BACKGROUND: On account of the importance of iodine in the synthesis of thyroid hormones, different levels of dietary iodine can affect the occurrence of ascites syndrome in broilers.OBJECTIVES: The current research aimed to investigate the effects of different sources and levels of iodine on performance, carcass traits, ascites mortality, thyroid hormones, and serum biochemical parameters of broiler chickens under cold stress condition.METHODS: This experiment was performed using 375 one-day-old male broiler chickens in a completely randomized design with five treatments, five replications, and 15 birds per replication. To induce ascites, the room temperature was reduced to 15 °C from 14 days and this temperature was maintained until the end of the period. The experimental treatments included: control treatment (basal diet with iodine at the recommended level, 1.25 ppm), basal diet + potassium iodide (KI) with iodine levels (6.25 and 3.75 ppm), and basal diet + calcium iodate [Ca(IO3)2. H2O] with iodine levels (6.25 and 3.75 ppm).RESULTS: The effect of the treatments on the performance indices was not significant throughout the experiment. The lowest percentage of ascites mortality, heart weight, and triiodothyronine (T3) were observed in the treatment (6.25 ppm), which was significantly different from the control treatment (P<0.05). The lowest ratio of right ventricle to total ventricles (RV/TV) was related to potassium iodide treatment (6.25 ppm), which indicated tendency (P<0.10). Chickens receiving higher levels of iodine (6.25 ppm) had higher thyroxine than those receiving lower levels (3.75 ppm) (P<0.05) and showed a lower ratio of triiodothyronine to thyroxine compared to those (P<0.05).CONCLUSIONS: The results of this experiment implied that the use of higher levels of dietary iodine (6.25 ppm), especially as potassium iodide, reduces broiler’s ascites mortality under cold stress conditions.

BACKGROUND: Ammonia accumulation in warm-water fish pond can lead to mortality or reduction in growth and body immune indices.OBJECTIVES: The present study aimed to investigate the effects of chronic sub-lethal unionized ammonia (NH3) on growth indices and gill and kidney histopathology l, after a 30 – day trial in common carp (Cyprinus carpio).METHODS: Herein, 180 fish with an average weight of 4.5±0.5 g were divided into six tanks. Two groups, including one control group and one treatment group (with three replicates for each one), were considered. The treatment fish were exposed to 0.1 mg/l on un-ionized ammonia (NH3) for 30 consecutive days. Following one -month, ammonia exposure growth indices and histological analysis of gill and kidney were investigated.RESULTS: The results showed that exposure to 0.1 mg/l of NH3 led to a significant reduction in growth indices. Additionally, edema and epithelial lifting with hyperplasia in the second lamella were detected in the gill of the treatment group. The kidney was characterized by focal renal tubules degeneration and necrosis, congestion, and increase in the melano-macrophage centers.CONCLUSIONS: Although chronic exposure to 0.1 mg/l of unionized ammonia was not found to cause mortality in common carp, it could have some side effects, such as a decline in growth indices and histopathological effects in kidney and gill tissues. Thus, for higher production, sublethal levels of ammonia should also be taken into account in common carp ponds.

BACKGROUND: During the modification of several races, which has been done on chickens, there have been several changes in the function of neural pathways and receptor density involved in the control of food intake and appetite. Melanocortin system and its receptors are involved in the central regulation of nutritional behaviour and energy balance. Therefore, this study was designed to investigate the role of this system in the central control of food and water intake in birds.OBJECTIVES: The present study aimed to evaluate the role of MCR3 and MCR4 receptors in controlling the food and water intake in birds.METHODS: This work was performed on 48 Ross 308 broiler chicks through two experiments (each experiment in four groups). Primarily, stereotaxic surgical guide cannula was implanted in the chickens. Subsequently, in the first experiment, the chickens were divided into the four following groups: the control solution, 0.2, 2, and 10 nmol/5µl of SHU9119 (Non-selective antagonist of MCR3 and MCR4 receptors) In the second experiment, the chickens were also divided in four groups: the received control solution, 0.2, 2, and 10 nmol/5µl of MCL0020 (Selective MCR4 receptor antagonist) via intracerebroventricular (ICV) injection. Afterwards, cumulative food and water intake were measured at 30, 60, 90, 120, 150, and 180 minutes after the injection.RESULTS: The results of this study showed that ICV injection of SHU9119 and MCL0020 increased cumulative food intake (P>0.05), but did not affect cumulative water intake (P<0.05).CONCLUSIONS: According to the findings herein, central melanocortin system is one of the systems involved in central control of food intake in birds.

BACKGROUND: Ovine theileriosis is an important hemoprotozoal disease of sheep and goats in tropical and subtropical regions which causes high economic loss in the livestock industry. OBJECTIVES: The aim of this study was the differential detection of Theileria species in sheep using PCR method. METHODS: Two hundred blood samples of sheep were investigated in order to differentially diagnose Theileria species. DNA was extracted from blood samples and DNA samples were amplified using specific primers designed for 18S rRNA, TamS1 and TaSp genes. RESULTS: In this study, from 200 examined samples, 42 samples (21%) were infected by Theileria spp. and none of them were infected by Babesia spp. Moreover, from these 42 positive samples, 24 samples (57.1%) were only infected by T. ovis. 12 samples (28.5%) were only infected by T. lestoquardi, 2 samples (4.7%) were only infected by T. annulata and 4 samples (9.5%) were simultaneously infected by T. lestoquardi and T. ovis. The results of nucleotide sequencing showed that PCR product of 18S rRNA from T. lestoquardi has 99 and 95% similarity with T. annulata and T. ovis respectively. T. lestoquardi and T. annulata showed 86% similarity. Also TaSp gene of T. ovis in comparison with T. annulata and T. lestoquardi showed 96 and 86% similarity, respectively. CONCLUSIONS: In the present study could be shown that the two genes (TamS1 and TaSp) from examined three genes could be used for Theileria species specific diagnosis by PCR.

BACKGROUND: Application of different source of minerals and their effect on metabolic performance a current issue in animal science and research centers. OBJECTIVES: The objective of this study was synthesis of selenium nanoparticles and to investigate its effect compared with other selenium sources on the blood parameters associated with the liver functional index of Holstein dairy cow. METHODS: This study was conducted in two phases: laboratory and farm. Oxidation-reduction chemical reactions were used to synthesize selenium nanoparticles. The formation and non-change of Se nanoparticles size were confirmed by particle size analyzer. In order to perform farm experiment, 6 dairy cows were allocated into three treatments and 2 replicates in a 3×3 Latin square experiment with 28 days change over the period. The animals were distributed to three treatment groups. Treatments (diets) were 1) control (sodium selenite source), 2) colloid sodium selenite and 3) selenium nanoparticles. Blood parameters associated with the liver functional index, including albumin, bilirubin and total cholesterol were measured in the present experiment. Also, dry matter intake of cows was recorded. RESULTS: The blood plasma cholesterol of cows fed the colloidal sodium selenite was higher than cows fed the selenium nanoparticles (P-Value =0.01). The blood serum albumin (P-Value =0.03) and bilirubin levels (P-Value =0.04) were lower in group 3 compared with group 1. Dry matter intake was not affected by treatments. CONCLUSIONS: According to the results of this experiment it seems selenium nanoparticles supplementation   improves blood parameters associated with the liver functional index, which can better improve immune system of dairy cows than two other sources of selenium.

BACKGROUND: Staphylococcus aureus is one of the most important human pathogens that cause infection and also food intoxication by secreting various enterotoxins. Conventional culturing methods to detect S. aureus have some limitations such as being time-consuming due to bacterial growth and low precision and sensitivity in detecting viable but non-cultivable cells. OBJECTIVES: The objective of this study was to detect and quantify enterotoxigenic (A-E) S. aureus in cream pastry products applying PCR coupling with propidium monoazide (PMA) to distinguish dead and live cells. METHODS: One hundred samples were randomly collected from pastry shops in Amol, in a period of 2 months. After preparing dilutions, bacterial pellets were separated and treated with PMA before DNA extraction. Real time PCR was conducted in order to quantify S.aureus cells and enterotoxigenic strains using specific primers. RESULTS: Results of conventional method were close to PMA-qPCR data (P>0.05), but data from qPCR that includes live and dead cells shows more bacterial count than two other methods. Sensitivity of the method applied in the present study, detecting low number of S.aureus cells (less than 10/g) seems considerable. CONCLUSIONS: Findings showed that applying PCR coupling with PMA results in more reliable data than conventional culturing method. Regarding this approach being time-effective, considerably sensitive and specific, it is expected that it be used in food quality control labs in monitoring systems in future.

BACKGROUND: Titanium dioxide nanoparticles (TiO2NPs) are used in many commercial products, including paints, sunscreens and edible products, and can be used directly and indirectly in aquaculture. Due to the widespread application of these nanoparticles, the investigation of their possible effects on aquatic organisms is necessary. OBJECTIVES: The purpose of this study was to investigate the histopathological effects of waterborne TiO2NPs on the gills, liver and intestine of Caspian trout. METHODS: In this study, 126 fish (27.46±4.3 g) were tested in six concentrations of TiO2NPs (0, 0.01, 0.1, 1, 10 and 100 mg/L) for 4 days. At the end of the experiment, tissues were evaluated to determine the effects of tissue damage caused by TiO2NPs. RESULTS: The 96-h exposure to TiO2NPs did not cause fish mortality. Accordingly, investigated TiO2NPs are classified as "relatively non-toxic". The most important tissue changes caused by short-term exposure to TiO2NPs were hyperplasia and hypertrophy, lamellar fusion, necrosis in gills; foci of melanomacrophage deposits, aggregation of blood cell, hepatocytes with pycnotic nuclei, vacuolation, necrosis in liver; thickening of lamina propria, erosion of villi and necrosis in intestine. CONCLUSIONS: Although TiO2NPs are relatively non-toxic,  due to the tissue damage observed, these nanoparticles can be harmful to Caspian trout.

BACKGROUND: Diarrhea syndrome is associated with irrecoverable damages in the husbandry industry worldwide due to losses resulted from fatality, weight loss, growing weak calves and treatment costs. Hence, investigation of diarrhea causes in different areas is important to attempt management strategies to prevent and control it. OBJECTIVES: Present study was carried to investigate prevalence of some important entropathogens in diarrheic calves until three months old, in Shahrekord suburb husbandries. METHODS: Fecal samples were taken from 82 female calves in first day of diarrhea and were examined for isolation of salmonella, Escherichia coli, clostridium, cryptosporidium, and coccidia through common microbiological and parasitological methods. RESULTS: In general, prevalence of isolated organisms were: salmonella 36.6%, Escherichia coli 24.4%, clostridium 9.8%, cryptosporidium 9.8%, and coccidian 7.31%, and Escherichia coli K99 were isolated from four calves. The most prevalent pathogens were Escherichia coli and Salmonella. CONCLUSIONS: The calves are unavoidably exposed to infectious causes of diarrhea during their whole lifespan, because they acquire organisms from environment immediately after birth. Therefore, attempts at efficient management methods, hygienic principles and receiving enough colostrum, particularly in cold seasons, may be efficient in the control, prevention and decrease of diarrhea and its subsequent losses.

BACKGROUND: Heavy metals and metalloids are among the most stable and resistant to decomposition elements that, in the presence of high concentrations in aquatic tissues, threaten their own and human health. OBJECTIVES: The aim of this study was to determine the composition and order of the elements accumulation in the edible muscle tissue of pike from Siah Darvishan River as one of the most valuable and economical fish and also to evaluate its health for human nutrition. METHODS: In the present study, concentration of eleven elements (As, Fe, Hg, Zn, Pb, Se, Cd, Cr, Cu, Mn, Ni) in the muscle tissue of 25 pike (Esox lucius) collected with the Cast net in the summer of 2016 from Siah Darvishan River, Guilan province, Iran were surveyed by Varian Atomic absorption spectroscopy. RESULTS: The lowest and highest mean accumulation of elements were obtained as follows: Zinc 25.89 - 28.80, Iron 21.85 - 24.26, Copper 6.78 - 8.15, Manganese 1.77 - 2.12, Lead 0.68 - 0.73, Selenium 0.59 - 0.62, Arsenic 0.53 - 0.62, Cadmium 0.38 - 0.41, Nickel 0.24 - 0.28, Chromium 0.17 - 0.19 and Mercury 0.087 - 0.098 microgram per gram dry weight, respectively. CONCLUSIONS: According to the results of this study, mean concentrations of all elements in the muscle tissue of pike, except the four elements Manganese (1.956 ± 0.178), Lead (0.698 ± 0.028), Arsenic (0.572 ± 0.044) and Cadmium (0.393 ± 0.018) were observed to be lower than explained threshold limit value (TLV) of FAO/WHO international standard.

BACKGROUND: Nowadays due to the extensive use of antibiotics, antimicrobial resistance is recognized as a global concern for the health of animals and humans. The consequences of antimicrobial resistance are resistance of zoonotic pathogenic factors and reductions in the effectiveness of treatment for many diseases. OBJECTIVES: The aims of this study are the monitoring and prevalence of antimicrobial residues of the poultry carcasses in Kerman poultry abattoirs. METHODS: A cross sectional study was conducted from June 2015 to October 2016. A total of 474 samples were collected from Kerman province poultry abattoirs and tested with four plate test (FPT) method. Data were analyzed  using Descriptive statistics for qualitative data with 95 % confidence interval. RESULTS: A total of 38 samples were positive (8/02 %), Antibiotics isolates included: Fluoroquinolone, Macrolide, Cephalosporin, β-lactam, Tetracycline, Sulfonamide and Amino glycoside. The highest rate of antibiotics isolated in positive samples was Fluoroquinolone (36/1 %) and the lowest rate was cephalosporin (4/1 %). Half of the samples were positive for one type of antibiotic (Fluoroquinolone), 28/9 % for two types of antibiotics, 13/1 % for three types of antibiotics, 5/2%  for five kinds of antibiotics and 2/6 % for six kinds of antibiotics. CONCLUSIONS: The results of the study showed that about 10 percent of the meat consumed in this province has antimicrobial residues. Therefore, it can be suggested that proper management strategies for controlling the veterinary drug usage in poultry farms be implemented.