BACKGROUND: Numerous studies have investigated the positive effect of chitosan and nano-chitosan loaded clinoptilolite on growth performance, digestive enzyme activity, and intestinal histomorphology in different fish species. However, there are no data evaluating the potential effect of the composites on the fish stomach.OBJECTIVES: In the current study, the effects of chitosan and nano-chitosan loaded clinoptilolite on histological features and pepsin activity in the rainbow trout stomach were considered.METHODS: Chitosan and nano-chitosan loaded clinoptilolite were synthesized, and then two hundred and forty fish (~27.75 g) fish were distributed in eight groups each in three replicates. Ten days after adaptation, the fish were fed with eight diets, including control diet (CTR), clinpotilolite (T1), chitosan composites (T2, T3, T4), and nano-chitosan composites (T5, T6, T7) for 70 days. Afterward, all fish in each tank were anesthetized in clove extract (50 μl/l), and tissue samples were obtained for pepsin activity (n= 5) and histological assay (n = 5).RESULTS: The groups administrated with nanochitosan composites showed the highest pepsin activity (P˂0.05). Additionally, histological examinations exhibited a higher epithelial height, increased mucosal density, and oxynticopeptic cells hypertrophy in fish fed composites compared to the CTR group (P˂0.05). Meanwhile, nanochitosan composite administration could cause higher reaction of secreted granules to periodic acid–Schiff (PAS) staining.CONCLUSIONS: The findings demonstrated the potential application of chitosan and nano-chitosan loaded clinoptilolite composites for improvements in the histomorphology and pepsin activity of the rainbow trout stomach, resulting in higher growth performance.

BACKGROUND: Yersiniosis is known as one of the most prevalent bacterial diseases in fish, which causes high mortality and economic losses in cultured fish farms every year. OBJECTIVES: The present study was conducted to investigate the changes in hematological indices and gut histopathology in Caspian roach (Rutilus caspicus) exposed to Yersinia ruckeri. METHODS: 60 Caspian roach broodstock with an average weight of 63.4 ± 2.1 g were divided into three groups (with two replicates for each group), including one treatment, one positive control, and one negative control groups. The treatment group was intraperitoneally injected with Yersinia ruckeri bacterium at a dosage of 3.8 × 107 cell/fish. The positive group just received normal saline (0.9 % NaCl) via intraperitoneal injection. No injection was performed in the negative control group. RESULTS: Symptoms appeared on the fourth day after exposure and 20 % of the fish in the treatment group died 5 days after the challenge. Cumulative mortality reached 53 % on day 9 after the challenge.  According to hematological analysis, the challenge with Yersinia ruckeri led to a significant increase in white blood cell counts (WBC) compared to the control groups. Moreover, 10 days following exposure, the treatment group experienced hypochromic macrocytic anemia. Gut histopathology was characterized with necrosis and detachment of intestinal epithelial cell and inflammatory cells infiltration in the treatment group. CONCLUSIONS: Based on the obtained results herein, Yersinia rackeri can cause acute disease in Caspian roach; therefore, preventing and controlling this disease is essential for these fish in infected regions.

BACKGROUND: Plasma lipoprotein profile is one of the effective mechanisms in testicular tissue development and spermatogenesis process in roosters. OBJECTIVES: The present study was conducted to investigate the effect of dietary supplementation of l-carnitine during pre-pubertal period on testicular histology, spermatogenesis indexes and plasma lipoproteins of immature cockerels METHODS: A total of twelve Ross broiler breeder males (12 weeks) for 22 weeks in a completely randomized design with two treatments (0, and 250 mg/kg of L-carnitine in the diet) and six replications were used. Feeding program, and photoperiod regimen was performed based on ROSS 308 management handbook. To achieve the objectives of the study, at the age of 34 weeks, four birds were randomly selected from each treatment and after collecting blood samples from the veins under the wings, the birds were slaughtered. Finally, plasma cholesterol, LDL and HDL concentrations using a commercial kit and testicular parameters (number of seminiferous tubules, number of Sertoli cells, height of epithelium seminiferous tubules, seminiferous tubules diameter, spermatogenesis index, and tubular differentiation index) after preparation of 5-μm paraffin sections, were analyzed by SAS software. RESULTS: The results showed that the number of seminiferous tubules, and the number of Sertoli cells were significantly affected by l-carnitine (p < /em><0.05). L-carnitine supplementation in the diet of immature cockerels before sexual maturity significantly increased the spermatogenesis index (p < /em><0.003) and tubular differentiation index (p < /em><0.02). HDL levels were significantly affected by l-carnitine supplementation (p < /em><0.007). There was a significant tendency in LDL concentration (p < /em>=0.09) and LDL/HDL ratio (p < /em>=0.059) between treatments, but no significant differences were observed in cholesterol concentration between treatments. CONCLUSIONS: According to the results of this study, feeding immature cockerels before sexual maturity with 250 mg l-carnitine improves testicular tissue development and spermatogenesis process.

BACKGROUND: Ammonia accumulation in warm-water fish pond can lead to mortality or reduction in growth and body immune indices.OBJECTIVES: The present study aimed to investigate the effects of chronic sub-lethal unionized ammonia (NH3) on growth indices and gill and kidney histopathology l, after a 30 – day trial in common carp (Cyprinus carpio).METHODS: Herein, 180 fish with an average weight of 4.5±0.5 g were divided into six tanks. Two groups, including one control group and one treatment group (with three replicates for each one), were considered. The treatment fish were exposed to 0.1 mg/l on un-ionized ammonia (NH3) for 30 consecutive days. Following one -month, ammonia exposure growth indices and histological analysis of gill and kidney were investigated.RESULTS: The results showed that exposure to 0.1 mg/l of NH3 led to a significant reduction in growth indices. Additionally, edema and epithelial lifting with hyperplasia in the second lamella were detected in the gill of the treatment group. The kidney was characterized by focal renal tubules degeneration and necrosis, congestion, and increase in the melano-macrophage centers.CONCLUSIONS: Although chronic exposure to 0.1 mg/l of unionized ammonia was not found to cause mortality in common carp, it could have some side effects, such as a decline in growth indices and histopathological effects in kidney and gill tissues. Thus, for higher production, sublethal levels of ammonia should also be taken into account in common carp ponds.

BACKGROUND: The interdigital pouch is an invagination of the skin which locates between the digits in several species of the artiodactyla. It secretes pheromones that play important biological functions in the conspecific chemical communication. OBJECTIVES: This study has been carried out in order to determine the anatomical and radiological structure of the interdigital pouch in native goats. METHODS: Eighty interdigital pouches (40 forefeet and 40 hind feet) of 10 female and 10 male, one to three-years-old, healthy native goats in slaughterhouses of Chaharmahal va Bakhtiari were selected. After dissection, topography of each pouch was determined in the feet. For radiologic studies, contrast urografin media were injected into the pouch and then radiographs and photographs were obtained. Different parts of each pouch were identified and measured between the two limbs in both sexes. Data were analyzed by t-test. RESULTS: In native goats, the pouch, which was observed in all feet,  was a primitive type and located in the space between two hooves at the level of pastern joint. The pouch represents an equilateral triangle with an apex next to the first phalanx and the base near the second phalanx. The best radiographic view for pouch in native goats was dorsopalmar or dorsoplantar. Detection of the pouch in the forelimb was more than that of the hindlimb. Except for the base of pouch, the means of the other parts in male were significantly higher than females. It is difficult or impossible to define the exact radiological and topographical limits of the pouch in goat, due to the absence of secretion, excretory duct and orifice and also the dispersion of structure. CONCLUSIONS: Based on this study, it can be concluded that although the interdigital pouch has only been reported in sheep, deer, moufflon and antelope, it was also found in native goats, but it is not common.

BACKGROUND: The trachea is the main air passages which is important for taxonomic reasons. The structure of trachea varies considerably in different avian species. OBJECTIVES: This study has been carried out in order to determine the histological and histochemical structure of the trachea in ostriches. METHODS: Sixteen tracheas of 8 female and 8 male nine-month-old healthy blue-necked African ostriches in slaughterhouse of Isfahan were selected. Each trachea divided into cranial, middle and caudal portions and fixed in 10% neutral buffered formalin. Tissues sections were stained with H&amp;E and special stains included Masson’s trichrome, Verhoeff’s, Foot’s, Van Gieson’s, Periodic acid-Schiff, and Alcian blue. RESULTS: The trachea of blue-neck ostriches was composed of tunica mucosa-submucosa, cartilaginous, muscular and serosa. The epithelium was ciliated pseudostratified columnar contained simple alveolar goblet mucous glands. These glands reacted negatively to Periodic acid-Schiff but positively to Alcian blue. The propria-submucosa was composed of dense connective tissue. The muscularis mucosa was absent. Tunica cartilaginous and muscular was made up of sternotrachealis muscle and cartilaginous rings. The rings were only composed of hyaline cartilage. There is no osseous tissue in the tracheal rings. Tunica serosa was composed of loose tissue contained parasympathetic ganglia, adipose tissues, vessels, and all the connective fibers. Three final cartilage rings were shaped tympanum of the syrinx. The histological structure of the trachea showed no significant differences between the male and female ostriches. Except for the decreased number of mucous glands in caudal portion of the trachea, the histological structures of the trachea showed no considerably differences among various portions. CONCLUSIONS: Based on this study, it can be concluded that although the histological and histochemical structure of the trachea in ostrich was similar to those of some other species, but that there were also some differences.

BACKGROUND: Meat is one of society's most important nutritional needs, the price of which is higher than other food groups. In recent years, the use of meat products has increased due to human lifestyle changes. Fraud in meat products occurs for various reasons, including the economic value of meat. Therefore, it is crucial to use fast and accurate methods of identifying these frauds.OBJECTIVES: The purpose of this study is to determine the unauthorized tissue by a histological method as well as to determine the unauthorized species used in meat products of factories in Hamadan province.METHODS: In the summer of 2021, fifty samples were collected from active production units of the Hamedan province that were available in the Hamadan city market and transferred to the laboratory for histological laboratory and animal species determination by PCR test. For the histology test based on the national standard 6103, the samples were subjected to fixation, passage (dehydration, clearing, impregnation with molten paraffin), blocking, sectioning, and H&amp;E staining. PCR method was used to determine the type of animal species used in the production of the collected samples.RESULTS: The results confirmed the presence of unauthorized tissues, including bone, cartilage (articular and respiratory cartilage), skin, and glandular organ in meat products. Also, PCR test results showed that chicken meat was found in 100% of the samples labeled with beef.CONCLUSIONS: The presence of illegal tissue and the use of chicken meat in products labeled as beef meat is evident in the sausages produced in Hamadan province.

BACKGROUND: Regarding the economic values of meat, adulteration in meat products is probable. OBJECTIVES: This study was carried out to evaluate the histological method for the quantitative detection of meat in Kabab Loghme and cooked sausage model. METHODS: Five Kabab samples (containing 70 % meat) and cooked sausage (30, 50, 70 and 90% meat), were prepared. Then, each sample was divided into three parts and one piece was taken from each part and fixed in 10% neutral-buffered formalin. The samples were routinely processed for light microscopy and embedded in paraffin. The paraffin-embedded blocks were cut into 6 μm sections and stained using hematoxylin and eosin (H &amp; E) for histological study. RESULTS: The histometrical analysis indicated that the estimated percentages for the added meat in kabab did not show significant difference with the real related percentages. On the other hand, the amount of meat was difficult to estimate especially in cooked sausage. CONCLUSIONS: The findings of the present research suggest the histological technique as a complementary method for quantitative evaluations of meat in raw meat products. However, the quantitative evaluation of meat in raw meat products was more convenient than in processed ones.

BACKGROUND: Population growth and the need for food, especially proteins, have increased the interest in using inexpensive and available supplements to increase protein production. ObjectiveS: The aim of this study was to evaluate the effect of Qom region zeolite as a supplement to the histological and histochemical structure of broiler chicken intestine and to compare it with commercial zeolite. Methods: In this experimental study a total of 200 broiler chicks were purchased from Qom poultry and randomly divided into five groups including the control group; the experimental group of Qom zeolite which was subsequently subdivided into three different doses including (Z1 = 0.5 %, Z2 = 1%, Z3 =1,5%); and finally the anzymite group which received the commercial zeolite. 42 days later, 10 samples were selected from each group and after tissue preparation, the slides were stained with hematoxylin-eosin, PAS period, and toluidine blue; then microscopic assays were applied using the Image-j 1.49f software. Data analysis was done with SPSS 20 and One-way ANOVA and Tukey’s post hoc test. PResults: The height of the epithelial cells decreased in the anzymite group but the number of mucosal glands and goblet cells increased significantly (P<0.05). Except for Z1 group in other Qom zeolite treatment groups (Z2 and Z3), the number of goblet cells increased significantly (P<0.05). Therefore, the effect of zeolite higher than 1.5% may be comparable with anzymite. Conclusions: Our results showed that zeolite does not have any effect on increasing the absorption rate of the small intestine, but could stimulate the function of goblet cells and intestinal glands, so Qom zeolite with higher percentage could have the same effect as anzymite

BACKGROUND: Cryptorchidism is a congenital anomaly in which one (unilateral cryptorchidism) or both (bilateral cryptorchidism) testes fail to descend into the scrotum.                  OBJECTIVE: The aim of this study was to describe the anatomical and histological structure of the inguinal testis in the adult donkey. METHODS: In this study, after examination of the 59 donkeys, three of them with unilateral cryptorchidism in inguinal region were identified. These animals were euthanized, and their testicles were removed and evaluated biometrically. Then, the samples were fixated in 10% formalin solution and after sectioning, were stained with Hematoxylin-eosin and PAS, and examined under a light microscope. RESULTS: The results showed that the inguinal testes were stiff, epididymis was not determined and their size and weight were less than scrotal testes. The difference between the weight of cryptorchid and healthy testicles was statistically significant (p<0.05). Seminiferous tubules had lost their natural shape and inner cavity tubes did not have germ cells, and only a limited number of Sertoli cells could be seen. Remaining seminiferous tubules were only visible in the mediastinum. The cortical and subcapsular regions were without tubes and were occupied by loose connective tissues. CONCLUSIONS: Results indicated that the inguinal testes in adult donkeys lost their natural structure and more connective tissues and blood vessels are substituted.