فصلنامه آسیب شناسی درمانگاهی دامپزشکی
سال شانزدهم شماره 4 (پیاپی 64، زمستان 1401)

Proventriculitis is a disease characterized by enlargement of the proventriculus. Several factors including infectious and non-infectious agents play a role in its development. Reoviruses could be considered as a main causal agent of proventriculitis in chickens. Based on clinical evidence and reports of the prevalence of reovirus infection in poultry farms in Iran, the enlargement of proventriculus and proventriculitis may be related to the reovirus infections. In the present study, to detect reoviruses in the proventriculus samples, the S1 gene was amplified by RT-PCR (Reverse Transcription-Polymerase Chain Reaction). According to the findings, out of 75 proventriculus samples collected from 15 broiler farms with large proventriculus in Isfahan province, 46 samples (61.33% of the samples) and 10 farms (66.66% of the studied farms) were positive for reovirus based on the amplification of the 532 bp fragment related to the S1 gene. The collected proventriculi were all macroscopically larger than normal and had more thickness. The area connecting the proventriculus to the gizzard was loose and lacked sufficient consistency. In addition, the mucosal layer of the proventriculus was slimy and contained yellow secretions. In all the histopathological sections related to positive samples, necrosis along with inflammatory cells were visible in the superficial and deep glands of the proventriculus. In general, it seems that there is infection with reoviruses in broiler chickens of Isfahan province and this infection can play a role in causing the inflammation and enlargement of the proventriculus, therefore, necessary measures should be taken to control and prevent this infection in broiler chickens.

Infection with the Salmonella genus of bacteria causes chronic and acute diseases in poultry leading to significant economic losses to the poultry industry. The aim of the present study was to evaluate the antibiotic resistance pattern of Salmonella serotypes isolated from a number of laying poultry flocks in the northwest of the country and to investigate its relationship with the performance of those farms. Eighty samples were taken from 20 flocks suspected of salmonellosis .The samples were cultured in selective and differential cultures of Salmonella. After isolation of Salmonella serotypes, the antibiogram test was performed to determine the antibiotic sensitivity. In order to check the performance of suspicious flocks, the history of the flock was obtained and the amount of mortality and production drop was calculated by statistical methods.The results indicated that 40% of the flocks were positive in terms of the presence of Salmonella, with 30% of the flocks affected by Salmonella gallinarum, 5% by Salmonella enteritidis, and 5% by concurrent presence of both Salmonella enteritidis and Salmonella gallinarum. The highest antibiotic sensitivity of Salmonella serotypes was recorded from fosfomycin and danofloxacin with a frequency of 100% and soltrim with a frequency of 78.6%. The highest antibiotic resistance was observed against erythromycin with a frequency of 75% and chlortetracycline with a frequency of 53.6%. Based on the results, there was a statistically significant difference in  the amount of flock mortality and production drop between Salmonella negative and Salmonella positive herds (p<0.05). Also, more vigilant use of antibiotics is required due to the high levels of resistance shown by Salmonella against various antibiotic drugs.

Mold contamination of feeds is a common problem in poultry industry. The aim of this study was to investigate mold contamination of laying hen diets around Tehran (Shahriar and Malard). For this purpose, 5 laying poultry farms were subjected to random sampling so that a total of 60 samples were taken from each poultry farm during four consecutive seasons. For counting and separation of molds, surface cultivation in the culture medium was used. After the primary growth of molds, slide culture was prepared and the macroscopic and microscopic indices of molds were defined. Seven types of molds were separated by macroscopic and microscopic studies. In terms of the total number of molds in laying poultry farms in each season, no significant difference was observed, but between seasons a significant difference was observed (p<0.001), as such, the number of molds in autumn (3.11±0.10 Log CFU/g) and winter (3.35±0.10 Log CFU /g) showed the highest level of contamination in all laying poultry farms. Also, the lowest number of mold contamination was observed during the spring and summer in all laying poultry farms. Fusarium, Penicilium, Aspergillius flavus, Mucor, Aspergillus niger, Alternaria and Ulocladium were the most prevalent molds in all seasons. Overall, there was a seasonal trend in the amount of mold contamination with maximal contamination observed during autumn and winter seasons.

Sexually differentiating traits in males, the emergence of primary and secondary sexual traits and numerous systemic effects are controlled by the hormone testosterone, therefore testosterone and its various esters, including enanthate, are produced and supplied for medicinal, livestock and even sports purposes. Nandrolone has many similarities to testosterone in terms of its chemical structure, and nandrolone decanoate, a long acting ester, is more effective than nandrolone. On the other hand, the adverse effects of androgen abuse, such as suppression of spermatogenesis and testicular atrophy, can be seen in the long term. The similarities of these two drugs and their uses and the adverse effects of their abuse was the main reason to investigate and compare the effect of testosterone enanthate and nandrolone decanoate administration on testicular tissue and spermatogenesis coefficients in rats. For this purpose, 21 adult male rats were randomly allocated into 3 groups of control (without drug injection), treatment with nandrolone decanoate (10 mg/kg per week) and treatment with testosterone enanthate (5 mg/100 g per week). After 8 weeks,  tissue samples prepared from the testicles of rats were stained with hematoxylin-eosin  and subjected to histopathological study. The results showed that both drugs had a significant adverse effect on the diameter and height of the epithelium of the seminiferous tubules and the thickness of the interstitial tissue of the testis. Also, the coefficients of spermatogenesis, including tubular differentiation coefficient, spermiogenesis coefficient and regeneration coefficient, were negatively affected by both drugs, although, only the effect of testosterone enanthate was significant (p<0.05). Overall, the administration of anabolic steroids leads to numerous histopathological changes in the male reproductive system.

As a poison, nicotine leaves irreparable effects on various tissues of the body, including the reproductive system. Coenzyme Q10 has a tremendous effect in raising the body's antioxidant level and preventing poisoning. In the current study, the protective effect of coenzyme Q10 supplementation on the changes induced by nicotine in the rat ovary was investigated. For this purpose, 32 adult female Wistar rats were randomly divided into 4 groups of 8. The rats of the first group (control) were only fed with the usual diet, but the animals of the second group were treated with nicotine at the rate of 0.2 mg/kg, the rats of the third group were treated with coenzyme Q10 at the rate of 75 mg/kg and the animals of the fourth group were treated simultaneously using nicotine and coenzyme Q10 (with the same amounts) through gavage. At the end of the study period (45 days), the animals were euthanised and blood samples were taken for hormonal and antioxidant tests. Also, ovarian tissue was sampled for histological studies. In animals treated with nicotine, there was an increase in follicular atresia, tissue damage, an increase in malondialdehyde and nitric oxide, along with a decrease in the number of ovarian follicles, a decrease in the amount of estrogen and follicle stimulating hormones, and the activity of superoxide dismutase, glutathione peroxidase and catalase. But in animals receiving nicotine and coenzyme Q10 at the same time, there was a significant improvement in ovarian function and structure. This study shows coenzyme Q10 can play a protective role against oxidative stress and tissue changes caused by nicotine in the ovaries of rats with the mechanism of balancing the antioxidant status and reproductive hormones.