BACKGROUND: Nowadays, researchers are converted silver to nanometer dimensions and using nanotechnology to achieve suitable performance and preserve the poultry health and they are used silver nanoparticles are used for poultry nutrition as a nutritional supplement. On the other hand, at the molecular level no complete reports in poultry breeding have been provided. OBJECTIVES: This study was conducted to evaluate cytochrome P450 gene expression in broiler chickens fed with silver nanoparticles. METHODS: This experiment a completely randomized design with 450 single-day Cobb 500 broiler chicks was divided into five treatments and six replications (15 birds in each replicate). Chickens were fed with (1) control (basal diet), (2) basal diet containing 1% zeolite, (3) basal diet containing 1% of zeolite-coated with 0.5% silver nanoparticles, (4) Basal diet containing with 0.15% organic acids and (5) Basal diet containing 1% of zeolite-coated with 0.5% of silver nanoparticles and 0.15% organic acids in with or without heat stress condition. RESULTS: Results demonstrated the level of expression of cytochrome P450 in broilers fed zeolite (Z) in the 21st day of experiment, silver nanoparticles coated with zeolite in combination with organic acid (NSOA) in 42nd day without heat stress condition and silver nanoparticles coated with zeolite (NS) in day 42 with heat stress condition in intestine and liver had significant increase in expression in comparison with control (C) treatment (P<0.05). CONCLUSIONS: In conclusion, result showed that zeolite and silver nanoparticles were identified as inorganic, chemical and exogenous substances in liver and intestine and up-regulated expression of pollution biomarkers genes. Whereas this effect is not identified in organic acid.

BACKGROUND: Diagnosis of Cryptosporidium species based on morphological characteristics is very limited and has no taxonomic value alone, and therefore the use of molecular methods removes these limitations to some extent. OBJECTIVES: The aim of this study was to determine the predominant Cryptosporidium genotypes in calves with diarrhea. METHODS: Study were conducted in calves aged less than 3 months for a period of 2 years. During the study period, 160 dung samples were collected from neonatal calves and examined first microscopically and then by molecular techniques. Stools were analyzed for the presence of Cryptosporidium oocysts by Sheather's Sugar Flotation Solution followed by Ziel-Neelsen staining method. DNA of parasite was extracted and multiplex nested-PCR protocol basis on the 18srRNA were done to identify three cattle-adapted species (C. andersoni, C. bovis and C. ryanae) plus the zoonotic species C. parvum. RESULTS: 110 fecal samples were collected from livestock in Alborz province and 50 fecal samples were collected from livestock in Shahroud city. Of the 160 animals examined, 90 were female and 70 were male. In total, out of 160 animals examined, 85 cases (53.12%) had diarrhea, of which 55 cases (34.37%) were positive using Ziel-Neelsen staining. Since all positive cases were related to diarrhea samples and related to calves under one month old, a significant relationship was observed between diarrhea status and the presence of this parasite (p < /em><0.05). In terms of seasonal distribution, no difference was observed in the rate of diarrhea and positive parasitic cases. The presence of 305 bp band in all Ziel-Neelsen positive samples confirmed the presence of C. parvum in all samples. CONCLUSIONS: Neonatal calves are more likely to be infected with Cryptosporidium parvum, as confirmed by the present study.

BACKGROUND: Health and welfare of dogs can be adversely affected by ectoparasite infestations and these infestations pose severe risks to human health due to close contact between dog and human. OBJECTIVES: This study was carried out to detemine the frequency of ectoparasite infestation in referred dogs to veterinary hospital of Ferdowsi University of Mashhad, Mashhad, Iran. METHODS: From April 2017 to April 2018, a total of 460 dogs were examined for ectoparasites. Age, gender, season, breed, keeping place, hair length, hair colour, pruritus, alopecia and distribution of parasites on different parts of the body of each examined dog were recorded in a questionnaire. RESULTS: Out of 460 dogs examined, 99 (21.52%) were found to be infested with ectoparasites. Forty-eight  (10.43%) dogs were infested with Ctenocephalides canis and Pulex irritans. Rhipicephalus turanicus, Sarcoptes scabiei, Hippobosca longipennis and Rhipicephalus sanguineus were found on 14 (3.04%), 10 (2.17%), 10 (2.17%) and 9 (1.95%) dogs, respectively. Infestation with Wohlfahrtia magnifica, Demodex canis, Otodectes cynotis, Haemaphysalis erinacei and Linognathus setosus were observed in 9 (1.95%), 3 (0.65%), 2 (0.43%), 1 (0.21%) and 1 (0.21%) examined dogs, respectively. There was a statistically significant association between ectoparasite infestation and sex, keeping place and pruritus (p < /em><0.05). No statistical relationship was found between ectoparasite infestation and age, hair colour, hair length, season and alopecia (p < /em>>0.05). CONCLUSIONS: This is the first study conducted on dog ectoparasite infestation in Mashhad district, Northeast Iran. Fleas were the most common ectoparasites and although ectoparasite infestation rate was relatively low, high species diversity was observed. Some of these ectoparasites have zoonotic importance.

BACKGROUND: Replenishing fish oil with vegetable oils and using dietary supplements plays an important role in the metabolism of fats in aquatic animals. Corn oil is one of the vegetable oils that can be a good alternative to fish oil. OBJECTIVES: The aim of this study was to investigate the effects of replacing fish oil with corn oil and the use of dietary supplements L-carnitine and betaine on the metabolism of fats and blood indices of rainbow trout. METHODS: 450 rainbow trout (9.12±0.26 g) were divided into four treatments (three replicates) and were fed with manual diet containing fish oil (1st treatment), corn oil (2nd treatment), fish oil with 500 mg/kg of food containing L-carnitine and betaine (3rd treatment) and corn oil with 500 mg/kg of food containing L-carnitine and betaine (4th treatment) for eight weeks. At the end of study, fatty acid profiles of the treatments were determined by gas chromatography (GC) and blood indices and their weights were also examined. RESULTS: At the end of the experiment, the weight index did not show a significant difference. In the replacement of fish oil with corn oil, the levels of PUFA n-3, C18:3n3, C20:3n3, C20:5n3 and C22:6n3 fatty acids significantly decreased in fish carcasses and the PUFA n-6, C18:2n6, C20:2n6 and C20:4n6 increased significantly, but no significant difference was observed in total SFA and MUFA fatty acids. L-carnitine and betaine increased the EPA accumulation in fish oil and corn oil significantly, and the number of white blood cells in corn oil, L-carnitine and betaine fed fish (fourth treatment) were increased compared to fish oil treatment (first treatment), significantly (p < /em><0.05). CONCLUSIONS: Considering the effect of corn oil, L-carnitine and betaine supplements on increasing the n-6 PUFA fatty acids, essential EPA and white blood cell counts, the use of corn oil and L-carnitine and betaine supplements in rainbow trout diet is recommended.

BACKGROUND: Nowadays, the tendency to use food packaging with antimicrobial activity of natural origin has increased. The use of edible and biodegradable films has been considered as an appropriate alternative to non-degradable plastic coatings. OBJECTIVES: In this study, the effect of coating with wheat starch and Pennyroyal (Mentha pulegium essential oil was investigated on microbial and physicochemical characteristics of rainbow trout fillet in cold conditions. METHODS: For this purpose, different treatments under the influence of starch, starch and Pennyroyal essential oil (1%), starch and Pennyroyal essential oil (2%) were prepared and physicochemical and microbial changes were evaluated at specified intervals (0, 4, 8, 12 and 16 days). RESULTS: In the microbial test, the count of total bacterial and other bacteria by starch and starch + 1% and 2%, the essential oil was decreased in different days, also the difference between the control group and other treatments was significant (p < /em>≥0.05). The highest effect of pH reduction belonged to starch + 1% and 2% essential oil in different studied days. The level of pH was not different among different treatments on day 0 of storage. However, there was a significant difference between the control group and treatments on the fourth, eighth, twelfth, and sixteenth days of storage (p < /em>≥0.05). The results of the oxidative test showed that on the 16th day of storage, the lowest level of TBA was related to the treatment with starch + 2% essential oil and the highest value was related to the control group. In fact, the application of the coating layer delayed the oxidation process. CONCLUSIONS: This study demonstrated antioxidant and antibacterial properties of the composition of edible starch and pennyroyal essential oil on the increased shelf-life of Rainbow trout fillet.

BACKGROUND: Dactylogyrus is one of the most common external parasites on                the gills of Cyprind fish. These parasites are highly host specific and many species only have a specific host. OBJECTIVES: Since there are reports of silver carp specific Dactylogyrus species isolated from big head carp and vice versa, the investigation of Dactylogyrids have been done in these two fish species. METHODS: 81 silver carp and 82 big head carp were caught from 10 fish farms in Guilan province and after preparing wet mounts of body surface Dactylogyrus parasites divided and fixed by glycerin jelly. In order to perform morphometric assessments on captured images, Image J software was used for 7 point to point distances. Drawing of parasites was done by drawing tube and then compared by identification keys and parasites identified. For molecular investigation the genomic DNA was extracted from one parasite specimen and 28S rDNA region of Dactylogyrus specimens were amplified by related primers in PCR. RESULTS: Sequences were deposited in GenBank with accession numbers MG825611 and MG825765 respectively for D. hypophthalmichthys and D. suchengtaii isolated from Hypophthalmichthys molitrix, and also MH023397 and MH023399 respectively for D. aristichthys and D. nobilis isolated from Hypophthalmichthys nobilis. The phylogenetic tree shows the genetic affinity of isolated parasites from these two fish. CONCLUSIONS: It seems hybrid fish are sometimes produced accidentally in fish reproduction centers of Iran. Racial impurity of silver carp and big head carp is not only the reason of poorer breeding efficiency in fish farms but also these hybrid fish are hosts of more parasitic species.

BACKGROUND: Major histocompatibility complex (MHC) is a group of genes which codes for binding of antigenic peptides and presenting them to T cells. MHC molecules polymorphism is associated with presenting different antigens, immune and autoimmune responses. One of the most important dog MHC genes is DRB1. The association between this gene and its alleles with Atopic Dermatitis has been reported. OBJECTIVES: In this study, the association between canine Atopic Dermatitis and DLA-DRB1 alleles has been evaluated using HRM (High Resolution Melting) genotyping method. METHODS: Blood samples were collected from 20 dogs with Atopic Dermatitis and 20 healthy dogs. Frequency of different DRB1 genotypes, as well as heterozygosity and homozygosity of alleles were analyzed using HRM. Their associations with Atopic Dermatitis were evaluated by statistical analysis. RESULTS: Based on the HRM analysis, genotypes were grouped in 9 types (A-I). Statistical analysis showed that the presence of type D allele in the exon II of DLA-DRB1 gene increases the risk of Atopic Dermatitis (Odd ratio=0.206 and p < /em>=0.064). A significantly increased risk of Atopic Dermatitis in heterozygous samples was also observed (Odd=0.158 and p < /em>=0.090). CONCLUSIONS: The results of this study showed that some alleles of DLA-DRB1 gene can play a role in the sensitivity or resistance to Atopic Dermatitis in dogs.

BACKGROUND: Phosphorous is an essential nutrient for poultry. Receiving too much phosphorous by livestock and excretion of excess phosphorus, can lead to environmental pollution. OBJECTIVES: Determining the ileal and total tract digestibility of phosphorus and calcium in di-calcium phosphates produced in Iran. METHODS: A total of 720 day-old male Ross 308 broilers were randomly divided into 8 treatments with 6 replicates of 15 birds in each. In control treatment phosphoric acid was used as a source of phosphorus. The other dietary treatments included one of the seven domestic samples of di-calcium phosphates (A to G). Chromium oxide was used as a marker in the diets. On day 21, after collecting of feces, all birds were slaughtered via neck dislocation. Then, the last one-third of ileum was removed. The contents of the intestine were collected for each replicate and after drying were sent to the laboratory to determine the chromium oxide, phosphorus, and calcium amounts. Percentage of ileal and total tract digestibility of phosphorus and calcium for each sample were calculated separately. RESULTS: The effect of type of di-calcium phosphate samples in feed on ileal and total tract digestibility of calcium and phosphorus was highly significant (p < /em> < 0.001). Ileal digestibility in control was 69.8 percentage, while the lowest was observed in the E and F samples, and the highest value was related to sample A. Digestibility for phosphorus in control diet was 53.4 percentage throughout gastrointestinal tract. The lowest amounts of total tract digestibility of phosphorus were observed in treatments E and F, respectively, while the highest total tract digestibility was related to treatment A with 47.9 per cent. CONCLUSIONS: It could be concluded that ileal digestibility is more accurate in evaluating phosphorus bioavailability and sample A had the highest biological value, while the lowest was related to the samples E and F.

BACKGROUND: Arrhythmias play an important role in reducing the performance of racing horse. There are no studies that maintained the same condition for all horses, and in previous studies, the conditions for all horses were not the same. OBJECTIVES: The purpose of this study was to evaluate the prevalence of arrhythmias during exercise include warm-up and trotting. METHODS: This study was carried out on 30 sport horses. Modified base-apex has been used for electrocardiogram recording. Electrocardiogram was taken by telemetry device in all conditions, all horses were examined in the electric lounge. Warm-up period was 10 minutes and consequently 10 minutes trotting was done, and ECG was recorded during exercise. RESULTS: 18 horses had SVPCs during warm-up and 9 showed SVPCs during trotting; also, 4 horses showed VPCs during trotting. AVB II happened in one horse during warm-up. CONCLUSIONS: The occurrence of SVPCs and VPCs during rest is abnormal, but it is common during physical activity. To better understand the importance of these arrhythmias more studies are needed.

BACKGROUND: The Schirmer tear test (STT) is widely used in both human and veterinary ophthalmology. Two types of STTs have been developed: STT I and STT II. OBJECTIVES: The purpose of this research was to determine the reference value for measuring tear production of the Caspian horse by using the Schirmer tear test strip. METHODS: Twenty apparently healthy male and female Caspian horses, aged between 2 and 15 years old and weighing between 192±32 Kg were selected. After physical examination and reviewing the horse's health history and assuring their health, the Schirmer tear test was performed. To produce a higher volume of tears in horses, compared to other animal species, we used the Schirmer tear strip (Schirmer‐ Eickemeyer®, Germany), for 30 seconds instead of one minute in the lower conjunctival sac. In this study, we investigated the effect of age and gender on tear production in the Caspian horse, as well as the comparison between the left and right eyes tear production. RESULTS: The study shows that the results of STT I in the study animals illustrated the mean±SD STT I value was 23.38±3.6 mm/min (range, 15–30 mm/30s). Based on the results of this study, the variants of age and gender had no significant effects on the STT1 results in the Caspian horses. No significant difference was noted between the amount of tear production in the left and right eyes. CONCLUSIONS: Considering the importance of rapid diagnosis of dry eye syndrome and preventing its subsequent disorders such as Keratoconjunctivitis Sicca, the results of this study can be used as the reference value in the future to measure the amount of moisture of caspian horses of the Caspian horse.