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Nile tilapia (Oreochromis niloticus) is currently one of the most farmed freshwater fish and contributes significantly to total global aquaculture production. The genetically improved strain of O. niloticus (GIFT) was introduced to Papua New Guinea (PNG) in 1999 to improve food and income security. The high cost and low availability of commercial fish feed hinder the growth of GIFT farming in PNG. Stable carbon and nitrogen isotopes were used to determine the role of supplementary and natural food sources in the diet of GIFT in pond‐based aquaculture. Two treatments were used: treatment 1 was daily feeding, and treatment 2 was weekly feeding, each with three replicates. Isotopic analysis of muscle tissue and all potential food sources showed that pellet feed contributed 7% to the growth of GIFT in daily‐fed ponds and 33% in the weekly‐fed ponds. Highly enriched δ15N values for chicken manure, compared to depleted values for GIFT and other natural food sources in both treatments, clearly indicate insignificant contributions of this input to production. After 90 days of cultivation, the average final body weight of GIFT receiving daily feed inputs was 134 g (average 19 cm), while for weekly‐fed it was 92 g (17 cm). The feed conversion ratio (FCR) was poor (6.4:1) in the daily‐fed GIFT ponds compared to a better, and preferable, FCR (1:1) in the weekly‐fed ponds. The findings of this study show that pelleted feed was not the major contributor to the growth of GIFT. Genetically improved farmed tilapia aquaculture should focus on enhancing natural food availability for fish production.  相似文献   
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Chakma J  Sammut SM 《Science (New York, N.Y.)》2011,331(6017):532-3; author reply 533-4
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OBJECTIVE: To determine prevalence of adverse effects associated with epidural administration of morphine with or without bupivacaine in dogs and cats undergoing surgery and evaluate effects of epidural administration of morphine on postoperative pain severity. DESIGN: Retrospective study. ANIMALS: 242 dogs and 23 cats. PROCEDURE: Morphine with or without bupivacaine was administered prior to surgery with a Tuohy needle, spinal needle, or epidural catheter. In 18 dogs that underwent surgery twice, results of preemptive epidural administration of morphine with or without bupivacaine were compared with results of systemic administration of oxymorphone and ketoprofen. RESULTS: The delivered fraction of isoflurane was significantly lower in animals given morphine and bupivacaine than in animals given morphine alone. Analgesia was of significantly longer duration in dogs given morphine and bupivacaine than in dogs given morphine alone. During anesthesia, mild respiratory and cardiovascular depression was reported. Seven dogs and 2 cats had urine retention, and 2 dogs developed pruritus. Six dogs vomited when a second dose of morphine was given epidurally the day after surgery. Eight of 72 dogs had delayed hair growth. In 18 dogs that underwent surgery twice, the delivered fraction of isoflurane was significantly lower and the duration of analgesia was significantly longer when morphine with or without bupivacaine was given epidurally than when oxymorphone and ketoprofen were given. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that preemptive epidural administration of morphine with or without bupivacaine is a safe and effective method of inducing long-lasting analgesia in dogs and cats and is superior to standard management of postoperative pain with repeated injection of oxymorphone and ketoprofen.  相似文献   
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Aquaculture, particularly marine‐based production, is one of the fastest growing industries in Indonesia. Indonesia's competitiveness in the trade of aquaculture products is constrained by a lack of research and development (R&D) of new aquaculture species candidates. Mariculture has the greatest potential due to Indonesia's vast marine resources and archipelagic geography. Although there are over 3,000 species of marine fish in Indonesia, only 14 species have been widely cultured, largely finfish. Production is dominated by shrimp, groupers and milkfish. Traditionally, candidate species for mariculture in Indonesia and elsewhere have often been selected on their market value before their biological suitability for culture has been established leading to partially successful R&D efforts or even failure. The present study developed a framework for selecting marine fish species to support mariculture R&D in Indonesia based on an improved analytic hierarchy process (AHP). The approach combined various quantitative and qualitative data and involved different R&D stakeholder groups in the selection process. Ten species that had not been previously researched for their aquaculture potential were identified. The modified approach addressed the interaction complexity of criteria and different preferences across the stakeholders. The involvement of different stakeholders in the selection process not only ensured acceptance of the selected species for further research, but also tested the validity and consistency of the method used in this study. The methodology has relevance for mariculture globally given that efficient candidate selection can help focus efforts and investment in mariculture R&D.  相似文献   
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The Mekong Delta is the most important rice‐ and shrimp‐producing region for food and economic security in Vietnam. Rice‐shrimp farming is practised where salinity fluctuates substantially between wet and dry seasons. Research points to several potential risk factors for rotational systems, but how these link directly to both rice and shrimp production remains poorly quantified for systems that stock and harvest animals year‐round. We examined water and soil quality of 18 rice‐shrimp‐crab ponds, in which shrimp and crab are grown in both wet and dry seasons, in the Cà Mau Province of Vietnam. Multiple lines of evidence indicated that environmental conditions experienced by both rice and shrimp were suboptimal and contributed to low yields and survival. Year‐round cropping of shrimp and crab was associated with sustained suboptimal salinity, intensified by drought, for the wet‐season cultivation of rice. Although rice seedlings were sown in all 18 ponds, only three had a harvestable crop. Low shrimp production and survival was associated with sustained suboptimal water temperatures (too high), salinity (too high in the dry season and too low in the wet season) and dissolved oxygen concentrations (too low). Food availability and quality may also have affected shrimp production. Improving productivity of rice‐shrimp‐crab ponds in the study region may require (1) separation of rice and shrimp crops and improving efficiency of soil washing practices such that salinity conditions are more suitable for each when grown, and (2) management intervention to increase oxygenation of water, and the availability and quality of food for shrimp.  相似文献   
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