Occurrence of tetracyclines,sulfonamides, fluoroquinolones and florfenicol in farmed rainbow trout in Iran

This study was carried out to determine the occurrence of tetracyclines, sulfonamides, fluoroquinolones and florfenicol residues in rainbow trout muscle samples (n = 138) obtained from Iranian trout farms. Concentrations of the antibiotics were determined using competitive enzyme-linked immunosorbent assay method. At measurable levels, 63.1%, 16.7%, 19.6% and 40.6% of the samples contained the residues of tetracyclines, sulfonamides, fluoroquinolones and florfenicol, respectively. The detected range of concentrations for positive samples was 1.43–101.4 µg/kg for tetracyclines, 4.03–90.4 µg/kg for sulfonamides, 6.75–99.8 µg/kg for fluoroquinolones and 0.11–172.6 µg/kg for florfenicol. The residues of the antibiotics in trout samples did not exceed the maximum residue levels recommended by the Institute of Standards and Industrial Research of Iran. However, the high occurrence of tetracyclines and florfenicol in the samples is alarming and could be a potential hazard for public health. Further investigations should be performed to determine the residues of antibiotics in other farmed fish species in Iran.     

Possibilities to control Ichthyophthirius multifiliis infestation with medicated feed in rainbow trout (Oncorhynchus mykiss) and chub (Leuciscus cephalus)

In the present study, the treatment of ichthyophthiriasis with medicated feed was investigated in rainbow trout, Oncorhynchus mykiss, and chub, Leuciscus cephalus. The anti-parasitics toltrazuril and imidocarb; the antibiotics doxycycline, erythromycin and sulphadiazine and the anti-inflammatory acetylsalicylic acid were tested. In vitro experiment revealed that all tested anti-parasitics and antibiotics were effective in killing the isolated trophonts and theronts. Minimum doses for killing 100 % of the viable trophonts and for inhibiting the development of theronts were 3 mg/L for doxycycline, 30 mg/L for erythromycin, 2 mg/L for imidocarb dipropionate, 30 mg/L for sulphadiazine and 20 mg/L for toltrazuril. Acetylsalicylic acid (40 mg/kg fish/day), doxycycline (3 and 6 mg/kg/day), erythromycin (40 mg/kg/day), imidocarb dipropionate (5.0 mg/kg/day), sulphadiazine (40 mg/kg/day), toltrazuril (20 and 40 mg/kg/day) and combinations of doxycycline and toltrazuril (3?+?20 mg/kg/day, 6?+?40 mg/kg/day) were tested as medicated feed. When administered as medicated feed, only doxycycline, toltrazuril and combinations of doxycycline and toltrazuril reduced the fish mortality and infestation level. Best results were obtained by feeding a combination of 6 mg/kg/day doxycycline and 40 mg/kg/day toltrazuril. In O. mykiss, this treatment reduced the mortality rate from 100 to 50?±?14 % after 10 days and the infestation level from grade 4 (≥100 trophonts per skin mucus sample) to 3.5 (50–100 trophonts). In L. cephalus, the mortality rate was decreased from 100 to 39?±?5 % and the infestation level from grades 4 to 2 (ten to 50 trophonts) after 10 days.     

Sequence analysis of infectious pancreatic necrosis virus isolated from Iranian reared rainbow trout (Oncorhynchus mykiss) in 2012

Infectious pancreatic necrosis virus (IPNV) is the causal agent of a highly contagious disease that affects many species of fish and shellfish. This virus causes economically significant diseases of farmed rainbow trout, Oncorhynchus mykiss (Walbaum), in Iran, which is often associated with the transmission of pathogens from European resources. In this study, moribund rainbow trout fry samples were collected during an outbreak of IPNV in three different fish farms in north and west provinces of Iran in 2012; and we investigated the full genome sequence of Iranian IPNV and compared it with previously identified IPNV sequences. The sequences of different structural and nonstructural-protein genes were compared to those of other aquatic birnaviruses sequenced to date. Our results show that the Iranian isolate falls within genogroup 5, serotype A2 strain SP, having 99 % identity with the strain 1146 from Spain. These results suggest that the Iranian isolate may have originated from Europe.     

Determination of histamine content in muscle tissue of rainbow trout (Oncorhynchus mykiss) during ice storage

In this study, the histamine concentration in the muscle tissue of whole rainbow trout (Oncorhynchus mykiss) was monitored during ice storage for a period of 18 days (0, 3, 6, 9, 12, 15 and 18th day). Results showed that the concentration of histamine increased linearly (P?<?0.05) during ice storage (except the 18th day). Histamine was not detected at the first and third day of storage. The first detection of histamine was in the sixth storage day. Initial concentration of histamine was 1.09 μg/g and finally reached to 4.30 μg/g. The maximum histamine levels was reported to be below the Australian Food Standards Code (2001) safe level (200 mg/kg), and histamine levels were low even after 18 days of storage and remained below the Food and Drug Administration (2001) tolerance level during ice storage. It seems that the levels of histamine could be a suitable freshness indicator of rainbow trout during ice storage.     

Identification of a novel piscine Cryptosporidium genotype and Cryptosporidium parvum in cultured rainbow trout (Oncorhynchus mykiss)

This study reports for the first time the presence and molecular characterization of Cryptosporidium in farmed rainbow trout (Oncorhynchus mykiss Walbaum, 1792). A total of 360 fish, with no apparent clinical signs of disease, were collected and classified into groups according to their size. Cryptosporidium oocysts were detected by immunofluorescence microscopy in 33 specimens (9.2%), which were located in pyloric caeca samples (42.4%), intestinal scrapings (39.4%), or at both locations (18.2%). In the smallest (youngest) fish group, a higher percentage of positive samples were detected in the pyloric caeca relative to the intestinal location (58.8 vs. 17.6%; P = 0.01), including a cluster with more than 10 oocysts observed in the pyloric caeca of one specimen. PCR amplification and sequencing of fragments of SSU-rDNA and hsp70 genes identified a novel Cryptosporidium piscine genotype (genotype 9) in two specimens and Cryptosporidium parvum in seven fish, including the specimen in which the oocyst cluster was observed. Moreover, Cryptosporidium oocysts were detected in farm water samples (41.7 and 16.7% from influent and effluent, respectively). Although Giardia was not found in gastrointestinal samples, Giardia cysts were observed in 50.0 and 33.3% of the influent and effluent water samples, respectively. The results support the existence of natural infections by C. parvum in freshwater cultured fish, suggesting that the rainbow trout could shed infectious oocysts in aquatic environments and it may be a potential source of human infection when this edible fish is handled.

     

Haematological reference ranges of cultured Clarias gariepinus in the Lower Benue River Basin,Nigeria

Blood samples were collected from 170 cultured African sharptooth catfish (Clarias gariepinus) to establish haematological baseline values of this important tropical pisciculture fish species in the Guinea savannah agro-ecological zone of Nigeria. The total red blood cell count and the total white blood cell count were obtained by haemocytometry, while the packed cell volume and haemoglobin were obtained by microhaematocrit and cyanomethmoglobin methods, respectively. The results obtained varied between gender and age and were as follows: total red blood cell count, 1.72?±?0.34?×?10⁶/mm³ in juveniles and 4.50?±?0.57?×?10⁶/mm³ in adults; total white blood cell count, 15.50?±?1.1510³/mm³in juvenile and 16.41?±?1.21?×?10³/mm³in adults; packed cell volume, 30.08?±?7.78 % in juveniles and 39.59?±?3.93 % in adults; haemoglobin, 9.43?±?3.45 g/dl in juveniles and 10.99?±?3.29 g/dl in the adults; mean corpuscular volume, 173.75?±?41.93 fl in juveniles and 87.01?±?14.37 fl in adults; mean corpuscular haemoglobin, 51.11?±?13.10 pg in the juveniles and 26.81?±?8.61 pg in the adults, while the mean corpuscular haemoglobin concentration values obtained are 32.61?±?10.42 g/dl in the juveniles and 33.80?±?10.0 g/dl in the adults.     

Comparative efficacy of two anesthetic agents in the Sobaity sea bream,Sparidentex hasta (Valenciennes 1830)

It is known that responses to the same anesthetic can vary considerably among different fish species. In this investigation, the efficacy of two anesthetic agents (clove powder and 2-phenoxyethanol) was compared in Sobaity sea bream, Sparidentex hasta (Valenciennes 1830). Induction and recovery times for S. hasta anesthetized with anesthetic agents were dose-dependent (P?<?0.05). The onset of individual phases of anesthesia and recovery times depended significantly on the concentration of the anesthetic used (P?<?0.05). An inverse exponential relationship was observed between concentrations of anesthetic and induction time, whereas exponential relationships were observed between concentrations and recovery times for both anesthetic agents evaluated. The lowest effective concentrations based on the efficacy criteria of complete anesthetic induction within 180 s and recovery within 300 s were determined to be 100 mg?L^?1 (induction time 1.92?±?0.10 min and recovery time 2.48?±?0.17 min) for clove powder and 200 μL?L^?1 (induction time 2.55?±?0.14 min and recovery time 5.66?±?0.62 min) for 2-phenoxyethanol. Clove powder was proven to be more effective, and the latter appears to meet many of the criteria of an ideal anesthetic for this fish species.     

Evaluation of sperm characteristics and plasma testosterone in the goldfish (Carassius auratus) during four consecutive seasons

The overall objective of the study was to investigate changes in quantitative parameters of goldfish (Carassius auratus) semen, testosterone (T), and gonadosomatic index (GSI) during the four seasons of the year (spring, summer, autumn, and winter). Simple environmental and hormonal treatments were used to induce out-of-season spawning in goldfish. The semen was taken from goldfish in different periods during the four seasons, and the characteristics of sperm and pH were analyzed. Plasma levels of T, GSI, and histological studies of the testes, as well as a range of indices of ovarian development, were measured. No significant differences were observed between volumes of semen which can be extracted per fish, in the four seasons (P?>?0.05). Significant differences were found between sperm motility at different seasons (P?<?0.05), as the maximum total duration of motility was observed in autumn (109.25?±?14.00 s). Sperm density showed a higher value during summer (57.30?±?10.41?spermatozoa (spz)?ml^?1) and winter (65.09?±?80.40 spz ml^?1) than values that were obtained from spring (48.00?±?7.08 spz ml^?1) and autumn (40.42?±?16.54?×?10⁹ spz ml^?1) (P?<?0.05). However, spermatocrit (in percent) was higher in winter (39.90?±?4.74) compared with other seasons (P?<?0.05). Values of pH were higher in autumn (7.87?±?0.05) and in winter (7.83?±?0.03) than values that were obtained from other seasons. The peaks of T and GSI during spermiation in spring (T, 21.08 ng/ml, and GSI?=?5.21 %) and in summer (T, 23.32 ng/ml, and GSI?=?6.10 %), when most gonadal development took place, were statistically significantly higher than the levels observed during autumn (T, 15.08 ng/ml, and GSI?=?3.21 %) and winter (T, 22.18 ng/ml, and GSI?=?2.78 %) (P?<?0.05). Our results provided the statistically significant evidence of seasonal variation in sperm characteristics, T and GSI, for goldfish. These findings may be used to: (1) optimize semen collection for hatchery production and (2) characterize the potential impact of seasons on sperm quality and plasma androgen levels.     

Serum biochemical parameters of endangered Caspian brown trout, Salmo trutta caspius (Kessler, 1870)

Serum biochemical parameters are important aspects in the management of endangered species such as endangered Caspian brown trout. The values of these parameters can be used for confirming any changes in the quality of waters and related soils. Serum samples of 20 (10 females?+?10 males) Caspian brown trout fish with same total weight and length were analysed. We compared the plasma concentrations of calcium (Ca; female, 2.4?±?0.4; male, 2.6?±?0.5 mmol/l), magnesium (Mg; female, 0.7?±?0.3 mmol/l; male, 0.8?±?0.3 mmol/l), sodium (Na; female, 139.9?±?3.9 mmol/l; male, 149.2?±?5.7 mmol/l), potassium (K; female, 3.4?±?0.3 mmol/l; male, 4.3?±?0.7 mmol/l), and chloride (Cl; female, 128.5?±?2.3 mmol/l; male, 133.3?±?3.8). According to the results, there were no differences in the Ca and Mg between the sexes. However, male fish have higher Na, K and Cl than females.     

Hematological and serum biochemical indices changes induced by replacing fish meal with plant protein (sesame oil cake and corn gluten) in the Great sturgeon (Huso huso)

This study was carried out on the possibility of replacing fish meal in fish diets with two plant protein sources (sesame oil cake and corn gluten). Experimental diets with 47.5 % of crude protein were prepared in four replacement levels of 0, 160, 320, and 480 g?kg^?1, respectively. Great sturgeons have been fed for 8 weeks. Experimental diets showed a significant reduction (P?<?0.05) in the hemoglobin, glucose, iron, and phosphorus plasma, while significant differences were not found in hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, white blood cell, red blood cell, lymphocyte, neutrophil, eosinophile, calcium, triglyceride, total protein, and cholesterol of plasma (p?>?0.05). The results of the present study revealed that the maximum levels of fish meal replacement by corn gluten and sesame oil cake in diets of Beluga (Huso huso) could be between 16 and 48 % of total protein sources of diet.     

Gastrointestinal response and endotoxemia during intense exercise in hot and cool environments

This study investigated plasma lipopolysaccharides (LPS) concentration and intestinal permeability after 60-min run at 70 % maximum oxygen uptake (VO_2max) in hot [33 °C, 50 % relative humidity (rH)] and cool (22 °C, 62 % rH) conditions. Fifteen volunteers gave their informed consent to participate in this study. Their venous blood samples were taken before, after, 2 and 5 h after exercise in each of the conditions. The order of the two environmental conditions in which they exercised in was randomised and counterbalanced. Plasma LPS concentration increased by an average of 54.0 % (95 % confidence interval: 30.7, 75.1 %) after exercising in the hot trial but no significant changes were observed in cool trial, where mean plasma LPS concentration was 12.0 ± 6.4 pg mL^?1 (before), 10.9 ± 5.4 pg mL^?1 (after), 10.7 ± 6.0 pg mL^?1 (2 h after) and 10.6 ± 5.7 pg mL^?1 (5 h after). Median (range) plasma claudin-3 (CLDN3) concentration was significantly higher after exercise (hot: 8.2 [1.0–13.0] ng mL^?1 and cool: 7.6 [0.6–13.4] ng mL^?1) as compared to before exercise (hot: 6.6 [0.7–11.8] ng mL^?1 and cool: 6.7 [0.8–12.6] ng mL^?1) (p < 0.05), but there is no significant difference observed between trials (p > 0.05). Changes in intestinal permeability are only affected by exercise while exercise-induced endotoxemia is affected by environmental conditions. This study, thus, highlights that an increase in intestinal permeability is not sufficient to trigger exercise-induced endotoxemia, suggesting that post-LPS translocation events may have a greater impact in its occurrence.     

Anti-parasitic activities of specific bacterial extracellular products of Streptomyces griseus SDX-4 against Ichthyophthirius multifiliis

The ciliate Ichthyophthirius multifiliis is one of the most pathogenic parasites of fish maintained in captivity. In this study, effects of bacterial extracellular products of Streptomyces griseus SDX-4 against I. multifiliis were determined. The fermentation liquor of S. griseus was extracted successively in a separating funnel with petroleum ether, ethyl acetate, and n-butanol. In vitro assays revealed that the n-butanol extracts (NBu-E) and ethyl acetate extracts (Eto-E) of S. griseus were observed to be more effective against theronts than the other extracts with median effective concentration (EC₅₀) values of 0.86 and 12.5 mg L^?1, respectively, and significantly reduced the survival of the tomonts and the total number of theronts released by the tomonts (P?<?0.05). All encysted tomonts were killed when the concentration of NBu-E was 30.0 mg L^?1. Results of in vivo test demonstrated that the number of I. multifiliis trophonts on the grass carp treated with NBu-E was markedly lower compared to the control group at 11 days after exposed to theronts (P?<?0.05). In the control group, 100 % mortality was observed owing to heavy I. multifiliis infection at 11 days after the exposure. On the other hand, only 9.5 % mortality owing to parasite infection was recorded in the groups treated with the NBu-E (30 mg L^?1). The median lethal dose (LD₅₀) of NBu-E for grass carp was 152.4 mg L^?1. Our results indicate that n-butanol extract of S. griseus will be useful in aquaculture for controlling I. multifiliis infections.     

Effect of cryotherapy on muscle recovery and inflammation following a bout of damaging exercise

The purpose of this study was to determine the effect of cryotherapy on the inflammatory response to muscle-damaging exercise using a randomized trial. Twenty recreationally active males completed a 40-min run at a ?10 % grade to induce muscle damage. Ten of the subjects were immersed in a 5 °C ice bath for 20 min and the other ten served as controls. Knee extensor peak torque, soreness rating, and thigh circumference were obtained pre- and post-run, and 1, 6, 24, 48, and 72 h post-run. Blood samples were obtained pre- and post-run, and 1, 6 and 24 h post-run for assay of plasma chemokine ligand 2 (CCL2). Peak torque decreased from 270 ± 57 Nm at baseline to 253 ± 65 Nm post-run and increased to 295 ± 68 Nm by 72 h post-run with no differences between groups (p = 0.491). Soreness rating increased from 3.6 ± 6.0 mm out of 100 mm at baseline to 47.4 ± 28.2 mm post-run and remained elevated at all time points with no differences between groups (p = 0.696). CCL2 concentrations increased from 116 ± 31 pg mL^?1 at baseline to 293 ± 109 pg mL^?1 at 6 h post-run (control) and from 100 ± 27 pg mL^?1 at baseline to 208 ± 71 pg mL^?1 at 6 h post-run (cryotherapy). The difference between groups was not significant (p = 0.116), but there was a trend for lower CCL2 in the cryotherapy group at 6 h (p = 0.102), though this measure was highly variable. In conclusion, 20 min of cryotherapy was ineffective in attenuating the strength decrement and soreness seen after muscle-damaging exercise, but may have mitigated the rise in plasma CCL2 concentration. These results do not support the use of cryotherapy during recovery.     

Stress alters food intake and glucosensing response in hypothalamus, hindbrain, liver, and Brockmann bodies of rainbow trout

In fish food intake is altered under stress conditions, and in a fish teleost model like rainbow trout food intake is associated with the activity of the glucosensor systems. Thus, we aimed to evaluate the possible interaction of stress with the response of glucosensor mechanisms in rainbow trout. Thus, we subjected rainbow trout (via intraperitoneal injections) to normoglycaemic (control), hypoglycaemic (4 mg.kg^-1 bovine insulin) or hyperglycaemic (500 mg.kg^-1 glucose body mass) conditions for 5 days under normal stocking density (NSD, 10 kg fish mass·m^-3) or stress conditions induced by high stocking density (HSD, 70 kg fish mass·m^-3). The experimental design was appropriate since hypoglycemia and hyperglycemia were observed in fish under NSD whereas in normoglycaemic fish HSD induced changes in stress-related parameters similar to those reported in fish literature, such as increased levels of cortisol and glucose in plasma and decreased levels of glycogen in liver. Food intake did not respond to changes in plasma glucose levels in fish under HSD conditions, in contrast with the decreased food intake observed when glucose levels increased in fish under NSD conditions. Moreover, the changes with the increase in plasma glucose levels in parameters involved in glucosensing in liver, Brockmann bodies (BB), hypothalamus, and hindbrain of fish in NSD either disappeared (DHAP and GAP levels, and GK, PK, and GPase activities in liver; glucose, DHAP and GAP levels in BB; glucose and DHAP levels, and GK and PK activities in hypothalamus; glycogen and DHAP levels, and GSase activity in hindbrain) or changed (cortisol levels in plasma; glycogen and GAP levels, and GSase and FBPase activities in liver; GK and PK activities in BB; GK and PK activities in hindbrain) in fish under HSD. Those changes suggest for the first time in fish the existence of an interaction between glucosensing capacity and stress. The readjustment in the activity of glucosensor systems is also associated with changes in food intake resulting in an inability of the fish to compensate with changes in food intake those of circulating glucose levels as observed in fish under non-stressed conditions.     

Hematological assessment of health status of African catfish Clarias gariepinus (Burchell 1822) experimentally challenged with Escherichia coli and Vibrio fischeri

Clarias gariepinus were challenged with one of the following treatments: 1?×?10⁵ colony-forming units (CFU)/ml of Escherichia coli (EC1), 2?×?10⁵ CFU/ml of E. coli (EC2), 1?×?10⁵ CFU/ml of Vibrio fischeri (V1), 2?×?10⁵ CFU/ml of V. fischeri (V2), gavaged with distilled water (CW), and not gavaged (C). Fish inoculation with bacteria was done via oral gavage. Fish were maintained in the laboratory for 7 days after the bacterial inoculation, after which various hematological parameters such as percentage packed cell volume (PCV), percentage red blood cell lysis, white blood cell (WBC) counts, and differential white blood cell counts (neutrophils, lymphocytes, monocytes, and eosinophils) were determined. Fish challenged with bacteria have a significantly reduced percentage PCV but a significantly higher percentage of red blood cell lysis, WBC counts, neutrophils, lymphocytes, monocytes, and eosinophils compared to the controls. In all cases, effects tend to be strongly dependent on the CFU of the bacteria with effects generally more pronounced in fish infected with 2?×?10⁵ CFU/ml of either E. coli or V. fischeri. The results of this study indicate that the health status of C. gariepinus is seriously compromised by bacterial infection, and hematological parameters are reliable enough in the assessment and quick diagnosis of the health status of fish infected with bacteria.     

Selected biochemical parameters in plasma of blood and semen of Persian sturgeon,Acipenser persicus

The investigation of blood and seminal plasma biochemical parameters is essential for fish stock conservation and development of artificial propagation methods via extender improvement. In this research, comparison of blood and seminal plasma compounds and their relationship in Persian sturgeon, Acipenser persicus, were studied. Seminal plasma contained 59.53?±?2.56 mEq/l sodium (Na⁺), 4.72?±?0.31 mEq/l potassium (K⁺), 1.45?±?0.075 mEq/l chloride (Cl^?), 9.1?±?1.42 mEq/l calcium (Ca²⁺), 0.7?±?0.072 mEq/l magnesium (Mg²⁺), 0.11?±?0.021 g/dl total protein, 6.67?±?1.04 mg/dl cholesterol, 15.2?±?0.65 mg/dl triacylglycerol, and 18.22?±?4.16 mg/dl glucose. Also, blood biochemical values were determined (mean?±?SEM) for Na⁺ (123.2?±?1.31 mEq/l), K⁺ (2.77?±?0.088 mEq/l), Cl^? (97.18?±?1.23 mEq/l), Ca²⁺ (6.67?±?0.24 mEq/l), Mg²⁺ (1.29?±?0.074 mEq/l), glucose (198.49?±?18.03 mg/dl), triacylglycerol (214.22?±?13.38 mg/dl), total protein (3.62?±?0.23 g/dl), and cholesterol (127.11?±?6.94 mg/dl). The mean blood and seminal osmolality values were 244.62?±?3.66 and 86.9?±?4.22 mOsm/kg, respectively. Results of the comparison between biochemical parameters of seminal and blood plasma indicated that the concentrations of all parameters of blood plasma were significantly (P?++ and Na⁺ of the seminal plasma (P?P?相似文献   

Growth of rainbow trout hemopoietic cells in methylcellulose and methods of monitoring their proliferative response in this matrix

A technique for the clonal culture of rainbow trout leukocytes in a methylcellulose matrix can be used to identify growth factors and other substances affecting cell proliferation and development in fish. Methylcellulose supports colony formation by rainbow trout leukocytes isolated from the major hemopoietic organ, the pronephros. The addition of rainbow trout serum dramatically increased the number of colonies formed, scored by counting colonies. As an alternative measure of cell proliferation, ³H-thymidine incorporation by cells can be easily measured in methylcellulose cultures. This method requires only small amounts of test substances, is rapid, and is superior for assessing the growth-stimulating ability of some substances, such as bacterial lipopolysaccharide, which stimulated growth but not the formation of discreet colonies by rainbow trout cells.     

Influence of supplementation of prebiotic, probiotic, and antibiotic to wet-fed wheat-based diets on growth, ileal nutrient digestibility, blood parameters, and gastrointestinal characteristics of broiler chickens

A feeding trial was conducted to investigate the effects of dietary supplementations of prebiotic, probiotic, and antibiotic to wet wheat-based diets on broiler performance, carcass yield, organ weights, and histomorphological measurements of the small intestine. One hundred and sixty-day-old male broiler chicks were randomly assigned to one of four dietary treatments for 6 weeks. The dietary treatments were: (1) control (1.2 g water/gram of dry feed); (2) control diet supplemented with antibiotic (15 mg/kg of virginiamycin); (3) control diet supplemented with 1 g/kg probiotic (8?×?10⁵ colony forming units (CFU) of Bacillus subtilis/gram); and (4) control diet supplemented with 1 g/kg prebiotic (Aspergillus sp. meal). The body weight and feed intake were significantly (P?<?0.05) increased by the dietary inclusion of the antibiotic compared with the control and pre- and probiotics-fed broilers. Moreover, an improvement in performance traits was observed in broilers fed with the pre- and probiotics. Relative abdominal fat weight was significantly (P?<?0.01) greater for the broilers fed diets containing antibiotic than control diets. Protein digestibility was significantly higher (P?<?0.05) for birds supplemented with virginiamycin compared with the control and prebiotic birds. The addition of either pre- or probiotic increased (P?<?0.05) the villus height/crypt depth ratio and villus height in both duodenum and ileum. However, the ileal crypt depth was significantly increased for pro- and prebiotic supplementations compared with antibiotic (P?<?0.05).