

An experiment was conducted to investigate the effects of different levels of feed restriction on immunological response and performance of broilers under heat stress condition. A total number of 240 cockerels from Ross commercial strain (308) were used as a completely randomized design. Chickens were kept under heat stress (35±2 DC) for 4 hours a day (from 12 to 16 pm) from 7 to 21 days of age. Treatments were different levels of feed restriction (70, 80 and 90 percent of control birds) from 7 to 14 days of age and 80 and 90 percent of control birds from 7 to 21 days of age. According to results at 42 days of age no significant differences were observed for relative weights of bursa and spleen to body weights and also for antibody titers against Infectious Bursal Disease (IBD) vaccine between control group birds and birds under different levels of feed restriction. Also at 42 days of age no differences among treatments were found for daily feed intake, daily weight gain and feed conversion, but for 7 to 21 days of age they were lower in feed restricted birds. According to these results, feed restriction under heat stress conditions for longer periods has less effect on antibody titre of IBD than high severity feed restriction. Also, feed restriction till 21 days of age did not have any harmful effect on broiler performance under heat stress conditions.

This experiment was conducted to evaluate the effects of reduction vitamin premix between 29 and 42 day of age in broiler chickens fed diets based on wheat and barley on performance and meat quality. A total 112 male broiler chicks (Ross 308) were allocated to 7 treatment groups, with 4 replicates per each treatment and 4 birds per replicate pen. Feed intake and weight gain were measured at 35 and 42 days and feed conversion ratio was calculated. At days 35 and 42 of ages, one bird from each replicate was bled, to determine the enzymes aspartate amino transferase (AST) and alkaline phosphatase (ALP) as an indicator for lacking of vitamins E and B6. The slaughtered and measured tissue antioxidant (TBARS) were frozen for 6 months. The results of this trial showed that there were no significant differences in performance and aspartate amino transferase with reduction or withdrawal of vitamin premix from diets in 29-35 days. However, there were significant differences between the treatment without vitamin premix (T1) and other treatments for these performance and aspartate amino transferase in 36-42 days of age (P<0.05). The results of thiobarbituric acid reactive substances (TBARS), ALP showed there were significant differences between the treatment without vitamin premix (Tl) and other treatments for these TBARS value and ALP in 35 day of age (P<0.05). Also, TBARS values showed the significant differences between the treatments without vitamin premix (TI) and 33% vitamin premix and other treatments for birds slaughtered at 42 days of age (P<0.05). In conclusion, the results of the present study indicated that in the battery cage system it is possible to reduce dietary vitamin premix (66%) during finisher period but withdrawal can negatively affect the performance and meat quality of broiler chickens.

Traumatic Reticuloperitonitis (TRP) is one of the most common gastrointestinal diseases of cattle that have high economic importance. Radiography of the reticulum in cattle is a useful supplementary method for diagnosing and treatment decision-making tool of the disease. The present study was performed to assess the diagnostic value of radiography in cattle for TRP diagnosis. The study was performed on 23 cows referred to veterinary clinic during the 2005- 2006. All cows were clinically suspected to TRP. First standing lateral radiography of reticular region was taken. Then, ultrasonographic, surgical or post-mortem results were used as the gold standards procedure for agreement or rejection of the TRP in the cows. Radiographic findings of cows were compared with ultrasonographic, surgical or postmortem finding and then evaluated statistically. Of 17 cows with the disease at surgery or autopsy, radiological findings in 15 cases were positive. The accuracy, sensitivity, specificity, positive predictive value and negative predictive value of radiography for identifying cows with TRP were 91%, 88%, 100%, 100% and 75%, respectively. The results were suggested that the following radiographic findings are important for diagnosis of TRP: observation of a metal foreign body with abnormal position on the reticulum, abnormal position and contour of the reticular wall, cranioventral abdominal masses and observation of gas inclusions or gas capped fluid on the reticular area. Diagnostic value of the radiography increase, when there is observed two or more of these findings. The present study results suggest reticular radiography is a useful method in detecting TRP in cattle.

This survey was carried out to determine the infestation rate of Oestrus ovis larvae and its seasonal dispersion in Urmia. A number of 402 sheep heads were examined in Urmia slaughterhouse and all o. ovis larvae of each head were collected. Thirty three sheep heads were examined each month during 12 months from 2006 to 2007. Of 402 heads, a number of 122 heads (30.34%) were infested with o. ovis larvae. The prevalence of nasal myiasis in spring, summer, fall and winter were 32.32%, 28.43%, 33.66% and 27% respectively which were not significantly differed (P>0.05). The results showed that the infestation rate of o. ovis in different age groups including 6-24 months, 2 to 4 years, and older than 4 years were 17.39%, 28.33% and 35.68% respectively. The age specific infestation rates among age groups were significantly differed (P<0.05). The highest and lowest infestation rates were in Gezel and Haraki breeds, respectively. The differences in infestation rate among sheep breeds were not statistically significant (P>0.05). This study suggests a high rate of infestation to o. ovis in Urmia.

In present study, the frequency of Giardiasis in horses in Ahvaz was investigated. The feces samples were taken from 100 horses that keep in seven horse breeding clubs, during spring and summer 2009. The ages of horses were from 1 month to 27 years old. Fecal samples were stained by Tri-chrome. Results were analyzed with Chi-square Test and Fisher's exact test. The results showed that the rate of infection to Giardia was 40%. There was not significant difference between infection to Giardia and sex and age. It seems; the rate of infection to Giardia in the studied horses is high in comparison to other studies that were done in other countries.

Mutation studies in different prolific sheep breeds have shown that the effectiveness programs in this reqard are necessary for improving sheep population. One of the important agents on prolificacy is transforming growth factor beta superfamily (TGFb). The growth differentiation factor 9 (GDF9) family is belong to TGFB superfamily.FecGH mutation that belongs to the GDF9 family has additive effects for litter size and ovulation rate in carrier sheep. The present study was therefore designed with the objective to evaluate FecGH mutation in the Lory-Bakhteyari and Arabic sheep. Results show no FecGH mutation is in Lory-Bakhteyari and Arabic sheep. So mutation of FecGH is not cause of prolificacy in these breeds. Further research requires evaluating fecundity gene and genotyping of these sheep breeds.