Veterinary Research Forum

Abstract Numerous studies have explored the molecular epidemiology of H9N2 viruses in Iran; however, continuous monitoring remains vital for timely interventions to mitigate potential damage. This study examined the molecular characteristics and evolutionary features of Iranian H9N2 viruses by sequencing the complete genomes of two viruses, Marand and Baneh, isolated in 1998 and 2022, respectively, alongside other Iranian strains from GenBank. All Iranian viruses were identified as low-pathogenic avian influenza viruses, as evidenced by the presence of the di-basic motif K/RSSR cleavage site. Notably, all Iranian viruses isolated from 2009 onward had an L at position 216 in the hemagglutinin receptor binding site, whereas earlier viruses exhibited a Q/L at the same position, an essential mutation that enhances replication in mammalian cells. The molecular evolutionary rates for the Iranian hemagglutinin (HA) and neuraminidase (NA) genes were estimated at 4.50 × 10^-3 and 3.60 × 10^-3 substitutions per site per year, respectively. Error-prone replication of H9N2 viruses has resulted in the continuous evolution of Iranian strains over two decades, characterized by three phases of population growth. Maximum likelihood phylogenetic analysis revealed that the HA and NA genes of H9N2 viruses from domestic chickens belonged to the G1 sublineage. Additionally, the internal genes of some viruses displayed evidence of reassortment with other subtypes, indicating potential gene exchange with other viruses. These findings underscored the importance of ongoing surveillance of H9N2 viruses in both domestic and wild bird populations, given the human-like receptor-binding preference and the possibility of genetic reassortment with various viral subtypes.

Abstract Newcastle disease (ND) is a highly contagious and severe disease that affects birds, including domestic poultry, causing significant economic losses to the poultry industry. The disease is caused by the ND virus (NDV). Despite extensive vaccination efforts against NDV, controlling the disease remains challenging, primarily due to the emergence of new genotypes. Recent attention has focused on calcium phosphate nanoparticles (CaP NPs) as promising adjuvants for vaccines. This study aimed to design and construct CaP NPs containing inactivated NDV genotype VII and evaluate their safety and humoral immunogenicity in chickens. Following virus propagation in specific-pathogen-free eggs and inactivation with formalin, CaP NPs containing inactivated NDV were prepared using in situ and adsorption methods. The NPs were characterized for shape, size, polydispersity index and surface charge. Chickens were immunized subcutaneously with CaP NPs containing inactivated NDV and the humoral immune response against NDV was assessed using HI and enzyme-linked immunosorbent assays. Results showed a significant increase in the mean antibody titer against NDV in chickens treated with both NP structures compared to control groups. No significant difference was observed between the two NP preparation methods. The safety of CaP NPs containing inactivated NDV was confirmed. However, mucosal immunization with these NPs did not yield satisfactory results indicating the need for further research. Overall, this study confirmed the positive role of CaP as an adjuvant in enhancing the humoral immune response against NDV via injection and highlighted the need for continued research on mucosal immunization with the NPs.

Abstract Male and female broiler chickens differ in performance and this will cause unwanted experimental errors in research. For this reason, single-sex or mixed-sex broilers are used in most studies. This study aimed to assess the performance differences between groups of chickens with varying male/female ratios to determine how sex ratio can affect performance criteria. Birds (N = 550) were separated by sex and placed in 11 groups (pens) according to the male/female ratios, including group 1 (10 males + 0 female), group 2 (9 males + 1 female), group 3 (8 males + 2 females), group 4 (7 males + 3 females), group 5 (6 males + 4 females), group 6 (5 males + 5 females), group 7 (4 males + 6 females), group 8 (3 males + 7 females), group 9 (2 males + 8 females), group 10 (1 male + 9 females), and group 11 (0 male + 10 females). The results showed that male broiler chickens had higher feed intake and body weight gain than female broiler chickens, but the feed conversion ratio was not affected by gender. The digestibility of phosphorus, bone strength, bone density, bone calcium and phosphorus, pH, and redness and water holding capacity of meat were higher in male broilers. The dripping loss was higher in female broilers. This study showed that male and female broiler chickens differed in most of the parameters examined in the research, and the use of separate breeding affected the research results. 

Abstract During the fifth month of 2024, many outbreaks of the avian influenza virus occurred in Vietnam, during which the first human infected with avian influenza A (H5N1) was reported. Therefore, influenza control strategies including vaccine production are necessary for poultry and improving the number of candidate vaccine viruses that do not replicate well in eggs for vaccine production. We previously reported that the ST-2009 virus had a negative propagation capacity in eggs. Chimeric neuraminidase (NA) genes were generated by replacing the 5' and 3' packaging signals of PR8 A/PR/8/34 strain with the coding region of the NA genes of ST-2009. Compared to those of the control, the new viruses containing chimeric NA genes exhibited significantly greater hemagglutination titers in embryonated chicken eggs. This study showed that the packaging efficiency of new viruses containing chimeric NA and replacing chimeric NAs improved the hemagglutination titer of viruses that were unable to propagate in eggs.

Abstract This study focuses on understanding how the sensitivity patterns of common probiotic Lactobacillus species differ between healthy and colibacillosis-diseased broiler chickens and explores any correlation between these patterns and avian pathogenic Escherichia coli (APEC). Ileum samples were collected from the healthy (n = 10) and colibacillosis-diseased (n = 10) broiler poultry farms. Lactobacillus and E. coli were identified and incidence rate of six probiotic Lactobacillus species (L. acidophilus, L. brevis, L. casei, L. plantrum, L. delbrueckii, and L. fermenti) was determined, and their susceptibility to different antibiotics (ampicillin, chloramphenicol, erythromycin, kanamycin, tetracycline, and vancomycin) was tested. A total of 120 Lactobacilli were examined. Certain Lactobacillus spp. from healthy birds (L. brevis) and those affected by colibacillosis (L. acidophilus) showed better sensitivity and lower multiple antibiotic resistance to chloramphenicol, erythromycin, and kanamycin. Statistical analysis revealed significant correlations between ampicillin and chloramphenicol, ampicillin and erythromycin, ampicillin and tetracycline, and ampicillin and vancomycin resistance. Also, a significant correlation was observed between erythromycin and tetracycline, and kanamycin and vancomycin. All APEC strains showed multiple antibiotic resistance. A strong positive correlation was found between resistant Lactobacillus spp. and APEC isolates from diseased birds, indicating co-occurrence of antibiotic resistance. The study suggests that antibiotic resistance in APEC and Lactobacillus species may spread through horizontal transfer, highlighting the need for improved anti-microbial management in poultry systems.

Abstract China's burgeoning animal husbandry sector has witnessed a notable expansion in goose farming. Among the various health challenges, a novel goose astrovirus (GoAstV) has emerged as a significant threat to the industry, necessitating prompt detection strategies to mitigate its economic impact. This research introduces a novel detection approach using real-time fluorescence-based reverse transcription recombinase-aided amplification (RT-RAA), offering a rapid and reliable method for GoAstV identification. We meticulously designed specific primers and probes, and optimized the RT-RAA reaction conditions. The assay's specificity, sensitivity, repeatability, and clinical efficacy were rigorously assessed. Our method achieves detection within a swift 26-min window at a constant temperature of 39.00 ˚C, boasting a detection threshold as low as 1.19 × 10² copies per μL. Notably, the assay exhibited no cross-reactivity with closely related viruses, including Newcastle disease virus, avian influenza virus H9 subtype, goose circovirus, goose parvovirus, duck Tembusu virus, and avian adenovirus type 4. Validation through testing of 40 clinical samples confirmed a 100% agreement with pre-existing data. The study's outcomes underscore the high specificity, sensitivity, and operational simplicity of the developed RT-RAA assay, positioning it as an ideal candidate for the rapid and on-site detection of GoAstV.

Abstract The Iraqi indigenous chicken (IIC) is a native breed known for its remarkable ability to thrive in harsh environments. However, the primary challenge with this breed is its lower productivity levels especially when compared to commercial strains. This study evaluated the performance of 120 layers of IIC in comparison with an equal number of Hy-Line W-80 layers across multiple traits including feed efficiency (FE), feed conversion ratio (FCR), daily feed intake (DFI), egg mass (EM) and total egg number (EN) production. Over a period spanning four consecutive weeks intervals significant differences were observed between the two lines across all measured parameters. Hy-Line W-80 consistently exhibited superior FE, with values ranging from 0.49 to 0.54 compared to IIC values that ranged from 0.23 to 0.26. Similarly, Hy-Line W-80 demonstrated lower FCR values ranging from 1.85 to 2.03 contrasting with IIC (3.77 to 4.37). The DFI was notably higher in Hy-Line W-80 (ranging from 104.30 to 106.00 g per day) compared to IIC (73.75 to 90.20 g per day). Furthermore, Hy-Line W-80 consistently outperformed IIC in EM production with values ranging from 52.33 to 56.67 compared to IIC values (19.83 to 21.47). Another superiority of Hy-Line W-80 was observed by showing higher EN over IIC layers in all sixteen weeks of investigation. In conclusion, Hy-Line W-80 consistently outperformed IIC in various parameters such as FE, FCR, DFI, EM and EN production. Accordingly, these data could be exploited in selective breeding and genetic improvement strategies to enhance the productivity of IIC.

Abstract Crude fiber (CF) is a vital component in poultry nutrition with a notable phytonutrient effectively indicating the presence of indigestible biomass in food due to the absence of digestive enzymes for CF in broilers. This study aimed to analyze the properties of a multi-enzyme cocktail (MEC) Bacillus sonorensis BD92 (BsBD92) comprised of xylanase, β-glucosidase, exo-glucanase, and endo-glucanase enzymes. Also, this study intended to look at the growth performance and intestinal histology of broilers in the starter and finisher phases by the addition of MEC BsBD92 to their diet. To evaluate the efficacy of MEC BsBD92, 140 one-day-old unsexed Cobb500 broiler chicks were randomly divided into seven groups receiving different diets. The characterization of exo-glucanase, xylanase, β-glucosidase, and endo-glucanase showed that their peak activities were observed at a temperature of 50.00 ˚C and a pH of 5.50. The 6.00% CF and 2.00 X MEC BsBD92 improved the intestinal morphology and feed conversion ratio, demonstrating a synergistic effect on growth performance. Whereas, increasing meat percentages to 61.06 and 65.09 g per 100 g body weight during the starter and finisher phases was also observed, respectively. The lipid profiles revealed significant variations in triglyceride and cholesterol levels. This study provides an innovative approach, considering not only lowering the feed cost using inexpensive fibrous feedstuffs but also improving the feed efficiency through supplementation of MEC BsBD92.

Abstract All fresh poultry eggs differ greatly in chemical components. Many chemicals have been investigated in this field, but the presence of differences in odor components between species has not yet been investigated. For this reason, this study aimed to determine the volatile compounds of the eight different poultry species eggs and the differences among them. In this context, 180 eggs (20 from each species) were purchased from different farms, and the volatile compounds of raw eggs were determined by the solid phase micro-extraction method. Following the analysis, 41 volatile compounds and 12 organic groups were identified. The variety and ratios of these compounds varied among the species, with pigeon eggs containing the greatest number of compounds (19 compounds) and quail, partridge, and pheasant eggs containing the lowest numbers (seven compounds). Acetamide, 2-fluoro-, and D-limonene compounds were found in every species of eggs. The other species eggs did not contain any of the 10 volatile chemicals detected in pigeon eggs, eight in chicken eggs, and one in quail eggs. It was discovered that the eggs volatile compounds counts and chemical profiles varied, indicating differences in their tastes, smells, and aromas. The volatile chemicals found in this study may be species-specific and can be used as indicators to identify which eggs belong to which species.

Abstract This study was conducted to determine the effect of different cage densities and meat storage periods on some meat quality parameters in drumstick and breast meat of brown and white spent hens. The study used three different cage densities as low (5 hens per cage), normal (seven hens per cage) and high (10 hens per cage) including 396 hens as 198 Hy-Line Brown (HB) and 198 Isa Tinted (IT). The feeding of chickens was ad libitum (20 - 60 weeks). At the end of the study, a total number of 54 chickens (27 HB and 27 IT) were slaughtered. Some chemical and microbiological analyses were carried out by separating the drumstick and breast area of the slaughtered chickens. According to the results of the research, the redness and yellowness values of the breast area were higher in the ITs. The effect of cage density was significant only for yellowness in the drumstick area. The effects of storage time, lightness and yellowness in the drumstick area and lightness value in the breast area were found to be significant. Bacterial density and thiobarbituric acid reactive substances values of both breast and drumstick regions of spent hens were higher in HBs, while pH values were higher in ITs. The bacterial density in the meat was increased during the storage period. In conclusion, cage density, genotype and storage time affected the microbiological and chemical quality of spent chicken meat. With this result, it can be said that meat quality studies, which mostly focus on broilers, are also important in spent hens.

Abstract The study aimed to investigate the impact of wet feeding on broiler chicken performance and intestinal histomorphometry. The research was conducted at the Veterinary College, Udaipur, India, using 144 commercial broiler chicks from day 1 to 6 weeks of age. The chicks were divided randomly into three experimental groups, each with four replicates comprising 48 birds. The control group (G1) was fed dry; while, group 2 (G2) received wet feed supplemented with 1.00 g water per g of feed and group 3 (G3) received wet feed supplemented with 1.20 g water per g of feed. Results revealed that G3 had significantly superior feed conversion ratios, lower feed intake, and increased body weight and weight gain compared to G2 and G1. Among the three treatment groups, there were no variations in blood plasma indicators. In comparison with G1, duodenum and ileum in G2 had higher villus height. The G3 revealed higher net profit margins and 18.89% saving of feed compared to G1, suggesting that it may be a valuable tool for lowering chicken feed costs.

Abstract The aims of current investigation were to study the growth performance, carcass traits, meat quality and expression profile of Myostatin (MSTN), Insulin-like growth factor-1 (IGF-I), Myogenin (MyoG) and Myogenic regulatory factor 4 (MRF4) genes in three commercial broiler strains including Ross (Ross 308), Cobb (Cobb 500), and Arian in 2023. A total number of 240 one-day-old chicks were reared under an equalized standard management condition for 6 weeks. Performance, organ weights, meat quality and the expression level of the myogenic genes in the pectoral muscle were investigated. The lowest body weight (BW), feed intake, weight gain and highest feed conversion ratio (FCR) was observed for Arian at the end of the study. The meat quality was similar between strains. The IGF-I expression level was significantly higher on 42 days of age in Cobb compared to Ross and Arian. The MRF4 expression level was significantly higher on 28 days of age in Cobb compared to Ross. The MyoG expression level was significantly lower in Arian compared to Cobb on 42 days of age. Furthermore, the MSTN expression level was significantly lower in Cobb compared to Ross and Arian on 42 days of age. The remarkable differences in gene expression levels at the end of the rearing period was supported by higher growth performance and BW of Cobb compared to Ross and Arian strains. In conclusion, the findings of current study could conveniently help assess the performance of these broiler strains under similar rearing condition.

Abstract In this study, the effects of nanocurcumin on acetaminophen-induced acute hepatorenal toxicity in domestic pigeons (Columba livia) were investigated. Fifteen pigeons were randomly assigned into three groups. Group I was served as a negative control group and received tap water as a placebo. Pigeons in groups II and III were administered acetaminophen at the beginning of the experiment (hr 0). Group III was further treated with nanocurcumin, at 12 hr after acetaminophen administration, being continued every 12 hr for two days. The birds were observed for clinical signs of acute drug toxicity. Blood samples were collected from the pigeons at hr 0, 12, 24 and 48 of the experiment for biochemical analysis of the serum. The results showed that acetaminophen toxicity increased the serum levels of aspartate aminotransferase, alanine aminotransferase, urea and uric acid in the pigeons. Nanocurcumin treatment of acetaminophen intoxicated pigeons attenuated increases in biomarkers of the liver and kidney functions towards control levels. Also, the consumption of nanocurcumin minimized histopathological changes in the liver and kidney. A mortality of 60.00% was seen in the acetaminophen-induced toxicity group; while, none of the birds treated with nanocurcumin died. It can be concluded that nanocurcumin alleviates the acetaminophen-induced acute toxic liver and kidney damages, which can lead to pigeon mortality.

Abstract An internationally recognized syndrome that leads to deaths among domestic and ornamental pigeons, particularly after racing, is young pigeon disease syndrome (YPDS). Pigeon circovirus (PiCV) is regarded as one of the potential factors contributing to the occurrence of YPDS. This survey was conducted to determine the prevalence of PiCV infection and molecularly characterize the PiCV in pigeons suspected of YPDS. Eighty fecal samples were collected from 80 diseased pigeons (exhibiting symptoms such as lethargy, weight loss, crop stasis, vomiting and diarrhea) from 20 lofts in different areas of Ahvaz, Iran. Also, 20 fecal samples were obtained from 20 clinically healthy pigeons. The nested broad spectrum polymerase chain reaction test was done to identify the circovirus, using primers targeting part of the replication-associated protein gene with 350 bp, and several positive samples were sequenced. This study showed that PiCV was detected in 86 out of the 100 samples (86.00%). Two types of circoviruses were determined in the samples. One type of the detected circoviruses was PiCV which based on phylogenetic analysis had high genetic similarity with A, B, G and H genotypes of PiCV. The other type of detected circoviruses was closely related to beak and feather disease virus (BFDV) which causes one of the most significant viral diseases in psittacine birds. This is the first report of BFDV identification in pigeons.

Abstract Mycoplasma synoviae, which causes the disease known as chicken synovitis, causes serious immunosuppression. We developed a rapid insulated isothermal polymerase chain reaction (iiPCR) assay for on-site detection of M. synoviae using a primer and probe set targeting the variable lipoprotein and haemagglutinin (vlhA) gene. In addition, the specificity, sensitivity, repeatability, and clinical detection of this method were evaluated. Our iiPCR assay detected M. synoviae clinical isolates and samples successfully and produced negative results on Mycoplasma galliscepticum, avian viral arthritis, Escherichia coli, Salmonella, Staphylococcus aureus and Corynebacterium, indicating that the PCR reactions were specific. Additionally, our iiPCR assay detected the prepared positive standard plasmid diluted 10 times (1.00 × 10^-1 - 1.00 × 10^-10) as a template. The undiluted positive plasmid was positive and double distilled water was negative indicating that the PCR reactions were sensitive, respectively. Finally, the vlhA positive standard plasmid with dilution multiple of 1.00 × 10^-4 - 1.00 × 10^-6 was repeatedly detected three times to evaluate the repeatability of the iiPCR method established in this experiment showing that the iiPCR of M. synoviae is repeatable. The established iiPCR was also used to detect 50 chicken joint enlargement samples. The thermostatic detection PCR established in this experiment was comparable to a reference real-time PCR (qPCR).

Abstract Purification is an important step in the production of viral vaccines that strongly affects product recovery and subsequent immune responses. The present study was carried out with the aim of improving the purification of infectious bursal disease virus (IBDV) by the tangential flow filtration (TFF) method. Then, the effect of the purified virus on the induction of immune responses against IBDV in specific pathogen free (SPF) chickens was investigated. The IBD07IR strain was propagated in embryonated SPF eggs. The virus was purified using a 100 kDa cassette. The quality of the recovered viruses was evaluated by titration. A total number of 60 SPF chickens were randomly divided into three groups (n = 20) and received the concentrated viral antigen, commercial live IBDV vaccine and phosphate-buffered saline at the age of 3 weeks by eye drop method. The bursa of Fabricius was examined histopathologically for possible changes. Sera were collected at 1-week intervals from day 0 until the end of 6 weeks after vaccination. The IBDV-specific antibody levels, induction of cell-mediated immunity and mRNA expression levels of cytokines were evaluated. The results showed that despite a relative raise in virus titer from 7.66 to 8.17 embryo infectious dose (EID)₅₀ mL^-1 following purification, both the purified IBDV and commercial vaccine are able to induce strong immune responses against the virus. Within a context of egg-based IBDV vaccine production, a single-step TFF can be applied for the relatively purification. This platform requires a further study in the selection of multiple membranes to optimize the operating conditions and final product.

Abstract The different microorganisms that make up the normal microbiota of birds can be present in different substrates such as the soil and other elements that make up the habitat. In the case of the cattle egret, the intestinal microbiota can change due to partially migratory habits. Thus, this study aimed to isolate and identified fungi and yeasts with zoonotic potential obtained from cattle egret (Bubulcus ibis) droppings settler in Tulancingo, Hidalgo, at Eastern economic zone of Mexico. Cattle egret droppings were collected for analysis, a total of 240 pool samples, which were spread on Sabouraud agar and incubated at 25.00 - 37.00 ˚C for 2 to 3 days. Filamentous fungi and yeast were identified by morphology and Lactophenol Blue staining or Chinese Ink stains. Filamentous fungi genera Mucor spp. (42.35%), Rhizopus spp. (26.71%); Penicillium spp. (13.35%); Paecilomyces spp. (11.40%); Scedosporium spp. (1.95%); and, from yeasts such as Cryptococcus spp. (2.29%); Rhodotorula spp. (1.95%) were identified. In this work, the presence of filamentous fungi genera and yeasts with zoonotic potential were isolated from droppings of cattle egret. The clinical presentation of fungal infections in humans can occur when immunosuppression is present or different predisposition factors are conjugated. The presence of birds and their dropping in anthropogenic activities is not a predisposing factor for the presentation of the disease in immunologically competent humans.

Abstract Infectious bursal disease virus (IBDV) in turkeys may result in immunosuppression, and inability of turkeys to resist nonpathogenic or less pathogenic organisms. A total number of 120 day-old commercial male turkeys were purchased and blood samples were collected from 20 day-old turkeys, remaining 100 were divided into four equal groups and kept in separated rooms. Groups 1 and 2 were infected with 10⁴ CID₅₀ of IBDV via intra-bursal route on day 1; Groups 1 and 3 were each infected with 10⁶ EID50of AIV (H₉N₂) via the oculo-nasal routes on day 30. All groups were vaccinated against Newcastle disease vaccine (NDV). Detection of avian influenza virus H9N2 in trachea and cloaca swabs and in the tissues, was confirmed by Real-time polymerase chain reaction. Anti- NDV–AIV and anti-IBD titers were measured using HI and ELISA tests, respectively. The present study showed that infectious bursal disease changed the pathogenesis of (AIV) H9N2 by affecting AI virus replication and resulted in an increase shedding due to prolonged duration of sever clinical signs. The extent of shedding and virus replication need further study.

Abstract Early development of the digestive tract is crucial for achieving maximal growth and development of chickens. This study examined the effects of in ovo (IO) feeding of 0.70 mL of dextrose (10.00% and 20.00%) or amino acids solutions into the yolk sac at day 14 of incubation on small intestine histomorphometry and histomorphology, intestinal development, hatchability, body weight, and liver glycogen reserves in newborn chicks. Results showed body weight in amino acid fed hatchlings was higher than control and dextrose groups non-significantly, but hatchability was lower in amino acid group than others. Also, diameter of glycogen vacuoles in all IO treatment groups was more than control. Administration of exogenous dextrose and amino acids solutions into the yolk sac enhanced intestinal development by increasing the size and surface area of the villi and changed villi shape as well. It seems that dextrose or amino acids solutions could improve the intestinal villi development, while they did not affect finger-like villi in jejunum.

Abstract Fertility is one of the most important parameters in breeder farms and cockerels play an outstanding role in fertility of eggs in broiler breeder units. Todays, supplementation of feed-additives such as organic selenium is used to increase fertility. The aim of this study was to evaluate the effects of different levels of Nano-Selenium (Nano-Se) on expression of molecular markers of spermatogonial stem cells (SSCs) in testis of broiler breeder males. A total of 30 roosters of 40 weeks age were randomly divided into 5 groups. Groups were as follow: 1) control (normal diet), 2) diet supplemented with 0.3 mg/kg sodium Selenite, 3) diet supplemented with 0.15 mg/kg Nano-Se, 4) diet supplemented with 0.3 mg/kg Nano-Se and 5) diet supplemented with 0.6 mg/kg Nano-Se. At the end of experimental period, birds autopsied and samples from testis of all birds were taken. The samples were used to examine the β1-integrin (CD29), thy-1(CD90 and NANOG mRNA expression by quantitative Real-Time PCR. The results of this study showed that testis of the groups fed with diets supplemented with 0.6mg/kg and 0.15mg/kg of Nano-Se had the highest and lowest mRNA expression of SSCs markers, respectively. In conclusion, the present study indicated that Nano-Se had advantages to sodium Selenite and 0.6 mg/kg of Nano-Se supplemented in males' diet in broiler breeders farms may contributes to optimal fertility via increasing mRNA expression of SSCs markers of roosters' testis and could be used to delay reduction of fertility caused by aging in broiler breeder males.

Abstract Duck beak atrophy and dwarfism syndrome (BADS) is a newly emerged disease in China since 2015. In October 2017, an unidentified disease occurred in Cherry Valley ducks, Chongqing municipality, the southwest of China. The affected birds showed short beak and growth retardation clinical signs. The disease caused approximately 20.00% morbidity and serious weight loss due to retarded growth. In order to identify the causative agent of BADS, liver, spleen, lung and heart samples were collected for virus isolation, hemagglutination test, PCR identification, and partial gene sequencing. The isolated virus was tentatively named SC16. Hemagglutination test indicated that the virus was negative to chicken red blood cells. Based on the PCR and sequencing results, the causative agent of BADS was a novel duck-origin goose parvovirus (DGPV) while no another co-infection pathogen was found in this case. Further analysis could provide insights into the control strategies of DGPV in ducks.

Abstract Fungal infections cause significant economic losses in the poultry industry either due to their direct infectious nature or due to mycotoxins production. Hatchery contamination with fungi can threaten chicken health. In this regard, geographical and seasonal distributions of airborne fungal contamination of 25 hatcheries in Mazandaran province, northern Iran, were investigated using an open plate method. The results of this study showed that hatcheries have various fungal contaminations, among which the most common were respectively Cladosporium (31.07%), Penicillium (24.00%), Aspergillus (20.63%), sterile hyphae (14.70%) and Alternaria (6.20%) from different regions. The results revealed that the highest level of fungal isolation was in spring and autumn. This study also showed that the concentration of fungal air spora in forest and seaside locations was significantly greater than mountainous ones. In spite of the regular disinfection in commercial hatcheries, fungal contamination was found in different parts.

Abstract Fertility reduction due to sub-fertile males is a major concern in breeder flocks. Phenotypic traits of broiler breeder males and their relationships with fertility can be used as reliable indicators for identification and removal of sub-fertile males from the breeder flocks. This study was conducted to investigate semen traits (semen volume, sperm motility, sperm viability and sperm count) and testes histomorphometric features including tubule differentiation index (TDI), spermiation index (SPI), Sertoli cell index (SCI) and mitotic index (MI) of broiler breeder males with the same age but different phenotypic traits. According to phenotypic traits, 12 broiler breeder males (Ross-308 strain) were classified into three equal groups. Group 1: roosters with fertile phenotypic traits (fertile), group 2: roosters with the lowest fertile phenotypic traits (sub-fertile) and group 3: roosters with moderate fertile phenotypic traits (moderate). The results confirmed potential relationship between phenotypic traits and fertility in broiler breeder males. Semen traits and histomorphometric features of broiler breeder males' testis of the group 3 were more similar to those of the fertile roosters. Therefore, it can be concluded that exclusion of these roosters from the breeder flock may have undesirable effects on flock fertility.

Abstract Avianmetapneumovirus (aMPV), also known as avian pneumovirus or turkey rhinotracheitis virus, is the causative agent of turkey rhinotracheitis and swollen head syndrome in chickens. Four aMPV subgroups (A-D) have been reported previously based on their genetic and antigenic differences. Evidence suggests that the live bird markets (LBMs) play an important role in the epidemiology of the avian viral diseases. A total number of 450 oropharyngeal samples from eight different species of birds (migratory and local) were collected from LBMs of Gilan province, Iran, from October to December 2016. The presence of aMPV was determined by reverse transcription polymerase chain reaction (RT-PCR) based on nucleoprotein gene. The aMPV was detected in 30.60% of the examined birds including chickens (37.00%), turkey (33.00%), Eurasian teal (25.00%), common blackbird (33.00%), and Eurasian woodcock (25.00%). Bioinformatics analysis and a phylogenetic tree based on partial nucleotide sequences of the N gene showed that the detected aMPVs were belonged to subtype B. This is the first report of aMPV in non-commercial birds in Iran. Knowledge of the frequency and types of infected birds with pneumoviruses allow a better understanding of the epidemiology of aMPV in Iran.

Abstract Mycoplasma gallisepticum (MG) is economically important pathogen of poultry causes airsacculitis and frequently infraorbital sinusitis in turkeys. Infections may remain without clinical signs, but they can make birds susceptible to secondary infections.This study was carried out for molecular detection and phylogenetic analysis of MG infections in commercial and backyard turkey flocks in some parts of Iran. A total number of 600 swab samples were collected from 18 commercial and 31 backyard turkey flocks. The PCR technique was performed for detecting 16S rRNA gene in the samples. Positive sample were subjected for sequencing of mgc2 gene. The results showed that 48.38% of backyard and 16.66% of commercial farms were positive for MG. These findings suggested the presence of MG in the commercial and backyard turkeys’ farms of Iran. The molecular analysis indicated high sequence similarity between some Iranian turkeys isolates with Indian and Pakistanian MG isolates. Furthermore, substitutions of MG nucleic acids and correlated amino acids sequences may lead to some antigenic modifications.