Effects of photoperiod on growth of larvae and juveniles of the anemonefish Amphiprion melanopus

Rearing of anemonefishes is now relatively routine compared to the culture of cardinalfishes (Apogonidae) or angelfishes (Pomacanthidae). However, it is still a labor intensive, time intensive and expensive procedure. To reduce time and cost of rearing anemonefishes, experiments were undertaken to improve the methods for rearing Amphiprion melanopus. These experiments were conducted to determine the effect of the length of photoperiod on larval duration, growth to metamorphosis and early juvenile phase. Growth of larvae was significantly faster and the duration of the larval phase was significantly shorter, under a photoperiod of 16 hours light/8 hours dark, compared to the photoperiods of 12 hours light/12 hours dark and 24 hours light/0 hours dark

Nutrition of monogastrics: A summary of research conducted under the German Federal Programme for Organic Agriculture and other forms of Sustainable Agriculture

The thematic focus of monogastric nutrition runs very regularly through the entire federal programme. A strong focus was on the use of feed made from 100% organic origin (EC Eco-Regulation). In experiments in 2006 on the use of roughage in outdoor rearing pigs, for example, it was shown that Jerusalem artichoke can lead to significantly higher weight gains, compared to the control, while weight gain decreased significantly in some cases using other roughages. In another project in 2007, the various processing methods for soybean cake and feed produced therefrom were tested on broiler chickens, laying hens and pigs. The aim was to develop a suitable technology to inactivate the anti-nutritive components in soy and thus to increase the protein digestibility and the nutritional value. At the same time, as part of a broad collaborative project, the use of five different roughages (straw, hay, clover silage, maize silage and Jerusalem artichokes) were compared in organic piglet production. It could be demonstrated that the feeding of various roughages resulted in a stabilisation of the intestinal flora in comparison to the control group. In particular, by feeding various roughages, the Clostridium perfringens population can be significantly reduced. A review of the compensatory protein uptake of organic pigs has found that it cannot be concluded that an economically relevant compensation takes place, and that under the specific feeding restrictions of organic farming GfE recommendations for lysine supply for the initial fattening period are estimated too high. In studies of different genotypes, management and feeding strategies it was also found that turkey diets with reduced ME (metabolisable energy) and amino acid levels, in combination with free-range management, result in a lower animal loss and high growth and carcass performance. In a review of the use of the microalga Spirulina platensis in a feeding trial with fattening broilers a positive dose-response effect was observed. The higher the amount of Spirulina absorbed, the better the carcass weights. Due to the high cost of the Spirulina product (despite improved fattening and carcass performance) the economics of its use in broiler production are unfavourable. Thus the application of this product is only recommended in the first phase of the rearing (1-14 days). The aim of another project was the development of NIRS calibration which allows a more timely determination of the constituents, especially the protein and amino acid contents (AS), of organically produced grain legumes immediately after harvest, in order to create optimal, demand-based rations. In 2007, a database for feed was created to assist in ration design. In 2011 a number of projects started in which various locally available protein feeding stuffs will be tested in different feeding trials with pigs. The supply of essential amino acids within the available protein feed, especially for poultry, is often insufficient, and another research project is testing approaches to produce high-quality protein feed in the form of clover silage and use this feed in feeding trials with laying hens and broilers. The first results of these projects are expected in 2015. Further results from the BÖLN research on animal nutrition in monogastric animals are regularly published at www.bundesprogramm-oekolandbau.de

Survival and Phenology of \u3ci\u3eAgrilus Planipennis\u3c/i\u3e (Coleoptera: Buprestidae) Reared on a Newly Developed Artificial Diet Free of Host Material

The final phase in the development of an artificial diet that contains no ash host material and the phenology of the emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Bupresidae) on that diet are documented. A diet containing powdered ash phloem exists, but host material introduces potential variability and contamination, and the cost and effort needed to collect and process it can be high. The post-embryonic development of A. planipennis was evaluated on four artificial diets lacking host material, and effects of variations in diet layer thickness and moisture content were also investigated. The best diet and rearing method resulted in 67.8% survival to pupation and 51% to adult. Larval size and development rate were comparable to published accounts for emerald ash borer larvae developing on susceptible host plants. Important advances include reduction of antimicrobial components to the lowest functional level; change of protein sources from wheat germ, brewer’s yeast, and casein to soy flour and casein; reduction of diet moisture content to 50%; and adding a fresh layer of diet to spent diet half-way through larval development. The artificial diet represents a step toward the development of a standardized mass- production system for A. planipennis

The effect of a 24-hour photoperiod on the survival, growth and swim bladder inflation of pre-flexion yellowfin tuna (Thunnus albacares) larvae

The effects of two different continuous photoperiod regimes on survival, growth and swim bladder inflation of pre-flexion yellowfin tuna (Thunnus albacares) larvae were investigated. Each photoperiod regime was tested twice with a different larval cohort to confirm the observed results. Trials 1 and 2 tested the effect of a reduced night-time light intensity (10-molesm-2s-1=30% of the daytime intensity) and found that those larvae reared for 8days under the 24h lighting (24-L) photoperiod exhibited a slight improvement in survival compared to those reared under the control photoperiod of 12h light (12-L), however these improvements were not significant. In addition, those larvae reared under this photoperiod regime were equal in length to those in the control. Trials 3 and 4 compared the same variables in larvae reared under a continuous photoperiod (24-L) with a constant light intensity of 30-molesm-2s-1, against those reared under the aforementioned 12-L photoperiod. Survival of larvae under the continuous photoperiods were 9±1% (n=2) and 10±2% (n=3) for Trials 3 and 4, respectively, compared to less than 1% in both control treatments; differences that in both cases were highly significant. In addition, in both trials larvae cultured under the 24-L photoperiod were significantly larger and exhibited more advanced development than those reared under the 12-L photoperiod, however swim bladder inflation was significantly lower. We suggest that the improved survival and growth achieved under a continuous photoperiod is due to the extended foraging time combined with the prevention of mortality caused by night-time sinking

Workshop and desk study to appraise technical difficulties associated with organic pullet rearing

Background To date, Regulation (EC) 1804/1999 and UKROFS Standards allow conventionally reared pullets up to 18 weeks of age to be brought into systems of organic egg production. Pullets must be reared according to the rules laid down in Regulation (EC) 1804/1999 and according to UKROFS Standards for at least six weeks, before the eggs may be sold as organic eggs. The derogation for pullet rearing has been agreed for a transitional period expiring on 31 December 2003. If pullets are to be reared from day old in an organic system in accordance with Regulation (EC) 1804/1999 and UKROFS Standards this may potentially create a number of technical problems, which may disadvantage UK producers considering organic egg production. A series of workshops and a literature review were commissioned by MAFF to provide possible solutions to these technical problems. Objectives 1. To organise a workshop involving key members of the egg sector of the poultry industry, representatives of organic sector bodies and of MAFF to consider technical problems that may occur when rearing pullets organically, and to identify possible solutions. 2. To address some of the perceived technical problems by reviewing the available literature on conventional pullet rearing and assessing the extent to which published results can be applied to organic systems. 3. To reconvene workshop members to discuss findings from the literature review, to identify research priorities and to consider mechanisms for technology transfer. Methodology There were three separate but related stages to the project. Stage one comprised a workshop involving representatives of the egg sector of the poultry industry, of the Soil Association, of ADAS and of MAFF, and attendees were specifically invited to comment on the likely difficulties that might be experienced when attempting to rear pullets in an organic production system. Stage two was a desk study in the form of a literature review. Literature searches of the major international abstracting databases were done using key words related to the technical problems highlighted by workshop one attendees. Stage three was a second workshop where attendees discussed the findings from the literature, identified research priorities and considered mechanisms for technology transfer. Results The outcome of workshop one was that several likely difficulties associated with rearing pullets in an organic production system were identified and these included; 1) the application of light programmes in pullets receiving natural light when the maximum daily light period is 16 hours; 2) nutrition; 3) housing and pasture management, and; 4) food safety risks. Implications of findings, future work and policy relevance The implications of the findings are that with current scientific information there will be technical difficulties associated with rearing pullets in an organic system. The most important technical difficulties are to do with photoperiodism, nutrition, pasture management and rotation, and methods of controlling injurious feather pecking. Also a maximum permissible daylength of 16 hours for rearing organic pullets would mean that producers in Northern European countries may be disadvantaged. The project addressed MAFF’s policy of supporting the development of organic livestock production within the UK. The project has provided information to MAFF and the egg sector of the poultry industry about the key technical problems associated with organic pullet rearing, possible solutions to these problems and, where scientific information is missing, future research needs have been identified

The Pitfalls of Using a Child Support Schedule Based on Outdated Data

A strong rationale for updating child support guidelines arises from changes over time in the measurement of expenditures on children, as well as changes in the empirical relationship between expenditures on children and the income of parents. Such changes affect the accuracy of the numerics upon which states' child support guidelines are based. This study evaluates an alternative child support guideline that was proposed for Virginia and draws lessons for other states that similarly base their guidelines on older survey data. Regression results show that over time, the child expenditure and household income relationship has changed considerably. Furthermore, the largest increases in expenditures attributable to children have occurred for lower- and middle-income households

Gravel galore: Impacts of clear-cut logging on salmon and their habitats

Timber harvest may have both direct and indirect effects on salmon, and with a few exceptions those effects result in lowered survival of salmon in their stream habitats compared with unlogged forest (Hicks et al. 1991b). Some impacts may be seen immediately or shortly after logging, whereas others can take decades to be expressed. Central to analyzing these effects is the context of the freshwater environment in which salmon are spawned and reared, and the life histories of the salmon species. This chapter will examine the effects of timber harvest on the freshwater habitat and life stages of salmon. It will also investigate the hypothesis that the salmon species least affected by timber harvest are those with the least reliance on stream habitats

Artificial rearing influences the morphology, permeability and redox state of the gastrointestinal tract of low and normal birth weight piglets

Background: In this study the physiological implications of artificial rearing were investigated. Low (LBW) and normal birth weight (NBW) piglets were compared as they might react differently to stressors caused by artificial rearing. In total, 42 pairs of LBW and NBW piglets from 16 litters suckled the sow until d19 of age or were artificially reared starting at d3 until d19 of age. Blood and tissue samples that were collected after euthanasia at 0, 3, 5, 8 and 19 d of age. Histology, ELISA, and Ussing chamber analysis were used to study proximal and distal small intestine histo-morphology, proliferation, apoptosis, tight junction protein expression, and permeability. Furthermore, small intestine, liver and systemic redox parameters (GSH, GSSG, GSH-Px and MDA) were investigated using HPLC. Results: LBW and NBW artificially reared piglets weighed respectively 40 and 33% more than LBW and NBW sow-reared piglets at d19 (P < 0.01). Transferring piglets to a nursery at d3 resulted in villus atrophy, increased intestinal FD-4 and HRP permeability and elevated GSSG/GSH ratio in the distal small intestine at d5 (P < 0.05). GSH concentrations in the proximal small intestine remained stable, while they decreased in the liver (P < 0.05). From d5 until d19, villus width and crypt depth increased, whereas PCNA, caspase-3, occludin and claudin-3 protein expressions were reduced. GSH, GSSG and permeability recovered in artificially reared piglets (P < 0.05). Conclusion: The results suggest that artificial rearing altered the morphology, permeability and redox state without compromising piglet performance. The observed effects were not depending on birth weight