Journal of Veterinary Research
Year:2012 | Volume:67 | Issue:4|Papers Count:14

BACKGROUND: The growing interest in substitution of chemical food preservative with natural ones has fostered researches on plant essential oils and extracts.OBJECTIVES: The purpose of the current study was to evaluate the effect of Zataria multiflora Boiss. essential oil on growth respose, the percent of growth inhibitory and morphology of Penicellium citrinum.METHODS: Different concentrations of the essential oil (0, 50, 100, 200, 400, 600 ad 1000 ppm) were used in agar dilution method to evaluate growth and spore production parameters. The cultured mold were studied by scanning electron microscope. Values among groups were compared using 1-way ANOVA.RESULTS: It was found that the effect of different concentrations of essential oil on radial growth and sporulation was statistically significant (p<0.05). The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) both were 400ppm. According to scaning electron microscopy the treatment with the oil led to alterations in hyphal morphology.CONCLUSIONS: Our results suggest that Zataria multiflora Boiss. essential oil can be used as a natural preservative against Pencillium citrinum in foods.

BACKGROUND: The effects of probiotic and calcium butyrate (Ca-butyrate) as feed additives on performance and immune response have been shown in laying hens.OBJECTIVES: The aim of the present study was to investigate the effects of different levels of probiotic and Ca-butyrate on performance, egg quality, blood parameters and immune response in laying hens METHODS: Two hundred and eighty eight Hy-Line W-36 hens (62 to 70 wks of age) were used in a 2×3 factorial arrangement with three levels of probiotic (0, 0.07 and 0.01 percent) and two levels of Ca-butyrate (0 and 0.1 percent) in a completely randomized design of 6 treatments and 8 replicates.RESULTS: The results showed that feed intake, feed conversion ratio, egg production, shape index, yolk index, haugh unit, egg weight and specific gravity were not affected by probiotic and Ca-butyrate. While egg weight and egg mass were significantly (p<0.05) increased using. probiotic compared with the control diet, such an effect was not observed due to Ca-butyrate addition. However, shell thickness showed significant increase (p<0.05) in response to Ca-butyrate. The interaction between different levels of probiotic and Ca-butyrate was only significant for feed conversion ratio (p<0.05). Antibody titer against sheep red blood cell (SRBC) was not affected (p>0.05) by experimental treatments. The concentration of serum albumin was significantly increased (p<0.05) by adding probiotic and Ca-butyrate to feed. Furthermore, significant increase (p<0.05) in total serum protein was pronounced in response to probiotic and Ca-butyrate. However, other serum metabolites (total calcium, triglycerides and cholesterol concentrations) were not affected by treatments. The relative percentage of heterophiles and heterophiles to lymphocytes ratio were significantly decreased (p<0.05) using probiotic.CONCLUSION: Dietary probiotic and Ca-butyrate can be considered as additives to improve immune responses in laying hens.

BACKGROUND: Neospora caninum, a pathogenic protozoan parasite, has been considered as a major cause of infectious bovine abortion throughout the world.OBJECTIVES: The aim of the present study was to determine the seroprevalence of N.caninum antibodies in native and crossbreed cattle of Hamedan province, Iran.METHODS: Serum samples of native (n=139) and crossbreed cows (n=261) were examined using ELISA method values were analyzed by description analysis.RESULTS: The frequency of prevalence for N.caninum antibodies was shown as much as 20%. Furthermore, the most and the least frequency rates were shown in cattle over 4 years old (32.33%) and less than 2 years old (7.32%), respectively (p<0.05). Meanwhile, 64% of cows which had abortic chain were seropositive (p<0.05).CONCLUSIONS: It can be concluded that N.caninum should be considered as a causative agent for abortion in native and crossbreed cattle in Hamedan province.

BACKGROUND: Hypocalcaemia as one of the most important ovine metabolic diseases occurs during late gestation and early lactation.OBJECTIVES: The aim of this study was to investigate the physiological effects of experimentally induced hypocalcemia on serum biochemical, enzymatic and electrolyte changes.METHODS: Ethylene diamine tetra-acetic acid (EDTA) solution (4.6 %) was intravenously infused to 5 healthy sheep (experimental group). Meanwhile, 5 healthy sheep received 0.9% saline solution (IV) and kept at similar condition as control group. In both groups serum was collected before and after EDTA infusion at different time points. Aspartate transaminase (AST), alanine transminase (ALT), glucose, blood urea nitrogen (BUN), total protein, calcium (Ca) and inorganic phosphorus (Pi) levels were measured.RESULTS: Clinical signs of hypocalcemia and/or changes in heart rate was caused by EDTA infusion. Serum calcium levels showed significant decrease (39.2% at its maximum state) following EDTA infusion (p<0.05), compared to the pre-infusion state. Pi levels showed significant decrease (57.8% at its maximum state) during 1 to 4 hours following EDTA infusion. Meanwhile, it was accompaning with an increase (9.9% at its maximum state) at 5.5 to 22 hours after EDTA infusion. Increase in serum glucose levels during 1 to 3 hours following EDTA infusion was determined as much as 60% (38.44 mg/dl) at its maximum state. An increase (51.1% at its maximum state) was shown in blood urea nitrogen levels after EDTA infusion in experimental group. Changes in total protein, ALT and ASTwere not significant before and after EDTA infusion.CONCLUSIONS: While, experimental hypocalcemia can be accompanied with a decrease in serum Ca level, time dependent alterations in Pi and an increase in glucose and BUN levels can be observed. However, AST, ALT and total protein values can be without any changes.

BACKGROUND: Viral (H9N2) polymerase complex in Avian influenza viruses is composed of the PB1, PB2, and PA protein subunits. These subunits are crucial for viral transcription and replication.The PB1 subunit forms the core of the polymerase complex. It plays a key role in RNA synthesis.OBJECTIVES: Survey on molecular characterization of PB1gene in H9N2 viruses and determination of genetic relationship between Iranian H9N2 viruses and other Asian viruses.METHODS: Seven H9N2 viruses were isolated from commercial broiler chickens in Iran during 2008-2009 and their PB1 genes were analyzed by RT-PCR and sequencing. Meanwhile, nucleotide sequences (Open Reading Frame: orf) of the PB1 genes were used for phylogenetic tree construction.RESULTS: Phylogenetic analysis of the PB1 gene showed that all Iranian viruses form a separate unknown sublineage. On the other hand, while nucleotide sequence comparisons indicated high genetic diversity in Iranian viruses, a close homology (95-96%) was shown with H5 or H7 subtypes when compared with established H9N2 Eurasian sublineages (G1, Korean and Y280-like).CONCLUSIONS: The results indicate that H9N2 viruses in Iran have undergone striking reassortment to generate some new genotypes.

BACKGROUND: In the first time, avian Influenza (AI) infection, subtype H9N2, was isolated from chicken in 1988 in Qazvin province and since then has become endemic in Iran. Waterfowls, such as wild ducks, are natural reservoirs for all types of influenza A viruses and cause virus circulation in environment and poultry population. In 2006, Iranian Veterinary Organization confirmed that 135 dead swans in Gilan province were positive for H5N1 avian influenza virus.OBJECTIVES: The purpose of this study was to determine the role of domestic ducks in avian influenza virus circulation (subtypes: H5, H7 and H9) in Gilan province during 2010-2011 through molecular surveillance techniques. METHODES: 550 cloacal swabs from Mallard and Pekin ducks were tested in rural areas of Shaft and Fouman cities. Meanwhile a breeding farm in Gilan was tested by RT-PCR assay for detection of AI virus subtypes (H5, H7 and H9) according to OIE protocols.RESULTS: We did not detect AI viral RNA in 550 samples which were tested for type A and subtypes H5 and H7.CONCLUSIONS: While waterfowls could have a crucial role in emergence of new influenza virus strains, no AI viral RNA mentioned subtypes was detected for the mentioned subtypes. These findings could be due to restrict control programs following 2006 AI outbreak in the mentioned region. However, surveillance programs for monitoring AI viruses need to be continuously performed.

BACKGROUND: Mycobacterial infection or Mycobacteriosis is one of the most important zoonotic bacterial diseases in fish, especially in aquarium fish, worldwide. Despite the importance of this disease, there is no record about the surveillance of this disease in Ahvaz region-Iran.OBJECTIVES: In this investigation the occurrence of Mycobacterium spp. in ornamental fish was studied using PCR technique.METHODS: In this survey, 150 fish were obtained from aquarium shops of Ahvaz. The fish was belonged to 5 species, i.e. Scatophagus argus, Astronotus ocellatus, Heross severus, Caesioteres sp. and Symphysodon aequifasciatus. The fish were transferred to the laboratory and examined after dissection. Meanwhile, liver, kidney and spleen samples were collected for PCR analysis. RESULTS: 80% of the examined fish showed no gross lesions at necropsy. However, only in a few fish some symptoms such as emaciation and anorexia were observed. In this study only 1 out of 150 fish (Heros severus) was detected as positive in PCR examination. Meanwhile, in DNA sequencing the bacterial species was recognized as Mycobacterium bovis. Other fish species showed no infection with Mycobacteria in PCR examination.CONCLUSIONS: Due to no pathogenesis of M. bovis in fish, this positive specimen can be considered as a transmission to fish from infected persons or feed products. These negative findings show that this Iranian region can be considered as a free one for these particular pathogens.

BACKGROUND: To improve breeding programs in dairy cattle artificial insemination using sexed sperm has been applied in different farms.OBJECTIVES: To evaluate pregnancy rate and economic benefit of artificial insemination with sexed sperm in Holstein dairy heifers of Shiraz industrial farms.METHODS: The insemination data of 200 heifers in five farms including sperm types (sexed or conventional) and insemination date and times were collected from March 2009 to March 2010.RESULTS: The pregnancy rate of conventional sperms (72.2%) were significantly higher than the sexed sperms in heifers (49.2%; p=0.001). The sexed sperms insemination showed lower fertility in the winter (36.3%) when compared with the autumn values (73.9%; p=0.02). Cost and benefit analysis showed that costs of the first and the second insemination with sexed sperms were higher than the conventional ones. On the other hand, after the second insemination the economic benefit for the sexed sperms was lower than the conventional one. However, the cost and benefit analysis for sexed sperm values showed a trend to the convential ones.CONCLUSIONS: If the fertility rate of the sexed sperm insemination in healthy heifers reach to the 90 percent of the conventional sperm, sexed sperm insemination can be more beneficial than the conventional one after two insemination.

BACKGROUND: Omeprazole as an inhibitor decreases abomasal acid secretion. On the other hand, acidity would be a determinant for absorption of Immunoglobulins.OBJECTIVES: The aim of this study was to evaluate the effect of increasing abomasal pH due to Omeprazole administration on the rate of intestinal immunoglobulin absorption in newborn lambs.METHODS: 30 lambs immediately after birth were divided into 6 groups of 5 animals each as follows: Group1; The lambs received colostrum from birth to 84 hours after birth. Group2; The lambs were fed by colostrum + Omeprazole (4mg/Kg) from birth to 84 hours after birth. Group 3; The lambs were given milk for the first 24 hours and after then until hour of 84 by colostrum + Omeprazole. Group 4; The lambs were fed with milk + Omeprazole for the first 24 hours and after then until hour of 84 with colostrum + Omeprazole. Group 5; The lambs received milk for the first 6 hours after birth and after then received colostrums until hour of 84. Group 6; The lambs were fed with milk + Omeprazole in the first 6 hours after birth and after then until hour of 84 by colostrum + Omeprazole. Blood samples were collected at 0, 24, 48, 72 and 96 hours after birth. The total IgG was measured by ELISA method.RESULTS: Serum IgG levels in group 4 showed significant decrease when compared with the control (group 3). However, no significant difference was shown in the serum IgG levels among groups.CONCLUSIONS: The results of this study showed that after birth increase in abomasal pH do not make effect on IgG absorption.

BACKGROUND: Vitamin C is an essential nutrient for teleost fish. It plays vital role in immune system function.OBJECTIVES: A feeding trial was conducted to determine the effects of different levels of dietary vitamin C supplement on growth performance, hematological indicators and response to heat stress in rainbow trout (Oncorhynchus mykiss) fingerlings kept at different densities.METHODS: The fingerlings (initial weight of 2.1 ± 0.1) were reared in triplicate groups in fiberglass tanks at two different densities (400 and 600 /m2). The fish were fed with four experimental diets containing different levels of vitamin C (0, 100, 200 and 1000 mg vitamin C /kg diet) for 9 weeks. To evaluate the effect of heat stress on survival, fish were exposed to different temperatures (24, 26 and 28 oC) at the end of feeding experiment.RESULTS: Growth performance in fish which fed diets containing different levels of vitamin C (100, 200 and 1000 mg /kg diet) was significantly (p<0.05) higher than those fed diet without vitamin C supplement. In terms of hematological indicators, it was shown that different levels of vitamin C significantly (p<0.05) effected the hematocrit, hemoglobin and red blood cell (RBC) count. However, it did not make any effect on the MCH and MCHC values. On the other hand, stocking density only had significant effect on RBC count.CONCLUSIONS: Survival of fish which fed diets containing different levels of vitamin C was significantly (p<0.05) higher than those fed diet without vitamin C in response to heat stress.

BAKGROUND: Johne's disease or Paratuberculosis as a chronic granulomatosis enteritis in ruminants will be caused by Mycobacerium avium subsp. Paratuberculosis. Detecting whole bacterial cell wall antigens would be helpful in potential applications for diagnosis, vaccine production, and elucidation of pathogenesis.OBJECTIVES: To determine secreted somatic cell antigens of Mycobacterium avium subspecies Paratuberculosis.METHODS: Standard strain (III-V) of Mycobacterium avium subspecies Paratuberculosis DNA was extracted from the cultured and gene analysis was done using PCR to confirm bacterial purity. On the other hand, protein concentrations in both media and cell entracts were determined. Furthermore, all proteins pattern were shown by SDS-PAGE.RESULTS: Electrophoretic findings showed some somatic antigens in the range of 19-100 KDa.CONCLUSIONS: These purified somatic antigens can be used for further study and potential application in vaccine production.

BACKGROUND: Improvement of sperm quality as a research field in reproductive biotechnology of domestic animal can be considered as a key element for in vitro fertilization.OBJECTIVES: The aim of the present study was to investigate the effects of insulin and leptin on ovine sperm capacitation/acrosomal reaction, viability and fertilization.METHODS: The semen samples of 10 Bakhtiari rams were collected by artificial vagina. Using dose response study, the most efficient doses of insulin and leptin were chosen. Each sample was assigned to four experimental groups including insulin (1nM), leptin (100nM), mixed of leptin-insulin and control (without hormone). Sperm capacitation/acrosomal reaction, viability and fertilization were evaluated by chlortetracycline staining, eosin-negrosin and in-vitro fertilization methods, respectively. values were compared among groups by 1-way ANOVA.RESULTS: Values of capacitation/acrosomal reaction rate showed significant increase in response to insulin and leptin at 30, 60 and 120 min time points. The sperm viability was significantly (p<0.05) increased in response to insulin when compared with the control group at 30 min time point, without any effect in the other time points. On the other hand, insulin and leptin did not show significant effect (p>0.05) on sperm fertilization. CONCLUSIONS: This study indicated that insulin and leptin improved ram sperm capacitation/acrosomal reaction and viability while their effects on in vitro embryo production were inconsiderable.

BACKGROUND: Infectious hematopoietic necrosis (IHN), viral hemorrhagic septicemia (VHS) and infectious pancreatic necrosis (IPN) as important viral diseases of salmonids, especially rainbow trout can be led to mass mortality among cultured fish.OBJECTIVES: The aim of the present study was to show if IHN, IPN and VHS viruses can be detected in Iranian and imported rainbow trout eyed eggs and to compare their abundances among the hatcheries of 3 regions (Farsan, Koohrang and Lordegan) in Chaharmahal va Bakhtyari Province.METHODS: In each area, three hatcheries were selected, 20 eyed eggs were randomly sampled from each farm. The samples were transferred into the sterile tubes and identified by reverse transcriptase -PCR. Meanwhile, physicochemical factors were recorded for each fish.RESULTS: While total infection rate in eggs was 23.3 %, the level of infection for IPN, IHN and VHS was 12.5%, 10% and 0.83%, respectively. In this respect, maximum and minimum frequency were observed in Farsan (19.15%) and Koohrang (0.83%). Comparison of the infected of eggs, based on their origin, showed that the infection rates in Iranian and imported eggs were 20% and 3.33%, respectively.CONCLUSIONS: The results revealed that rainbow trout eggs should be considered as major source for transmission of aquatic viruses. Hence, molecular identification of above mentioned viruses in rainbow trout eggs should be done.