Effect of stocking density and feeding regime on larval growth,survival, and larval development of Japanese flounder,Paralichthys olivaceus,using live feeds

This research examined the effect of initial stocking density and feeding regime on larval growth and survival of Japanese flounder, Paralichthys olivaceus. Larval rearing trials were conducted in nine 50‐L tanks with different initial stocking densities combined with different feed rations (20 larvae/L with standard feed ration [LD], 80 larvae/L with standard feed ration [HD], and 80 larvae/L with four times the standard feed ration [HD+]). Larvae were stocked on 0 days posthatch (DPH) following hatching of the fertilized embryos. Larval total length (TL), survival rates, and final densities were observed on larval settlement (32 DPH) to evaluate larval rearing performance. At 32 DPH, there were no significant differences (p > .05) in TL or survival rates between the LD (46.5 ± 17.0%) and HD+ (40.3 ± 9.4%). The TL and survival rate of HD (23.1 ± 3.5%) were significantly lower than that of LD and HD+ (p < .05). However, the larval density of HD was significantly higher than that of LD (p < .05). HD+ achieved the best larvae production (32.27 ± 7.51 larvae/L), supported by sufficient food source, high water exchange, and proper water quality management (routine siphoning, surface skimming). The larval‐rearing protocols and larval development from hatching to metamorphosis is described in detail, with corresponding photographs taken during the experiment.     

The active site of methanol synthesis over Cu/ZnO/Al2O3 industrial catalysts

One of the main stumbling blocks in developing rational design strategies for heterogeneous catalysis is that the complexity of the catalysts impairs efforts to characterize their active sites. We show how to identify the crucial atomic structure motif for the industrial Cu/ZnO/Al(2)O(3) methanol synthesis catalyst by using a combination of experimental evidence from bulk, surface-sensitive, and imaging methods collected on real high-performance catalytic systems in combination with density functional theory calculations. The active site consists of Cu steps decorated with Zn atoms, all stabilized by a series of well-defined bulk defects and surface species that need to be present jointly for the system to work.     

Versuche,Obstbau und Bienenhaltung im Altenlande gegenseitig zu fördern

Ohne Zusammenfassung     

The effect of different levels of soybean extract meal on the apparent digestibility of crude nutrients and amino acids in colostomized laying hens

Four colostomized laying hens per group were given a ration of barley and soya bean oil meal (SBM) with 12.5, 25.0 and 37.5% SBM resp. The crude protein intakes were 14.0, 17.7 and 21.4 g per animal and day. The lysine intake raised from 681 mg (group 1) to 1275 mg (group 3) per animal and day. The digestibility of dry matter and of the N-free extracts of the ration decreased with the rising SBM portion in the ration. The digestibility of crude protein remained constant. The investigated amino acids (Lys, His, Arg, Cys, Met) were higher digested in the 37.5% SBM ration than in the 12.5% SBM ration. The following digestibility values for SBM were found by means of the difference method: Dry matter 52.5%, crude protein 83.1%, crude fat 51.7%, crude fibre 5.5%, N-free extracts 50.6%. The level of the SBM did not influence the digestibility of the crude nutrients. The apparent digestibility of lysine from SBM depended on the level of intake and was found to be 82.3, 83.4 and 89.0%, resp. There were no differences in the digestibility of other amino acids.     

The effect of different high doses of field peas on the digestibility of their crude nutrients in colostomized laying hens

Five groups of five colostomized laying hens each received 0 g, 15 g, 30 g, 45 g and 60 g peas of the variety Grapis per animal and day with Triticum rations. The apparent digestibility of the crude nutrients of the rations and the peas was determined, ascertained according to the difference method in dependence on their quotas in the rations. The digestibility of the N-free extracts of the peas increases by 3 digestion units each under the influence of the increasing intake of peas, so that the digestibility of the organic matter of the peas increases with the growing quota. On an average of the 20 individual values the following digestion values for the pea variety Grapis are indicated: organic matter 66.9%, crude protein 78.5%, crude fat 48.7%, N-free extracts 70.3%. Energy concentration amounts to 572 EFU-hen/kg dry matter.     

Adoption Potential for Conservation Agriculture in Africa: A Newly Developed Assessment Approach (QAToCA) Applied in Kenya and Tanzania

Conservation agriculture (CA) is often promoted as a set of cropping practices to reduce soil erosion and maintain soil fertility, while decreasing production costs and increasing crop yields. However, CA adoption is extremely low in Africa. Most investigations on constraints of its adoption leave out (i) the characteristics of CA as an emerging innovation and (ii) the wider institutional context. A comprehensive self‐assessment tool for a systematic evaluation of factors influencing the CA adoption process at the field, farm and regional scale in a variety of regional contexts in Africa is still lacking. In an attempt to fill this knowledge gap, this article presents the motivation, development and testing of a Qualitative expert Assessment Tool for CA adoption in Africa (QAToCA) and its application. QAToCA is directed to regional experts, research teams and managers of development projects with a focus on CA, and allows them to assess their CA activities along a systematic, expert‐based list of questions and criteria. Specifically, it aims at assessing the adoption potential of CA under the varied agro‐ecological, socio‐economic, cultural and institutional conditions of Africa as well as the specific supporting and hindering factors influencing this process. As an example, its application in Kenya and Tanzania identified a relatively high CA adoption potential. The following factors, however, are noticed to require further improvement: accessibility of markets for CA products and inputs; adaptation of machinery and seeds to the CA practices; introduction of quality implementation measures; and a renewed motivation (interest) among CA service providers. Copyright © 2012 John Wiley & Sons, Ltd.     

A niche-based gap analysis for the conservation of odonate species in the Brazilian Amazon

1. Despite the current rates of deforestation and the expected climatic changes, protecting species in their natural habitats is still the simplest, cheapest, and most effective way of safeguarding biodiversity. Here, the network of protected areas in the Brazilian Amazon was evaluated to assess its effectiveness in safeguarding species of Odonata.
2. Ecological niche models were built to assess the suitability of the habitat for 503 Amazonian odonate species. Then, the effectiveness for the protection of odonate species of three classes of protected areas (strictly protected area, sustainable use area, and indigenous territory) was evaluated.
3. Approximately 30% of the species are protected within the network of protected areas. These findings highlight the importance of protected areas for safeguarding most odonate species in the Amazon. For under-represented or gap species, additional resources are still needed for effective management and protection on some private properties, which need to set aside land for conservation. In this way, it is possible to preserve habitats for odonate species and guarantee their conservation in the Amazon.

     

Utilization of 15N marked urea by the laying hen. 2. Incorporation and metabolism of 15N for the synthesis of egg protein

In an N-metabolism experiment 3 colostomized laying hybrids received 2870 mg 15N-excess (15N') per animal in 6 days in the form of urea with their conventional feed rations. During the 8-day experiment the 21 eggs laid were separated into eggshell, white of egg and yolk. Weight, N-content and 15N' were determined of the individual fractions of the eggs. On an average of the 21 eggs 4.6% of the heavy nitrogen was in the egg-shells, 50% in the white of egg and 45.5% in the yolk. 2.8%, 4.5% and 5.5% (hens 1...3) of the 15N' consumed were detected in the eggs. The maximum 15N'-output in the white of egg was reached on the 6th day, whereas 15N'-output in the yolk showed a nearly linear increase in the time of the experiment. The results show that labelled nitrogen from urea is incorporated into the egg to a lower degree than after the feeding of 15N-labelled proteins and that the development of its incorporation into the white of egg and the yolk differ from that after the feeding of 15N-labelled native proteins.     

Land-use by immigrant Baoulé farmers in the Taï region,South-west Côte d'Ivoire (Ivory Coast)

This paper discusses the cropping system of immigrant Baoulé farmers in the rain-forest area of South-west Côte d'Ivoire (Ivory Coast). The area harbours one of the last substantial rain-forest reserves of humid West Africa. Part of it is known as Taï National Park, and has been adopted as one of UNESCO's Man and Biosphere Programme areas.The park area is threatened by farmers in search of land.Soils in the area typically show a low intrinsic nutrient content (particularly phosphorus and potassium), low pH values, a low CEC, and, locally, high levels of gravel.In the Baoulé cropping system fields are kept under perennial crops, mainly cacao, after having been used for food crop cultivation during the first two years. Yam, the most important food crop is grown on mounds. Next to the inherent poverty of the soil, this cropping technique, which disrupts the structure of the top soil is seen as one of the causes for low yields of cocoa on Baoulé farms in the area. Yields per ha amount to c. 60% of that of the national average.The conclusion is that the Baoulé agricultural production system is ill-adapted to the local ecosystem.Measures to improve adaptation include: Introduction of crop species adapted to adverse soil conditions (e.g. rubber, oilpalm), to buffer cacao plantations through planting of shade trees, to apply fertilisers, and to make use of biological nitrogen-fixation.Generally, the remedies proposed involve investments in terms of cash and labour on the part of the farmers. It is argued that farmers will not change their current cropping practices as long as there is forested land in the vicinity. The presence of the Taï forest, c. 300.000 ha of virgin rain-forest, impedes the process of change towards more intensive land-use practices.

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Résumé Aménagement du terroir par les paysans immigrés Baoulé dans la région Taï, Sud-Ouest Ivoirien Ce document traite le système agricole des paysans immigrés Baoulés dans les régions des forêts tropicales humides du Sud-Ouest Ivoirien. Cette région héberge une des dernières réserves substantielles de la forêt tropicale de l'Afrique de l'Ouest. Le Parc National de Taï est la partie de la forêt que l'UNESCO a adoptée dans le cadre du Programme Homme et Biosphère.A l'heure actuelle les intrusions des paysans à la recherche de terre menacent le parc.Une des caractéristiques de cette région est que les sols montrent un niveau bas de nutrients intrinsiques (notamment le phosphore et la potasse), des valeurs basses de pH, une faible capacité d'absorption cationique et, localement, des niveaux élevés de gravier. Les paysans Baoulé plantent des cultures pérennes, surtout le cacaoyer, après avoir produit des cultures vivrières pendant les deux premières années. L'alinment principal, l'igname, est cultivé dans les buttes. A part la pauvresse inhérente au sol, cette technique culturale, qui dérange la structure de la couche arable du sol, est considérée comme une des causes des bas rendements du cacaoyer aux exploitations agricoles Baoulé dans la région. Les rendements par hectare n'atteignent que 60% de la moyenne nationale.On peut conclure que le système de culture Baoulé est mal adapté à l'écologie locale. Les mesures à prendre pour améliorer l'adaptation comprennent: L'introduction des cultures mieux adaptées aux conditions de sol défavorables (par exemple le hévéa, le palmier à huile), protéger les plantations de cacaoyer en mettant des arbres ombreux, l'application des engrais, et l'emploi de la fixation biologique de l'azote par certains arbres légumineux. En général, les solutions proposées entraînent des investissements en termes financiers et de travail de la part des paysans. Il est souligné que les paysans ne changeront pas leur système du culture actuel tant que les forêts sont à proximité. Donc, la présence de la forêt Taï, environ 300.000 hectares de forêt tropicale primaire, empêche le processus de changement en pratiques d'aménagement du terroir.

     

Effect of proline‐enriched abalone feed on selected metabolite levels of slow‐growing adult Haliotis midae

Abalone is currently considered South Africa's most successfully produced aquaculture export product, with a 76% share of the total value generated by the aquaculture sector. A major risk factor for this sector is slow growth rates experienced during farming. Abalone feeds are often supplemented with amino acids in an attempt to enhance abalone growth. This is a first investigation of the effect of added proline to standard abalone feed, on the metabolite profile of slow‐growing abalone. A targeted liquid chromatography tandem mass spectrometry metabolomics research approach was followed to recognise the metabolic response of abalone showing slower growth performance. The addition of proline to the standard abalone diet was found to serve as a substrate for amino acid catabolism in slower growing abalone, by means of proline breakdown to assist with energy production via the tricarboxylic acid cycle. Other amino acids and urea cycle intermediates, that is, arginine, asparagine, ornithine and creatine further support energy production via the action of protein catabolism in slow‐growing abalone. Additionally, the importance of understanding how abalone respond metabolically to modified feed highlights the use of metabolomics to answer abalone aquaculture farming questions.