مجله تحقیقات دامپزشکی
سال شصت و چهارم شماره 1 (بهار 1388)

Different techniques have been employed to improve the technological properties of meat. One of the most important techniques is adding proteolytic enzymes which could simultaneously increase the tenderization and solubility of meat proteins. The purpose of this investigation was to study the effect of different levels of the enzyme ficin on ovine and bovine meat and to determine the best condition for solubilization of meat proteins. Ficin was partially purified from figs tree latex by cationic exchange chromatography. Meat samples were treated wilh different activities of ficin and the effect ofenzyme was followed by measuring nitrogen solubility index (NSI) and electrophoresis. NSI was determined by homogenization of ficin-treated meat in the presence of buffers, centrifugation and nitrogen determination of the supernatant by kjeldal. The solubility of meat proteins increases with increase in the activity of added ficin and with increase in the incubation time (p<0.001). Presence of salt significantly increased the solubility of meat proteins up to 65% (p<0.01). The SDS-PAGE pattern of soluble proteins showed the molecular weight of proteins was in the range of 15-105 KDa and was similar in ovine and bovine meat. Also by increasing the unit activity of enzyme form 0.8 to 2.6 units. most protein bands were disappeared or decreased in intensity. These results indicated that the velry high activity of ficin results in disruption of the structure of myofibrillar proteins and excessive break down of these proteins to smaller peptides which either precipitate or can not be detected by electrophoresis.

Subgroup J Avian Leukosis Virus (ALV-J) was isolated in the late 1980s from meat-type chickens in the United Kingdom. ALV-J with exception of some acute variants, cause myeloid leukosis in meat-type chickens with long incubation period.In this study while the status of Avian Leukosis Virus Subgroup J in six different strain of broiler grandparent flocks of Iran evaluated, the evaluation of different primers and some molecular methods also were done. For this reason, 100 blood samples, which had EDTA, 100 mixed of white blood cells and plasma and 100 feather pulps were collected from one farm of each broiler grandparent strain. PCR and nested PCR were methods that used for the study. In molecular study before the extraction of DNA from samples; In order to decrease the number of samples, 10 mixed of white blood cells and plasma, blood or feather pulp pooled. In molecular study with PCR all of samples were negative, but in nested PCR reaction, from six broiler strains, five strains infected to ALV-J. The results indicate that the most of broiler strains in Iran have been infected to ALV-J. The results also indicate that we can simply use pooled samples for the study of ALV-J in a flock by nested-PCR test.

Cryptosporidium parvum is an apicomplexan protozoan parasite which causes diarrhea in both human and wide range of animals. Since this protozoa causes remarkable economic losses in cattke industry in Iran, the molecular determination of porotozoa and characterization of its protein pattern and immunogenic antigend are the aim of this study. In this study, diarheatic fecal samples of calves suspected for cryptosporidiosis were collected and identified. Purification and concentration of cryptosporidial oocysts from fecal samples was performed. Oocysts were confirmed as Cryptosporidium parvum by semi-nested PCR using specific primers designed from 18srRNA gene of Cryptosporidium parvum. A calf with negative antibodies against Cryptosporidium parvunm was infected with 5 ×106 oocysts. 5 days after inoculation, oocysts were isolated and purified. Soluble proteins from sporozoites were prepared and analyzed by SDS-PAGE and western blotting. There was an intense recognition of some10 to 100 kDa, ten low molecular weight proteins were recognized between 20-40 kDa, six separated protein bands was recognized between 40-70 kDa, immunoreactive proteins were present at different molecular weights between 17-260 kDa. Three antigens of apparent molecular weights 20-30 kDa, three antigen bands between 40-60 kDa and 2 bands 70-75 kDa were identified. Antibody responses to cryptosporidial antigens at high molecular weights were successfully diagnosed with apparent molecular weights 130,170,216 and 257kDa.

The Prostate gland is the major accessory gland in male dogs. Prostate disease is a common problem in older intact male dogs. The aim of this study was to determine prostatic dimensions by plain radiography and urethrocystography in dogs and compare them with actual sizes. Plain radiography and urethrocystography were performed on 10 intact young adult male dogs. After necropsy length, width, height, volume and weight of prostate glands were measured. All statistical analyses paired t test, linear regression and correlation coefficient were performed. Prostate glands of 9 dogs could be evaluated with urethrocystography and reliable length and height of prostate gland were measured. Means of prostatic length and height were smaller than their actual sizes but still had significant correlation (p|£|0.05). Equations between prostatic and actual lengths and depths in urethrocystography were L=0.91 × l + 0.57 (R2 = 0.84) and Z= 1.36 × z - 0.79 (R2 = 0.76) respectively. The results of this investigation were showed that urethrocystography could be used for prostatic measurement. This method can be as a reliable technique, whenever ultrasonography can not be performed.

The growing interest in substitution of chemical food preservatives by naturalones has fostered researchs on plantessentiak oils and extracts. In this study effect of different concentrations of Zataria multiflora Boiss. Essential oil (0, 0.005, 0.015 and 0.03%) on Bacillus cereus ATCC 11778, (103cfu /ml), was evaluated using sterilized samples (16 bottles containing 80 ml barley soup) and 4 different incubating temperatures (8, 10, 15 and 25? C) during 21 days. Data analysis was done using two way ANOVA. It was found that effect of different concentrations of essential oil on growth rate of Bacillus cereus ATCC 11778 was statistically significant (p<0.01). The results suggested that Zataria multiflora Boiss. essential oil can be considered as a natural preservative in some foods

In order to study the effect of concomitant use of a probiotic with Lactobacillus origin (Primalac) and a coccidiosis vaccine (Paracox-5) in experimental coccidial infection of broilers, 600 day old male broiler chickens were randomly divided into five groups of 120 with four replicates. Groups three, four and five received probiotic, coccidiosis vaccine and probiotic + coccidiosis vaccine, respectively. At 26 days of age all groups(except first group) were challenged orally with a suspension of sporulated oocystes of E. acervulina, E. maxima and E. tenella. Serum carotenoid levels were determined before challenge and 6 days after that. OPG of the feces was measured at 6 to 10 days post challenge. Performance parameters were also determined during the experiment. OPG of the treated groups with vaccine and /or probiotic were significantly lower than the positive control (p< 0.05). It was concluded that and coccidiosis vaccine probiotic with Lactobacillus origin (to some extent) are able to control negative impacts of coccidial infection. In the meantime simultaneous usage of probiotic and coccidiosis vaccine, did not have any interaction with efficacy of the vaccine.

Ornithobacterium rhinotracheale (ORT) has been identified as one of the emerging respiratory bacterial pathogens in turkey and chicken flocks. Diagnosis of ORT infection has been faced some difficulties in isolation and identification of the bacterium based on the biochemical properties. A reliable identification method that can be used in routine laboratory investigations is of importance. The Purpose of this study was diagnosis of ORT using polymerase chain reaction (PCR) in comparison with culture. The PCR was optimized using the primer combination OR16S-F1 and OR16S-R1, positive control of ORT bacteria, and 7 other bacteria such as Haemophilus paragallinarum and Pasteurella multocida as negative control. All samples were prepared for DNA extraction by use of phenol- chloroform method. Sixty pooled tracheal and infraorbital sinus samples from 30 broiler flocks slaughtered at an abattoir in Gazvin province were examined for presence of ORT using culture and PCR assay. A fragment of 784-bp was amplified in 5 positive known ORT samples, but not in other 7 bacteria as negative controls. 19 out of 60 primary samples including 11 homogenized tracheal samples and 8 infraorbital sinus swabs, and also all 17 suspected and purified colonies identified microbiologically as ORT were positive in PCR assay. One out of 41 negative primary samples in PCR test became positive through the culture. Then the propagated bacterium was confirmed in PCR. Fifteen out of 30 flocks (50%) were positive in PCR test and only one of them was negative in culture. Upon the results the PCR method of this study can be used as a reliable and rapid identification of ORT in samples suspected to ORT infection. However, it is better to use a combination of the PCR and culture in order to maximize the diagnosis of ORT infections. Key words: diagnosis Ornithobacterium rhinotracheale (ORT), polymerase chain reaction (PCR), broiler.

Influence of both dietary and bath administration of Eucalyptus globules labill was evaluated on some immunological variables of common carp (Cyprinus carpio) under temperature less than optimum in order to determine stimulatory effect of the essential oils. Fish weighing 30-35 g were bathed or fed with different doses of 30, 60 and 120 |m|l/L or mg/kg feed for a period of 8 days. Serum lysozyme activity, bactericidal activity, total white blood cells, total protein, globulin and albumin were measured on days 1, 2, 8, 15 and 23 after the essential oils administration. On day 23 post administration the remaining fish from each group were intraperitonealy injected with killed Aeromonas hydrophila (6×108cells/ml) and antibody titer was measured 3 weeks later. The obtained results showed that Eucalyptus globules had a limited immunostimulatory effect on these immunological variables although antibody titers and total white blood cells in some test groups were significantly (p<0.05) higher than the control one. The reduction of the immunological factors is probably related to the lower water temperature, inappropriate administrating dose and duration of essential oils administration.

This study was conducted to investigate the effects of diets containing different levels of hull-less barley on caecal microflora of broiler chicks. Two hundred and forty one-day old male broiler chicks (Arbor Acres strain) were used in a completely randomized design with 4 tratments, and 3 replicates were allocated to each treatment. Different levels of hull-less barley in diets had not significant effects on total bacterial count, E.coli, Clostridia and Lactobacillus population in caeca at starter period(21days old), but at 49 days of age, caecal Lactobacilus population increased significantly by increasing the levels of hull-less barley in diets(p<0.05). Based on the results of the present study, it can be stated that inclusion of hull-less barley in diets, change the caecal microflora of broiler chicks. These components reduced pathogenic bacteria (Clostridia) and increased the usefull bacteria (Lactobacillus).

The extreme polymorphism in MHC B-F genes enables the chickens to recognize enormous numbers of foreign peptides to trigger an immune reaction. Study of this genetic resources is very important and it is essential to avoid the loss of genetic variability. Genetic polymorphism among Arian strain, a endogenous broiler chickens in Iran, was investigated. In this study PCR-SSCP was carried out for revising the polymorphism in MHC (B-F) in Arian broiler chicken. 65 samples of chicken DNA belonged to 2 groups of parents (25) and hybrids (40) were analyzed. 7 distinct profiles have been demonstrated for two groups. Two profiles were identical between two groups. Two of all profiles have been demonstrated by previous studies and 5 were new in this study. From this study it was concluded that MHC (B-F) diversity exists within Arian broiler chicken that might be useful for selecting desirable immunological traits.

An investigation was under taken to evaluate the out of season reproduction performance of ewe. A flock consisting 119 ewes was synchronized via implementation CIDR over a period of 12 days, following by injection of PMSG (400 IU). The ewes inseminated and divided to three experimental groups. Group1: Injection of GnRH (5ml) at day 12 post insemination, group 2: Received CIDR for 5 to 15 days post insemination and group 3(control): ewes did not receive any treatment. Data were analyzed in Chi- Square method by SAS soft were. Fertility in group1, 2 and 3 were 40, 30 and 30.76 percent and fecundity were 65.0, 37.5 and 43.5 percent and twining rate were 62.5, 25.0 and 41.6 percent, respectively. Results reveal that supplementation of progesterone or GnRH would not enhance reproductive performance in the ewe in out of season. Key words: GnRH, ewe, CIDR, fecundity, twining rate.

Diagnosis of Nutritional Secondary Hyperparathyroidism in preliminary stage was studied by determination of serum profiles as first key for early diagnostic method. On the other hand compare between two treatment methods for osteoprothic cases has concerned in second part of survey. Treatment performed by drug consumption and changes in food regimes for two seperated groups. 50 osteoprotic and 50 normal 2-3 month old kittens were selected randomly. Radiographic exams were our landmark to selection of osteoprothic kittens. Serum calcium (Ca), parathormon(PTH), phosphorus(P) and serum alkaline phosphatase(AP) levels measured in all of them. Serum profiles have in osteoprothic and normal ittens were compared by student t-test and paired t-test. Comparative study showed significant decrease in serum P and increase in PTH in the first group (Osteoporotic kittens) (P<0.05). No significant changes have seen in serum Ca and AP in both groups.

Chitosan is a natural antimicrobial which is derived from non-toxic animal resources. This study investigated and compared the antimicrobial characteristics of chitosan which was extracted from shell of Artemia cyst in the lake of Urmia with the same commercial chitosan feature to that of crab shell from A.P.T firm in Vietnam. The experiment was carried by means of two fulded method to find the minimum inhibitory concentration (MIC) of commercial chitosan and Artemia chitosans and (4,2,1,0/5,0/25,0/125,0/062 mg/ml) (6/4,3/2,1/6,0/8,0/4,0/2,0/1 mg/ml) on Staphylococcus aureus, Escherichia coli, Salmonella typhimurium and Listeria monocytogenes. MIC of Artemia chitosan for those bacteria and MIC of commercial chitosan were determined 500 ppm and 800 ppm. In the next phase, each of those four bacterias was separately exposed to MIC Artemia chitosan and during 8 h of incubation at 37?C were artificially cultivated every 2 h and colonies appearing on the plates after 24 h of incubation were counted and the death time graph of the bacterias was drown to study their destruction process in the presence of MIC of Artemia chitosan. Experimental achievements showed that in this period of destruction speed in Staphylococcus aureus was more than others and the destruction speed of Salmonella typhimurium was the least. Also studying the achieved pictures by electronic microscope from the from two bacterias, gram-positive Staphylococcus aureus and gram-negative Escherichia coli which were exposed to MIC of Artemia chitosan (500 ppm) depicted that the speed of influence by Artemia chitosan on gram-positive bacteria is much more than gram-negative bacteria. Results of this study depicts great abilities of Artemia chitosan in destroying studied bacteria in comparis on with those of commercial one.