IRANIAN JOURNAL OF VETERINARY RESEARCH (IJVR)
Year:2010 | Volume:11 | Issue:3 (32)|Papers Count:14

This study describes the prevalence of cardiac dysrhythmias occurring over a single 24 h period in ponies and compares the heart rate and frequency of dysrhythmias in two groups of ponies of different ages. Electrocardiograms were recorded using a Holter monitoring system from twenty four ponies aged less than 15-year-old (n = 14) and greater than 15-year-old (n = 10). Subsequent analyses of cardiac rhythm revealed that only 3/24 ponies maintained a regular rhythm throughout the recording period. In the remaining 21 ponies, 6 different types of dysrhythmias were detected, the majority of which were vagally mediated; sinus arrhythmia (n = 12), sinoatrial block (n = 6) and second degree atrioventricular block (n = 10). Premature beats of both atrial (n = 3) and ventricular (n = 1) origin were observed only in the older group. There were no significant differences between the 2 groups with respect to mean 24-h heart rates or the prevalence of cardiac dysrhythmias.

The objective of this study was to determine the effects of feeding different levels of monensin on feed intake, milk production and composition, and milk fatty acid profile in lactating Holstein cows. Four multiparous cows averaging 517 ± 47 (SD) kg in body weight and 101 ± 19.8 (SD) days in milk were housed individually in tie-stalls. The study was conducted as a 4 × 4 Latin square design for four periods (14-d for adaptation and 7-d for sampling). Cows were offered four dietary treatments (0, 10, 20, or 30 mg of monensin/kg of DM) as total mixed ration, twice daily. Dry matter (DM) intake was similar among treatments. Monensin supplementation significantly increased (P<0.05) milk yield and 4% fat corrected milk (FCM). Milk fat and protein percentages were not affected by monensin supplementation, but fat yield was increased. Monensin reduced the percentage of the short-chain and saturated fatty acids in milk fat, but had no effect on the percentages of medium- and long-chain fatty acids. Monensin supplementation increased (P<0.05) unsaturated fatty acids concentrations in milk fat. Based on the results of this study, feeding monensin was effective in inhibiting the biohydrogenation of unsaturated fatty acids in the rumen, and consequently increased the percentage of unsaturated fatty acids in milk fat, which improves the health characteristics of milk for human consumption.

The present study was designed to examine the anatomical parameters of the cardiopulmonary system, the function of venous blood gas parameters and the development of ascites incidence in two genetic line chickens. Three hundred forty day-old chickens from two pure broiler breeder lines, which were different in their growth rate and susceptibility to ascites syndrome were obtained. The relative heart and lung weights, the volumes of the heart, lung and thorax cavity, the incidence of ascites, and the venous blood gas parameters in these two genetic line chickens were followed. In the present study, the incidence of ascites and right ventricular hypertrophy was markedly higher in the fast-growing broiler chickens compared to the slow-growing chickens, as two genetic line chickens exhibited significant differences in their growth performance traits. The volumes of the thorax cavity, before and after removing the heart and lung tissues, were lower in fast-growing broiler chickens compared to the slow-growing chickens. The relative lung volume was significantly lower in the fast growth chickens than the slow growth chickens at the earlier age, but it did not differ at the later age. Additionally, a rise in carbon dioxide tension and a decline in oxygen pressure in the venous blood of rapid growth compared to the slow growth broiler chickens were observed. It could be concluded that there is an association between the insufficiencies of the cardiopulmonary system with the function of the venous blood gas parameters and the development of ascites syndrome in fast growing broiler chickens.

Contamination sites of Pseudomonas fluorescens were traced in the production line for milk pasteurization in a large dairy plant in Shiraz, Iran. Samples of raw and pasteurized milk were collected at six sites along the line. All milk samples were incubated at 7°C until the aerobic plate count had reached 106-107 cfu mL-1. Colonies were picked randomly and identified. No growth of gram negative psychrotrophic bacteria (GNP) was detected in the immediately pasteurized milk samples (just after the pasteurization), during long incubation at 7°C. Recontamination most often occurred in the filling step. In this study 34.1 and 4.9% of the milk packages showed contamination with GNP and P. fluorescens, respectively. Twenty three P. fluorescens isolates were examined for phenotypic characteristics and 16S-23S PCR ribotyping. Phylogenetic analysis was conducted on the phenotypic and genotypic characteristics. The P. fluorescens isolates were shown to belong to 6 biotypes (B1-B6). The predominance of a particular ribotype was often observed for a given biotype, although there were two ribotypes in each of the B2 and B6 biotypes. The 16S-23S PCR-ribotyping technique allowed differentiation between the isolates. Based on this method, the isolates belonged to 5 subtypes. Phylogenetic analysis based on 16S-23S PCR-ribotyping and phenotypic characterization could be helpful in tracking contamination routes in the production line for milk pasteurization.

Fourteen primiparous Holstein cows (180.0 ±4.3 days in milk) with a mean (±SD) daily milk yield of 35.0 ± 1.3 kg and a body condition score of 3.2 ± 0.2 were allotted into two groups (n = 7), and were fed a ration consisting of (dry matter basis) 35% corn silage, 25% alfalfa hay and 40% concentrates. Salt was provided free choice. The experiment was performed during the period of heat stress, i.e., when the temperature-humidity index was greater than 72. One group was offered desalinated water containing 570 mg total dissolved solids (TDS) and another group was offered water containing 1400 mg TDS per L. Milk yield was measured weekly, and milk samples were taken on days 21 and 42 for determination of milk composition. Blood samples were taken on days 21 and 42 from the median caudal vein of the tail and the serum concentrations of Na+, K+, Ca2+, Mg2+, tri-iodothyronine (T3) and thyroxine (T4) were measured. Ruminal fluid was taken by rumenocentesis on day 42 for determination of volatile fatty acids (VFA) and pH. Milk yield, milk composition, serum concentrations of T3 and T4, Na+, Ca2+ and Mg2+, ruminal fluid VFA concentration and pH were not significantly affected by water TDS (P>0.05); however, cows receiving desalinated water produced 2 kg more milk per cow per day. Serum K+ concentration was significantly higher in cows consuming saline water (P<0.05). The present data indicated that water with a TDS of 1400 mg per L had no adverse effect on lactating cows; therefore, it is not necessary to desalinate water in the region under study. However, in light of the possible effects of saline water on thyroid hormones, further studies concerning the influence of saline water on the metabolism of high producing cows in hot climates are warranted. 

Embryonic stem cells (ESCs) are originally derived from the ICM of blastocysts and are characterized by their ability to self-renew and their pluripotencies. Only a few reports have been published on ESC isolations and line establishment in animals, even fewer in horses. However, it is still important to isolate equine ESCs for animal biotechnology and therapeutic applications. In the present study, we tried to derive horse ESC lines from the ICM of blastocysts fertilized in vivo and maintain their pluripotencies in different conditions. The primary horse ESCs were able to self-renew when they were cultured in basic medium on γ-irradiated MEFs. After 15 passages, immunohistochemistry of the putative horse ESCs showed that some cells in the colonies were positive for Oct-4, SSEA-1, GCTM-2, TRA-1-60 and TRA-1-81. Moreover, to optimize the culture conditions, these putative horse ESCs were cultured in basic medium supplemented with human leukemia inhibitory factor (hLIF) only, human basic fibroblastic growth factor (hbFGF) only, or hbFGF plus hLIF with or without heterologous (MEF) feeder cells. Based on our results, the heterologous feeder (MEF) cells are necessary to maintain the undifferentiated state for horse ESCs, and ESC-like cell morphology of horse ESCs were well maintained in the basic medium supplemented with or without hLIF. This result suggested that hLIF was neither prerequisite nor negative for maintenance of horse ESCs; bFGF seemed to be negative for maintenance of horse ECSs and the combination of hLIF and bFGF was unable to improve the culture condition.

The objective of the present study was to determine whether there was an association between the in vitro antimicrobial sensitivity test results of subclinical mastitis pathogens and bacteriological cure following intramammary treatment using a combination of nafcillin, penicillin, and streptomycin (NPS). Eighty-six intramammary pathogens from 43 cows were examined in this study. Most intramammary infections were due to coagulase-negative staphylococci, coliforms, and environmental streptococci. The antibiotic sensitivity to NPS was determined using the Kirby-Bauer disc diffusion method. Bacteriological cure rates for sensitive, intermediate, and resistant isolates in the standard treatment group (3 intramammary infusions of NPS once daily) were 84.4, 88.9, and 100%, respectively. These figures in the extended treatment group (6 intramammary infusions of NPS once daily) were 100% for the 3 categories. Bacteriological cure was not associated with the sensitivity test result. Based on this study, Kirby-Bauer sensitivity test results were not useful as predictors of the bacteriological outcome of subclinical mastitis treated with intramammary NPS.

The purpose of this study is to describe the histological and histochemical features of digestive tract in two aquarium fishes with different types of feeding habits which are omnivorous (Walking catfish) and carnivorous (piranha), respectively. Five adult Walking catfish (L: 26.4 ± 3.4 cm, W: 265 ± 55 g) and five adult piranha (L: 23.6 ± 4.5 cm, W: 247 ± 50 g) were used for this study. The fishes were killed by decapitation method and small pieces (0.5 cm ´ 0.5 cm) from the esophagus, cardiac, fundus and pyloric portions of the stomach, proximal, distal parts of intestine and pyloric caeca were fixed by immersion in Bouin’s solution. The specimens were processed through routine paraffin embedding technique and cut at 5-7 µm and stained with hematoxylin and eosin, Van Gieson, Verhoof, Alcian blue, PAS, and AB+PAS technique for different microstructural and microfibrilar structures. The morphological and histochemical structures of all specimens were studied with a light microscope and micrographs were prepared. The esophagus of Walking catfish and piranha are found to have numerous deep longitudinal folds, stratified squamous epithelium with numerous mucous cells which react positively to PAS and AB stains. Taste buds and muscularis mucosa were not seen in the esophagus of both species. The muscularis mucosa was organized in longitudinal and circular layers of striated muscular fibers. The mucosa of the stomach was formed by simple columnar epithelium with folds and gastric pits formed by the invagination of the mucosal layer into the lamina propria. The surface epithelium of the stomach reacted positively to PAS but negatively to AB staining. The mucosal surface of the intestine in Walking catfish and piranha has numerous folds lined by simple tall columnar cells, along with goblet cells which reacted positive to PAS and AB staining, so that goblet cells in the intestine of Walking catfish were significantly more than in piranha. The Caeca pyloric was found only in piranha and it showed an elongated fold lined with columnar cells and numerous mucous cells which reacted positively to PAS.

Theileria species are common in tropical and subtropical regions and cause great economical losses in ruminants. Two species, T. lestoquardi and T. ovis, are suspected to cause ovine theileriosis in Iran. The epidemiological aspects of ovine theileriosis in Iran are poorly understood and further investigations by sensitive and precise techniques are required. In a previous study, a sensitive and specific PCR-RFLP method was used for the identification of Theileria spp. in sheep. In the present study, Theileria species involved in ovine theileriosis were determined in five different regions in eastern half of Iran (Zabol, Lar, Ferdows, Semnan and Gorgan). Blood samples were collected in EDTA. Of 220 blood samples obtained from sheep in different regions, 60% (132.220) were positive for Theileria spp. by nested-PCR compared with 22.27% (49.220) by microscopic examination. Using RFLP of PCR products, out of 132 positive blood samples, 55.3% (73.132) were positive for T. lestoquardi and 44.7% (59.132) were positive for T. ovis. The infection with these two Theileria species in different areas is compared in the article. This is the first report in which ovine theileriosis has been studied in different regions in Iran using molecular identification techniques.

The effect of subcutaneous injections of vitamin C on the seminal characteristics of Markhoz bucks (2–4-year-old) was studied. The bucks, trained to serve an artificial vagina, were randomly allotted into three equal groups (n = 4) and received daily either zero (1 mL normal saline; control group), or 20 (VitC20 group) or 40 (VitC40 group) mg per kg body weight vitamin C from July 06, 2006 to Oct. 06, 2006. Blood samples were taken from the jugular vein at monthly inter, als, and semen samples were collected at 15-day intervals. Testicular dimensions in the scrotum (circumference, width, and length) were also determined on the day before semen collection. The ejaculates were evaluated for volume, sperm concentration, pH, motility, and abnormal and live sperm. Testicular measurements were not affected by administration of vitamin C. The interaction between vitamin C and the sampling time was significant (P<0.05) for the concentration of vitamin C in the blood plasma and seminal fluid, sperm motility, sperm viability, sperm abnormality, and the number of live-normal sperm in the ejaculate. Vitamin C increased the levels of vitamin C in blood and seminal plasma. Both doses of vitamin C increased the percentage of progressively motile sperm showing forward motility. VitC40 injection for 90 days increased sperm motility and the effect was still evident up to 30 days after the cessation of injections. The percentage of live sperm and mass motility showed similar trends. Both doses were equally effective in decreasing the percentage of abnormal sperm. The total number of live and normal sperm in the ejaculate increased by vitamin C injections and the effect was still evident after the injections had been discontinued. The present data indicates the importance of vitamin C in the reproduction of male goats, as also shown for several mammalian species. They further show that under certain conditions, the in vivo synthesis of this vitamin in ruminants might not be sufficient for optimum reproduction.

Cryptosporidium parvum is a zoonotic protozoan parasite with a wide range of vertebrate hosts. The present study was conducted to determine the prevalence of Cryptosporidium parvum in urban and rural dogs of the Ahvaz area. Faecal samples were collected randomly from 93 dogs between May 2005 and September 2007. The studied dogs were divided into two groups (urban and rural) and based on age into three groups (<6 months, 6 months–3 years and >3 years). The results were analyzed by using Chi-square analysis and Fischer’s exact test. Prevalence to Cryptosporidium parvum antigens was 4.3% (4 of 93) by means of ELISA, indicating that this antigen is present in the ecosystem. The infection was more prevalent in rural dogs (6.4%; 3 of 47) in comparison with urban dogs (2.17%; 1 of 46), nevertheless, there were no significant differences between the different groups (P>0.05), but the infection was more prevalent in diarrheic dogs (17.65%; 3 of 17) compared with non-diarrheic dogs (1.3%; 1 of 76), and the difference was significant (P=0.019). Infection was not significant in the different age groups (P>0.05). Concurrent detection of Cryptosporidium parvum with canine distemper (one sample) and parvovirus (one sample) were shown in the studied dogs. Modified Ziehl-Neelsen staining was also carried out and the prevalence of infection was 2.15% (2 of 93). The use of ELISA allowed the detection of more positive cases than light microscopy. This study showed that Cryptosporidium parvum can be a risk factor, particularly for those dogs in contact together in the population of urban and rural dogs.

Rabies is acutely fatal encephalitis caused by a neurotropic virus. This virus belongs to the family of Rhabdoviridae and genus of Lyssavirus. The virus is almost always transmitted to human through infected mammalian saliva. Rabies is inoculated to a wound by an infected animal bite. Since infection is established in the CNS, the outcome is almost always fatal. According to the outstanding role of vaccination against rabies in animals, as well as post-exposure treatment regimen in human, production of cell-cultured rabies vaccine is the most common interest of researchers. Two BHK-rabies vaccines, one made in the Pasteur Institute of Iran and two in Schering-Plough Animal Health of Madrid, Spain have been tested on 12 dogs divided into two groups. Sera were taken monthly over 18 months. To evaluate the titer of the rabies-neutralizing antibody, these sera were analyzed by the rapid fluorescence focus inhibition test (RFFIT) in the end of each month. Both study groups showed a sufficient immunogenic response without any significant difference at least one year after first vaccination. With respect to the effective immunization of rabies vaccines, their annual injections would be sufficient. According to the results, at the end of the study (18th month) serum titer in only one dog (No. 7) was less than protective level. Two animals in group one (No. 2 and No. 5) also had serum titers less than protective level. Mean of post vaccination antibody titer were not different in either groups (P=0.35).

This is a report of a penile fibrosarcoma in a two-year-old crossbred Holstein bull. The ulcerated tumor mass with dimensions of 7 × 9 × 6.5 cm, was enveloped the glans and body of the penis. It had a white-gray color at cross section appearance. There was no metastatic evidence of regional lymph node enlargement. Histopathologically, elongated spindle-shaped cells arranged densely in the interwoven pattern had a low rate of mitosis with oddly-shaped nuclei and pleomorphism. Immunohistochemically, the neoplastic cells were positive for vimentin and S100, but negative for α-smooth muscle actin, desmin, C-KIT and GFAP.

A Holstein heifer with symptoms of dystocia was admitted in the Large Animal Clinic at the University of Tabriz. In the vaginal examination, the fetus was found at posterior presentation and by doing some obstetrical maneuvers, a male calf was delivered. An interesting phenomenon was the presence of two skin sacs in dimensions of 12 × 12 cm and 12 × 18 cm at the right and left upper cervical regions, respectively; and also the heart beats under the neck skin at the lower cervical region. Due to severe dyspnea, after 2 min the calf died. At necropsy, the heart was located outside of the thoracic cavity, under the neck skin. The direction of the heart axis was reversed as the base was directed caudoventrally and the apex craniodorsally. Unlike a normal calf’s heart, the shape of its apex was rounded like a dog heart. Histopathologic examination revealed severe congestion, edema and hemosiderosis in the lungs, passive venous congestion and scattered foci of cardiomyolysis in the myocardium. Based on anatomical and histopathological findings, the disorder was diagnosed as bovine fetal Ectopia cordis cervicalis associated with two cervical sacs.