Background: Heat stress is one of the most important environmental stressors challenging poultry production worldwide. Understanding and controlling environmental stressors is crucial for successful poultry production. OBJECTIVES: The aim of the present study was to investigate the effects of melatonin supplementation and darkness regime on reducing the negative effects of heat stress in broiler chickens. METHODS: A total of 400 broiler chickens (Arian) were obtained and subjected to four different groups. The control chickens were grown in normal conditions without receiving any treatment. The positive control birds were grown similar to the control but exposed to an acute heat stress for 6 h/d from days 35 to 40. The dark group chickens were reared under a dark schedule and exposed to heat stress. The birds of the fourth group were reared similar to the positive control but received 40 ppm melatonin in the diet from days 30 to 40 of age. Dead birds were autopsied. The weekly growth performance of chickens was determined and blood samples were taken for hormonal analysis. RESULTS: The number of dead birds due to heat stress was significantly decreased in chickens subjected to the dark program and/or those which received melatonin in the diet compared with those of positive control chickens. Such differences were accompanied with the significantly lower levels of plasma T3, T3/T4 and corticosterone in these groups of chickens. Additionally, plasma thiobarbituric acid reacting substances level was significantly higher in positive control broilers compared to their counterparts. CONCLUSIONS: Our findings indicate a reduction of metabolic rate and heat production in dark regime and melatonin supplementation that can reduce the side effects of heat stress and, therefore, reduce the mortality rate.

Background: Rhodoccocus equi, Brucella abortus, and Pasteurella multocida are important veterinary bacterial pathogens that in recent years have been resisted to current antibiotics, and this problem threats the livestock industry. To control this resistant microorganisms, use of new antibacterial compounds, such as thiazole derivatives, in veterinary is necessary. OBJECTIVES: In this study, antibacterial effects of thiazole derivatives on Rhodoccocus equi, Brucella abortus, and Pasteurella multocida were evaluated. METHODS: Synthesized thiazole derivatives were prepared in DMSO, then the disk diffusion method was used to measure growth inhibition zone diameter and the broth microdilution method was applied to determine the minimum inhibitory concentration (MIC). RESULTS: Results showed that thiazole derivatives had no significant inhibitory effects on B. abrotus, while they had inhibitory effects on R. equi and P. multocida with inhibition zone 12.7±0.4 -30.1±0.2 mm and MICs 32- 256 μg/ml. CONCLUSIONS: Results of this study indicate that thiazole derivatives have considerable inhibitory effects on R. equi and P. multocida as veterinary bacterial pathogens.

Background: Avian chlamydiosis is a zoonotic disease ofbirds caused by the intracellular bacterium Chlamydia psittaci. Avianchlamydiosis leads to severe respiratory disease in young turkeys and eggproduction losses in layers. OBJECTIVES: Due to paucity of information about theprevalence of chlamydial infection in the turkey population in Iran, this studywas conducted to detect chlamydial infection in some Iranian turkey flocks indifferent provinces. METHODS: A total of 177 samples were taken from turkeysand first verified as Chlamydiaceae by Chlamydiaceae-specificreal-time polymerase chain reaction (real-time PCR) by detection of the 23S RNAgene of Chlamydiaceae (Ct values ranging from 34 to 38) and thenpositive samples were investigated for the presence of C. psittaci by anested PCR. RESULTS: Seventeen of 177 samples (9.6%), correspondingto 13 farms of 48 examined farms were positive for Chlamydiaceae byreal-time PCR. None of the positive samples were found to be C. psittaciin the nested PCR. CONCLUSIONS: This study showed no C. psittaciinfection in the turkey population in Iran. We recommend investigation on otherfarm animals and wild populations for possible chlamydial infection and forbetter understanding of the source and epidemiology of this agent. Due to thechallenges that exist for sampling and the relevant impact on reducing positivesamples, investigation by parallel and complementary techniques may be usefulin showing the true prevalence of infection in the target populations

Caudal duplication is an abnormality which usually affects the digestive, urogenital and even respiratory systems. It forms a graded series from slight duplication to near separation of two fetuses caudocranially. In some conjoined twins, duplication process may cranially proceed up to the head region. This kind of developed conjoined monocephalus twin has been reported in many domestic species and is classified as thoracopagus or omphalopagus twins according to the presence of one or two hearts, respectively. A male dead conjoined monocephalus twin lamb attached from neck to thorax was used for this study. Lateral and dorso-ventral digital radiography and anatomic dissection were performed on the case. The results showed that duplication process of the gastrointestinal tract interestingly  prevented cranial to the midgut, while more cranial organs such as heart, lungs and even brain were seen duplicated. Duplication anomaly has been mostly reported cranially in cattle and caudally in sheep. Nevertheless, if duplication process does not occur completely, some body organs of the resulting conjoined twin will remain unduplicated. Duplication process of this case is thought to strengthen Spencer’s spherical theory.

Background: The increasing resistance to antifungal drugs and the reduced number of available drugs led to the search for therapeutic alternatives among aromatic plants and their essential oils, empirically used by antifungal effects. OBJECTIVES: The purpose of the current study was to evaluate the antifungal activity of Trachyspermum ammi essential oil (EO) against the most frequent pathogenic fungi including Candida, Aspergillus, Chrysosporium and Trichophyton species. METHODS: EO from the seeds of the plant was obtained by hydrodistillation. Susceptibility tests were expressed as growth inhibition zone (diameter) using disk diffusion method and minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) using broth microdilution method. RESULTS: Results of susceptibility tests showed that T. ammi EO was effective against all the tested strains. The diameters of growth inhibition zone of the EO were between 11 mm and 60 mm. The EO was also the most active, with MIC and MFC values ranging from 0.3 to 2.5 mg/ml and 0.6 to 5 mg/ml, respectively. The EO of T. ammi showed a significant degree of antifungal activity against different Candida species in comparison with other fungi (p<0.05). CONCLUSIONS: The present study indicated that T. ammi EO has considerable antifungal activity, deserving further investigations for its clinical application for treatment of fungal infections.

Background: Motile Aeromonas species cause heavymortalities in carp farms during spring and summer in Iran. Objectives: The aim of this study was to detect phenotypicand genotypic characterization of motile Aeromonas species isolated fromdiseased carps in some northern and southern provinces of Iran. Methods: A number of 40 samples from 22 fish farms werecollected. The identified motile Aeromonas species were sequenced andphylogenetic tree was drawn by MEGA6 using UPGMA analysis. Results: A number of 19 bacterial isolates wereidentified as motile Aeromonas sp. by biochemical tests, and the DNAsegments of 16S rRNA gene of all these strains gave 1200 bp after running on 1%agarose electrophorus gel. Also, the sequencing results showed that thebacterial samples were determined as A. hydrophila and A. veroniibiovar veronii. Conclusions: Phylogenetic analysis revealed that motile Aeromonasstrains in this study were separated in two clusters and four  genogroups with high similarities

Background: Calf diarrhea is an important disease that is caused by different pathogens including bacteria, virus and parasites and is associated with economic losses. Objectives: In this study, we evaluated the antibacterial activities of Zatacin (Z. multiflora aerial part ethanol extract), colistin, co-Trimoxazole and enrofloxacin against clinical isolates of Salmonella sp, E. coli and Campylobacter sp isolated from diarrheic calves. Methods: Disc diffusion method and microbroth dilution assay were used for antimicrobial evaluation. Results: In disc diffusion method, the antibacterial activity of Zatacin increased dose dependently. The sensitivity of different isolates of E. coli, Salmonella sp and Campylobacter sp to Zatacin was almost the same. The antibacterial activity of Zatacin was lower than that of enrofloxacin but it was higher than co-Trimoxazole and colistin. The means of MIC values of Zatacin for E.coli were higher than that of Campylobacter sp and Salmonella sp but its means of MBC values for E. coli were lower than that of two other bacteria. Conclusions: Zatacin can be used as an antimicrobial agent in treatment of infectious causes of calf scours instead of antibiotics with undesired adverse effects on animal and humans.

Background: Milk fever in cattle, sheep and goats occurs  around the time of parturition and is caused by hypocalcemia. OBJECTIVES: The aim of this study was to investigate the physiological effects of experimental hypocalcemia on electrocardiography, hematology and serum biochemical changes in Markhoz goat breed. METHODS: Ethylene diamine tetra- acetate solution 4.6% was intravenously infused to 5 healthy goats (experimental group) and 5 healthy goats received 0.9% saline solution (IV) as control group. In both groups, electrocardiogram was recorded in base apex lead and serum was collected before and after infusion. Electrocardiography, biochemical and hematologic parameters were measured. Clinical signs of hypocalcaemia were caused by EDTA infusion. RESULTS: The results in experimental group showed a significant decrease in calcium, lactate dehydrogenase, potassium, and increase in glucose concentration, (p<0.05).The white blood cells, lymphocytes, eosinophils decreased significantly (p<0.05). Magnesium concentration, creatine phosphokinase, alanine transaminase, aspartate transaminase, phosphorus, red blood cells, hemoglobin, hematocrit, Mean cell volume, Mean cell hemoglobin did not show significant change (p>0.05), heart rate change, presence of arrhythmias and its type were significant (p<0.05). But, QRS pattern, T shape, P, QRS and T amplitude, S-T and Q-T interval waves had no significant change (p>0.05). No significant change was seen in control group. CONCLUSIONS: The results indicate that evaluating some biochemical, enzymatic, hematological and electrocardiography changes can be helpful in the diagnosis of hypocalcemia.

Background: Ovarian cysts are among the diseases which cause reproductive failure and economic losses in dairy herds. High yelding dairy cattles are suseptable to reproductive failure caused by ovarian cysts, as a result of their exposure to stressful coditions during lactation. OBJECTIVES: This study aimed to monitor metabolic profile tests in dairy cows with ovarian cysts in comparison with cycling cows. METHODS: Forty high-yelding Holstein dairy cows were enrolled for this study (20 cows with ovarian cysts and 20 cyclic cows). Seven weeks after parturation, 40 cows without retained placenta, including healthy ones were selected. Ovarian cysts were detected as follicular-like structures, >20 mm in diameter, persisting for at least 7 days, without corpus luteum and were monitored by ultrasound examination. Blood samples were collected from the jugular vein and delivered to the laboratory for measurement of calcium, magnesium, phosphorus, sodium, potassium, beta-hydroxy butyric acid, non esterified fatty acids (NEFA), glucose, cortisol, insulin and BUN. RESULTS: In this study, when serum calcium, phosphorus, sodium, potassium, magnesium and glucose of cows with ovarian cysts were compared with cows that had normal ovarian status, there was no significant difference. BUN, beta-hydroxy butyrate, NEFA and cortisol of cows with ovarian follicular cysts as compared to the cows with normal ovaries, showed a significant increase. Serum insulin values decreased significantly in ovarian follicular cystic cows than in cyclic cows. CONCLUSIONS: Increasing blood cortisol and decreasing blood insulin may play a major role in the formation of ovarian cyst and any detectable change in NEFA, BHBA and BUN.

Background: Skin lesions of filarial worms are usually common in livestock. In camels, the most reported species is Onchocerca fasciata, which involves subcutaneous connective tissue and the nuchal ligament. OBJECTIVES: The aim of this study was to investigate the prevalence and pathology of camel onchocerciasis in Iran’s central desert. METHODS: Carcasses of 144 dromedary camels of both sexes and different ages, slaughtered at the slaughterhouse of three provinces in the central arid parts of Iran, were examined for  O. fasciata infection. In addition, the blood smears of tested animals were searched microscopically for the presence of microfilariae. RESULTS: The results of this study show that seventeen (11.8%) of the tested animals harbored one or multiple nodules containing the worm. Nodular lesions were mainly on the two sides of neck and abdomen. Histopathologically, multifocal granulomatous inflammatory reactions were observed to be associated with the parasites in the affected areas. Transverse and longitudinal sections of the worms were observed within the granulomas. The granulomas were composed of thick fibrous walls, the cellular infiltrate of lymphocytes, plasma cells, macrophages, multinucleated giant cells and eosinophils, associated with different degrees of coagulation necrosis and calcification around the parasites. No positive case was found in blood films. CONCLUSIONS: In this study, it was found that onchocerciasis is one of the relatively common skin lesions of camels in Iran. However, parasitemia is not common in the central partsof the country. Histopathologic changes in tissues are quite similar to granulomatous inflammations seen in other cutaneous infections.