IRANIAN JOURNAL OF VETERINARY RESEARCH (IJVR)
Year:2010 | Volume:11 | Issue:1 (30)|Papers Count:16

The naturally occurring antioxidants: vitamin E, b-carotene and vitamin C are known to ameliorate the oxidative stress generated during various physiological and pathological conditions. The oxidative stress may occur at different sites, different times, and by different mechanisms in the animal system. Lower levels of the anti-oxidant vitamins are associated with poor fertility and production levels in ruminants. These antioxidants need to be replenished/regenerated or supplemented at appropriate timings in order to optimize the ruminant health and productive/reproductive performance.

The purpose of this study was to evaluate the effects of different time combinations of dexamethasone and acetylcysteine on experimentally induced corneal ulcers in dogs. Experimental corneal wounds were created surgically to the anterior one third of the cornea in the center of all eyes of 15 mixed breed dogs. The eyes were divided into five groups according to planned post-operative medications: group 1, one drop of N-acetylcysteine 3% and one drop of dexamethasone 0.1% immediately after surgery; group 2, two drops of N-acetylcysteine 3% from day 1, one drop of N-acetylcysteine 3% and one drop of dexamethasone 0.1% from day 15; group 3, two drops of N-acetylcysteine 3%; group 4, two drops of dexamethasone 0.1%; group 5 (control), two drops of normal saline. When applied immediately after corneal ulceration, dexamethasone 0.1% (group 4) decreased corneal haze significantly and did not delay corneal wound healing. Addition of dexamethasone 0.1% to N-acetylcysteine 3% from day 15 (group 2) significantly suppressed opacity at two months after the beginning of the study, but when dexamethasone 0.1% associated to N-acetylcysteine 3% immediately after corneal ulceration (group 1), significant delay in corneal wound healing was induced. It is concluded that combination of dexamethasone 0.1% and NAC 3% immediately after surgery may delay corneal wound healing, also use of these drugs individually, has no obvious clinical effect on corneal haze. On the other hand, use of these drugs in combination with each other may reduce the corneal haze in later months after discontinuation of drugs. However, further studies using larger groups of animals are needed to demonstrate the effectiveness of these pharmacological modulators following experimentally induced corneal wounds in dogs.

A total of 128 spiny eels Mastacembelus mastacembelus (Mastacembelidae) were collected from the Greater Zab river at Iski Kalak town, west of Erbil city, Kurdistan region, Iraq, from July 2007 to the end of June 2008. The fish were examined for ecto and endo parasites. The study revealed the existence of 16 species of parasites (with a total prevalence of 89.06%) including: two species of protozoans (Trypanosoma sp. and Trichodina pediculus), one species of monogenetic trematodes (Mastacembelocleidus heteranchorus), six species of digenetic trematodes (Allocreadium transversale, Asymphylodora macracetabulum, Pseudochetosoma salmonicola, Clinostomum complanatum, Diplostomum flexicaudum and D. spathaceum), two species of cestodes (Polyonchobothrium magnum and Ligula intestinalis), two species of nematodes (Agamospirura sp. and Procamallanus viviparus), one species of leech, crustacean and arachnoide (Cystobranchus mammillatus, Argulus foliaceus and Arrenurus sp. respectively). Five species of these parasites (T. pediculus, A. transversale, D. flexicaudum, C. mammillatus and Arrenurus sp.) were recorded for the first time in Iraq. In addition, M. mastacembelus was regarded as a new host for A. macracetabulum, C. complanatum and A. foliaceus.

To follow-up the present study, 40 mature female rats were used. The animals were divided into test, control and sham groups. The rats in the test group were laparotomized and unilateral ovariectomy was done. On the 1st and 2nd met-oestrous after operation, the tissue samples were dissected out and processed for histological study. The intact ovary in the test group underwent a significant (P<0.05) hypertrophy and compensatory changes including double angiogenesis, high cytoplasmic vacuolation in granulosa cell types of corpus luteum, compensatory follicular development, decreasing of follicular atresia, approximately double ovulation rate and increase in the width of cortex and medulla. The uterine horn on the intact side was approximately similar to the control and sham, while morphometric analyses showed that the horn on the ovariectomized side had significant decrease in the thickness of different layers. Scattering of endometrial glands on the uterine horn of the intact side was normal, showing a dense basophilic appearance in haematoxyline and eosin staining sections. The horn on the ovariectomized side showed low gland scattering. Histomorphometric analyses showed no significant differences between the vaginas in the three different groups. Distribution of mast cells (MCs) as essential cells participating in angiogenesis was investigated. In the test group, mast cells were considerably increased in number around the blood vessels in the medulla of the intact ovary and intact uterine horn. Mast cells were very low in number on the horn on the ovariectomized side.

This study was conducted to investigate the possible involvement of the histaminergic system in the mediation of ghrelin-induced feeding behavior in broiler chickens. In the trial 1, the effect of intracerebroventricular (ICV) injection of ghrelin on feed intake was examined in 3-h feed-deprived broiler chickens. In the trials 2 and 3, the chickens were received ICV chlorpheniramine (an H1 receptor antagonist) and cimetidine (an H2 receptor antagonist) prior to ghrelin injection, respectively. Cumulative feed intake was measured at 3-h post injections. Infusion of ghrelin (0.3, 0.6 and 1.2nmol) decreased feed intake dose-dependently (P<0.05). Pre-treatment of chlorpheniramine (100μg) attenuated the inhibitory effect of ghrelin on feed intake (P<0.05), while such an effect was not noticed by pre-injection of cimetidine (100μg). The results suggest that there is an interaction between ghrelin and the histaminergic system (through H1 receptors) on control of feed intake in broiler chickens.

The copper level in the serum of 1280 and liver of 200 goats raised in the mountain areas of Khuzestan province, Iran were determined. Copper, molybdenum and iron content of soil and pastures as well as sulfur content of the pastures were seasonally estimated. Mean serum copper levels of goats in Behbahan, Ramhormoz, Eizeh and Masjed-Soleyman districts were 8.14±0.21, 1.98±0.12, 7.74±0.11 and 6.97±0.14 µmol/L, respectively. The results showed that the blood copper of goats in the area was significantly (P<0.05) low in autumn and winter in comparison with spring and summer. The liver copper concentration was low in Behbahan, Eizeh and Masjed-Soleyman and at a deficient level in Ramhormoz. The results also revealed a high level of molybdenum in the soil and pasture as well as high amounts of sulfur in pastures of the studied areas. In this survey the status of copper in many goat flocks around the studied towns was dangerously low. Many liver samples had a copper concentration below 30 mg/kg and many serum copper concentrations were below normal. The results of this study confirm the presence of a secondary copper deficiency in goats in the mountain areas of Khuzestan province.

Oxyntomodulin (OXM), a proglucagon-derived peptide, is a well known anorexigenic peptide found in the gut and brain of mammals. The present study was carried out to investigate the central effect of OXM on food intake in non-fasted and fasted Ross broiler chicks. At four weeks of age, a guide cannula was stereotaxically implanted into the right lateral ventricle of each bird. Two experiments were conducted on free-feeding (non-fasted) and 6-h fasted broilers. In each experiment, eight birds were used in a replicated 4 × 4 Latin square design. The birds were given an intracerebroventricular (ICV) injection of different doses of mammalian OXM. Intracerebroventricular injection of OXM at doses of 1.5, 3 and 6 nmol significantly (P<0.05) decreased food intake for 3 h post injection in both non-fasted and fasted chicks. It may be concluded that central OXM may exert a suppressive effect on food intake in chicks.

Escherichia coli O157:H7 is found in cattle farms and can live in the intestine of healthy cattle. Most cases of human illnesses including nonbloody diarrhea, hemorrhagic colitis and hemolytic uremic syndrome can be traced, either directly or indirectly, to cattle. One strategy for reducing the risk of Enterohemorrhagic Escherichia coli (EHEC) infections in human is to reduce the prevalence of infection in cattle. Antiserum against whole cell of isolated E. coli O157:H7 from cattle showed inhibition of adherence of this strain to HEP-2 cells and intestine of model mice. The ability of this antiserum in blocking the attachment of bacteria to HEP-2 cells in 1:1280 titer and to intestine tissue of mice in 1:640 titer are significant. Histology of intestine tissue confirms our results. The difference between in vivo and in vitro titrations for blocking the attachment depends on these two different conditions.

To investigate the influence of hypoxia during the early stage of incubation on embryonic development and hatching events, and consequently on incidence of ascites in broiler chickens, one thousand fertile eggs were incubated in two commercial incubators. Half the eggs were incubated in a low altitude incubator until hatched. The second half were incubated in a high altitude incubator until day 10 and then transferred to a low altitude incubator. Day-old chicks from each group were housed and reared at a high altitude farm. Chicks from the high altitude incubator hatched earlier and showed significantly higher body weights than their counterparts in the lower altitude. High altitude embryos indicated significantly (P<0.001) higher plasma corticosterone, T3 and T4 levels at day 10 and 19 of incubation. During the growing period, high altitude hatched chickens indicated lower right ventricular hypertrophy and ascites mortality than the low altitude hatched chickens. These results indicated that early prenatal hypoxia due to high altitude may change the endocrine functions of embryos, enhanced embryo growth, shorten the hatching process of chickens and consequently decrease the incidence of ascites incidence in broiler chickens.

VP2 gene coding region of a vaccinal strain (D78) of infectious bursal disease virus (IBDV) was cloned in a eukaryotic expression vector, pSec Tag2A. The gene was placed downstream of Ig k chain leader sequence, under the control of human cytomegalovirus (hCMV) immediate early enhancer and promoter. The construct pSec Tag2A-VP2 was transfected in COS-7 cell line and the expression and secretion of VP2 was assessed by dot blotting and antigen captures ELISA. The antibody used in the immunological assays was a neutralizing monoclonal antibody (1A6) against VP2. Positive reaction with the antibody indicated the construct was functional with respect to expression and secretion of a native VP2.

The aim of this study was to provide preliminary quantitative information on selenium and iodine status of sheep in Markazi province, Iran. Selenium and iodine status of grazing sheep were measured for 57 different flocks in 14 regions over one year. The districts were selected to represent major sheep growing areas in the province. Blood samples were collected from 2 to 3-year-old ewes during summer, autumn and winter. Samples were analyzed for blood glutathione peroxidase (GSHpx) activity and plasma inorganic iodine. There were significant differences between regions and seasonal differences in terms of blood GSHpx activity and plasma inorganic iodine concentration (P<0.01). Low levels of GSHpx activity (<60 IU/gHb) and plasma inorganic iodine (<5 mg/dl) in some regions or some seasons indicated the need for dietary supplementation of these minerals.

In order to investigate the prevalence of Mannheimia haemolytica infection in cattle, nasal and nasopharyngeal swabs and blood samples were obtained from 250 cattle after slaughter at Ahvaz (southwestern Iran) abattoir. Nasal and nasopharyngeal swabs were cultured on blood agar and incubated at 37oC for 24-48 h. The suspected bacterial cultures were processed for isolation of M. haemolytica following routine bacteriological techniques. Sera were tested by indirect hemagglutination test (IHA) to reveal antibodies against the organism. M. haemolytica was isolated from 1.6% of the sampled cattle. Statistical analysis showed that there was no relationship between age and sex with bacterial infection. Serological studies showed that 71.6% of tested sera contained antibody (titer³1/16) against M. haemolytica. There was no association between age and sex with serological results.

In order to study the bacterial flora of dead-in-shell ostrich chicks, twelve unhatched eggs which did not have external pipping during the hatching period were transferred to the laboratory of microbiology. The egg shells were accurately disinfected and the embryos were removed and placed in a sterile plate. The surface of each embryo was swabbed with a sterile swab which was also plunged through the yolk sac and the embryo contents and the swab were inoculated into tryptic soy broth (TSB) or nutrient broth. To enrich Salmonella spp., another swab was prepared as above and inoculated into Selenite-F broth. These media were incubated at 37oC for 24 h and then subcultured by streak plate method on solid media. Different bacterial colonies on solid media were isolated in pure cultures for further identification. The results of this study showed that the predominant bacterial flora of dead-in-shell embryos of ostrich were Bacillus spp. (45%) and Staphylococcus spp. (25%).