BACKGROUND: Salmonella are endemic on most large intensive dairy farms and salmonellosis is a common cause of neonatal morbidity and mortality. Disease and mortality usually reflect a variety of management events and environmental stressors that contribute to compromised host immunity and increased pathogen exposure. OBJECTIVES: In this study, PCR method was used to identify Salmonella Enteritidis, Infantis, Dublin and serovars isolated from diarrhea samples and aborted fetuses of Tehran and Alborz provinces dairy Farms. Further observation showed that the isolation of S. Enteritidis and S. Infantis is closely related to the consumption of contaminated poultry meat powder in diet of cows. METHODS: Forty-one Salmonella were isolated from diarrhea and aborted fetus samples in Tehran and Alborz provinces Farms and were confirmed by biochemical assays, then the isolates were identified by serological methods by polyvalent and monovalent Salmonella antisera. DNA of samples was extracted by Boiling method and was tested by PCR. Salmonella serovars were identified according to the presence of specificgenes for Salmonella Enteritidis, Infantis and Dublin.  RESULTS: All samples were tested by PCR were positive. 32 samples were identified as Salmonella Enteritidis (78/04 %), 4 samples were identified as Salmonella Infantis (9/77 %) and 5 samples were identified as Salmonella Dublin (12/19 %). CONCLUSIONS: According to the results, it seems that PCR can be used as a alternative method to the expensive and time consuming biochemical and serological methods for identifying Salmonella serovars. As Salmonella Enteritidis was usually isolated from poultry, isolation from cows may be due to has been used chicken meat powder in diet of the dairy farms.

BACKGROUND: Colony Collapse Disorder is a mysterious phenomenon in which worker bees abruptly disappear from a beehive. Objectives: The aim of this study was to estimate the prevalence of CCD and its relation to climate and Nosema spp infections. Methods: This Cross sectional study was done from April to September 2016. With respect to different climatic zones of the country, a total of 183 ‎apiaries were selected. In each apiary, 5 percent of the colonies were ‎randomly sampled. Adult bee samples were then examined for the presence of Nosema infections using PCR. Data were analyzed by Chi-square using SPSS version 21.0. Results: The results showed the prevalence of colony collapse disorder in the studied apiaries at 26.8%. The CCD prevalence was ‎20.5% in ‎humid, ‎16.1% in semi humid‎, ‎22.7% in very humid, 38.2% in arid, ‎43.8% in semi-‎arid and ‎16% in Mediterranean conditions. Comparing CCD phenomenon in different climatic regions, there were significant differences (P<0.05). The prevalence of Nosema ceranae infection was 85 (46.4%), however, infection with Nosema apis was not observed in the samples either in pure form or as ‎associated infection. There was no statistical significant difference between symptomatic and asymptomatic apiaries with colony collapse disorder in terms of presence or absence of N.ceranea (P>0.05).  Conclusions: The results suggest that climate could influence the prevalence of Colony Collapse Disorder. It may be due to different foraging resources in under studied area. According to findings of this study it seems that N.ceranea alone cannot be the cause for CCD. Further studies are needed to clarify the interactions between climate and other possible causes.

BACKGROUND: Based on previous studies, aquaculture systems affect on flesh quality in cultured species. In biofloc system, as a modern and new aquaculture system, animals use microbial flocs as feed and it seem such flocs affect on bodycomposition. OBJECTIVES: The aim of this study was to evaluate growth and chemical, microbiological and sensory properties of common carp meat cultured in Biofloc system. METHODS: Three hundred healthy fingerlings were randomly distributed in 12 tanks (70 L) at a density of 8.3 kg m-3 and fed experimental treatments: commercial diet as a control and three biofloc treatments including sugar beet molasses biofloc (SBM+BFT), sugar biofloc (S+BFT) and corn starch biofloc (CS+BFT). Fish in BFT treatments were fed at 75% of the daily feeding rate of control. At the end of experiment, growth performance and survival investigated. In addition to evaluate cultured fish meat quality, sensory properties of raw fish (day 0), rigor mortis (3, 6 and 24 h after catch), bacterial count, pH, expressible moisture and TVN were also assessed during 16 days, (every 4 days). RESULTS: The results indicated that the lowest food conversion ratio (FCR) and highest condition factor was observed in fish fed BC which differed significantly from control (P<0.05). No significant difference among treatments was observed in rigor mortis and bacterial count (P>0.05). pH in carp flesh increased gradually during storage time (P<0.05), but at the end of the storage period no significant difference was found between the treatments (P>0.05). The lowest primary TVN was seen in BS treatment (9.0 ± 0.2 mg N/100g flesh) but in other treatments TVN was higher than 20 mg/ 100g flesh (P<0.05). CONCLUSIONS: Overall, based on the results of this study, biofloc cultured fish flesh had acceptable quality in comparison with control fish.

BACKGROUND:  Considering the progressing tendency of administration of nanomaterials products in the world and their entrance to aquatic ecosystems, their toxicity assessment on the aquatic environment and proposing the biocompatible solutions in their production seems indispensable. OBJECTIVES: In this study, the toxicity of silver nanoparticles (AgNPs), chemical and biosynthetic forms were evaluated using the biomarker, artemia nauplii (Artemia fransiscana). METHODS: For toxicity assessment, the OECD standard method was used. The artemia nauplii were exposed to additive serial concentration of biosynthetic and chemical silver nanoparticles. For biosynthesis of silver nanoparticles, aqueous extracts of two species of marine macroalgae Ulva flexuosa (green algae) and Sargassum boveanum (brown algae) were used. Artemia nauplii mortality in the times of 12, 24, 36 and 48 hours after exposure to silver nanoparticles were recorded and analyzed via Probit software. RESULTS: Survey findings showed that not only the toxicity of these three types of silver nanoparticles on artemia nauplii increased in a dose- dependent manner, but also their toxicity increased along with duration of exposure time. The toxicity of these nanoparticles were significantly different (P<0.05). The 48 h LC50 value of chemical AgNPs in the artemia nauplii was 31.8 mg/l, while 48 h LC50 for biosynthesis AgNPs  produced by U. flexuosa, and S. boveanum were 366.96 and 141.16 mg/l respectively. CONCLUSIONS: Comparison of the toxicity of these three types of AgNPs on artemia nauplii showed that, the chemical form of AgNPs was more toxic (up to 10 times) than a biosynthetic form of AgNPs. Moreover, the source of biosynthesis of silver nanoparticles had a considerable impact on toxicity of final production, because a biosynthetic form of AgNPs produced by U. flexuosa was less toxic than the same form prepared from S. boveanum.

BACKGROUND: The sources of fish oil for use in aquaculture is limited and different oil sources vary in fatty acid composition. OBJECTIVES: The main objective of this experiment was to determine the effects of plant oil sources such as soybean and canola oils with or without L-carnitine supplement on some blood biochemical parameters and growth performance of fingerlings rainbow trout. METHODS: In 3×2 factorial experimental design, 180 rainbow trout with 28±2 g initial body weight were randomly divided into six groups with three replicates and fed two times a day at ad libitum by dietary treatments during 10 weeks. The experimental diets contained three dietary oil sources such as fish, soybean and canola oil; and two supplemental dietaries L- carnitine levels (0 and 1 g.kg-1). Feed conversion ratio, specific growth rate, feed intake, body weight gain and blood biochemical parameters of fish such as albumin, total protein, triglyceride, cholesterol and high-density lipoprotein (HDL) were measured at the end of the experiment. RESULTS: Replacement of fish oil by soybean and canola oil had no significant effect on growth performance such as body weight gain, feed intake, feed conversion ratio, specific growth rate, hepatosomatic index, carcass weight and condition factor of fish. L-carnitine supplement significantly improved weight gain and feed conversion ratio and increased condition factor of fish (P<0.05). Soybean oil significantly increased cholesterol and triglyceride level, and canola oil decreased HDL and globulin level in blood serum of fish (P<0.05). CONCLUSIONS: Results of this study showed that fish oil could be wholly replaced by soybean or canola oil in the diet of rainbow trout and also physiological responses and growth performance of fish to carnitine supplement were affected by dietary oil sources.

BACKGROUND: Antioxidant compounds and unsaturated fatty acids play an important role in improving the immune response and intestinal microflora in broiler chickens. Objectives: The aim of this study was to investigate the effects of different sources of antioxidant and soybean and rapeseed oils on humoral immune responses, intestinal microflora and some of the blood parameters of broiler chicken. Methods: A total of 480 male broiler chicks (Ross 308) were randomly allocated in a factorial arrangement (2×5) based on a completely randomized design with 10 treatments and 4 replicates during 42 days of age. Experimental factors consisted of different sources of antioxidant (rosemary, thymus and satureja essential oils at level of 300 ppm and vitamin E at concentration 200 mg/kg and without antioxidant) and vegetable oils (soybean and rapeseed oils at concentration of 4 percent of diet). Immune characteristics and intestinal microflora population were evaluated. Results: The use of different soybean and rapeseed oils had no significant effect on antibody titer (P>0.05) but the use of antioxidants improved immune responses against Newcastle disease (P<0.01). Also, the use of rosemary, thymus and satureja essential oils increased serum level of blood high density lipoprotein and reduced blood low density lipoprotein (P<0.001).  Furthermore, the concentrations of cholesterol and triglyceride increased in without  antioxidant treatment (P<0.001).Also, use of antioxidant treatments caused significant decrease of heterophil to lymphocyte ratio (P<0.05), then these result are consistent with the immune response against Newcastle disease. Furthermore, escherichia coli to lactic acid bacteria ratio increased in rosemary and thymus essential oils treatments compared with without antioxidant treatment (P<0.05). Conclusions:The use of dietary soybean and rapeseed oils did not have a significant effect on different traits of broiler chicken, but adding dietary antioxidants improved immune responses and intestinal microflora and in between different antioxidants, the use of essential oils compared with vitamin E  induced significant improvement of traits.

BACKGROUND: Increasing population and food provision is one of the most important problems in the world, thus aquaculture plays an important role in the production of food and human needs. OBJECTIVES: This study was to investigate the effect of Celmanax prebiotic on growth performance, hematological and biochemical factors of juvenile Oncorhynchus mykiss. METHODS: For this study, 780 juvenile rainbow trout with an average weight of 18 ± 2 g were randomly divided into four groups with three replications. 0, 2, 4 and 6 percent of Celmanax were added into diets and the fishes were fed with 5% of body weight for 8 weeks 3 times. At the end of experiment, investigation of the growth indices, blood sampling and serum preparation for hematological and biochemical tests were performed. RESULTS: The results showed that fishes fed with diets containing 4% Celmanax prebiotic had better growth indices (final length, final weight, weight gain, percentage of weight gain and specific growth rate) compared to control (P≤0.05). Comparison between experimental treatments demonstrated that immune indices significantly increased with increase of prebiotic levels in the diet (P≤0.05). So that, the highest level of hemoglobin, red blood cell, white blood cell and neutrophil were related to fishes fed with 6% of Celmanax prebiotic diet. Also, the highest levels of immunoglobulin, albumin, glucose and lsozyme and the lowest levels of cholesterol and triglyceride and cholesterol were observed in fishes fed with 6% of Celmanax prebiotic diet, which showed a significant difference with control (P≤0.05). CONCLUSIONS: Increasing levels of Celmanax prebiotic in the diet caused an improvement in the growth and immunity system of rainbow trout.

BACKGROUND: Lactococcusis disease due to Lactococcus garvieae, one of the most important zoonotic bacterial diseases. Objectives: The purpose of this study was to evaluate the effect of Cinnamon essential oil and Nisin on the growth of Lactococcus garvieae. Methods: The effect of cinnamon essential oil with concentrations of 0, 0.25 and 0.75%, and Nisin 0, 0.4 and 0.8 μg/mL on growth of this bacteria at 4 and 8 °C during 0, 3, 6, 9, 12, 15 days of storage was investigated. Results: The results of this study showed that on samples kept at 4 °C, bacterial growth was delayed until the fifteenth day using cinnamon essential oil or Nisin, and in the case of cinnamon, the growth rate of bacteria in the ninth and fifteenth days was below 2 log cfu/g. While the combination of 0.8 μg/ml Nicin and 0.75% essential oil of cinnamon postponed growth on the third day. At 8 °C, Nisin, the cinnamon essential oil alone and in combination (similar to 4 ºC) until the sixth day prevented bacterial growth. Compared to the control treatment, the concentration of Nisin and cinnamon essential oil had a significant difference in inhibitory bacterial growth (P<0.05). The results also showed that the combination of Nisin and cinnamon essential oil, had a significantly higher effect than their single state. Conclusions: Results indicate that Nisin and cinnamon essential oil effectively inhibit the growth of Lactococcus garvieae in the rainbow trout fillet.

BACKGROUND: Honey bee Chalkbrood disease is a fungal disease that is distributed in apiaries in the north provinces of Iran. Chalkbrood causative agent is Ascospaharea apis that can survive in colonies products for many years. Many chemical materials are used for control of Chalkbrood disease in honeybee colonies that can make some problems in honeybee consumer products, so  that survival of safe material and methods for honeybee colonies treatments is a important aim in honeybee research field. OBJECTIVES: In this study antifungal effects of the Lactobacillus casei, Lactobacillus acidophilus and Bifidobacterium bifidum on the Ascospharea apis causative agent of honey bee Chalkbrood disease is examined. METHODS:  Simultaneous inoculation, Agar spot, Confrontation assay, Overlay assay methods are used. LABs are cultured in MRS and A.apis is cultured in SDA media. RESULTS: L.casei and L.acidophilus had moderate effects on the A.apis growth, but B.bifidum and LABs cell free supernatants(CFS) could not  inhibit growth of  this fungi. CONCLUSIONS: Results of this survey show that LABs have antifungal activities on the honey bee Chalkbrood disease agent in culture medium and may be used as an alternative method for control of this disease in the honeybee colonies.

BACKGROUND: Due to the incomplete microbial population of the gastrointestinal tract in infant animals, the occurrence of any kind of stress causes gastrointestinal microbial imbalance and gastrointestinal disorders in the animal. The use of probiotics in diets of experimental animals improves the production of volatile fatty acids in rumen as the main stimulants of ruminal papillae. In this case the beneficial microbial population promotes in the rumen and its products improve the health and animal performance. OBJECTIVES: The aim of this study was to investigate the effects of different levels of Protexin™ probiotics in milk replacer on digestive tract development and ruminal parameters of suckling Zel lambs. METHODS: To conduct this experiment, 24 male lambs were used at 10 days of age with mean weight (4.2 ± 0.53 kg) in 4 treatments and 6 replicates per each treatment as individual pens for 60 days. Treatments include control (without probiotic) and 3, 6 and 9 g (×109 cfu/g) of probiotic in milk replacer. In day 60 of experiments, pH values were measured by a portable digital device and ammonia nitrogen and number of protozoa in rumen fluid were measured in laboratory. Ruminal morphological results were studied after animal was slaughtered. RESULTS: The results of ruminal parameters showed that adding 9 g probiotic resulted in a significant increase in ammonia nitrogen and number of ruminal fluid protozoa compared to other levels (P<0.05). There were not significant differences in pH and VFA of ruminal fluid indicated no significant difference among treatments. In rumen morphology results, there was a significant difference between treatments in weight of empty whole digestive tract, rumen, omasum and abomasums weight and the volume of reticulum and abomasum (P<0.05) and this difference was significant between treatment of 9 g probiotic and other treatments. Also, the effect of experimental treatments was significant on length and width of the rumen papillae (P<0.05), so that level of 9 g probiotic was higher than other levels. CONCLUSIONS: The results showed that the addition of probiotic in milk replacer of experimental lambs significantly increased ruminal VFA and developed the ruminal morphological traits, so that in these traits, amount of 9 g probiotic had better performance than the other levels.