Ideal Feed Research Articles

Histomorphological studies of broiler chicken fed diets supplemented with either raw or enzyme treated dandelion leaves and fenugreek seeds.

Aim:Herbal plants and their derived products are extensively used particularly in many Asian, African, and other countries of the world as they are considered as ideal feed additives because of their non-residual effect and ability to influence the ecosystem of gastrointestinal microbiota in a positive way. Further, the enzymatic treatment of these herbs helps in their efficient utilization by the host. Dandelion leaves and fenugreek seeds have been reported to have positive effect in terms of improving the performance of broiler chicken, but not much literature is available regarding their effect on gut histomorphology; therefore, the present study was conducted to explore the effect of these herbs either alone or in combination with or without enzyme treatment on histomorphology of liver and small intestine of broiler chicken.Materials and Methods:To achieve the envisaged objective, 273-day-old commercial broiler chicks were procured from a reputed source and reared together until 7 days of age. On the 7th day, the chicks were individually weighed, distributed randomly into 7 groups of 3 replicates with 13 chicks each. Birds in the control group were fed diets without additives (T1). The other six treatment groups were fed the basal diet supplemented with 0.5% dandelion leaves (T2), 1% fenugreek seeds (T3), combination of 0.5% dandelion leaves and 1% fenugreek seeds (T4), enzyme treated dandelion leaves 0.5% (T5), enzyme treated fenugreek seeds 1% (T6), and combination of enzyme treated dandelion leaves (0.5%) and (1%) fenugreek seeds (T7). The histomorphological study of liver and small intestines was conducted among different treatment groups.Results:The results revealed the hepato-protective nature of both dandelion leaves and fenugreek seeds either alone or in combination with or without enzyme treatment when compared with the control group. Moreover, the histomorphological findings of jejunum revealed the beneficial effect of dandelion leaves, fenugreek seeds and enzymes on the intestinal mucosa in terms of cellular infiltration, architecture of villi, villus height/crypt depth ratio, thereby improving the intestinal health.Conclusion:The dandelion leaves and fenugreek seeds have hepato-protective nature and beneficial effect on the intestinal morphology particularly when included along with enzymes in the diet of broiler chicken.

Regulation of gametogenesis and zoosporogenesis in Ulva linza (Chlorophyta): comparison with Ulva mutabilis and potential for laboratory culture

Green Ulvophyte macroalgae represent attractive model systems for understanding growth, development, and evolution. They are untapped resources for food, fuel, and high-value compounds, but can also form nuisance blooms. To fully analyze green seaweed morphogenesis, controlled laboratory-based culture of these organisms is required. To date, only a single Ulvophyte species, Ulva mutabilis Føyn, has been manipulated to complete its whole life cycle in laboratory culture and to grow continuously under axenic conditions. Such cultures are essential to address multiple key questions in Ulva development and in algal–bacterial interactions. Here we show that another Ulva species, U. linza, with a broad geographical distribution, has the potential to be grown in axenic culture similarly to U. mutabilis. U. linza can be reliably induced to sporulate (form gametes and zoospores) in the laboratory, by cutting the relevant thallus tissue into small pieces and removing extracellular inhibitors (sporulation and swarming inhibitors). The germ cells work as an ideal feed stock for standardized algae cultures. The requirement of U. linza for bacterial signals to induce its normal morphology (particularly of the rhizoids) appears to have a species-specific component. The axenic cultures of these two species pave the way for future comparative studies of algal–microbial interactions.

Studies on the Algal Distribution in Various Salt-Pans of Kanyakumari District, Tamilnadu, India

Aquaculture is a popular food producing sector with the target of farming useful organisms in water for food production. Microalgae are one of the many organisms cultured as live feed recently in India. Majority of the algal species can adopt themselves physiologically to a very wide range of salinity. Algae are efficient bio accumulators of inorganic nutrients. Microalgae grow efficiently in a medium having a variety of substances and nutrients in low concentrations instead of a single nutrient in high concentration. Recently, the utilization of saltworks for the production of artemia has increased considerably as it is an indispensable source of food for a number of fish and shrimp larvae. Salt-pans have a ruling temperature of around 24° to 35°C and a temperature of 25° to 30°C is sufficiently favoured to have an increase in biomass content of microalgae. The high nutritive value and adaptability to various environment with a wide range of pH, nutrients and other physical conditions make the microalgae an ideal feed in marine aquaculture enterprise and also a supplement item in human and animal nutrition. The cultivation of these algae with a proper scientific know-how, will improve not only the hatchery need of culture of fishes and shrimps, but also develop the socio-economic status of the coastal people. So, a study was conducted and it unfolds the distribution of algae in different stages of various salt-pans.

Investigation of the maximum load alleviation potential using trailing edge flaps controlled by inflow data

The maximum fatigue load reduction potential when using trailing edge flaps on mega-watt wind turbines was explored. For this purpose an ideal feed forward control algorithm using the relative velocity and angle of attack at the blade to control the loads was implemented. The algorithm was applied to time series from computations with the aeroelastic code HAWC2 and to measured time series. The fatigue loads could be reduced by 36% in the computations if the inflow sensor was at the same position as the blade load. The decrease of the load reduction potential when the sensor was at a distance from the blade load location was investigated. When the algorithm was applied to measured time series a load reduction of 23% was achieved which is still promissing, but significantly lower than the value achieved in computations.

Chemical composition and in vitro total gas and methane production of forage species from the Mid Rift Valley grasslands of Ethiopia

AbstractThere is increasing interest in sustainable land use in the tropics to optimize animal production while also reducing methane (CH4) emissions, but information on nutritive value and CH4‐emission potential of tropical forage species is limited. Samples of 24 grasses and five other forages were collected during the main rainy season on randomly positioned quadrats in semi‐arid grassland in the Mid Rift Valley of Ethiopia. Samples were pooled by species, analysed for chemical composition and incubated with rumen fluid to determine total gas and CH4‐emission potentials using a fully automated in vitro gas production apparatus. Organic matter digestibility (OMD) and metabolizable energy (ME) contents were calculated from chemical composition and gas production data. Large variability was observed among forages for all nutritional variables considered. The grasses Eleusine multiflora, Pennisetum stramineum, Dactyloctenium aegyptium, Eragrostis aspera, Cenchrus ciliaris and Eragrostis cilianensis showed relatively high OMD (68–72%) and ME values (9·1–10·2 MJ kg−1 dry matter). Melinis repens, E. multiflora and the non‐legume forb Zaleya pentandra showed relatively low CH4 to total gas ratios; these species may have potential for use in low CH4‐emission forage diets. Acacia tortilis fruits had high content of crude protein and moderate ME values, and may be an ideal feed supplement for the grazing ruminant. Sodium content was below the recommended level for ruminants in all the forage species. Overall, the pasture stand during the main growing season was evaluated as having moderate nutritional quality.

Preferential oxidation of CO in the presence of excess of hydrogen on Ru/Al2O3 catalyst: Promoting effect of ceria–terbia mixed oxide

The promoting effect of a Ce0.80Tb0.20O2−x mixed oxide on the catalytic behavior of a Ru supported on a commercial alumina catalyst for preferential CO oxidation in the presence of excess hydrogen reaction (PROX) has been investigated. Ru supported on this alumina and ceria–terbia mixed oxide has also been studied as reference systems. N2 physisorption, X-ray diffraction, high-angle annular dark field–scanning transmission electron microscopy (HAADF–STEM), CO and H2 chemisorption, and diffuse reflectance infrared Fourier transform have been used to characterize these Ru catalysts. The Ru/Ce0.80Tb0.20O2−x–Al2O3 catalyst resulting from the modification of the Ru/Al2O3 sample with the ceria–terbia mixed oxide exhibits higher activity for PROX reaction and wider working temperature window than Ru/Al2O3 and Ru/Ce0.80Tb0.20O2−x samples. This remarkable behavior is due to the simultaneous occurrence of CO oxidation and CO hydrogenation to methane on the former catalyst. Moreover, Ru/Ce0.80Tb0.20O2−x–Al2O3 catalyst is the most active catalyst under the ideal PROX feed. It also shows high activity in presence of CO2 and H2O. The CO methanation also has been performed over Ru/Ce0.80Tb0.20O2−x–Al2O3 catalyst. The hydrogen concentration in the PROX feed has been varied in order to study the effect of hydrogen on PROX activity. The PROX reaction and transient experiment have been carried out using in situ diffuse reflectance infrared Fourier transform technique. The combination of Ru nanoparticles and the promotion effect of ceria–terbia are attributed to the unique performance of PROX reaction over Ru/Ce0.80Tb0.20O2−x–Al2O3 catalyst.

Grain quality traits important in feed barley

Grain quality traits important in feed barley Spring barley (Hordeum vulgare L.) traditionally has been a major cereal crop for animal feed especially in Northern areas and also in Latvia. It is complicated to define what the ideal feed barley should be, as the requirements widely differ not only for different species, but even for different age groups of the same species of animals. Therefore, the breeding of feed barley has been developing very slowly and building on the basis of agronomic and beer barley quality parameters. Targeted breeding of barley varieties for a definite application purpose of the grain is connected with selection according to different criteria. The present article shows that the feed quality of barley is influenced both by physical grain quality indicators (colour, grain weight and size, hull content, 1000 grain weight, volume weight and grain hardness) and by the chemical composition (carbohydrates, non-starch polysaccharides, amino acids, fibre, protein, fat, minerals and vitamins). On the basis of the information collected, a profile of a high quality feed barley variety for different groups of animals is defined.

Reconstruction of corneal surface layer using human amniotic epithelial cells modified by lentiviral vector-mediated EGFP gene

Background Studies demonstrated that human amniotic epithelial cells (AECs) have some characteristics of embryonic stem cells and they were used to re-establish the surface of eyes. Human AECs may serve as new seed cells in tissue engineering for corneal epithelium reconstitution in the future. Objective The present study was to investigate the application value of human amniotic epithelium cells transfected by lentiviral vectormediated enhanced green fluorescent protein (EGFP) gene as new seed cell source for engineering the corneal surfacelayer. Methods Lentiviral vector carrying the objective gene EGFP was transfected into human amniotic epithelial cells (pLenti6/V5-DEST),and the transient expression of the transgene in the human amniotic epithelial cells was observed under the fluorescence microscope. Flow cytometry was used to detect the positive expression rates of EGFP in transfected cells. The transfected human amniotic epithelial cells were seeded onto the fresh corneal stromal surface of New Zealand white rabbit and cultured in vitro. The stem cell deficiency ( SCD ) models were established by cutting off the limbus of cornea in 20 eyes of New Zealand white rabbits, and the model rabbits were then divided into 2 groups randomly. The transplanted grafts carrying the pLenti6/V5-DEST-EGFP gene-transferred human amniotic epithelium cells were regarded as the pLenti6/V5-DEST-EGFP group, and the corneal stroma graft without any epithelial cell served as the control group. The opacity of stroma and corneal conjunctivalization and vascularization were observed daily. The rabbits' eyes were extracted one month after operation. The expression of EGFP in the cornea was detected under the fluorescence microscope, and the expression of CK8, CK18 and CK12 in cornea was detected by immunohistochemical staining. Results The shape of the transferred human amniotic epithelial cells resembled normal human amniotic epithelial cells. 48 hours after the transient transfection of EGFP presented with the highest expression level throughout the observation duration, with a positive expression rate of EGFP of 61.5% ,showing significant differences in comparison with that of 12 ( 5.24% ) , 24 ( 38.27% ) or 96 ( 39. 10% ) hours ( P ＜0. 05) post-transfection; but no obvious difference was found in the positive rate of transiently transfected EGFP between 48 hours and 72 hours ( 58.36% ) ( P＞0. 05 ). Six cornea grafts were clear in 1 month and two corneas were rejected during the observation period in the pLenti6/V5-DEST-EGFP group. A few new blood vessels were seen around the graft. Ten corneas of the control group became opaque and cloudy with new blood vessels growth around the grafts. Imunohistochemistry revealed the positive expressions of CK8, CK1 8 and CK12 in the corneal epithelial layer in the pLenti6/V5-DEST-EGFP group. However,the expression of CK12 was absent in the control group. Conclusion Human amniotic epithelium cells transfected with the pLenti6/V5-DEST-EGFP gene is a new and ideal feed cell type to reconstruct the corneal surface layer. Lentivirus is a relatively safe gene transfection vector. Key words: Lentiviral vector; Enhanced green fluorescent protein; Gene transfection; Human amniotic epithelial cells; Corneal transplantation

Friction compensation using a double pulse method for a high-speed high-precision table

Friction error in reverse motion is one of the principal factors influencing the contour accuracy of high-speed and high-precision computer numerical control (CNC) machine tools, on which closed-loop control is used. On the basis of transient response analysis of servo systems which a conventional proportion–integration–differentiation control strategy are used, the reason for quadrant protrusions occurring in circular motion for worktables is discovered, and the characteristics of the friction error during the feed process such as emergence time, duration, and magnitude of the error due to friction can be predicted correctly. A new approach of compensating for friction error using double compensation pulses is proposed in this article. The first compensation pulse made the worktable escape from the dead zone at the best times, and the second one made the worktable approach to the ideal feed path along the guide as fast as possible. Parameters of compensation pulses such as magnitudes, widths, and starting time are determined by simple mathematic calculation. Results of simulations and experiments show that the method using double pulses proposed in this article can effectively compensate for the friction error in circular motions for a high-speed and high-precision table.

Effect of different forms of Artemia biomass as a food source on survival, molting and growth rate of mud crab (Scylla paramamosain)

An experiment was conducted to evaluate the effect of different forms of Artemia biomass as a food source on survival, molting and growth rate of mud crab Scylla paramamosain. Instar 1 crablets with a mean weight of 0.0082 ± 0.0007 g were reared both individually and communally and fed with different diets consisting of fresh shrimp meat (control feed), live Artemia biomass, frozen Artemia biomass and a dried Artemia-based formulated feed for 40 days. The highest survival was obtained for crablets receiving live Artemia (92.5% and 75.8%) followed by the groups fed with frozen biomass (90.0% and 47.5%), the control feed (72.5% and 24.2%) and the dried Artemia-based diet (60.0% and 21.7%) for individual and communal cultures, respectively. The intermolt period, the total number of moltings and the growth rate, which were determined on individually reared crabs, showed the same pattern as for survival. The results suggest that crab performance decreased in the following order: live Artemia>frozen Artemia > fresh shrimp meat > dried Artemia-based formulated feed. Live Artemia biomass proved an ideal feed for nursery of Scylla paramamosain crabs. Frozen Artemia biomass may be an alternative in times of shortage. Our findings illustrate the high potential for local utilization of Artemia biomass in Vietnam for reliable production of mud crab juveniles.

Accurate analysis of printed reflectarrays considering the near field of the primary feed

An analysis technique is proposed for the analysis of reflectarrays placed in the Fresnel zone of the primary feed. The technique is based on the classic analysis of reflectarrays considering local periodicity, improved by considering the near field radiated by the feed horn instead of ideal feed models. The incident field on each reflectarray cell is obtained by applying field transformation to the measured far field (FF) of the horn antenna. The stronger variation of the incident field is considered by increasing the number of samples per reflectarray cell for the incident and reflected waves. This enhanced analysis has been applied to the analysis of a multi-fed and multiple-shaped beam reflectarray placed in the Fresnel zone of the feed horns. The antenna was proposed as a central station antenna for a local multipoint distribution system in the 24.5-26.5-GHz band. The antenna was designed by considering an approximate FF feed model in the radiation pattern synthesis and the reflectarray design. The results obtained through the enhanced analysis are compared with those from measurements of a prototype, validating the proposed analysis procedure and providing a significant improvement with respect to conventional analysis.

Alternatives to Nitric Acid Stripping in the Caustic‐Side Solvent Extraction (CSSX) Process for Cesium Removal from Alkaline High‐Level Waste

Effective alternatives to nitric acid stripping in the Caustic‐Side Solvent Extraction (CSSX) solvent have been demonstrated in this work. The CSSX solvent employs calix[4]arene‐bis(tert‐octylbenzo‐18‐crown‐6) (BOBCalixC6) as the cesium extractant in a modified alkane diluent for decontamination of alkaline high‐level wastes, such as those found at the Savannah River and Hanford sites. Results reported in this paper support the idea that replacement of the nitrate anion by a much more hydrophilic anion like borate can substantially lower cesium distribution ratios on stripping. Without any other change in the CSSX flowsheet, however, the use of a boric acid stripping solution in place of the 1 mM nitric acid solution used in the CSSX process marginally, though perhaps still usefully, improves stripping. The less‐than‐expected improvement was explained by the carryover of nitrate from scrubbing into stripping. Accordingly, more effective stripping is obtained after a scrub of the solvent with 0.1 M sodium hydroxide. Functional alternatives to boric acid include sodium bicarbonate or cesium hydroxide as strip solutions. Profound stripping improvement is achieved when trioctylamine, one of the components of the CSSX solvent, is replaced with a commercial guanidine reagent (LIX® 79). The more basic guanidine affords greater latitude in the selection of aqueous conditions in that it becomes protonated even at mildly alkaline pH values. Under process‐relevant conditions, cesium distribution ratios on stripping are approximately 100‐fold lower compared with the current CSSX performance. The tolerance to surfactants is good, and the extraction properties of the solvent remain unchanged over three successive extract‐scrub‐strip cycles. From the point of view of compatibility with downstream processing, boric acid represents an attractive stripping agent, as it is also a potentially ideal feed for borosilicate vitrification of the separated 137Cs product stream. The possibilities for use of these results toward a dramatically better next‐generation CSSX process, possibly one employing the more soluble cesium extractant calix[4]arene‐bis(2‐ethylhexylbenzo‐18‐crown‐6) (BEHBCalixC6) are discussed.

Comparative Study of Hydrodemetallization (HDM) Catalyst Aging by Boscan Feed and Kuwait Atmospheric Residue

Two feeds, a high-metal feed, namely, Boscan heavy crude (BHC), and a conventional low-metal feed, such as atmospheric residue from Kuwait export crude (KEC-AR), were studied with regard to their capacity to deactivate a hydrodemetallization (HDM) catalyst typically used in Kuwait refineries. Feed properties, such as 1300 wt ppm metal (V + Ni), 10 wt % asphaltenes, and 12 wt% CCR, make BHC an ideal feed to accelerate the deactivation of catalysts in an aging test. The competitive adsorption of coke and metals shortens the lifetime of the HDM catalyst tested in a pilot plant experiment under operating conditions applied in Kuwait refineries by ≈80% compared to KEC-AR. During the start of the run phase (up to 240 h), the HDM catalyst accumulated ≈6 times more metals and ≈1.5 times more coke when aged with BHC instead of KEC-AR. At the end of run, the maximum metal on catalyst (MMOC) in both experiments, accelerated test with BHC (1944 h) and life test with KEC-AR (9720 h), was ≈24.5 g of metal (V + Ni)/100 ...

Cloning and expression ofBacillusphytase gene (phy) inEscherichia coliand recovery of active enzyme from the inclusion bodies

To isolate, clone and express a novel phytase gene (phy) from Bacillus sp. in Escherichia coli; to recover the active enzyme from inclusion bodies; and to characterize the recombinant phytase. The molecular weight of phytase was estimated as 40 kDa on SDS-polyacrylamide gel electrophoresis. A requirement of Ca(2+) ions was found essential both for refolding and activity of the enzyme. Bacillus phytase exhibited a specific activity of 16 U mg(-1) protein; it also revealed broad pH and temperature ranges of 5.0 to 8.0 and 25 to 70 degrees C, respectively. The K(m) value of phytase for hydrolysis of sodium phytate has been determined as 0.392 mmol l(-1). The activity of enzyme has been inhibited by EDTA. The enzyme exhibited ample thermostability upon exposure to high temperatures from 75 to 95 degrees C. After 9 h of cultivation of transformed E. coli in the bioreactor, the cell biomass reached 26.81 g wet weight (ww) per l accounting for 4289 U enzyme activity compared with 1.978 g ww per l producing 256 U activity in shake-flask cultures. In silico analysis revealed a beta-propeller structure of phytase. This is the first report of its kind on the purification and successful in vitro refolding of Bacillus phytase from the inclusion bodies formed in the transformed E. coli. Efficient and reproducible protocols for cloning, expression, purification and in vitro refolding of Bacillus phytase enzyme from the transformed E. coli have been developed. The novel phytase, with broad pH and temperature range, renaturation ability and substrate specificity, appears promising as an ideal feed supplement. Identification of site between 179th amino acid leucine and 180th amino acid asparagine offers scope for insertion of small peptides/domains for production of chimeric genes without altering enzyme activity.

The sweet potato sporamin promoter confers high-level phytase expression and improves organic phosphorus acquisition and tuber yield of transgenic potato

The sweet potato sporamin promoter was used to control the expression in transgenic potato of the E. coli appA gene, which encodes a bifunctional enzyme exhibiting both acid phosphatase and phytase activities. The sporamin promoter was highly active in leaves, stems and different size tubers of transgenic potato, with levels of phytase expression ranging from 3.8 to 7.4% of total soluble proteins. Phytase expression levels in transgenic potato tubers were stable over several cycles of propagation. Field tests showed that tuber size, number and yield increased in transgenic potato. Improved phosphorus (P) acquisition when phytate was provided as a sole P source and enhanced microtuber formation in cultured transgenic potato seedlings when phytate was provided as an additional P source were observed, which may account for the increase in leaf chloroplast accumulation (important for photosynthesis) and tuber yield of field-grown transgenic potato supplemented with organic fertilizers. Animal feeding tests indicated that the potato-produced phytase supplement was as effective as a commercially available microbial phytase in increasing the availability of phytate-P to weanling pigs. This study demonstrates that the sporamin promoter can effectively direct high-level recombinant protein expression in potato tubers. Moreover, overexpression of phytase in transgenic potato not only offers an ideal feed additive for improving phytate-P digestibility in monogastric animals but also improves tuber yield, enhances P acquisition from organic fertilizers, and has a potential for phytoremediation.

Dietary supplementation of salmon roe phospholipid enhances the growth and survival of Pacific bluefin tuna Thunnus orientalis larvae and juveniles

Previous studies have shown that feeding enriched Artemia induces growth failure in Pacific bluefin tuna (PBT) Thunnus orientalis larvae. This growth failure cannot be improved even if the docosahexaenoic acid (DHA) content in enriched Artemia is elevated to the same level as that in yolk-sac larvae, an ideal live feed for PBT larviculture. This might be caused by the differences in the DHA in the live feeds; i.e., yolk-sac larvae of marine fish have a high level of DHA in the larval phospholipids (PLs) but enriched Artemia store DHA in their neutral lipids (NLs). To test this hypothesis two experiments were conducted to evaluate the effect of dietary PL rich in DHA on growth and survival of PBT larvae (Experiment 1) and juveniles (Experiment 2). Three isoproteic and isolipidic artificial test diets (Diets 1, 2 and 3) and two reference live feeds (Diets 4 and 5) were prepared. Diets 1 and 3 were supplemented with NL and PL fractions of commercial salmon Oncorhynchus gorbuscha roe lipid (SRL) as the lipid source, respectively, whereas Diet 2 was supplemented with a mixture of both lipid fractions. Diets 4 and 5 were enriched Artemia and yolk-sac larvae of Japanese parrot fish Oplegnathus fasciatus, respectively. Diets 1, 3, 4 and 5 were given to PBT larvae for 10 days, whereas Diets 1, 2 and 3 were fed to PBT juveniles for 10 days. In Experiment 1, the growth and survival of PBT larvae fed Diet 3 (high PL fraction) were significantly improved when compared with larvae fed Diets 1 and 4, although the best growth and survival were obtained in larvae fed Diet 5. Similar results were obtained in Experiment 2; i.e., growth and survival were significantly improved in PBT juveniles fed Diets 2 and 3. In both experiments, fish fed Diets 2, 3 and/or 5 had higher total lipid contents, TAG levels, n-3 HUFA and/or DHA levels in NL fraction of the body when compared with fish fed Diets 1 or 4, while such a difference was not observed in the PL fraction. In juveniles over 90% of deaths were caused by collisions with the tank walls and the significant difference in mortality between treatments implies diet also affects behavior. SRL PL is concluded to enhance the growth and survival of PBT larvae and juveniles along with the accumulation of storage lipid and DHA in the body.

Production of two highly active bacterial phytases with broad pH optima in germinated transgenic rice seeds.

Phytate is the main storage form of phosphorus in many plant seeds, but phosphate bound in this form is not available to monogastric animals. Phytase, an enzyme that hydrolyzes phosphate from phytate, has the potential to enhance phosphorus availability in animal diets when engineered in rice seeds as a feed additive. Two genes, derived from a ruminal bacterium Selenomonas ruminantium (SrPf6) and Escherichia coli (appA), encoding highly active phytases were expressed in germinated transgenic rice seeds. Phytase expression was controlled by a germination inducible alpha-amylase gene (alphaAmy8) promoter, and extracellular phytase secretion directed by an betaAmy8 signal peptide sequence. The two phytases were expressed in germinated transgenic rice seeds transiently and in a temporally controlled and tissue-specific manner. No adverse effect on plant development or seed formation was observed. Up to 0.6 and 1.4 U of phytase activity per mg of total extracted cellular proteins were obtained in germinated transgenic rice seeds expressing appA and SrPf6 phytases, respectively, which represent 46-60 times of phytase activities compared to the non-transformant. The appA and SrPf6 phytases produced in germinated transgenic rice seeds had high activity over broad pH ranges of 3.0-5.5 and 2.0-6.0, respectively. Phytase levels and inheritance of transgenes in one highly expressing plant were stable over four generations. Germinated transgenic rice seeds, which produce a highly active recombinant phytase and are rich in hydrolytic enzymes, nutrients and minerals, could potentially be an ideal feed additive for improving the phytate-phosphorus digestibility in monogastric animals.

Recent developments in the application of live feeds in the freshwater ornamental fish culture

The industrial development of freshwater ornamental fish culture has been hampered by the lack of suitable live feeds for feeding the fish at the various production stages. This paper reports the recent developments in the applications of the freshwater rotifers ( Brachionus calyciflorus), Artemia nauplii, decapsulated Artemia cysts and on-grown Artemia in the freshwater ornamental fish culture. Results demonstrate that the rotifers are an ideal starter feed for dwarf gourami ( Colisa lalia), a typical freshwater ornamental fish species with larvae that are too small to ingest Artemia nauplii or Moina at its first feeding. Compared with the conventional yolk food, the use of rotifers as a starter feed significantly improves the growth and survival of the gourami larvae (Days 2–12), and the beneficial effects are extended to the subsequent Artemia-feeding phase (Days 13–32). The freshwater rotifers and Artemia nauplii are also useful in raising Discus larvae in the absence of their parents, which would eliminate the risk of larvae being eaten by the parent fish. Work on decapsulated Artemia cysts indicates that the cysts could be used as a substitute for Artemia nauplii or Moina in freshwater ornamental fish culture. The fry of all the five common ornamental fish species tested (guppy Poecilia reticulata, molly Poecilia sphenops, platy Xiphophorus maculatus, swordtail Xiphophorus helleri and neon tetra Hyphessobrycon herbertaxelrodi) could readily feed on the decapsulated cysts, and their performances in terms of stress resistance, growth and survival are comparable to or better than those fed on Artemia nauplii or Moina. A culture system for production of on-grown Artemia has also been developed specifically for the use in freshwater ornamental fish farms. The system, using diluted artificial seawater of 20‰ for culture, has a mean production rate of 3 kg/m 3 of water in a 12-day cycle and a production capacity of 8 metric tons of on-grown Artemia a year. With the system, farmers could produce any specific size of on-grown Artemia of up to 5 mm to suit the age and size of their fish, by varying the time of harvesting. This characteristic, coupled with the use of bioencapsulation technique to enhance the quality of the on-grown Artemia, would make the organism an ideal nursery diet for freshwater ornamental fish. All these results show that the live feeds used in marine foodfish hatchery could be applied to freshwater ornamental fish culture to improve their performance.

Optimizing the operational strategy of a mine-metallurgy or quarry-cement works complex

This paper deals with industrial complexes such as those consisting of: (a) a mine producing metal-bearing ore AND a furnace(s)/converter(s) where the ore is molten into metal, either directly, or after a mineralurgical concentration; and (b) quarries producing the raw materials required for the manufacturing of cement AND the kiln to which they are fed. Every mine or quarry operation results from the exploitation of a mineral deposit. This deposit is NEVER homogeneous. The raw materials which are extracted from the mine/quarry can never by safely fed to “the process” whether this is a cement kiln or a metal smelter, because the devices involved lack the flexibility required to absorb a very inhomogeneous feed. Furnaces and kilns are known to be very sensitive, sometimes dangerously so, with regard to deviations from a certain ideal feed composition. The purpose of this paper is to present the conditions required to optimize the operation of such complex, so as to maximize the production as well as the profit generated. Two key operations are involved: sampling (to know accurately the materials being dealt with) and bed-blending (to achieve the desired degree of homogeneity). The theories of sampling and bed-blending have been developed by the author and presented in various books.

Ideal feed pretreatment for reverse osmosis by continuous microfiltration

Investigations have established that majority of failure/inefficient operation of RO is due to improper/inadequate feed pretreatment. The conventional feed pretreatment techniques such as, sand filters, cartridge filters, chlorination, flocculation, etc are not capable to remove suspended solids, bacteria, colloids, etc completely which results in RO membrane fouling. From the performance of many installations of continuous microfiltration (CMF) technology it appears that this is the most satisfactory feed pretreatment process capable of ensuring highest degree of reliability for the RO system. The technology is fairly simple where the feed is allowed to pass through a barrier of 0.2 micron polypropylene membrane in continuous mode under a pressure gradient of 100 kpa. The filtrate thus obtained on the low pressure side is virtually free from any suspensions, bacteria, colloids, etc. Typically the SDI of the filtrate is lower than 3 which is far below the specified SDI by RO membrane manufactures. This fully automatic system works almost unattended and unlike conventional filters the quality of the filtrate is independent of feed quality variations. The rate of filtration is maintained for long term operations through an innovative backwash system using compressed air at 600 kpa. The paper describes the technology in details besides few case studies.