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: 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: Ostertagia  species are the main domestic ruminants abomasum worms, which cause parasitic gastritis. Parasitic gastritis is associated with disruption of the endocrine structure of abomasum, and influence the function and pH of abomasums. This can lead to weight loss, reduced milk and wool production with potentially mal-digestion of proteins. These cause the economic loss to animal husbandry industry. So, the national research priority in veterinary parasitology is identification of different native species of Ostertagia in Iran. OBJECTIVES: The main purpose of this study is identification and differentiation of Ostertagia species based on the molecular characterization. METHODS: During carcasses inspection at different abattoirs in Rey, Tehran, Mashhad and Bandar Abbas, 180 adult male worms of Ostertagia species from sheep and goat were collected. Morphological analysis was performed based on the morphometric characteristics of spicules. The ITS1, 5.8s and ITS2 ribosomal DNA was ampilified from individual worms by polymerase chain reaction (PCR) and then purified PCR product were sequenced and analyzed by Blast tool. RESULTS: 946 bp PCR products for all sequenced samples were compared with the released sequences of Ostertagia isolates available from GenBank and showed 2-3% differences and 97-98% similarity. CONCLUSIONS: The three species included in the present study are different in terms of molecular property (with 2-3% difference) and it is necessary to determine transmittance pattern and host affinity rules from each one to be used by program managers and evaluators for Prevention and Control programs.

BACKGROUND: Biological control of parasites by using entomopathogen fungi is the one of the recommended ways to control them instead of using the chemical agents. Entomopathogen fungi are not pathogenic for animals and plants, while ticks are one of the most important parasites of animals that can transmit very important microbial pathogens. Ixodes ricinus is a hard tick that infests animals and human. OBJECTIVES: This study demonstrated enzyme assay of entomopathogen fungi hosted on Ixodes ricinus.  METHODS: Enzymatic activities of chitinase, lipase and protease of fungal structures on the killed tick bodies have been assayed by standard sphectrophotometric methods.  RESULTS: Chitinase, lipase and protease activities showed significant differences among different fungal strains (p<0.05). This research, which was done for first time in Iran demonstrated the effect of some enzymes which affect on acaricidal  properties of native strain of entomopathogenic fungi  in Iran. CONCLUSIONS: This study reveals the relationship between enzyme level of fungal strains and  the possibility of selecting more effective strains of entomopathogenic fungi

BACGROUNDS: Heat stress causes the lower performance in broiler chickens. OBJECTIVE: This research was conducted to investigate the effect of betaine supplementation in broiler chickens under heat stress condition. METHODS: Two hundred one-day-old male broiler chicks (Ross 308) were used in a completely randomized design with 4 treatments and 5 replicates per treatment and 10 birds per each replicate. The experimental treatments were the heat stressed birds fed the different levels of 0.0 (without any dietary supplement), 0.05, 0.1 and 0.2% betaine. The experimental diets were added to the diets during the finisher period (day 25 to 42 of age) and under heat stress condition (32±1º C from 9.00 AM to 5.00 PM). RESULTS: The results showed that feed consumption was not affected by betaine supplementation. Consumption of 0.2% betaine resulted in a higher weight gain during the whole period as compared to 0.05 betaine and control diet (P<0.05). The consumption of all betaine levels caused the decreased feed conversion ratio during the finisher period (P<0.05) and 0.2% betaine resulted in lowest feed conversion ratio between the experimental treatments. Dietary betaine supplementation had no effect on internal organ weights of heart, liver, abdominal fat, spleen and bursa at day 42 of age (P>0.05). Furthermore, consumption of different betaine levels had no effects on blood indices, the amounts of blood enzymes and antioxidant status at day 42 of age (P>0.05). CONCLUSIONS: Totally, the consumption of 0.2% betaine improves the performance without any effects on blood indices and internal organs under heat stress condition.

BACKGROUND: Aflatoxins are secondary metabolites due to the growth of molds in animal feed. Lactic acid bacteria are microorganisms that can absorb aflatoxins. Objectives: the effect of the yeast Lactobacillus rhamnosus (PTCC 1637) on Aflatoxin B1 detoxification and absorption of toxin in in vitro (the cow rumen) was investigated. METHODS: For this purpose, the bacteria used in various treatments (live-treated, autoclave, heat-treated, treated with acid 100ºC) was prepared and added to the rumen of cattle. Aflatoxin B1 in different doses (0, 5, 10, 20) ppb in the rumen were added and at times one and two hours were incubated at 37°C. The amount of toxin residues was measured by ELISA using Europroxima kits. RESULTS: The results showed that microorganisms have been treated in an autoclave have the largest amount toxin removal (90.5 percent) (p<0.05). Also with increases the incubation time, the amount of toxin absorbed significantly (78%) increased (p<0.05) and with increasing concentrations of toxin in vitro the bacteria’s ability to absorb toxin increases. Conclusions: As a solution to the livestock feed industry bacterial cell wall or its compounds can be helpful in reducing Aflatoxin B1 toxin.

BACKGROUND: Aflatoxin M1 (AFM1) is the main monohydroxylated derivative of aflatoxin B1 (AFB1) formed in liver and excreted into milk. AFM1  creates  certain hygienic risks for human health. OBJECTIVES: The aim of this study was to determine AFM1 level in raw milk samples in Yazd province. METHODS: This investigation was a descriptive-cross sectional study. Eighty raw milk samples were collected from four cities (Yazd, Taft, Mehriz and Sadogh) in Yazd province in winter and spring seasons. The concentration of AFM1 was determined by ELISA method. The analysis of the results was performed using ANOVA and Chi-square tests. RESULTS: All samples (100%) were contaminated with AFM1, with the concentrations ranging from 3.18 to 92.24 ng/l with a mean concentration of 22.07 ng/l. AFM1 level in 13.7% of raw milk samples was higher than the maximum tolerance limit of 50 ng/l accepted by the European Union (EU). The contamination level of AFM1 in winter samples (28.21 ng/l) was higher than spring samples (15.92 ng/l). Also, the highest and lowest contamination levels were observed in milk samples collected from Sadogh (mean 42.21 ng/l) and Yazd (12.79 ng/l) cities, respectively. CONCLUSIONS: Results demonstrated AFM1 was detected with a mean concentration of 22.07 ng/l in milk samples of Yazd province. Moreover, 13.7% of samples contained AFM1 at hazardous levels for human health.

The effect of Antioxidant organic sulfur compounds on performance, prooxidant–antioxidant balance (PAB) of the Eimeria-infected broiler chickensBACKGROUND: Use of Garlic Powder (GP) and Total Sulfur Amino acid (TSAA) can improve redox status of broiler chickens fed with and infected by Eimeria and recover the negative effects of coccidiosis. OBJECTIVES: This experiment was carried out to evaluate the effects of GP and TSAA on feed intake (FI), feed conversion ratio (FCR) and prooxidant–antioxidant balance (PAB) of the chickens challenged with Eimeria oocysts species mix. METHODS: A 2×2×2 split-plot-factorial arrangement of treatments was used. 400 day-old male broiler chickens (Ross 308) were equally assigned to two plots (4 treatments each). Two hundred of the chickens were challenged with Eimeria oocysts species mix by oral inoculation at day 34 (infected plot) and the others were left as unchallenged (uninfected plot). In each plot, broiler chickens were randomly assigned to four treatments and fed one of following diets: basal diet, basal diet plus 0.5% GP, basal diet plus 50% more TSAA based on Ross 2009 recommendations, basal diet plus 0.5 % GP and 50% more TSAA based on Ross 2009 recommendations. RESULTS: The results showed that after inoculation birds with 7.5×102 Eimeria oocysts species mix significantly (p<0.05) reduced the FI to 20% and increased FCR to 14% and also increased serum PAB (p<0.05), especially for infected broilers that were fed with basal diet, however, supplementation of GP and TSAA were better for broiler chickens in infected plot than uninfected plot. CONCLUSIONS: These results indicate that addition of GP and TSAA to diet may recover the negative effects of coccidiosis  and  improve the performance and redox of broiler chickens infected by Eimeria.

BACKGROUND: Infectious bursal disease (IBD) is a highly contagious disease of young birds. Differentiation between classical virulent and very virulent IBDV (vvIBDV) isolate is very important for the poultry industry to choose the right vaccination program. Molecular and serological tests are time consuming and have variable sensitivity. However, the melting curve analysis is relatively fast method with high precision. OBJECTIVES: This study was designed to evaluate the efficacy of the melting curve analysis for differentiation of some Iranian IBDVs which their identity had been previously determined by RT-PCR/RFLP analysis. METHODS: In this study, after RNA extraction and reverse transcription and Real Time RT- PCR of IBDVs, high melting resolution at temperatures ranging from 81 to 92°C were performed. RESULTS: The findings of this study showed that in the high resolution melting curve analysis, the viruses were classified from A to D. Three vaccine strains of D78, Gumbokal, Bursa CE; IBD L; Bursine 2; and all field viruses were placed in groups A, B, C, and D, respectively. High resolution melting curve analysis after normalization also showed all viruses of this study were placed in 4 HRM genotypic group. Three strains, D78, Gumbokal, Bursa CE, produced similar and non-differentiable curve but were different from other vaccine and field strains. Two other vaccine strains, IBD L and Bursine 2, were different from each other and other viruses. CONCLUSIONS: We concluded that the real-time RT-PCR HRM technique is cost-effective and reliable among the currently used methods and can be used for differentiation of IBDV isolates.