BACKGROUND: This study was initiated to improve our understanding  of the health and environmental impact of silver nanoparticles (Ag-np). OBJECTIVES: The purpose of the study is application and direct effects of silver nanoparticles on Zebra fish (Danio rerio). METHODS: After characterizing the AgNPs using TEM, EDX, UV-Vis Spectroscopy, XRF and SEM methods, their effects on some vital tissues have been tested successfully in vitro. In this study, 540 fish (2±0.05 g) were randomly divided into 9 groups in triplicate for acute tests (0,10, 50, 100, 200, 400, 600, 800 and 1000 mg/kgfood). After short term (96h), chronic toxicity tests were evaluated using under lethal concentration (100, 400, 600 and 800 mg/kgfood) fed with experimental diet for 8 weeks. Fish in groups 1 to 4 were fed by food supplemented with 100, 400, 600 and 800 mg/kg food, respectively. Group 5 was fed with basal food without supplementation. After histopathology, heavy metals were measured by spectrum photometry reveal. RESULTS: According to the results of acute tests, the 96h LC50 values in 24, 48, 72 and 96h were 804.601, 486.637, 323.696 and 195.208 mg/kgfood AgNPs for the Zebra fishes respectively. According to the results of chronic toxicity tests, fed via oral administration of AgNPs produced significant histopathological effects. Also, the most important histopathological effects of AgNPs were observed in the liver (vasculature and exposure, degeneration of some hepatocytes), intestine (increase in the submucosa layer, narrowing of the intestinal lumen  and reduced intestinal absorption), gills (clubbing of gill secondary lamaleas, hyperplasia, hyperemia and shortening of the primary lamaleas gills) and kidney (degeneration, high increase in interstitial cells and dilatation of Bowman’s space of glomeruli), respectively. The greatest bioaccumulation of silver occurred in the liver, gills and muscle of fish respectively (p<0.05). CONCLUSIONS: The release of untreated nanoparticle waste to the environment should be restricted for the well-being of human and aquatic species.

BACKGROUND: Lactic acid bacteria are the most common class of bacteria used in aquaculture as probiotic. ObjectiveS: In this study the effects of various levels of Lactobacillus casei on the growth performance and digestive enzymes activity of juvenile Shirbot were evaluated. Methods: Four hundred-eighty juvenile Shirbot weighing 40 g were divided randomly in four treatments (in triplicate). Treatments of A, B and C were fed with 5×106 CFU g-1, 5×107 CFU g-1, 5×108 CFU g-1, respectively for 60 days. Control group was fed with free-probiotic diet. After the period, treatments were fed with free-probiotic diet for 15 days. Growth indices and digestive enzymes were examined on days 0, 30, 60 and 75. Results: In the Treatment B, Specific Growth  Ratio, Daily Weight Growth and Relative Growth Rate, after 30 days from the beginning of experiment improved considerably which, compared to control group had significant difference (p<0.05). Activity of chymotrypsin enzyme in treatment of group B after 30 days and similarly, trypsine in treatment of group C after 30 and 60 days, were increased significantly compared to control group (p<0.05). In the other points of sampling and enzymes, considerable difference was not seen (p>0.05). Conclusions: Results showed that 5×107 CFUg-1 of Lactobacillus casei for 30 days and 5×108 CFUg-1 for 60 days, are the best doses of probiotic.

BACKGROUND: Honey is recognized as having different biological properties including antioxidant effects. Phenolic acids and flavonoids are the main antioxidant in this apiary product. OBJECTIVES: In this study eight samples of Sabalan honey were screened to evaluate the antioxidant activity, total phenolic and flavonoid content. METHODS: Antioxidant activity of honey samples was determined by DPPH (2,2-diphenyl-1-picryl hydrazyl) method and β-carotene bleaching assay, total phenolic and flavonoid by Folin-Ciocalteu and Aluminium chloride methods, in addition, in all samples, some physicochemical parameters (pH, acidity, diastase activity, existence or nonexistence of HMF) were measured according to Iranian National Standardization N92. Data were analyzed using ANOVA (one-way). RESULTS: Total phenolic and flavonoid content of honeys ranged respectively from 15.71- 41.58 (mg GAE/100g honey) and 3.80-13.20 (mg QE/100g honey). Antioxidant activity was between 23.19%-94.25%, β-carotene bleaching inhibition 69.54%-85.69%, pH ranged from 3.63-3.83, Acidity 11.99-20.50 mEq/kg , diastase activity of all samples was negative except sample No.1. All samples had positive HMF results. CONCLUSIONS: Regarding the above results, it could be concluded that the honey samples have significant antioxidant activity. All parameters of physicochemical test were according to the international specifications except diastase and HMF tests, which may be due to improper processing and storage condition, heating treatment, old honey,etc.

Background: Colisepticemia is an acute fatal disease in farm animal neonates. Clinical finding of septicemia is non-specific and cannot be differentiate from signs of non-infectious disease or disease with local infection such as diarrhea. Object: Evaluation of clinical signs variations in calves with experimental septicemia with Escherichia coli O111:H8. Methods: Colisepticemia were experimentally induced in ten Holstein bull calves after an adaptation period. Vital signs and 7 clinical criteria were recorded from 24h before septicemia until 48h after that. Blood culture was performed and treatment was done based on antibiogram from 24h after challenge. Results: Changes of suckling reflex and shock were not significant. Changes of appetite, dehydration, behavior, standing ability, total score from 24h before the challenge to 24h after treatment were significant(P

BACKGROUND: Heat stress reduces the poultry performance through physiologic changes. OBJECTIVES: This experiment was conducted to evaluate the effects of different levels of tryptophane on performance, carcass characteristics and some blood parameters of broiler chickens under heat stress condition. METHODS: Two hundred and fifty one-day-old broiler chicks (Ross 308) were used in a completely randomized design with four treatments and five replicates (pen), 10 birds in each replicate. The chickens of experimental treatments were fed basal diet (control group) and the diets plus the different levels of 100, 120 and 130 and 140% of the Ross strain tryptophane requirements. The experimental diets were used during the finisher period (day 25 to 42 of age) and under heat stress (32±1 ºC as cyclic from 9.00 AM to 5.00 PM). RESULTS: The results showed that the weight gain was  increased linearly by increasing the tryptophane level to 110% of Ross requirements but increasing the tryptophane level to 120, 130 and 140% caused the deteriorated weight gain (p<0.05). The feed conversion ratio was linearly decreased during the finisher and whole the period by supplementation of tryptophane to 110 and 120% but the higher tryptophane levels (130 and 140%) increased the feed conversion ratio during these two periods (p<0.05). Increasing the tryptophane level to 130% of Ross requirements caused a linear increase in the amount of lactate dehydrogenase, alanine amino transferase and alkaline phosphatase (p<0.05). Dietary supplementation of tryptophane had no effect on the blood urea, protein, creatinine, albumin, glucose and cholesterol at day 42 of age but triglyceride (p>0.05). Increasing the tryptophane level to 140% caused the lower blood triglyceride content (p<0.05). CONLUSIONS: Totally, the results of recent experiment show that consumption of 110 and 120% tryptophane of Ross requirements is the best level for performance improvements in broiler chickens under heat stress.

BACKGROUND: The insoluble fiber content of poultry feeds is often considered as an unfavorable factor which reduces the nutritive value of diet. OBJECTIVES: The effects of barley hulls on performance traits of broiler chickens were evaluated. METHODS: The experiment was carried out using 200 Ross 308 broiler chickens in a completely randomized design with 5 treatments and 4 replicates. The experimental diets  consisted of a control hulls-free diet and four diets containing 0.75 or 1.5 percent barley hulls with particle sizes of less than 1 mm or between 1-2 mm. RESULTS: The dietary type did not affect feed intake of the experimental groups. In the whole the experimental period, the weight gain and feed conversion ratio in the broiler chickens feed, the diet that contained 1.5% barley hulls with 1-2 mm particle size improved compared to the control group (p<0.05). In the jejunum, fiber feeding resulted in an increased goblet cell number as compared to the control group (p<0.05). Unexpectedly, barley hulls feeding reduced the villi height compared to the control group (p<0.05). In jejunum the crypt depth in control birds was more than the treatment fed 1.5% barley hulls with less than 1 mm particle size (p<0.05). The ratio of crypt depth to villus height in control group was more than the birds fed the diet that contained 1.5% barley hulls with less than 1 mm particle size (p< 0.05). In ileum the chickens fed the control diet had more lactobacillus and less Escherichia coli than the majority of the treatment fed barley hulls. CONCLUSIONS: Inclusion of 1.5% barley hulls with particle size of 1-2 mm in diet improved performance traits of broiler chickens. On the other hand, using 1.5% barley hulls as a lignocelluloses source increased lactobacillus growth and reduced Escherichia coli population. This alteration in intestinal micro flora suggests a prebiotic effect for barley hulls in the gastrointestinal tract of broiler chickens.

BACKGROUND: The application of natural compounds including green tea extract (GTE) in food preparation and pharmaceutical industries is limited. Nowadays, encapsulation in nanoliposomes could be used as a delivery system to protect compounds during processing and storage. Objectives: In this study, physicochemical characterization of green tea extract encapsulated in nanoliposomes and its prebiotic activities on two probiotic bacteria Lactobacillus casei and Bifidobacterium lactis were evaluated in media and ice cream. Methods: At first, GTE encapsulated in liposomes by thin film layer method and with sonication liposomes reached to nanoscale. For evaluation of the prebiotic activity of nanoliposomal GTE on probiotics, 1% of nanoliposomal GTE in the presence of Lactobacillus casei and Bifidobacterium lactis was added to MRS broth and ice cream. Results: The mean diameter of nanoliposomes was about 44/7± 1/9 nm and had 0/203 ±0/014 polydispersity index. Entrapment eficiency of nanoliposomal GTE under the optimum conditions was 97%. Moreover, addition of 1% nanoliposomal GTE significantly increased the growth rate of Lactobacillus casei and Bifidobacterium lactis in culture media (p<0.05). The lowest reduction of Lactobacillus casei count during storage period was recorded in ice cream containing 1% of nanoliposomal GTE, while the control group showed the reduction of 4/16 log in Lactobacillus casei count. Similarly, addition of 1% of nanoliposomal GTE was most effective on survival of Bifidobacterium lactis in ice cream, since the bacterial count lowered only 0/84 log during the storage compared to 4/4 log reduction in control group. Conclusions:  The considerable effect of nanoliposomal GTE on growth and survival rate probiotics in media and ice cream has been presented in this study and  the use of nanoliposome encapsulation can be proposed as a new method to increase stability of natural compounds, during different processes.

BACKGROUND: Goldfish (Carassius auratus), a carp fish of Cyprinidae family, is one of the most popular aquarium fishes in Iran and also in the world. Ornamental fish trade, especially Goldfish, is aged over a hundred years. If we believe that any aquatic species or country has its own specific and unknown fauna of pathogens, the risks of transmission of these pathogens by importing ornamental fishes (whether at national, provincial or municipal level) will become more obvious. However, few researches have been done about parasitic infections in ornamental fishes. Objectives: Identification and investigation of fish pathogens, especially parasites, prior to transportation to new place is considerably important in the preventing and restricting the transmission of these pathogens.                      Methods: In this study, skin and gills of 100 goldfish were examined by wet mount in order to investigate monogenean parasites. Results: Nine species of parasites from 3 families (Dactylogyridae, Gyrodactylidae and Ancylodiscoididae) were isolated and identified in fishes, including 4 species of Gyrodactylus (Gyrodactylus kobayashii, Gyrodactylus Gurleyi, Gyrodactylus longoacuminatus and Gyrodactylus sp.), 4 species of Dactylogyrus (Dactylogyrus vastator, Dactylogyrus formosus, Dactylogyrus baeri and Dactylogyrus sp.) and 1 species of Ancylodiscoides. Gyrodactylus kobayashii (10%) were the most common parasites found, followed by Dactylogyrus vastator (9%). ConclusionS: Although these fishes are quite resistant against such pathogens, transporting them to a new aquatic ecosystem could transfer these parasites and cause infestation of healthy fishes, which brings about financial losses and casualties.

BACKGROUND: Coronaviruses have a wide range of host tropism causing respiratory, enteric and central nervous system diseases in pigs, cats, dogs, rodents, cattle, avian species and human. Coronaviruses undergo genetic mutations and recombination at high rates which make them able to infect a wide range of host species from different geographical locations. According to the possible existence of gammacoronavirus in Iranian bird population including pigeons and lack of information about virus prevalence, isolation and molecular characterization of pigeon coronaviruses are needed. OBJECTIVES: The present study was conducted to detect avian coronavirus in flocks of Tehran province.               METHODS: samples were randomly collected from 25 pigeon flocks of Tehran province (250 tracheal swabs and 250 cloacal swabs, 20 specimens from each flock) between 2014-2015. The viral RNA was extracted from swab samples and RT-PCR reaction was run using the QIAGEN one-step RT-PCR Kit with primers targeting nucleocapsid (N) gene and 3’ untranslated region (3’-UTR) of gammacoronavirus. RESULTS: Gammacoronavirus was detected in one out of 25 (4%) flocks. CONCLUSIONS: The results of this study approve the presence of  gammacoronaviruses  in pigeon population and help to complete the map of  epidemiology of the virus in Iran. According to the low prevalence rate of coronavirus in pigeons, samples should be collected from pigeons showing respiratory or enteric signs of disease or from pigeons having contact with other birds or those which are housed near poultry farms.

BACKGROUND: Pigeons can be carriers for some human and animal pathogens, one of the most important of which is Escherichia coli. OBJECTIVES: This bacterium is responsible for outbreaks of many human diseases. Our objective was to determine the prevalence of Escherichia coli in cloacal area of pigeons in Tehran city (Iran), and determine  the prevalence of some virulence genes and also antibiotics resistance pattern of isolates. METHODS: Altogether 117 samples of pigeon feces were collected from cloacal swab. The identification of bacteria was done by culture on differential culture media. Then antibiotic susceptibility test was performed by disk diffusion method. Isolates were tested for the presence of virulence genes stx1, stx2, eae and hlyA using multiplex polymerase chain reaction. RESULTS: Escherichia coli were detected in 82.9% of 277 samples from pigeons. Sulfamethoxazole was the least effective drug (85.6% resistance), followed by tetracycline (83.5%). No resistance was detected to co-amoxiclav. The prevalence of stx1, stx2 and eaeA is 3.09%, 6.18% and 2.06% respectively and hlyA was not found in any of isolates. CONCLUSIONS: The frequency of stx1 and stx2 distribution in animals and birds is not well understood as yet. Due to the close relationship of humans with birds like pigeons and presence of STEC strains in apparently healthy birds, necessitates  considering  precise regulations to restrict and prevent the prevalence of this life- threatening virus in Iran.