Effect of density on growth and feed consumption of the abalones Haliotis discus discus, H. gigantea, H. madaka and their hybrids     

Faruq Ahmed  Yasuyuki Koike  Carlos Augusto Strüssmann  Seiichi Watanabe 《Aquaculture International》2013,21(5):969-986

Effect of stocking density was studied in three abalone species Haliotis discus discus (HDD), H. gigantea (HG), and H. madaka (HM) and their hybrids [HDD × HM, HM × HG and HG × HM, mother first] by rearing individually marked abalones for 217 days at low (22 % of available surface area; LD), medium (53 %; MD), and high (126 %; HD) densities. Feeding rate (FR) and feed conversion rate were observed by measuring the amount of feed ingested at an interval of 2–3 days. Reduction of growth rate with the increment of density was found in all three species [Specific growth rate in weight (G _W ) HDD, LD: 0.121, MD: 0.093, HD: 0.069; HM: 0.12, 0.082, 0.061; HG: 0.254, 0.222, and 0.131] and the hybrids HDD × HM (0.18, 0.109, 0.108). The medium density produced the highest growth rates in HM × HG and HG × HM hybrids (0.284, 0.342, 0.28). A growth spurt was observed in all three species and hybrids in the last 44 days of rearing. FR varied from 0.72 to 7.97 % body weight and decreased with the increase in density in all species and hybrids. The results indicate differences in density thresholds for the three abalone species and their hybrids suggesting requirement of different aquaculture management strategies for them.  相似文献   

Population dynamics of citrus leaf miner on different varieties of citrus in correlation with abiotic environmental factors in Sargodha District,Punjab, Pakistan     

Irfan Mustafa  Muhammad Arshad  Abdul Ghani  Iftikhar Ahmad  Abu Bakar Muhammad Raza  Farzana Saddique  Saira Asif  Mobushir Riaz Khan  Haroon Ahmed 《Phytoparasitica》2014,42(3):341-348

From January 2010 to December 2011, samples of leaves from citrus varieties Kinnow, Musambi and Feutral were taken from the five tehsils (administrative subdivisions) of Sargodha District in Pakistan including Sargodha, Bahalwal, Silanwalli, Sahiwal and Kotmomin, to study the population trends in citrus leaf miner (CLM), Phyllocnistis citrella (Stainton) (Lepidoptera: Gracillariidae), and its correlation with various environmental factors: (temperature, humidity and rainfall); plant morphological factors: moisture contents of leaves, leaf thickness, surface area (cm ² ), and biochemical percentage of calcium, potassium and magnesium in leaves. The maximum population of CLM was observed on Kinnow and Feutral, followed by Musambi. The effect of these factors on the larval population was 8.39- 2.30(Mg)+2.73(K)-0.398(Ca)-0.100(Temp)0.038(Humidity)+0.567(Rain)+0.07(Moist) 1.01 (Thickness)-0.022(Surface area). This equation revealed that magnesium, calcium, temperature, humidity, leaf thickness and leaf surface area are negatively correlated with larvae population, whereas potassium, rainfall and moisture are positively correlated with larvae population.  相似文献   

Marketing systems of freshwater prawns in three coastal districts of Bangladesh     

Md. Kawser Ahmed  Shamima Sultana  Sadeka Halim  Md. Monirul Islam 《Aquaculture Economics & Management (Blackwell Science)》2016,20(3):272-282

The present study analyzes the prawn marketing chain before and after the implementation of a Danish-funded project (GNAEP) in three coastal districts of greater Noakhali, southeast region of Bangladesh. The results reveal that, before GNAEP, there was a longer prawn marketing chain with a number of intermediaries who used to share a considerable amount of market margin. However, after implementation of GNAEP, the prawn marketing chain has become shorter with a significant reduction of intermediaries which facilitates direct selling of prawns to processing plants through local Community Based Organizations (CBOs). The present prawn marketing system in the regions is in favor of prawn farmers. Farmers have greater advantages because 1) CBOs provide reasonable market price and actual weight, 2) CBOs can bargain with processing plants as the former are aware of the latest international market prices through Marketing Information System 3) number of intermediaries is lowered and 4) transport and preservation costs are reduced. The displaced intermediaries, some of whom are powerful persons in the society, have again started to influence the prawn market in different ways. This fact has opened up another discussion on how the power structure is shifting in this region and how they are affecting prawn marketing.  相似文献   

Layer by layer assembly of nanosilver for high performance cotton fabrics     

Hanan B. Ahmed  Hossam E. Emam 《Fibers and Polymers》2016,17(3):418-426

High performance cellulosic fabrics are of increasing attention as a wearable fabric with special functions. The current report deals with preparation of multifunctional cotton fabrics by using simple and facile layer by layer technique. Firstly, silver nitrate was reacted with carboxymethyl cellulose to prepare Ag nanoparticles-carboxymethyl cellulose composite. Multi-layers of the so-obtained composite were applied on the cotton fabrics using pad-dry-cure method. Ag nanoparticles were deposited with mean size of 18.2 nm onto cotton fabrics which served as a cross linker between carboxymethyl cellulose macromolecules and cotton macromolecular blocks. Application of composite multilayers brought new properties for the finished cloths such like coloration, ultraviolet resistance, electrical resistance and biocidal action. The ultraviolet transmission radiation was significantly reduced to 7-10 % after applying ten composite layers. Valuable antibacterial textiles which are required in different medical purposes could be successfully produced, as excellent antibacterial activities were achieved by using the reported method. The developed process can be easily adapted to the existing textile machinery, making it industrially viable to produce fabric’s versatility.  相似文献   

<Emphasis Type="Italic">Virgibacillus proomii</Emphasis> and <Emphasis Type="Italic">Bacillus mojavensis</Emphasis> as probiotics in sea bass (<Emphasis Type="Italic">Dicentrarchus labrax</Emphasis>) larvae: effects on growth performance and digestive enzyme activities     

Ahlem Hamza  Kais Fdhila  Dora Zouiten  Ahmed Sleheddine Masmoudi 《Fish physiology and biochemistry》2016,42(2):495-507

This study examined the effects of two probiotics (Virgibacillus proomii and Bacillus mojavensis) on the digestive enzyme activity, survival and growth of Dicentrarchus labrax at various ontogenetic stages in three separate experiments. These probiotics were incorporated as single or mixed into fish feed for a period of 60 days. The growth parameters, proximate composition of whole body, digestive enzymes and gut microbiology were monitored at regular. The increments in length and weight and the survival were significantly higher (P < 0.05), and the values of food conversions were significantly lower (P < 0.05) in fishes fed the probiotic. The administration of V. proomii and B. mojavensis in diet resulted in an increase (P > 0.05) in body ash and protein content and in the specific activity of phosphatase alkaline and amylase in the digestive tract of all the fishes. V. proomii and B. mojavensis persisted in the fish intestine and in the feed in high numbers during the feeding period (group 1: 5.8 × 10⁴ CFU/ml, group 2: 9.6 × 10⁴ CFU/ml, and group 3: 9.8 × 10⁴ CFU/ml day 60). The two probiotics V. proomii and B. mojavensis were adequate for improved growth performance and survival and for healthy gut microenvironment of the host.  相似文献   

Seed Priming Influence on Early Crop Growth,Phenological Development and Yield Performance of Linola (Linum usitatissimum L.)          下载免费PDF全文

Hafeez ur Rehman  Muhammad Qaiser Nawaz  Shahzad Maqsood Ahmed Basra  Irfan Afzal  Azra Yasmeen  Fayyaz ul-Hassan 《农业科学学报》2014,13(5):990-996

Reduced early crop growth and limited branching are amongst yield limiting factors of linola. Field response of seed priming treatments viz. 50 mmol L⁻¹ salicylic acid (SA), 2.2% CaCl₂ and 3.3% moringa leaf extract (MLE) including untreated dry and hydropriming controls was evaluated on early crop growth and yield performance of linola. Osmopriming with CaCl₂ reduced emergence time and produced the highest seedling fresh and dry weights including Chl. a contents. Osmopriming with CaCl₂ reduced crop branching and flowering and maturity times and had the maximum plant height, number of branches, tillers, pods and seeds per pod followed by MLE. Increase in seed weight, biological and seed yields was 9.30, 34.16 and 39.49%, harvest index (4.12%) and oil contents (13.39%) for CaCl₂ osmopriming. Positive relationship between emergence and seedling vigor traits, 100-seed weight, seed yield with maturity time, 100-seed weight and seed yield were found. The study concludes that seed osmopriming with CaCl₂ or MLE can play significant role to improve early crop growth and seed yields of linola.  相似文献   

Integrating genotype,fungicide, and spray schedule reduced gall (Physoderma) disease progression and enhanced grain yield in faba bean     

Bitew  Beyene  Fininsa  Chemeda  Terefe  Habtamu  Ahmed  Seid 《Journal of Crop Science and Biotechnology》2023,26(2):135-149

Journal of Crop Science and Biotechnology - Faba bean is a cool season food legume crop. However, productivity of the crop is constrained by faba bean gall (FBG), which is an emerging disease that...  相似文献   

Effects of different carotenoid supplementation sources with or without sodium taurocholate on growth,feed utilization,carotenoid content and antioxidant status in fry of the European seabass,Dicentrarchus labrax          下载免费PDF全文

Ahmed Elsayed Sallam  Abdallah Tageldien Mansour  Tarek Mohamed Srour  Ashraf Mohamed Abdelsameè Goda 《Aquaculture Research》2017,48(7):3848-3858

A total of 210 European seabass fry with an average body weight of 0.51 ± 0.03 g were divided into seven experimental treatments (three replicates per treatment). The seven experimental diets (45.64% CP) were formulated to contain synthetic astaxanthin (SA; 0.1 g kg^?1), marigold flower meal (MFM; 0.2 g kg^?1) or crab waste meal (CM; 10 g kg^?1), with or without sodium taurocholate (ST; 0.4 g kg^?1); the control diet contained no supplementation. The experiment was conducted for 8 weeks. The results show that seabass fry fed the diets containing different sources of carotenoids, especially with ST, demonstrated higher growth efficiency, survival (%), feed efficiency, protein and ether extract contents of fish body. The best results were found with Diet_MFM+ST. Whole‐body carotenoid levels increased significantly with all supplementation treatments; the highest level was observed with SA, followed by fish fed Diet_MFM and Diet_CM, especially with ST co‐supplementation. Moreover, thiobarbituric acid‐reactive substances were significantly reduced in fish fed the diets containing different sources of carotenoids compared to the control diet. The total antioxidant status significantly increased in fish fed Diet_SA and Diet_CM alone or with ST compared to the control group. In conclusion, these results reveal that Diet_MFM+ST is the most suitable treatment for improving growth, feed efficiency, and the protein and ether extract contents of seabass fry compared to other sources of carotenoids. The best oxidant/antioxidant balance and carotenoid content were achieved using SA, CM and MFM with ST supplementation.  相似文献   

Response to the ration levels on growth,body composition,energy, and protein maintenance requirement of the Indian catfish (<Emphasis Type="Italic">Heteropneustes fossilis</Emphasis>—Bloch 1974)     

Imtiaz Ahmed 《Fish physiology and biochemistry》2010,36(4):1133-1143

An 8-week growth study was conducted to determine the effect of ration level, energy, and protein maintenance requirement of catfish, Heteropneustes fossilis–Bloch, fingerling (7.90 ± 0.55 cm; 3.10 ± 0.28 g) by feeding casein–gelatin-based purified diet (40% CP; 3.61 kcal g-1 GE) at six ration levels 1–6% of BW/day, at 0800 and 1700 h, in triplicate, with 20 fish per trough fitted with water flow-through system of volume 55 L. Maximum live weight gain, best feed conversion ratio (FCR), best specific growth rate (SGR), and highest protein efficiency ratio (PER) were evident for ration levels of 4–5% body weight. However, second-degree polynomial regression analysis for weight gain, FCR, PER, protein, and energy retention data indicated that the break-points occurred at 5.08, 4.18, 4.05, 4.16, and 4.17% BW/day, respectively. Significantly (P < 0.05) higher body protein content was recorded at 4 and 5% rations. While a linear increase in body fat content with inverse relationship in moisture content was evident with increasing rations. Ash content remained insignificantly (P > 0.05) low at higher rations. Protein and energy retention values also produced significant (P < 0.05) differences. Based on the results obtained, it is recommended that feeding in the range of 4 to 4.5% BW/day, corresponding to 1.60–1.80 g protein and 14.46–16.27 kcal energy g100 g⁻¹ of the diet/day is optimum for the growth and efficient feed utilization of H. fossilis, while 2–3% ration levels (0.80–1.20 g protein and 7.23–10.84 kcal energy) suggest that these amounts approximate to the maintenance requirement of this fish.  相似文献   

Insecticidal potency of RNAi‐based catalase knockdown in Rhynchophorus ferrugineus (Oliver) (Coleoptera: Curculionidae)          下载免费PDF全文

Abid Hussain  Ahmed M Aljabr 《Pest management science》2016,72(11):2118-2127

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