338,503 research outputs found
Shrimp Feed Formulation and Feed Management
Successful and sustainable aquaculture of finfish and
crustaceans depends upon the provision of nutritionally adequate,
environmental friendly and economically viable artificial feeds.
Feeding increases the productivity of aquaculture farms and
constitutes the highest single cost item of running expenditure. In
view of this, it is imperative that artificial feeds besides being
scientifically formulated and optimally processed, should be
judiciously supplied considering the specific nutritional needs of
the cultivated species and the intensity of the culture operations.
In order to achieve maximum growth and best feed efficiency of a
given feed from a culture system, the feeding strategies employed
viz. feeding rate, frequency and methods of feeding are of primary
importance
Deep Markov Random Field for Image Modeling
Markov Random Fields (MRFs), a formulation widely used in generative image
modeling, have long been plagued by the lack of expressive power. This issue is
primarily due to the fact that conventional MRFs formulations tend to use
simplistic factors to capture local patterns. In this paper, we move beyond
such limitations, and propose a novel MRF model that uses fully-connected
neurons to express the complex interactions among pixels. Through theoretical
analysis, we reveal an inherent connection between this model and recurrent
neural networks, and thereon derive an approximated feed-forward network that
couples multiple RNNs along opposite directions. This formulation combines the
expressive power of deep neural networks and the cyclic dependency structure of
MRF in a unified model, bringing the modeling capability to a new level. The
feed-forward approximation also allows it to be efficiently learned from data.
Experimental results on a variety of low-level vision tasks show notable
improvement over state-of-the-arts.Comment: Accepted at ECCV 201
Protein and amino acid requirements of warm-water fishes: a tool to efficient and low-cost fish feed production in Nigeria
Numerous investigations have utilized various semi-purified and purified diets to estimate the protein and amino acid requirements of several temperate fishes. The vast literature on the protein and amino acid requirements of fishes has continued to omit that of the tropical warm water species. The net effect is that fish feed formulation in Nigeria have relied on the requirement for temperate species. This paper attempts to review the state of knowledge on the protein amino acid requirements of fishes with emphasis on the warm water species, the methods of protein and amino acid requirement determinations and the influence of various factors on nutritional requirement studies. Finally evidence are presented with specific examples on how requirements of warm water fishes are different from the temperate species and used this to justify why fish feed formulation in Nigeria are far from being efficien
Marine fish nutrition, feed formulation, feed production and feeding
Feeding rates, feeding frequency and time of feeding are all
important factors to be considered in feeding of the fish. As a
general rule of the thumb most of the vertebrates including fish
consume 2.5 to 3.0% of the body weight in dry matter. Feeding
rates and frequencies are related to fish growth. Small larval fish
and fry need to be fed a high protein diet frequently and usually
in excess. When fishes grow bigger, feeding rates and frequencies
should be lowered. Feeding fish is a labour intensive activity and
feeding frequency has to be programmed in such a way that it is
economically viable
Effect of a glyphosate-containing herbicide on Escherichia coli and Salmonella Ser. Typhimurium in an in vitro rumen simulation system
Glyphosate (N-(phosphonomethyl)glycine) is the most-used herbicide worldwide. Many studies in the past have shown that residues of the herbicide can be found in many cultivated plants, including those used as livestock feed. Sensitivity to glyphosate varies with bacteria, particularly those residing in the intestine, where microbiota is exposed to glyphosate residues. Therefore, less susceptible pathogenic isolates could have a distinct advantage compared to more sensitive commensal isolates, probably leading to dysbiosis.
To determine whether the ruminal growth and survival of pathogenic Escherichia coli or Salmonella serovar Typhimurium are higher when glyphosate residues are present in the feed, an in vitro fermentation trial with a “Rumen Simulation System” (RUSITEC) and a glyphosate-containing commercial formulation was performed.
Colony forming units of E. coli and Salmonella ser. Typhimurium decreased steadily in all fermenters, regardless of the herbicide application. Minimum inhibitory concentrations of the studied Salmonella and E. coli strains did not change, and antibiotic susceptibility varied only slightly but independent of the glyphosate application.
Overall, application of the glyphosate-containing formulation in a worst-case concentration of 10 mg/L neither increased the abundance for the tested E. coli and Salmonella strain in the in vitro fermentation system, nor promoted resistance to glyphosate or antibiotics
Performance of hemielliptic dielectric lens antennas with optimal edge illumination
The role of edge illumination in the performance of compact-size dielectric
lens antennas (DLAs) is studied in accurate manner using a highly efficient
algorithm based on the combination of the Muller boundary integral equations
and the method of analytical regularization. The analysis accounts for the
finite size of the lens and directive nature of the primary feed placed close
to the center of the lens base. The problem is solved in a two-dimensional
formulation for both E- and H-polarizations. It is found that away from
internal resonances that spoil the radiation characteristics of DLAs made of
dense materials, the edge illumination has primary importance. The proper
choice of this parameter helps maximize DLA directivity, and its optimal value
depends on the lens material and feed polarization. Index Terms: Beam
collimation, dielectric lens antenna, directivity improvement, edge
illumination, edge taper, hemielliptic lens.Comment: 5 pages, 9 figure
Incorporating Environmentally Compliant Manure Nutrient Disposal Costs into Least-Cost Livestock Ration Formulation
Livestock rations are formulated to minimize feed cost subject to nutritional requirements for a target performance level, which ignores the potentially substantial cost of disposing of nutrients fed in excess of nutritional requirements. We incorporate nutrient disposal costs into a modified least-cost ration formulation model to arrive at a joint least-cost decision that minimizes the sum of feed and net nutrient disposal costs. The method is demonstrated with phosphorus disposal costs on a representative dairy farm. Herd size, land availability and proximity, crop rotation, and initial soil phosphorus content are shown to be important in determining phosphorus disposal costs.environmental compliance, linear programming, livestock rations, manure disposal, Agribusiness, Environmental Economics and Policy, Livestock Production/Industries, C61, Q12, Q52,
Economic and environmental impacts of changes in culling parity of cows and diet composition in Japanese beef cow–calf production systems
The effects of changes in culling parity of cows and diet composition on economic and environmental outputs in Japanese beef cow–calf production systems were deterministically analyzed using a herd model simulation. The model simulated the annualized net revenue as an economic indicator and the overall environmental index derived from a life cycle assessment (LCA) as an environmental indicator. Biological factors (survivability, growth, reproduction, and feed requirements) and economic factors (returns from sales of live calves and cows’ carcasses and production costs) were included in the model. The model also included modified feed formulation methods, allowing us to analyze the effect of reductions in environmental loads caused by the change in diet compositions. The results of the present study indicated that later culling was economically and environmentally optimal under the current production system, which suggested that the selection of economically optimal culling parity of cows could result in environmentally optimization of the beef cow–calf production system. The difference in feed composition derived from the difference in feed formulation methods did not affect the determination of optimal culling parity, whereas the use of modified feed formulation methods could reduce environmental loads at a higher rate than that of economic benefits. However, the reduction rate of the environmental impact was much higher in the case of selection of the optimal culling parity than in the case of use of modified feed formulation methods, which stressed the importance of choosing the optimal culling parity of cows both from the economic and environmental points of view
Green protein from locally grown crops (OK-Net EcoFeed Practice Abstract)
• Choose an appropriate type of green crop, such as clover-grass or alfalfa, with an expected high protein and amino acid content. Consider soil types and weather patterns to grow a crop with a good and high quality yield.
• Harvest the field at regular intervals in order to achieve good plant growth and to obtain batches with more high quality protein and less fibre
• Harvesting procedures, which minimise soil content in the green material obtained from the field are necessary to obtain good quality green protein and to avoid wear of machinery and technical equipment
• Cooperation with a bio-refinery plant is a prerequisite in order to concentrate the protein into a green paste that can be dried and used in poultry feed.
• If not dried, the wet green paste can be stored in closed containers/plastic bags in cool conditions for a shorter period.
• Chemical analysis of the green protein concentrate is important in order to replace other protein sources such as soya and to carry out the correct feed formulation. This can be done together with advisors or feed companies
Fish larval nutrition and feed formulation: knowledge gaps and bottlenecks for advances in larval rearing
Despite considerable progress in recent years, many questions regarding fish larval nutrition remain largely unanswered, and several research avenues remain open. A holistic understanding of the supply line of nutrients is important for developing diets for use in larval culture and for the adaptation of rearing conditions that meet the larval requirements for the optimal presentation of food organisms and/or microdiets. The aim of the present review is to revise the state of the art and to pinpoint the gaps in knowledge regarding larval nutritional requirements, the nutritional value of live feeds and challenges and opportunities in the development of formulated larval diets.Norwegian Ministry of Fisheries; Research Council of Norway [CODE-199482, GutFeeling-190019]; Spanish Ministry of Science and Innovation MICINN + FEDER/ERDF [AGL2007-64450-C02-01, CSD2007-0002]; project HYDRAA [PTDC/MAR/71685/2006]; Fundacao para a Ciencia e a Tecnologia (FCT), Portugal; FEDER; EC [LIFECYCLE- 222719]; EU RTD [FA0801]info:eu-repo/semantics/publishedVersio
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