Factorial Approach to Determining Energy and Protein Requirements of Gilthead seabream (<i>Sparus aurata</i>) for Optimal Efficiency of Production

Requirements for dietary energy and protein in growing fish can be quantified using the factorial approach which assumes that the requirement is the sum of growth and maintenance. Thus dietary intake can be calculated using the respective partial efficiencies of utilization. Growth for gilthead seabream as a function of body weight and temperature was predicted by the equation: y = 0.92 · BW (kg) 0.613 · e 0.065 · T (where y = weight gain in g fish-1 day-1, BW = body weight in kg and T = temperature in 0C). The composition of the gain was measured by analyzing whole fish ranging from 1 to 420g. The energy content was dependent upon fish weight and increased from 5.0 to 11.0 MJ kg-1 body mass, whereas the protein content remained constant at 177g kg-1. The comparative slaughter technique was used to determine the loss in the fish during starvation and the values amounted to 42.5 kJ BW(kg) -0.83 day-1 and 0.42g BW(kg) -0.70 day-1 for energy and protein respectively. The efficiencies of utilization of digestible energy (DE) and digestible protein (DP) for maintenance and growth were determined by feeding seabream of two sizes at increasing feeding levels, from zero to maximum voluntary feed intake. To estimate optimal protein utilization for protein deposition seabream were fed diets formulated to contain varying DCP/DE ratios (34 - 15g MJ-1) in three consecutive trials. Fish were hand-fed to apparent satiation and the subsequent energy and protein gain were measured. The requirement for digestible energy for maintenance was determined to be 53.0 kJ BW(kg) -0.83 day-1 and for digestible protein 0.77g BW(kg) -0.70 day-1. The relationship between DE intake and energy gain was found to be constant at a value of kDEg = 0.56 and was independent of feed intake, body weight and DCP/DE ratio. Efficiency of protein utilization for growth varied between 0.33 and 0.56 depending on the DCP/DE ratio in the diet and optimal protein utilization for protein deposition was estimated to be kP = 0.48. Using these values allows optimization of practical feeding tables for seabream culture.Faktorielle Berechnung des Energie- und Proteinbedarfs von Goldbrassen (Sparus aurata) zur Optimierung der praktischen FütterungDer Bedarf wachsender Fische an Energie und Protein im Futter läßt sich mit Hilfe der faktoriellen Methode quantifizieren, die den Bedarf als Summe aus Wachstum und Erhaltung unterstellt. Die Aufnahme über das Futter kann daher unter Verwendung der jeweiligen partiellen Wirkungsgrade kalkuliert werden. Das Wachstum von Goldbrassen wurde als Funktion von Körpergewicht und Temperatur mit Hilfe der folgenden Gleichung berechnet: y = 0,92 · BW(kg) 0,613 · e 0,065 · T (mit y = Gewichtszunahme in g Fisch-1 Tag-1, BW = Körpergewicht in kg und T = Wassertemperatur in °C). Die Zusammensetzung des Gewichtszuwachses wurde durch Ganzkörperanalysen von Fischen im Gewichtsabschnitt von 1 bis 420 g bestimmt. Der Energiegehalt hing vom Gewicht des Fisches ab und stieg von 5,0 auf 11,0 MJ je kg Körpermasse an, während der Proteingehalt mit 177 g je kg konstant blieb. Mit Hilfe der vergleichenden Schlachttechnik wurde der Gewichtsverlust der Fische während einer Hungerperiode bestimmt. Die Werte betrugen 42,5 kJ BW(kg) -0,83 Tag-1 für Energie, beziehungsweise 0,42 g BW(kg) -0,70 Tag-1 für Protein. Die Wirkungsgrade für Erhaltung und Wachstum wurden für verdauliche Energie (DE) und verdauliches Protein (DP) bestimmt, indem Goldbrassen von zwei unterschiedlichen Größen zunehmende Futtermengen erhielten und zwar von Null bis zur maximalen freiwilligen Futteraufnahme. Zur Schätzung der optimalen Proteinausnutzung für den Proteinansatz erhielten Goldbrassen in drei aufeinanderfolgenden Versuchen Futter mit unterschiedlichem DCP/DE - Verhältnis (34 -15 g je MJ). Die Fische wurden per Hand bis zur offensichtlichen Sättigung gefüttert und der anschließende Energie- und Proteinansatz gemessen. Es wurde ein Erhaltungsbedarf an verdaulicher Energie in Höhe von 53,0 kJ BW (kg) -0,83 Tag-1, sowie an verdaulichem Protein in Höhe von 0,77g BW(kg) -0,70 Tag-1 ermittelt. Die Beziehung zwischen der Aufnahme an DE und Energieansatz erwies sich als konstant mit einem Wert von kDEg = 0,56 und war unabhängig von Futteraufnahme, Körpergewicht und DCP/DE-Verhältnis. Die Effizienz der Proteinausnutzung variierte zwischen 0,33 und 0,56 in Abhängigkeit vom DCP/DE-Verhältnis in der Ration. Die optimale Proteinausnutzung für Proteinansatz wurde als kP = 0,48 errechnet. Die Verwendung dieser Werte ermöglicht eine Optimierung der Fütterungstabellen für die praktische Fütterung bei der Haltung von Goldbrassen

The Quantile Regression Mixed Growth Model Can Help to Improve the Productivity in Gilthead Sea Bream (Sparus aurata) and European Sea Bass (Dicentrarchus labrax) Growing in Marine Farms

[EN] In this brief review, the evolution of Thermal-unit Growth Coefficient (TGC) is presented, from the initial model adapted to gilthead sea bream, until the Quantile TGC-Mixed Model. The two first adaptations were the effective temperature, and the quantile regression, that allowed the possibility of describing the evolution of weight distribution along the production cycle. The second adaptations consisted in considering the temperature seasonal curve and integrating the two growth exponents (1/3 and 2/3) in a mixed model. The final Quantile TGC-Mixed Model is a very interesting tool for evaluating production strategies in gilthead seabream and optimizing its economic profit, but each fish farm should have its own model in basis historical dataJover Cerda, M.; Estruch, VD. (2017). The Quantile Regression Mixed Growth Model Can Help to Improve the Productivity in Gilthead Sea Bream (Sparus aurata) and European Sea Bass (Dicentrarchus labrax) Growing in Marine Farms. Journal of Aquaculture & Marine Biology. 6(4):1-3. doi:10.15406/jamb.2017.06.00161S136

Protein deposition and energy recovery in gilthead sea bream (Sparus aurata): Evaluation of nutritional requirements. Corregendum

[EN] The energy and protein requirements for gilthead sea bream were studied until commercial weight. Gilthead sea bream with different body weights (from 24 to 422 g) were fed from starvation to apparent satiation, studying protein and energy in the interval of 21¿25 °C. Energy recovery (ER) was expressed in relation to the digestible energy intake (DEI), ER = 173.1 &#8727; (1 &#8722; e(&#8722; 0.00407 &#8727; (DEI-59.84))), and protein deposition (PD) was expressed with regard to digestible protein intake (DPI), PD = 2.97 &#8727; (1 &#8722; e(&#8722; 0.152 &#8727; (DPI-1.393))). Maintenance needs in summer conditions were found to be 1.393 g kg&#8722; 0.7 day&#8722; 1 of the digestible protein intake and 59.84 kJ kg&#8722; 0.82 day&#8722; 1 of the digestible energy intake. The response curves to the graded levels of intake of energy and protein should allow the diet formulation under several growth conditions and all sizes until commercial weight. Statement of relevance The feed conversion rate in Sparus aurata is not yet optimized, showing high values in farms. The knowledge of the efficiencies at different feeding rate, for the whole range of commercial weights, until 450 g, should help to improve the efficiency of feeding.Ignacio Jauralde Garcia was supported by Fundacion Alfonso Martin Escudero, Madrid, Spain. We are also grateful to Ralph Wilk for the English review. The authors wish to acknowledge Dr. Rodolofo Ballestrazzi of the Universitat degli studi di Udine for his support to Ignacio Jauralde during his stay in Italy.Jauralde García, I.; Martínez Llorens, S.; Tomás Vidal, A.; Jover Cerdá, M. (2017). Protein deposition and energy recovery in gilthead sea bream (Sparus aurata): Evaluation of nutritional requirements. Corregendum. Aquaculture. 476:65-73. doi:10.1016/j.aquaculture.2016.06.006S657347

Influence of filter medium type, temperature and ammonia production on nitrifying trickling filters performance

[EN] This work focuses on the achieving of optimal design and modelling of nitrifying trickling filters for closed circuit aquaculture turbot (Psetta maxima) farms. Several process parameters influential in nitrifying filtration were established on experimental biofilters and their efficiency was tested, based on the removal of nitrogen contained in total ammonia nitrogen (N-TAN) in a fixed time (24 h). Those process parameters were filter media types (Type A Biofill®, BactoBalls® and MECHpro® rings), temperatures (24.3 °C, 19.0 °C, 15.3 °C) and production of TAN (1.5, 3.0 and 4.5 g per day) while other process parameters values remained constant. TAN production was simulated with the addition of ammonium chloride (NH4Cl) in the recirculation system. Constant measuring of the total ammonia nitrogen concentration in the biofilter effluent was required to perform a model of N-TAN fluctuation based on a specific feeding regime and to ascertain performance differences between biofilters. At the end of the experiment, notable differences were observed in the ammonia removal rates depending on different process parameters. The BactoBalls® filter medium led to the highest mean N-TAN removal rates (0.24 g N-TAN removed m&#8722;2 day&#8722;1). The N-TAN removal rate generally increased with higher temperatures, the trials with the highest mean temperature (24.3 °C) led to the highest mean N-TAN removal rate (0.26 g N-TAN removed m&#8722;2 day&#8722;1). Similarly, the N-TAN removal rate increased with high TAN production. The trials in which production was 4.5 g per day showed the highest N-TAN mean removal rate (0.27 g N-TAN removed m&#8722;2 day&#8722;1).This research work is included in the national project "Design of a recirculating aquaculture system for aquaculture plants (2011-2014)" financed by Ministry of Science and Innovation, Spain.Godoy-Olmos, S.; Martínez-Llorens, S.; Tomas-Vidal, A.; Jover Cerda, M. (2016). Influence of filter medium type, temperature and ammonia production on nitrifying trickling filters performance. Journal of Environmental Chemical Engineering. 4(1):328-340. doi:10.1016/j.jece.2015.11.023S3283404

A two-stage growth model for gilthead sea bream (Sparus aurata) based on the thermal growth coefficient

Several authors have proposed models to describe fish growth taking the influence of temperature into account, and one of the most interesting is the "thermal unit growth coefficient" (TGC). Recent research has demonstrated that TGC varies throughout the growth cycle of fish, making it necessary to establish different stanzas. In this work, the original TGC model using 1/3 as an exponent was compared with a new model considering 2/3. Likewise, two stages for the growth of gilthead sea bream under commercial conditions in marine farms were detected by means of TGC seasonal models using the continuous temperature curve. A critical value for weight around 117g was obtained, which could mark the transition between two growth dynamics. To describe the weight evolution during a complete production cycle, the two growth stages were described by two separate seasonal TGC models (1/3-TGC model and 2/3-TGC model), and with an integrated model named the Mixed-TGC model, which presents interesting properties of continuity and differentiability and could be an important tool for fish farm management.V.D. Estruch and M. Jover were partially supported by the Universitat Politecnica de Valencia, PAID 2009-2010.Mayer, P.; Estruch Fuster, VD.; Jover Cerdá, M. (2012). A two-stage growth model for gilthead sea bream (Sparus aurata) based on the thermal growth coefficient. Aquaculture. 358-359:6-13. https://doi.org/10.1016/j.aquaculture.2012.06.016S613358-35

Physicians’ experience with follow-up care of childhood cancer survivors – Challenges and needs

BACKGROUND: Regular follow-up care is essential for childhood cancer survivors, but we know little about physicians’ experience with it. We aimed to describe: (1) involvement of Swiss physicians in follow-up care; (2) content of follow-up care provided; (3) problems encountered; and (4) additional resources needed. MATERIALS AND METHODS: Within this cross-sectional survey we sent adapted questionnaires via professional associations to a sample of medical oncologists (MOs), paediatric oncologists (POs), general practitioners (GPs) and paediatricians (P) in Switzerland. Only oncologists involved in follow-up care were asked to report problems. GPs and Ps not involved in follow-up could indicate why. All physicians were asked about the content of follow-up care provided and additional resources needed. RESULTS: A total of 183 physicians responded (27 MO, 13 PO, 122 GP, 21 P). Involved in follow-up were 81% of MOs, 85% of POs, 39% of GPs and 81% of Ps. Follow-up content differed between oncologists (MO and PO) and generalists (GP and P), with generalists examining or informing less in regard to the former cancer. POs reported more problems than MOs: many POs reported problems with transition of survivors to adult care (91%), and because of financial resources (73%) and time restraints (73%). MOs reported most problems during transition (23%). Not being aware of a survivor was the most common reason for GPs and Ps not participating in followup (74%). All groups reported a need for standardised protocols (85–91%) and specialised training (55–73%). GPs (94%) and Ps (100%) additionally desired more support from oncologists. CONCLUSIONS: To improve quality and efficiency of follow-up care a national follow-up care model including standardised protocols and guidelines needs to be developed

Konsumentenbefragung: Lupinen für die Humanernährung – Bekanntheit und Akzeptanz in der Schweiz

Die Konsumentenbefragung wurde im Rahmen des Projekts LUPINNO SUISSE durchgeführt. Hauptziel des Projekts LUPINNO SUISSE ist die Entwicklung von Anthraknose (Brennfleckenkrankheit) -toleranten Sorten mit geringem Alkaloidgehalt, um innovativen, pflanzenbasierten und proteinreichen Produkten der Weissen Lupine aus einer nachhaltigen, regionalen Land- und Ernährungswirtschaft zum Durchbruch zu verhelfen. Das Projekt umfasst: (1,2) Entwicklung von Sortenkandidaten mit einer Kombination von Alkaloidarmut und Anthraknosetoleranz; (3) Aufbau eines Züchtungsprogramms der Getreidezüchtung Peter Kunz (gzpk) zur Entwicklung von Sorten aus dem fortgeschrittenen Genpool des FiBL; (4) Prüfen der Anbaueignung und Umweltstabilität von Sortenkandidaten und Marktsorten; (5) Identifikation des Marktpotenzials der weissen Lupine, Befragungen, Berechnungen und Vernetzung der Akteure in der gesamten Wertschöpfungskette mit Durchführung von Workshops, insbesondere für Verarbeiter. Mit der Konsumentenbefragung wurde auf ein konkretes Bedürfnis des sich im Aufbau bestehenden Netzwerks reagiert. So wurde im Stakeholder Workshop vom 19.01.22 das Bedürfnis nach einer genaueren Kenntnis der Bekanntheit und Akzeptanz von Lupinenprodukten bei Konsumierenden identifiziert. Im Anschluss werden das Studiendesign inklusive Forschungsfragen und die Ergebnisse der Konsumentenforschung präsentiert