IRAQ JOURNAL OF AGRICULTURAL RESEARCH

ABSTRACT
This investigation was conducted to assess the effect of addition of different concentration of crude carotenoides extracted from shrimp shells. A combination of Hexane and Acetone (1:1, V:V) was employed for carotenoids extraction. The Crude extract was added at levels of 0.05, 0.10 and 0.15% to experimental diets that fed to common carp fingerling (Cyprinus carpio) for 50 days.
The growth parameters of fish together with chemical composition of flesh were determined on conclution of feeding trials. The feeding trails included four experimental treatments each induplicate with five fish for each treatments, each of the formulated diets contained 41.7% protein (dry base) and 1548.52 MJ/kg. metabolized energy. The obtained results revealed that fish fed with diet contained 0.15%. Crude carotenoides achieved the best growth parameters that averaged 11.8gm/fish gain weight, 0.22 daily gain (DWG), 55% relative growth rate (SGR), 0.004% specific growth rate (SGR), 1.10% food conversion rate. (FCR), 0.92% food efficiency rate (FER), 1.87gm protein intake (PI) and 5.92% protein efficiency rate. The chemical composition of fish flesh on trail termination showed that both fat and protein contents raised gradually as the rate of crude carotenoids increased to reach the highest value with treatment included 0.15% carotenoids.

The current study was undertaken to investingate the effect of magnetized water of common carp Cyprinus carpio L. A total 64 fish with an average weight of 45 g. Fish were divided randomly into four treatments. Eight fish distributed for each treatments, with two replicate. Control group without water magnetized, the first treated group (T1) used magneted water of 500 gauss , the secand group (T2) with 1000 gauss, the third group (T3) with 1500 gauss, was used two replicate for treatment, during the period of the experemt which last for 60 days. All fish were fid with the same nutrient , the power of magnification mentioned above were used tap water to determine the activity of the best magnetic waves for growth and to assess the activities of digestive enzymes. (trypsin, chymotrypsin), at zero time and after 60 days of feeding to different part of digestive tract (front, middle, posterior). The analysis of data expressed significant differences (p≤ 0.05) between all the treatments. The third treatments was obtained among the best result. The weight gain was 66.24, 44.24, and 87.5 g/fish for each treatment respectively. Trypsin and Chymotrypsin were distributed at zero time among all the digestive tract of experimental fish. The highest enzyme activity was found at the anterior and the middle parts, (p≤0.05) comparing to the posterior and the values were 0.02,0.22,and 0,24 unit / ml for trypsin enzyme and 0.2,0.67 and 0.63 unit/ml of chymotrypsin respectively for each three parts. The three treatments expressed the highest activity of enzyme in the anterior and middle parts of the intestine after 60 days of feeding, the values were 0.98, 0.73, and 0.44 unit/ml for anterior and 0.99, 0.81 and 0.45unit /ml for middle part for the three treatments respectively, and they differed significantly for the posterior part (p≤0.05) 0.02, 0,03 and 0.02 unit/ml of all treatments respectively of trypsin enzyme and 1.86, 1.56 and 0.08 unit/ ml for anterior part of the intestine and 1.91, 1,82 and 0.8 unit/ml of the middle part which are differ significantly while the posterior part wae 0.32, 0.32 and 0.41 unit/ ml for all treatments respectively of chymotrypsin enzyme. The results expressed in this study revealedthat the magneted water is better for rearing and growth of common carp fish up to 1500 gauss, which gave a better weight gains and increased the activity of trypsin and chymotrypsin enzymes.

The present study was conducted to determine the effect of herbicide glyphosate aqua on Mesopotamichthys sharpeyi .The experiment was comprised of four treatments as well as control treatment(without addition of herbicide), fish were randomly distributed as 10 fish for each aquarium. The first treatment with a concentration of 0.415 mg/l for a duration of six weeks exposure, the second treatment with a concentration 0.415 mg/l added only at the beginning of experiment, while the third treatment was treated with 0.207mg/l for a duration of exposure, the forth treatment was exposed to 0.207mg/l only at the beginning of experiment. At the beginning of the experiment, the four treatments showed that the emergence of neurological signs of involuntary and abnormal movements. A negative relationship were noticed between the concentration and the number of breathing, the first and third treatments which the addition of the pesticide continued for the duration of the experiment showed lack of food appetite and decreasing in fish weight during experimental period, while the second and fourth treatments were gradually improved in responding to external stimuli and restoring their normal breathing and movement. The results of histopathological studies showed that the first treatment characterized with significant histopathological changes in all test tissues (gills, liver and kidney), followed by third treatment which showed more than second and fourth treatments, no histopathological lesion were observed in examined organs of the fourth treatment.

The present study was conducted to determine the effect of magnetic water in common carp Cyprinus carpio. The experiment was comprised of four treatments, the first was control without magnetized water; the second treatment contained magnetized water valued 500 gauss, third was with 1000 gauss and fourth was with of 1500 gauss with replicate of each treatment during the duration of six weeks. In this experiment, the utilization of magnetized water to compare with the normal tap water to detect which magnetic intensity is the best to be used in next experiment as for as weight, length, and growth of fish is conserned via daily water samples to examine temperature, pH, dissolved O2, water surface tension, and blood picture of experimental fish including RBCs count, WBCs count, PCV, Hb concentration, in addition to determine the ions concentrations for Ca, Mg, Na, and Cl. The results showed significant decreases in mass and surface tension which related proportionally with increasing magnetic intensity, also the dissolved O2 , pH of water, concentration of ions in blood, and blood picture were recorded significant values related proportionally with increasing magnetic. The values of statistical analysis showed significant differences (p≤0.05) among all treated treatments especially the forth which revealed best results for growth, blood picture, and ions, followed by the third treatment, then the second treatment compared with control treatment.



The present study was conducted to determine the effect of magnetic water in common carp Cyprinus carpio. The experiment was comprised of four treatments, the first was control without magnetized water; the second treatment contained magnetized water valued 500 gauss, third was with 1000 gauss and fourth was with of 1500 gauss with replicate of each treatment during the duration of six weeks. In this experiment, the utilization of magnetized water to compare with the normal tap water to detect which magnetic intensity is the best to be used in next experiment as for as weight, length, and growth of fish is conserned via daily water samples to examine temperature, pH, dissolved O2, water surface tension, and blood picture of experimental fish including RBCs count, WBCs count, PCV, Hb concentration, in addition to determine the ions concentrations for Ca, Mg, Na, and Cl. The results showed significant decreases in mass and surface tension which related proportionally with increasing magnetic intensity, also the dissolved O2 , pH of water, concentration of ions in blood, and blood picture were recorded significant values related proportionally with increasing magnetic. The values of statistical analysis showed significant differences (p≤0.05) among all treated treatments especially the forth which revealed best results for growth, blood picture, and ions, followed by the third treatment, then the second treatment compared with control treatment.


The present study was conducted to determine the effect of magnetic water in common carp Cyprinus carpio. The experiment was comprised of four treatments, the first was control without magnetized water; the second treatment contained magnetized water valued 500 gauss, third was with 1000 gauss and fourth was with of 1500 gauss with replicate of each treatment during the duration of six weeks. In this experiment, the utilization of magnetized water to compare with the normal tap water to detect which magnetic intensity is the best to be used in next experiment as for as weight, length, and growth of fish is conserned via daily water samples to examine temperature, pH, dissolved O2, water surface tension, and blood picture of experimental fish including RBCs count, WBCs count, PCV, Hb concentration, in addition to determine the ions concentrations for Ca, Mg, Na, and Cl. The results showed significant decreases in mass and surface tension which related proportionally with increasing magnetic intensity, also the dissolved O2 , pH of water, concentration of ions in blood, and blood picture were recorded significant values related proportionally with increasing magnetic. The values of statistical analysis showed significant differences (p≤0.05) among all treated treatments especially the forth which revealed best results for growth, blood picture, and ions, followed by the third treatment, then the second treatment compared with control treatment.

The aim of study was to use the enzyme Lignin peroxidase which locality isolate from bacteria Streptomyces sp.by using solid fermentation for enzyme porduction product which is characterized to be durable, stand high temperature and neutral pH to reduction reduce the tannin in white corn Sorghum bicolor and used as substitute to yellow corn Zea mays in feeding common carp fingerling Cyprinus carpio L. This study was carried out in the laboratories of fish and Animal Resource Center-Agricultural Research Directorate for 80 days from 7/3/2016 to 25/5/2016.The enzyme activity evaluate by using 2,4-dichlorophenol as substrate. The results of chemical analysis for white corn after treatment by enzyme before and after grind reduce the tannin and fiber levels and increase protein ratio. The fished average weight was (25.12±3.75gm/fish) fed on seven experimenal diets contain two substitution levels of white corn for yellow corn, T1 and T2 used white corn without treatment substitution 50% and 100% for yellow corn, T3 and T4 used white corn treatment before grinded by enzyme (80 ml/kg) at same substitution level, T5 and T6used white corn treatment after grinded by enzyme (80 ml/kg) at same substitution and T7 without white corn for control. The results showed T5 and T6 were the best treatments in growth indices (total and daily weight gain and relative growth rate%), feed and efficiency conversion ratio and apparent digestibility rate.

Grass carp (Ctenopharyngodon idella) at an average weight of 25.44 + 1.08 g were exposed to gradual increasing in salt concentrations:tap water 0.1 (represents as control),4,8 and 12gm/l.to study the percentage ratio of packed cells volume(PCV%) and the concentrations of sodium and potassium ions in blood plasma. The obtained results showed that the PCV% was increased to 30, 34 and 37% while the salt concentrations were increased to 4, 8 and 12 gm/l. respectively, in comparison with control(27%).Sodium in blood plasma was increased to130.08,154.16 and 162.31 mM/l at gradual increase in salinity to 4, 8 and 12g/ l respectively, in comparison with control (122.14 mM/l). Potassium concentrations also increased to 10.22,14.64 and 19.78 mM/l, while the salinity increase to 4,8 and 12g/l respectively, in comparison with control (7.76mM/l). The trial concluded that the gradual increasing in salinity was stimulated the osmoregulation and improved the salinity tolerance of grass carp according to the new ambience.

Goldfish at an average weight of 42.36+ 2.24 g were exposed gradually to four salt concentrations are: tap water (0.1), 4, 8 and 12 g /l (where the first treatment represented control) to study the effect of high salt concentrations on the mechanism efficiency of ionic exchange and performance of gills by determining the ions concentrations of sodium and potassium in the blood plasma and calculate the number and ratio of chloride cells in goldfish. The results showed an increase in the sodium ion concentration in the blood plasma to 134.11,144.42 and 153.86 mM/l atsalt concentrations, 4, 8 and 12 g/l, respectively, compared with concentration in the control treatment (126.92 mM /l). As well as, potassium ion concentration has increased to 9.08 and 11.92 and 13.85 mM/l, with the increase of salinity to 4, 8 and 12 g/l respectively, compared with control treatment (6.88 mM / l). The number of chloride cells in the gills of goldfish has increased to 7.98 x 105 and 11.17x105 and 13.04 x 105 cell/g of scraped material with the increase of salinity to 4, 8 and 12 g/l, respectively, compared to the control treatment (5.34 x 105 cells/g of scraped material), and the ratios of chloride cells were increased to 8.41, 12.5 and 13.94% at salt concentrations, 4, 8 and 12 g/l, respectively,in comparison with the control treatment (6.12%). The current study concluded that the gradual increase in the salt concentrations was developed an ionic exchange efficiency of sodium and potassium, and stimulated gills performance through increasing the number and ratio of chloride cells and thus the salted enduranceability of the goldfish was increased according to the new environment.

This study was aimed to investigate the effect of the gradual increase of salinity to 4, 8 and 12 g/l. on food digestibility and gastric evacuation rate in goldfish Carassius auratus and,the concentration 0.1 g/l. (tap water) was represented as control. The results of digestibility trial showed that the total food digestibility were 57.04, 55.62 and 51.72% in salt concentrations 4,8 and 12 g/ l.respectively ,while it was 60.18% in control.The values of apparent digestibility of protein were 73.17, 67.78 and 66.18% in salt concentrations 4,8 and 12 g/l. respectively, in comparison with control (78.24%). While, the values of apparent digestibility of fat were 72.92, 63.14 and 60.40% in salt concentrations 4,8 and 12 g/ l. respectively, in comparison with control (74.65%). The increase of salinity as well raise the gastric evacuation rate, where the debut of feces was recorded after 5.20 h., 6.15 h. and 7.10 h. after food intake in salt concentrations 12, 8 and 4 g/ l. respectively, while it was 7.40 h. in control. Fish were fed a diet contained 32% protein during the study. The study summarized that the digestibility decreased, and the evacuation rate of goldfish increased with the gradual raising in water salt concentrations.

This study was aimed to investigate the effect of the gradual increase of salinity to 4, 8 and 12 g/l. on food digestibility and gastric evacuation rate in goldfish Carassius auratus and,the concentration 0.1 g/l. (tap water) was represented as control. The results of digestibility trial showed that the total food digestibility were 57.04, 55.62 and 51.72% in salt concentrations 4,8 and 12 g/ l.respectively ,while it was 60.18% in control.The values of apparent digestibility of protein were 73.17, 67.78 and 66.18% in salt concentrations 4,8 and 12 g/l. respectively, in comparison with control (78.24%). While, the values of apparent digestibility of fat were 72.92, 63.14 and 60.40% in salt concentrations 4,8 and 12 g/ l. respectively, in comparison with control (74.65%). The increase of salinity as well raise the gastric evacuation rate, where the debut of feces was recorded after 5.20 h., 6.15 h. and 7.10 h. after food intake in salt concentrations 12, 8 and 4 g/ l. respectively, while it was 7.40 h. in control. Fish were fed a diet contained 32% protein during the study. The study summarized that the digestibility decreased, and the evacuation rate of goldfish increased with the gradual raising in water salt concentrations.

The present study was conducted to investigate the effect of high salinity on the some stress parameters of common carp (Cyprinus carpio) which gradually exposed to salt concentrations of 5, 10 and 15g/liter, as well as tap water (control 0.1g/liter) for 90 days. An 80 fish were randomly distributed on eight glass tanks with 2 replicates as 10 fish/replicate at average weight of 15 ± 3 g to study the effect of salinity on the survival ratio and determine the lethal salt concentration which killed half number of fish (LC50), effect of a gradual increase in salinity on some of the physiological Parameters such levels of sodium and potassium in the blood plasma. The results of the experiment of survival ratio that had lasted 96 hours showed that the value of LC50 amounted to 17 g/l, and as regards to the effect of salinity in some of the physiological parameters of fish, it was observed that the gradual rise of salinity to 5,10 and 15 g/l led to disturbances in all fish. The level of sodium valued to highest concentration in the plasma at a salinity of 15 g/l (194.14 mmol/liter) and reached to 172.22 and 179.77 mmol/liter in the both concentrations 5 and 10 g/l respectively, in comparison with concentration the control treatment (130.42 mmol/liter). The same result recorded to the potassium ion which reached highest level (14.90 mmol/liter) in a salinity of 15 gram/liter, and as for the both concentrations of 5 and 10 g/l, where the potassium ion rised to 11.83 and 13.59 mmol/liter respectively, in comparison with the control treatment (7.12 mmol /liter). The trial concluded that the gradual increase in salinity was led to an increase in Soduim and potassium ion and Increased in Survival ratio when the Salinity rise.

This research was conducted on a random sample of ten of fish hatcheries in Waist province , included nine hatcheries from private sector and the one is a governmental hatchery (Al-Wehda central hatchery) for a period from 1/2/2015 to 1/6/2015. The aim of the research was to identify the reasons for the low survival rate of fish larvae inside the hatcheries. A questionnaire was prepared which included 9 questions . The results showed there were important reasons for the low survival rate including weakness of administrative procedures by the owners hatcheries including non-initialization routine operations for incubation ponds in a timely, no change of water ponds, presence of predators in the ponds, using little depth water, high stocking density of larvae per donum, staying of the larvae in the incubation ponds for longer periods than required, Lack of control over environmental conditions. This problems have led to reduce the survival rate of fish larvae in the ground incubation ponds where the ratio ranged between 15-23%, which is one of the most important problems that led to reduce productivity of hatcheries for fish carp fingerling. The researcher recommends a adoption of the results of this study by the ministry of agriculture and there is need to follow a practice for fish hatcheries and the importance to support technically and financially especially the private hatcheries in exchange to release higher quantities of fingerlings fish in Iraqi waters due to the importance in the development of the fisheries stocks in Iraq where the hatcheries are considered the only tribute of fry fish that prepared for breeding in fish farms, cages and Iraqi inland water fish.

The study was carried out on the most important commercial fish which stock are depleted, Pampus argenteus (Euphrasen,1788). The sample of catch from Iraqi marine water during April-2014, The proteins were estimated by extracting myofibrile proteins of Zubaidi, Electrolyte with Acryl Multi - Amide for separation of Protein. The results showed the presence of (10-11) protein package, and the molecular weights of Zubaidi P. Argenteus within the limits of standard proteins. When proteins are diagnosed, they are found to by within nine proteins (tropomysin,thymosin, myosin,troponin, ᴽactinin, C.protein, M1/M2, Fimbrin, actin) and molecular weight (41, 102, 182, 68, 75, 90, 73, 77, 53) K. Dalton While Zubaidi proteins were closely associated with each other very soon, the highest correlation between Actin and M1 / M2 was 11.262, while the lowest correlation between Myosin and Tropomysin (T) was 0.61.

The aim of this study was to determine the optimum crude protein level in the diet of common carp Cyprinus carpio in floating cages was determined depending on the growth parameters which include changes in body weight, relative growth rate , specific growth rate , feed conversion ratio , feed efficiency ratio, protein efficiency ratio and protein productive value. Sixth fish groups (30 fish/group) were cultured in floating cages for 90 days. The groups (average initial weight 113±3.5 g/fish) were fed on six diet. The first diet (control) contained 25 % crude protein while the 2nd, 3rd, 4th, 5th and 6th diets contained 27, 29, 31, 33 and 35% crude protein respectively. The statistical analysis of the data showed that there were no significant differences among the control and other experimental diets on fish ability in: Final weight, relative growth rate, specific growth rate , daily growth rate , feed conversion ratio and feed efficiency ratio as well as protein productive value. Fish fed on the 6th and 3rd gave significantly (p<0.05) higher total weight gain than others protein consumption and deposited protein were found to be significantly (p<0.05) lower in control group than the others and the 6th group was the high, while the opposite significant (p<0.05) finding was for the protein efficiency. It is evident from the above mentioned that the diet can contain 27% crude protein based on what is mentioned above.

This study conducted at Tigris River-Tikrit, Saladin, during the period from September 2013 to June 2014. Two stations selected to collect the samples, the first from was Al-Mhazim Village to Tikrit Bridge and the second was Elbo Ajeel Village to Al-Zallaya Village. Five physiochemical parameters for water river measured (Water temperature, pH, turbidity, dissolved oxygen, and total hardness). The difference in environment factors among months was examined. High value of water temperature, PH, turbidity and total hardness recorded in June, December, October, April and February respectively. Fifteen fish species recorded. Fourteen of them belonged to the family Cyprinidae that occupied 93.3% of the total species number and one belong to the family Mugilidae(Liza abu). The total number of fish collected were 1598, and weight (147141.51) gm. Cyprinion macrostomus was the dominated species by number with 459 (28.27%) of the total catch, then L. abu 235 (14.71%), Carrasius auratus 222(13.89%), Chondrostoma regium 198 (12.39%), and Carasobarbus luteus 188 (11.76%), and the lowest percentage 0.25% for Barbus xanthopterus. The main species of C. macrostomus, coarse L. abu, C. auratus, and C. luteus appeared in all months of fishing, with the highest catch rate of 39.55, 14.47, 13.07 and 14.07%, respectively in September, February, (December and February) and September respectively.

Age, growth and reproduction of Carasobarbus luteus in Tigris river-Tikrit have been studied during the period from September 2013 to June 2014.The total length and weight of the collected fish were ranged from 12.7-32.4 cm and 24.62-387.55 gm respectively. The greatest proportion of the sampled fish was 59.57% for the length group 16-20cm, and the higher percentage of catch was 15.41% during both September and December. Eight age group I-VIII recorded forC. luteus, and the third age group found in 72 specimen with 38.30% of total catch. The length-weight regression coefficients (b) was 2.837, and the condition factor (K) ranged from 0.46-1.73 with an average of 1.30. The values of b and K varied among sex, fish length and months. Sex ratio (male: female) was 1:1.69 in favor of female. Maximum gonadsomatic index was 9.51 for females in May and 5.32 for male in April. Fecundity ranged from 1068-12198 eggs with a mean of 5072 for females ranged in total length 17.5-27.0 cm.

Some biological aspects (length-weight relationship and condition factor) and morphological relationships for 66 Carasobarbus luteus from Tharthar Lake were studied during the period from November 2012 to September 2013.The total length and weight ranged from 12.6-31.3 cm and 26.55-483.20 gm. respectively. The greatest proportion of the sampled fish was 42.42% for the length group 16-20cm, and the higher percentage of catch was 33.33% during November. The length-weight regression coefficients (b) was 3.142, and the condition factor (K) ranged from 1.21-1.94 with an average of 1.46. The values of K increased with fish length, reached to 1.36, 1.45, 1.48 1.50 and 1.58 respectively.

A total of 85 specimens of Lucibarbus xanthopterus were collected from three sites from Tigris River during November 2015 to April 2016 , total length ranged among 7-33cm, fish were divided into four length groups. Heavy metal analysis was done and included measurement of Pb and Cd concentrations in water and in gills, muscle, liver and kidney of L. xanthopterus. The results showed that the mean concentration of Pb was higher than Cd in water and fish organs. The present results demonstrated that the concentration of both Pb and Cd in fish liver and kidney are much higher than that in gills and muscle. Pb level followed the sequence: liver > kidney > muscle > gills from site 1 and 2, while the orders of level of Pb in organs are as: kidney > liver > muscle > gills from site 3. As referring to levels of Cd that followed the sequence: liver > kidney> gills > muscle from site 1 and 3 , while the orders of concentration level of Cd in organs are as : kidney > liver > gills > muscle from site 2.
It can be concluded that the mean concentration values of dissolved Pb in water and fish tissues recorded more than dissolved Cd in all stations .

This study was carried out to investigate the effect of chitosan on some haematological parameters, biochemical profile, growth rate and survival rate of Cyprinus carpio L. challenged with Aeromonas hydrophila. A total of 100 common carp were divided into five dietary groups: The control group fed on chitosan-free diet; T1 was fed on diet supplemented with 0.75% chitosan; T2 was fed on diet supplemented with 1.5% chitosan; T3 was fed on diet supplemented with 2% chitosan, and T4 was fed on diet supplemented with probiotics for 45 days. Fish fed diets were challenged intramuscularly with 0.2 ml A. hydrophila at a concentration 1.2x107 CFU ml-1 on day 45. After 45 day of feeding trail and post challenge, Blood samples were takan to conduct the haematological parameters and biochemical profile. WBCs count revealed significantly increase (p ≤0.05) in chitosan-feeding group of fish (T1, T2 and T3) as compared with probiotic (T4) and control groups pre challenge and post challenge. Albumin, globulin levels and the ratio of albumin globulin observed a significant increase (p≤ 0.05) in all chitosan contaired trials at 45 and 60 days as compared with the control and probiotic groups. SGR (%) of the C. carpio were significantly affected (p<0.05) by dietary containing chitosan and probiotic. Post challenge with A. hydrophila the survival rate showed an increase in T3 and T2; 100 and 75% as compared with T1, and T4 and the control groups. Based on the obtained results it concluded 2% chitosan as fed additives could be used as prophylactic in common carp to improve protection against possible infection by Aeromonas hydrophila which that is beneficial for application in fish culture.

This study was, carried out to assess the efficiency of vitamin E and sodium selenite in reducing toxicity and accumulation of lead acetate in Cyprinus carpio L. For this purpose, 120 common carp with an average weight 65.50±0.25 g were randomly divided into 6 groups in duplicate (2 tank treatment-1). Each of the six treatment groups was fed the formulated diets continuously for 10 weeks at a daily rate 3% of body weight throughout the experiment as the following: Treatment 1 (T1) serves as control group without additives; Treatment 2 (T2) were fed diet mixed with vitamin E (VE) 6 IU plus Sodium Selenite (Se) 240μg kg-1 d.w; Treatment 3 (T3) were fed diet mixed with Lead Acetate (Pb) (20 mg kg-1 d.w); Treatment 4 (T4) were fed diet mixed with Pb (30 mg kg-1 d.w); Treatment 5 (T5) were fed diet mixed with Pb (20 mg kg-1 d.w) and VE 6 IU plus Se 240μg kg-1 d.w; Treatment 6 (T6) were fed diet mixed with Pb (30 mg kg-1 d.w) with VE 6 IU plus Se 240μg kg-1 d.w. At the end of the feeding trial (i.e. 10 weeks) several endpoints at various levels of biological responses were assessed such as DNA damage using COMET assay, lipid peroxidation by TBARS assay, hematological indices (viz Hb content, PCV value, RBC and WBC count) and Pb accumulation in different organs. The results indicated that the highest level of DNA damage (p<0.05) was observed in T4 compared to T3. Also, there were significant differences among Pb treatment groups T3 and T4 and Pb with VE+Se T5 and T6. For lipid peroxidation the highest level of TBARS was observed in T3 and T4. In contrast, the concentrations of TBARS were significantly decreased (p<0.05) in Pb with VE plus Se groups T5 and T6 compared to T3 and T4. The count of WBC's showed significant increases in T3, T5, T6 compared to T1 and T2. While, RBC's count were significantly decreased (p<0.05) in Pb treatment groups compared to T1 and T2. The Pb accumulation in organs was in the following order: kidneys> liver> muscles. in conclusion, the results indicate that vitamin E and Se reduced DNA damage and protect against lead toxicity which could be useful in aquaculture application.

The present experiment was carried out to study the effect of supplementing different dietary levels of antibiotic (Tylosin 20%) on the Apparent Digestibility Coefficient (ADC) and Apparent Protein and Fat Digestibility (APD), (AFD) of common carp (Cyprinus carpio L.). Fish were fed with a laboratorial manufactured diet with protein content of 31.04%, energy 1437 calories/kg, and of antibiotic Tylosin 20% added at different levels content 0, 20, 60, 100 mg/kg B.W. The statistical results of ADC showed significant differences (p<0.05) among all experimental treatments. T2 (83.05%) differed significantly from other treatments followed by treatment T1(81.82%), T4 (79.59%) and T3 (70.59%). The results of APD showed no significant differences (p>0.05) among all experimental treatments, where the highest value was recorded in T2 (93.25%) followed by T1,T3 and T4.The obtained results also showed significant differences among AFD of T3 (91.13%) and there were no significant difference among other treatments.