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: The growth and differentiation of skeletal pectoral limb girdle, wing and the ossification centers in these regions after hatching were investigated in pigeons. OBJECTIVES: The aim of this study was to determine the age of physical maturity and radiological and histological assessment of the ossification centers of pectoral limb in quail. METHODS: Fourteen pigeons after hatching were reared in similar and standard conditions and sampled once every 7 to 90 days. RESULTS: According to radiological and histological results, scapula, clavicle, and coracoid were observed after 7th and sternum at 14th day in all specimens. Bones of the humerus, hadius, hlna, hetacarpus II, hetacarpus III, hetacarpus IV, and proximal phalanx of digit III were observed after the 7th  day and radial carpal bone, ulnar carpal bone, proximal phalanx of digit II, distal phalanx of digit II, and distal phalanx of digit III at the 14th  day and head of humerus, ventral tubercle of humerus, phalanx of digit IV, and dorsal tubercle of humerus at 21st and ventral condyle of humerus and dorsal condyle of humerus at 28th. The histological results were evaluated based on prepared tissue sample from the proximal humeral portion. Lack of bone marrow was observed in all 1st day`s tissue samples and bone marrow conformation was commenced after the 7th day. The growth plate was not observed in all the samples and this issue is complementary to the information obtained from radiographic examination. CONCLUSIONS: According to this study, time taken to complete the ossification process and the formation of all parts of pectoral limb girdle and wing is 28 days after hatching.

BACKGROUND: The Eustachian tube is an osteocartilaginous channel connecting the tympanic cavity with the nasopharynx. There is no anatomical and histological research performed on this organ in buffalo. OBJECTIVES: Anatomical and histological study of Eustachian tube in buffalo will be useful for basic knowledge of this organ. METHODS: For this study 8 adult male and female buffalo's head were provided from slaughter house and their Eustachian tube were studied anatomically, then tissue samples were obtained and paraffin sections were prepared for using of staining methods such as H&amp;E (for general study), Verhoff (for elastic fibers), PAS (for carbohydrates) and Masson's Trichrome Stainning Kit (for collagen fibers). RESULTS: Anatomical results showed Eustachian tube was white and funnel- like tube, no curve and structurally supported by cartilage and in both sexes they had the same structure. Histological and Histochemical results showed the epithelium of Eustachian tube in buffalo is pseudostratified ciliated columnar and in some regions of the Eustachian tube epithelium was stratified squamous. In the first portion of Eustachian tube cartilage was elastic and then eustachian tube cartilage was hyaline. The glands of Eustachian tube in buffalo were mucous and non folicular tubal tonsil could be found around the pharyngeal opening with obviously lymphoid tissue. CONCLUSIONS:. The results of this research can be used as the basic anatomical and Histological knowledge in buffalo..

AbstractBACKGROUND: Beluga (Huso huso) is one of the sturgeons and currently is cultured artificially in Iran with different goals. The cardiovascular system is one of the important systems of the body, and heart is the most important organ in this system. So far, few studies have been done on the heart of sturgeons.OBJECTIVES: This study was done to determine the exact structure of beluga different parts of the heart septum using echocardiographic and histologic techniques. METHODS: Six immature male belugas (2.5 years old) were investigated in this study. For echocardiography, probe was placed on the ventral surface of body, between pectoral fins. At first, macroscopic morphologic studies of different parts of heart were done at the topographic place of them. For histological studies, usual methods of fixation and hematoxylin and eosin (H&amp;E) coloring were used. Prepared slides were studied by light microscope.RESULTS: All parts of the heart including the sinus venosus, atrium, ventricle, conus arteriosus and pericardium were clearly visible in different probe moves. The pericardium were covered surround heart`s structures having homogenous echo pattern. Sinus venosus had a very thin septum without any expansion and contraction. Atrium had a completed muscular septum with expansion and contraction. Ventricle muscular septum had two layers: an external compact layer and an internal spongy layer. Conus arteriosus was composed of obvious muscular septum and connective tissue. Histological studies showed three layers in beluga heart including epicardium, myocardium and endocardium. In overall, the histological findings were matched with the results of echocardiography. CONCLUSIONS: This study is the first investigation on echocardiographic feature of different parts of beluga heart. These results were coordinated with histological findings. Normal information and findings of this study can be used for investigation of various anatomic or pathologic changes in beluga heart in different research projects.

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.