Evaluation of calcium bentonite clay on nutrient digestibility of tilapia (Oreochromis niloticus)     

Dilawar Hussain  Abdul Mateen  Delbert M. Gatlin 《Aquaculture Research》2022,53(1):314-319

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Effects of a Bacteria-Based Probiotic on Subpopulations of Peripheral Leukocytes and Their Cytokine mRNA Expression in Calves     

Abdul Qadir QADIS  Satoru GOYA  Minoru YATSU  Yu-uki YOSHIDA  Toshihiro ICHIJO  Shigeru SATO 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2014,76(2):189-195

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Effect of cortisol on the metabolism of 17-hydroxyprogesterone by Arctic charr and rainbow trout embryos     

M.N. Khan  P.K. Reddy  R.L. Renaud  J.F. Leatherland 《Fish physiology and biochemistry》1997,16(3):197-209

The effect of cortisol on the in vitro metabolism of [³H]17-hydroxyprogesterone ([³H]17OHP) was studied during embryonic development of Arctic charr (Salvelinus alpinus) and rainbow trout (Oncorhynchus mykiss). In the absence of cortisol, rainbow trout embryos metabolized [³H]17OHP largely to androstenedione (A₄) and androstenetrione (11-KA) with a minor conversion to 17,20ß-dihydroxy-4-pregnen-3-one (17,20P). In the presence of cortisol, this biosynthesis was inhibited. On the other hand, cortisol had no apparent inhibitory effect on the nature of metabolism of [³H]17OHP by Arctic charr embryos. In these embryos [³H]17OHP was metabolized mainly to 17,20P with a minor conversion to A₄ and without the formation of 11-KA that was seen in rainbow trout.When incubated in the presence of [³H]cortisol both Arctic charr and rainbow trout embryos produced 11ß-hydroxyandrostenedione (11ß-OHA) as the major metabolite, with a minor conversion to an unknown steroid. The catabolism of the cortisol by salmonid embryos may reflect the ability of the embryo to inactivate or detoxify cortisol to protect itself from the adverse effects of this biologically potent steroid hormone The study indicates the existence of species-specific differences in the nature of metabolism of [³H]17OHP and the inhibitory effect of cortisol on this metabolism.  相似文献   

Sex differences in circulating steroid hormone levels in the red drum, Sciaenops ocellatus L.     

Wilbert D Kucherka  Peter Thomas  & Izhar A Khan 《Aquaculture Research》2006,37(14):1464-1472

Steroid profiles of cultured and captive red drum (Sciaenops ocellatus L.) were investigated to evaluate the potential use of circulating sex steroid levels as a tool for gender identification in this species. Cultured 18‐month‐old fish were maintained on a 120‐day shortened photothermal cycle to induce precocious maturation. Additionally, wild‐caught fish were maintained in captivity under simulated natural photothermal conditions from late spring to early fall. Circulating 11‐ketotestosterone (11‐KT) levels were significantly higher in males compared with females during the early stages of gonadal growth in both cultured and captive fish. Plasma testosterone (T) levels showed a similar trend; however, the differences were significant only when males were already producing sperm. 17β‐estradiol (E₂) concentrations were low in males and females before gonadal recrudescence but increased significantly with the progression of vitellogenesis in females. These results show that a test using a minimum concentration of circulating 11‐KT could be developed to differentiate between sexes in the early stages of gonadal maturation in red drum. Moreover, plasma E₂ concentrations could be used to identify vitellogenic females. The two steroids considered together could help avoid possible error in gender identification due to unusually high levels of certain steroids encountered in some individuals.  相似文献   

Growth, reproductive performance, muscle and egg composition in grass carp, Ctenopharyngodon idella (Valenciennes), fed hydrilla or formulated diets with varying protein levels   总被引：1，自引：0，他引：1  

Mohammad Afzal Khan  Ahmad Khalil Jafri  & Narendra Kumar Chadha 《Aquaculture Research》2004,35(13):1277-1285

Growth, reproductive performance, muscle and egg composition were investigated in grass carp, Ctenopharyngodon idella (Valenciennnes), fed hydrilla or formulated diets with varying protein levels. Five experimental diets, with varying levels (20%, 25%, 30%, 35% and 40%) of crude protein (CP), were used. One of the fish groups was fed hydrilla. Fish (44.1±0.3 cm; 913±9 g) were stocked (20 tank^?1) in outdoor concrete tanks (20 × 10 × 1.5 m) in duplicate, and fed to satiation, twice daily, at 09:00 and 17:00 hours for the experimental duration of 360 days. High (P<0.05) weight gain was recorded in fish fed 30% and 35% CP diets. However, values for gonadosomatic index (GSI), egg diameter, relative fecundity (eggs kg^?1 body weight), fertilizability and hatchability (%) were comparable (P>0.05) in fish at ≥25% of dietary protein intake. Hydrilla‐fed fish exhibited lower (P<0.05) values for the measured parameters. Crude protein content in muscle increased with dietary protein level. Highest (P<0.05) muscle protein was obtained in fish fed 35% CP diet. Muscle fat was comparable (P>0.05) among fish receiving formulated diets. Ash content was not significantly (P>0.05) different among fish of different dietary groups. Moisture content in fish fed formulated diets, with the exception of 20% CP diet, did not vary significantly (P>0.05). Eggs of fish fed formulated diets contained higher CP and fat contents than those of hydrilla‐fed fish. High (P<0.05) moisture content was noted in the eggs of hydrilla‐fed fish. Ctenopharyngodon idella fed formulated diet, with a minimum of 25% CP, showed better reproductive performance than those fed hydrilla.  相似文献   

Effects of stocking density on production and economics of Nile tilapia (Oreochromis niloticus) and freshwater prawn (Macrobrachium rosenbergii) polyculture in periphyton-based systems   总被引：1，自引：0，他引：1  

M Shahab Uddin  S M Shamsul Rahman  M Ekram Azim  M Abdul Wahab  M C Jarc Verdegem  & Johan A J Verreth 《Aquaculture Research》2007,38(16):1759-1769

The present research investigated the effect of stocking density on pond (75 m², depth 1.2 m) production of Nile tilapia (Oreochromis niloticus) and freshwater prawn (Macrobrachium rosenbergii) stocked at a fixed 3:1 tilapia:prawn ratio. Three stocking densities were tried in triplicate: 20 000 ha⁻¹ (treatment TP‐20), 30 000 ha⁻¹ (TP‐30) and 40 000 ha⁻¹ (TP‐40). The ponds were provided with bamboo as substrate for periphyton development. Bamboo poles (mean diameter 5.5 cm and 5.0 poles m⁻²) were posted vertically into pond bottoms, resulting in 60% additional substrate area in each pond. On average, 43 genera of algae and 17 genera of zooplankton were identified from pond water, whereas 42 genera of algae and six genera of microfauna were attached to bamboo substrates. No differences were observed between treatments in the ash‐free dry matter (AFDM), chlorophyll a and phaeophytin a content of periphyton (P>0.05). Survival of tilapia and prawn and individual weight gain of tilapia were lower (P<0.05) in treatment TP‐40. The net yields were higher (P<0.05) in treatments TP‐30 (2209 and 163 kg ha⁻¹ 105 day⁻¹ of tilapia and prawn respectively) and TP‐40 (2162 and 141 kg ha⁻¹ of tilapia and prawn respectively) than in treatment TP‐20 (1505 and 136 kg ha⁻¹ of tilapia and prawn respectively). The net tilapia yields were quadratic correlated (R²=0.92) with fish stocking density. The cost–benefit analysis shows that the net profit margin was highest in treatment TP‐30 (69%), followed by TP‐20 (50%) and TP‐40 (44%).  相似文献   

Neurotoxins in a toxic red tide of Heterosigma akashiwo (Raphidophyceae) in Kagoshima Bay, Japan   总被引：3，自引：0，他引：3  

S Khan  O Arakawa  Y Onoue 《Aquaculture Research》1997,28(1):9-14

In April 1995, an unusual large-scale red tide of Heterosigma akashiwo (Hada) Hada occurred, causing massive fish kills in Kagoshima Bay, Japan. Four neurotoxic components, HaTx-i , HaTx-ii a, HaTx-ii b and HaTx-iii , which corresponded to brevetoxin components. PbTx-2. PbTx-9, PbTx-3 and oxidized PbTx-2, were inferred from analysis of Heterosigma red tide toxins on TLC and HPLC.  相似文献   

Digestibility, faeces recovery, and related carbon, nitrogen and phosphorus balances of five feed ingredients evaluated as fishmeal alternatives in Nile tilapia, Oreochromis niloticus L.     

Oliver Schneider  Abdul K Amirkolaie  Jordi Vera-Cartas  Ep H Eding  Johan W Schrama  & Johan A J Verreth 《Aquaculture Research》2004,35(14):1370-1379

This study shows that alternatives for fishmeal in a fish diet affect not only fish growth but also faeces stability and nitrogen (N) and phosphorus (P) waste production. Wheat gluten diet (WGD), soybean meal extract diet (SBE), soybean meal diet (SBM), duckweed diet (DWD) and single‐cell protein diet (SCP) were evaluated as a fishmeal replacement on a 15% weight weight^?1 basis in tilapia diets. Fishmeal replacement affected dry matter (dm), protein, ash and P digestibility significantly. Faeces recovery (6.8–11.2%) was not significantly affected, although the amount of non‐recovered faeces and total faeces showed significant differences. Duckweed diet and SCP resulted in the largest amounts of non‐recovered and total faeces (199–210, 224–225 g dm kg^?1 feed dm). Compared with fishmeal diet (FMD), the WGD and SBE resulted in similar growth, but higher non‐faecal N losses (471–495 vs. 416 g N kg^?1 N). Soybean meal diet, DWD and SCP resulted in lower growth but less non‐faecal loss (409–450 g N kg^?1 N). The DWD and FMD had the highest N retention (480 g N kg^?1 N) compared with the other diets (431–451 g N kg^?1 N). Carbon retention, faecal and non‐faecal losses and P retention were similar for all diets (302–358, 142–176 and 489–523g C kg^?1 C, 606–704 g P kg^?1 P). Phosphorus faecal loss was lower for all diets (329–381 g P kg^?1 P) than for the FMD (401 g P kg^?1 P).  相似文献   

Effect of γ (Gamma)-radiation on the physico-mechanical properties of grafted jute fabric reinforced polypropylene (PP) composites     

G. M. Shafiur Rahman  Muhammad Abdullah Al Mamun  Mubarak A. Khan 《Fibers and Polymers》2014,15(2):340-346

The bleached jute fabric (BJF) reinforced polypropylene (PP) composites with various contents of acrylic acid (AA)-treated BJF and un-AA-treated BJF were fabricated by compression moulding method at 190 °C. The AA-grafted BJF reinforced PP composites were then irradiated by γ-ray at various doses. The mechanical properties of neat PP (N-P), ungrafted-BJF and PP composites (UG-BJFPC), AA-grafted-BJF and PP composites (AA-BJFPC) and γ-ray cum AA-grafted-BJF and PP composites (γAA-BJFPC) show maximum tensile strength (TS) of 30, 46, 47 and 51 MPa, maximum flexural strength (FS) of 34, 49, 50 and 54 MPa and maximum Young’s modulus (E) of 280, 428, 436, and 680 MPa, respectively. The increase of TS, FS and E from UG-BJFPC are 2 %, 2 %, and 2 % for AA-BJFPC and 11 %, 10 % and 59 % for γAA-BJFPC. The TS, FS and E are found to increase with radiation dose up to 500Krad and then decrease. The water absorption (WA) for UG-BJFPC, AA-BJFPC and γAA-BJFPC is respectively about 14, 10 and 9 %, indicating a gradual development of hydrophobic character of the composites first by AA-treatment and then by γ-ray-treatment. AA treatment on jute fabric and gamma irradiation on composite result in significant change of morphology of the jute fabric composites surface and better mechanical bonding between fabric and polymer matrix, as a result improved mechanical properties are found.  相似文献   

Trait phenotyping and molecular marker characterization of barley (Hordeum vulgare L.) germplasm from Western Himalayas     

Jan  Sami  Khan  M. N.  Jan  Sofora  Zaffar  Aaqif  Rashid  Rizwan  Khan  M. A.  Sheikh  F. A.  Bhat  M. Ashraf  Mir  R. R. 《Genetic Resources and Crop Evolution》2022,69(2):661-676

Genetic Resources and Crop Evolution - Barley (Hordeum vulgare L.) is one of the principal cereal crops grown in Western-Himalayas of India. A set of 105 barley&nbsp;genotypes including 38...  相似文献