BACKGROUND: Lead (Pb) induced oxidative stress is known to suppress growth performance in broiler chickens. The current study was carried out in an attempt to describe the specific underlying mechanisms of such phenomenon. OBJECTIVES: The objective of this study was to investigate the effect of Pb-induced oxidative stress on performance, antioxidant status and behavioral responses of broiler chicken. METHODS: Eighty day-old broiler chicks were randomly assigned to 2 dietary treatment groups of 4 pen replicates, namely i) basal diet containing no lead supplement (control) and ii) basal diet containing 200 mg Pb/kg of diet. RESULTS: The results showed that addition of lead decreased body weight gain (p<0.01) and feed conversion ratio (p<0.01). Also, consumption of contaminated diet significantly increased MDA and H/L Ratio and significantly decreased SOD and GPx activity (p<0.01). Moreover, addition of 200 mg/kg diet significantly increased sitting pasture and aggression behavior and decreased feeding behavior (p<0.01).               CONCLUSIONS: Our data conclude that Pb-induced oxidative stress adversely suppressed feed conversion ratio and growth performance. The proposed underlying mechanism for such phenomenon is Pb-induced oxidative stress by impaired antioxidant status and feeding behavior decreased the growth performance.

BACKGROUND: Indigenous chickens could serve as precious genetic resources that should be considered in conservation and breeding programs. The Major Histocompatibility Complex (MHC) has a strong association to disease resistance/susceptibility, production and reproduction traits in chicken. Therefore, identifying its polymorphism in populations under selective breeding could be used for selection of disease resistant and higher productive breeds. MHC association with quantitative traits could be  a result of its linkage with causative genes controlling these traits. Insulin-like growth factor 1 (IGF1) is a candidate marker for phenotypic traits in chicken which are associated with important production and reproduction features. Objectives: Based on this hypothesis, MHC polymorphism and its association to IGF1 gene (as a marker for production traits) were investigated in Khorasan indigenous chicken. Methods: In total, 313 DNA samples that belonged to the Khorasan indigenous chicken were analyzed. LEI0258 microsatellite marker and fragment analysis method was used for MHC genotyping. Single nucleotide polymorphism (SNP) of the IGF1 5’-UTR was detected by restriction fragment length polymorphism (PCR-RFLP) and PstI restriction endonuclease enzyme. Linkage disequilibrium between MHC and IGF1 loci were also determined using SAS/Genetics software and likelihood ratio test. Results: Collectively, 25 different alleles (185-493 bp) and 76 genotypes of LEI0258 microsatellite were identified in Khorasan population. Two alleles, A (PstI -) and B (PstI +) and three genotypes (AA, AB and BB) were identified for IGF1 gene. Significant linkage disequilibrium (p=0.0083) was observed between LEI0258 and IGF1 loci in this population. Conclusions: These results indicate a high MHC genetic diversity in Khorasan indigenous chicken as a valuable genetic resource. Results from MHC/IGF1 linkage study confirm the hypothesis that MHC association with production traits could be as a result of MHC linkage with causative genes controlling the traits.

BACKGROUND: Increase of people’s awareness about side effects of chemical food preservatives has raised public interest to consume products with natural preservatives such as essential oils. Garlic (Allium Sativum L.) is one of the medicinal plants in traditional medicine of Iran and it is necessary to evaluate its antimicrobial effects on some food borne bacteria such as E.coli O157:H7. This bacteria has low infectious dose and causes hemorrhagic colitis and hemolytic-uremic syndrome. OBJECTIVES: The purpose of this study is to evaluate inhibitory effect of garlic essential oil (Allium Sativum L.) on growth of E. coli O157:H7 and shiga-toxin 2 (Stx2) production. METHODS: The minimum inhibitory concentration (MIC) of garlic essential oil was evaluated by broth microdilution method and minimum bactericidal concentration (MBC) methods. Effect of subinhibitory concentrations (subMICs) of garlic essential oil on bacterial  growth over 72 h (at 35 °C) evaluated by surface plate counting and production of Stx2 were evaluated by kit (VTEC-RPLA). RESULTS: MIC and MBC of garlic essential oil were estimated 0/02% and 0/04%, respectively. Concentrations of 0.005%, 0/01% and 0.015% of garlic essential oil reduced the bacterial growth. Concentration 0/015% after 72 h reduced 2 log10 (cfu/ml) growth rate and was the most effective concentration. Concentration 0/005% reduced Stx2 production and higher concentrations inhibited Stx2 production. It was found that the effect of different concentrations of essential oil on growth and production of Stx2 by E. coli O157:H7 were statistically significant (p≤0.05). CONCLUSIONS: Garlic essential oil showed to be effective against bacterial growth and production of Stx2. This study indicated that garlic essential oil can be used as natural preservative in food system.

BACKGROUND: Glutamine supplementation to the pre-starter diet of broiler chicks could improve their performance during the first week of post-hatch. OBJECTIVES: This experiment was conducted to evaluate the influence of glutamine levels in the pre-starter diet on intestinal mucosa morphology and performance of broiler chicks. METHOD: A total of 160 Ross 308, one-day old broilers were used in a complete randomized block design with 3 treatments of 5 replicates. Diets were formulated to contain different levels of glutamine (0, 0.5 and 1%). Body weight and feed intake were measured at 6 and 13d. On d 0, 3, 6 and 13 post hatch, 2 birds per each replicate were weighted and killed, and samples of the duodenum, jejunum, and ileum were taken subsequently. RESULTS: Supplementation of diets with 1% glutamine improved growth performance and feed efficiency at 6 and 13 day post hatch (p<0.05). On d 3 and 6, glutamine supplementation increased villi height and width in the small intestinal significantly (p<0.05). On d 13, chicks fed glutamine added diet had a longer villi height and width than those fed the basal diet (p<0.05). Glutamine supplementation has also decreased crypt depth of jejunum and ileum at 3, 6 and 13, but increased crypt depth in duodenum at 3 and 6 d of age (p<0.05). Increase in glutamine levels of pre-starter diet increased villi height relative crypt depth of jejunum and ileum at 3 and 6 d of age. On d 13, chicks fed diet contain 1% glutamine had a higher villi height relative crypt depth than those fed the basal diet. CONCLUSIONS: Addition of 1% glutamine to the pre-starter diets improved broiler growth performance and resulted in better development of the intestinal mucosa in broiler chicks.

BACKGROUND: Soybean oil is one of the highly consumed vegetable oil worldwide. Nowadays, usage of genetically modified (GM) soybean seeds for soybean oil production is constantly increasing. The recommended methods for GMO detection are based on analysis of residual DNA in vegetable oil and highly processed food. However, the successful amplification of isolated DNA depends on the efficiency of DNA extraction method. Objectives: The purpose of this study was to apply three different DNA extraction methods for analysis of residual genomic DNA in crude and refined soybean oil to obtain high pure of DNA suitable for DNA amplification. Methods: Extraction methods were developed based on the specific binding of DNA molecules to the silica membrane (column) or resin. The isolated DNA was then analyzed by PCR technique using primer pairs, derived from 18S rRNA and 5.8S rRNA gene and soybean lectin gene. Results: The results showed that amplifiable DNA could not be extracted from crude/refined soybean oil in method 1. In method 2, by pre-treating of oil with PBS and subsequent precipitation with Isopropanol, the amplification was not observed but OD260 was decreased. In method 1 and 2 the DNA was not pure enough to be amplifiable. To remove more effectively contaminant, method 2 was combined with chloroform extraction as method 3. The extracted DNA from all examined oil samples could be amplified. ConclusionS: We believe that the purity of DNA in samples is decisive for amplification and not necessarily the low amount of DNA in samples. Method 3 can be determined as a suitable method for the isolation of the pure DNA.

BACKGROUND: Regulation of electrolytes levels and water in fish is very important because of its vast permeable surfaces that are in contact with the environment. Therefore, for homeostasis and osmoregulation, various adaptation mechanisms at different biological levels have  been developed. OBJECTIVES: The aim of this study was to determine the changes and adaptations of mitochondria-rich cells as an important cellular response to these changes.This was influenced by different environmental salinities in fish Sparidentex hasta which are very important economic species in the southern region of the country. METHODS: 180 fish, aged three months, 20 - 25 cm in length and weighing about 150 gr were exposed  directly to different concentrations of salt (5, 20, 40 and 60 ppt) for 1 week. Localization of the Na +, K +-ATPase in mitochondria-rich cells in gill epithelial were studied in different environmental salinities during the adaptation period.  was performed by using IgGα5 as immunohistochemistry method. RESULTS: NKA localization showed that the mitochondria-rich cells are in the filament and rarely in lamellar epithelium. Intensity reactive of the antibody used during the period showed an increase  in 5 and 60 ppt and decrease  in 40 ppt. CONCLUSIONS: Generally, tolerance and compatibility of Sparidentex hasta to salinity changes are due to rapid changes in mitochondria-rich cells to regulate the entry and exit of water and electrolytes. So to adapt with the new condition of environment some changes in the apical openings appear that regulate the amount of the carrier electrolyte enzymes in basolateral membrane. It also causes adaption of mitochondria activity to the new condition.

BACKGROUND: Following the ban on the use of growth stimulant antibiotics in many countries, interest has arisen in finding  a suitable alternative for antibiotics in poultry production. OBJECTIVES: The aim of this study was to investigate the effect of supplementation of two levels of nano-copper (0 and 100 mg/kg) and two levels of mannan oligosaccharide (0 or 1 g/kg) as natural growth stimulants on digestibility of nutrients and performance in broiler chicks. METHODS: At the end of the second week of breeding, 160 Cobb-500 broiler chicks were assigned in four treatment groups. For each treatment, four replicates (10 chicks per replicate) were considered. Experiment was conducted as a 2×2 factorial model in a completely randomized design. Results: No significant differences in digestibility of nutrients and growth performance between birds that ate the supplements with control group were observed (p>0.05). CONCLUSIONS: Mannan oligosaccharides and nano-copper on growth performance and nutrient digestibility in broiler chicks had no significant effect. At the doses used, concomitant supplementation of copper and mannan oligosaccharide did not have a positive effect on traits that were studied in broilers.

BACKGROUND: Biofloc technology is considered  a method that degrades organic waste by microorganisms and produces bacterial flocculation. OBJECTIVES: This study was performed to evaluate of the application of biofloc technology in therearing of common carp (Cyprinus carpio) fingerlings in intensive culture. METHODS: The experiment was designed in four treatments (Commercial diet as a control, 75% commercial diet + Biofloc, 50% commercial diet + Biofloc, 25% commercial diet + Biofloc) with carp fingerlings (Initial weight 58 ± .2 g) over a period of one month. Water exchange in Biofloc treatments was 1% during 24 h while water flow through system was used in control. At the end of experiment, all fish were intraperitoneally injected with 12×107 colony forming units (CFU) of Aeromonas hydrophila per fish. RESULTS:The results of the experiment indicated that the highest weight gain was observed in fingerlings fed 75% commercial diet + Biofloc that differed significantly from the group fed 25% commercial diet + Biofloc (p<0.05). There was no significant difference between control and 50% and 75% commercial diet as well (p<0.05). No significant difference was observed in case of condition factor, viscerosomatic index (VSI) and survival in experimental treatments (p>0.05). Also, Biofloc significantly increased ash content in muscle (p<0.05). The highest mortality (64.2 %) was observed in control inchallenge of Aeromonas hydrophila. CONCLUSIONS: The results suggest that the Biofloc technology can increase growth performances of carp fingerlings in intensive system and decrease water exchange via quality improvement.

BACKGROUND: Strepotococcosis caused by Streptococcus iniae is one of the important emerging bacterial diseases in aquaculture sector worldwide. ObjectiveS: In this study, the genetic diversity of S. iniae strains was assessed in some rainbow trout farms in Iran. Methods: Gram positive and catalase negative bacterial isolates were first obtained from 100 trout fish farms in 8 states using routine bacteriological and molecular (PCR) works. The genetic diversity of these bacterial isolates was then assessed using restriction fragment length polymorphism (RFLP) method. Results: Seventy-seven strains of Gram positive and catalase negative cocci were isolated from diseased trout. PCR analysis resulted in identification of 27 strains as S. iniae. RFLP analysis of these strains using 9 digestive enzymes resulted in production of 29 bands with different molecular weight (62-940bp).  Phylogenetic relationship of these strains grouped them in two distinct clusters. Twenty-six strains from Tehran, Mazandaran, Gilan, Lorstan, Fars and Charmaha-va-Bakhtiary provinces showed high homogeneous similarity above 99%, while one strain from Mazandaran province showed some differences with other strains. ConclusionS: S. iniae isolates in trout aquaculture in Iran possess  low genetic diversity.

BACKGROUND: The foramen magnum (FM) is an important landmark of the skull base and a transition zone between spine and skull as well as its close relationship to the brain and the spinal cord. So the FM has gained considerable interest due to its comparative anatomy, ontogeny, clinical, and animal breeding viewpoints. OBJECTIVES: The aim of this study was to determine morphology and morphometry of the occipital area of 20 mature and immature male Khouzestan river buffaloes. METHODS: 7 parameters of the occipital area and the shape of the FM in the skull of 20 mature and immature male Khouzestan river buffaloes were analyzed. RESULTS: The FM had 4 shapes including round, egg, oval, and tetragonal. In the mature and immature groups, the highest frequency of the FM shape belonged to oval. In the mature and immature groups, the tetragonal FM shape and the oval FM shape had the lowest frequency, respectively. The mean of the width, the length of the FM and the index of the FM in mature group was 38.60± 2.70, 35.34± 2.33, and 92.26±26 mm, respectively and 40.67± 1.51, 36.35± 2.33, and 90.23±3.65 mm in immature group, respectively. Amongst of the all parameters, the width and the length of the jugular process only differed significantly between mature and immature groups. CONCLUSIONS: The variations of the FM shape in river buffalo were more than those of reported animals. The  mean of  the length and  the width of  the FM,  the jugular processes width,  the length of the jugular process, the length  and width  of the  occipital condyles of male river buffaloes were greater than those of reported animals. The index of the FM in river buffalo was less than 100, which corresponded with the findings in rabbit, German shepherd and Pekingese dogs.