انجمن تحقیقات دامپزشکی
سال:1390 | دوره: | شماره: |تعداد مقالات:12

The objective of this study was to evaluate effect of different concentrations of catalase in two extenders on motility, viability and lipid peroxidation bull spermatozoa during semen freezing process. Thirty ejaculates collected from ten Holstein bulls were pooled and evaluated at 37oC. Pool ejaculated was split into two main experimental groups, 1 and 2. In experiment 1, specimen was diluted to a final concentration of 30×106 spermatozoa with citrate-egg yolk and in experiment 2; specimen was diluted with tris-egg yolk extender to the same concentration. In both experiments diluted semen was divided into three aliquots, including a control and two test groups. Each aliquot was rediluted with an equal volume of extender either without (control) or with one of the antioxidants contained one of the following antioxidants: catalase (CAT; 100 IU mL-1) catalase (CAT; 200 IU mL-1) and control group. No significant differences were observed in sperm viability and motility following addition of catalase enzyme at concentration of 100 IU mL-1 and 200 IU mL-1 to citrate-egg yolk extender. But the highest sperm viability was achieved by addition of 100 IU mL-1 and 200 IU mL-1 catalase to tris-egg yolk semen extender compared with the control group (P<0.05). Malondialdehyde levels did not change with addition of catalase in both extenders compared with the control group. The obtained results provide a new approach to the cryopreservation of bull semen, and could positively contribute to intensive cattle production.

The main goal of this study was to evaluate the possible effect of whole-body magnetic field (MF) exposure on the variations of corticosterone, Free-T3, Free-T4 and malonyl dialdehyde in plasma in 48 adult white New Zealand male rabbits. Animals were divided into six groups namely, C1 (normal diet, not exposed), C2 (normal diet, sham exposed), T1 (normal diet, exposed to electromagnetic field), C3 (high-cholesterol diet, not exposed), C4 (high-cholesterol diet, sham exposed) and T2 (high-cholesterol diet, exposed to electromagnetic field). In eight separate experiments, sham exposed groups (C2 and C4), were exposed to sham stimulated (without electromagnetic stimulation) for 5 days, 2 hour/day and the rabbits of the treatment groups (T1 and T2) were treated with triangular form 10 Hz of electromagnetic field for 5 days, 2 hour/day, while the control groups (C1 and C3) had no any exposure. At the end of the exposure, after a 12- hour fasting period, blood samples were taken and level of corticosterone, Free-T3 and Free-T4 were measured by Elisa kits and level of malonyldialdehyde was measured by spectrophotometric method. The results indicated that the blood serum levels of Free-T3, Free-T4 and Corticosterone in the T1 and T2 groups were significantly increased compared to those of their own control groups (P<0.05). Malonyldialdehyde levels in T2 animals showed a significant decrease compared to that of animals of C3 and C4 (P<0.05). We conclude that 10 Hz pulsed electromagnetic field can alter the levels of Free-T3, Free-T4 and corticosterone in animals with both normal diet and hyperchlosterol diet and also alter the amount of malonyldialdehyde in animals with hyperchlosterol diet.

The present study investigated the effects of microinjections of acetylcholine (a cholinergic agonist), physostigmine (a cholinesterase inhibitor), atropine (an antagonist of muscarinic cholinergic receptors) and hexamethonium (an antagonist of nicotinic cholinergic receptors) into the parafascicular nucleus of thalamus on the acute corneal nociception in rats. Acute corneal nociception was induced by putting a drop of 5 M NaCl solution onto the corneal surface of the eye and the number of eye wipes was counted during the first 30s. Both acetylcholine and physostigmine at the same doses of 0.5, 1 and 2 mg significantly (P<0.05) reduced the number of eye wipes. The intensity of corneal nociception was not changed when atropine and hexamethonium were used alone. Atropine (4 mg), but not hexamethonium (4 mg) significantly (P<0.05) prevented acetylcholine (2 mg) - and physostigmine (2 mg) -induced antinociceptive effects. The results indicated that at the level of the parafascicular nucleus of thalamus, the muscarinic cholinergic receptors might be involved in the antinociceptive effects of acetylcholine and physostigmine.

In this study we investigated histopathological changes of mice ovarian tissues following long-term administration of copper sulfate and induction of chronic copper poisoning. The study comprised of three different groups of twenty one mice as follows: The first group (Group 100) which treated by gavage with copper sulfate at a dose of 100 mg kg-1 for 5 weeks. The second group (Group 200), which received 200 mg kg-1 copper sulfate by gavage during experimental period (35 days), and control animals (Group C), which received the same volume of distilled water in the same way. The blood samples were obtained from 7 cases out of 21 animals of each group by cardiac puncture at the end of first, third and fifth week. Ovarian lesions were observed in group 100 after 35th day and in group 200 after 21st day. The histopathologic examination revealed widespread ovarian follicle atresia in group 200 after 35th day Atretic follicles had numerous cell debris and inflammatory cells in the antral cavity. In degenerative antral follicles granulose cells degenerated and desquamated into antrum. In some degenerative antral follicles infiltration of inflammatory cells into granulose cell layer and antrum were observed. The histopathlogic data indicate the possibility of adverse effect of copper poisoning on the mice ovarian tissue. Copper might be mediator of the effect of oxidative damage and play an essential role in reproductive system.

The present study was carried out to determine parasitic infection of sheep with gastrointestinal helminthes in a slaughterhouse in Fereidoonkenar city, Iran. A total number of 50 sheep were examined from April to September 2008. Nematodes were removed from abomasums, small and large intestines, and kept in A.F.A. solution (alcohol, formaldeyde, acetic acid, distilled water, and glycerine) for further diagnosis. Cestodes were removed from small intestine, washed with water, and stained with carmine acid. The results of this study indicated that 70% of examined animals were infected as follows: Ostertagia circumcincta and Marshallagia marshalli (38%), Trichostrongylus colubriformis (16%), Nematodirus spathiger (14%), Skrjabinema ovis (12%), Haemonchus contortus (10%), Camelostrongylus mentolatus (4%), and Gongylonema pulchrum, Cooperia punctata, Bunostomum trigonocephalum, Chabertia ovina (2%). Among examined animals, 14% infected with Moniezia expansa, 10% with Avitellina centripunctata and 2% with Helicometra giardi. The infection rate in younger animals was higher than in adults. The maximum infection rate was with O. circumcincta and M. marshali. No infection was found in examined rumens.

The objective of this study was to investigate whether or not the adverse effects of heat on sperm quality could be prevented by green tea extract (GTE) administration. Ninety adult male mice were randomly divided to two groups. The scrotum of each animal in the first group was immersed once for 20 min in a water bath maintained at 42oC (heat group, H) and the second group (control group, C) was maintained at 23oC. Heat-treated and control groups were allocated randomly into three subgroups. The first subgroup from heat-treated mice was administered sterile saline (heat saline, HS) and the two other subgroups were administered orally with two different doses of GTE including 500 and 750 mg kg-1 (HG500 and HG750) for 49 consecutive days. Likewise, the first subgroup from control mice was administered sterile saline (control saline, CS) and the two other subgroups were administered orally with 500 and 750 mg kg-1 of GTE (CG500 and CG750), respectively. Heat stress significantly reduced (P<0.05) sperm concentration, total sperm motility, progressive sperm motility and hypo-osmotic swelling-water test positive spermatozoa at the first 14 days after the heat treatment. However, a partial recovery was observed at the day 42, which was still significantly lower than that of the CS group. Administration of GTE in two doses (HG500 and HG750 treatment groups) following heat treatment could significantly recover adverse effects of heat on above-mentioned parameters during the first 28 days. The present study demonstrates that the adverse effects of hyperthermia on semen parameters might be recovered following administration of green tea extract in a short period of time.

Tendon never restores the complete biological and mechanical properties after healing. Bone marrow and recently adipose tissue have been used as the sources of mesenchymal stem cells, which have been proven to enhance tendon healing. Stromal vascular fraction (SVF), derived from adipose tissue by an enzymatic digestion, represents an alternative source of multipotent cells, which undergo differentiation into multiple lineages to be used in regenerative medicine. In the present study, we investigated potentials of this source on tendon healing. Twenty rabbits were divided into control and treatment groups. Five rabbits were used as donors of adipose tissue. The injury model was unilateral complete transection through the middle one third of deep digital flexor tendon. Immediately after suture repair, either fresh stromal vascular fraction from enzymatic digestion of adipose tissue or placebo was intratendinously injected into the suture site in treatments and controls, respectively. Cast immobilization was continued for two weeks after surgery. Animals were sacrificed at the third week and tendons underwent histological, immunohistochemical, and mechanical evaluations. By histology, improved fibrillar organization and remodeling of neotendon were observed in treatment group. Immunohistochemistry revealed an insignificant increase in collagen type III and I expression in treatments over controls. Mechanical testing showed significant increase in maximum load and energy absorption in SVF treated tendons. The present study showed that intratendinous injection of uncultured adipose derived stromal vascular fraction improved structural and mechanical properties of repaired tendon and it could be an effective modality for treating tendon laceration.

To describe proportion and pattern of culling in commercial dairy herds of Khorasan Razavi Province, this survey was carried out from 21st March 2008 to 20th March 2009 in 15 industrialized dairy herds. For each culled cow data related to parity at culling, last calving to culling interval and primary reason for culling were recorded. Annual herd exit rate was 20.9%. Out of a total of 652 culled cows, the proportions of culled dairy cows were due mainly to involuntary culling with very small proportion of voluntary culling (4%). The involuntary culling were mainly from infertility or reproductive disorders (23.6%), udder disorders (17.5%) and digestive tract disorders (15.9%). Average ± SD of parity at culling was 3.15±1.96. Culled cows from digestive tract disorders, injuries and infectious diseases were significantly younger than those of other culling reasons (P<0.05). Mean ± SD of last calving to culling interval was 194±159 days. Culled cows from digestive tract disorders, injuries and udder disorders were removed earlier in lactation period than cows culled from reproductive disorders, infectious diseases and lameness (P<0.05). Low proportion of voluntary and high percentage of involuntary culling specially from health problems should be considered as an important economic loss and precaution measures are necessary to reduce this loss.

For evaluation of citric acid and citrate effects on bovine epididymal protoplasmic droplets, fifty bovine testes were collected in the October 2007 till June 2008 from Urmia slaughterhouse and transported to the laboratory in a cool container filled with 5oC ice pack. Caudal epididymis was incised and sperm cells were put into Petri dishes containing hams f10 media with 10% fetal calf serum (FCS), which were kept in 37oC, CO2 incubator. Then sperm cells were counted and 50-milion per mL concentration was prepared. After this stage, three dilutions of citric acid (0.1, 0.2, 0.3 N) and one dilution of citrate (1 N), based on normal osmolarity and normal pH were added to a micro tube containing 25 milion per mL sperm. Then one-step eosin-nigrosin staining in 30-60-120-240-360 minutes was performed and slides were evaluated with 1000-x phase contrast microscope and 200 sperm cells per slide were counted. The results revealed significant difference between blank and citric acid 0.3 N. The proportion of protoplasmic droplet in group consisting of 0.3 N acid citric in 120-240-360 minutes, was significantly lower than that of blank (P<0.05). There was no significant difference between citrate – blank and citric acid 0.1 N-blank groups, but after 240 minutes significant difference was observed between blank & citric acid 0.2 N (P<0.05). In conclusions citric acid based on dilution and time duration can reduce the proportion of bovine epididymal sperm cytoplasmic droplets.

Cyclophosphamide (CP) is extensively used as an antineoplastic agent for treatment of various cancers, as well as an immunosuppressive agent. However, despite its wide spectrum of clinical uses, CP is known to cause several adverse effects including reproductive toxicity in humans and experimental animals. Crataegus monogyna is one of the oldest medicinal plant has been shown to be cytoprotective by scavenging free radicals. The present study was conducted to assess whether Crataegus monogyna fruits aqueous extract with anti-oxidant properties could serve as a protective agent against reproductive toxicity during CP treatment in a rat model. Male Wistar rats were categorized into four groups. Two groups of rats were administered CP at a dose of 5 mg in 5 mL saline kg-1 per day for 28 days by oral gavages. One of the groups received Crataegus monogyna aqueous extract at a dose of 20 mg kg-1 per day orally four hours after cyclophosphamide administration. A vehicle-treated control group and a Crataegus monogyna control group were also included. The CP-treated group showed significant decreases in the body and organ weights and spermatogenic activities as well as many histological alterations. CP treatment also caused a significant decrease in sperm count and motility with an increase in dead and abnormal sperms. Moreover, significant decrease in serum levels of testosterone and increased serum concentrations of FSH, LH, LDH, CPK and SGOT were observed in CP-treated rats. Notably, Crataegus coadministration caused a partial recovery in above-mentioned parameters. These findings indicated that Crataegus might be partially protective against CP-induced reproductive toxicity.

This survey was carried out to determine the infection rate of Coenurus cerebralis in Urmia abattoir, West Azerbaijan, Iran. A total of 402 sheep heads were examined and the number of C. cerebralis cysts per each head was recorded. Thirty three sheep heads were examined each month during 12 months from 2006 to 2007. Of 402 heads, a number of 75 heads (18.65%) were infected with C. cerebralis. The cysts located in the left and right hemispheres and cerebellum were 54.63%, 40.20% and 5.15%, respectively. The infected heads contained 1-4 cysts. The highest and lowest prevalence were detected in sheep in March (42.42%) and in July (2.94%), respectively. The infection rates according to age of sheep were 42.02% in 0.5 to 2 years, 22.50% in 2 to 4 years and 8.92% in older than 4 years. The age specific infection rates among age groups were significantly differed (P<0.05). Infection rate in Haraki breed (27.77%) was higher comparing to the rate in the Ghezel breed (21.13%) and Makoie breed (23.91%). However differences between sheep breeds were not statistically significant (P>0.05).

One hundred and five (105) Camels were investigated at the Maiduguri abattoir, Nigeria using floatation and sedimentation techniques for helminth parasites and haematological indices with the microhaematocrit reader. Overall, prevalence of infection was 92.4% [(Coccidia (8.5%), Strongyloides (8.5%), Trichuris (11.4%), Ciliates (6.7%), Ascaris sp. (3.8%), Moniezia sp. (1.9%), Amphistome sp. (0.9%) and Balantidium sp. (0.9%)]. There was no significant difference between infected and non-infected camels for blood parameters. There is need to regularly deworm camels and further study the impact of helminthes in the camel especially with respect to its zoonotic potentials in countries with significant population of camels.