Following the steering committee conclusions and recommendations (Tirana, Albania, 1992), a workshop on food production and feeding techniques was held from 19th to 21st of October, 1993 in the premise of the “Instituto do zoologia, Faculdate de Ciencies do Porto”, in Porto, Portugal.
Participants, from 15 states bordering or not the Mediterranean Sea (Bulgaria, Cyprus, Malta, Tunisia. Egypt, Morocco, Turkey, Croatia, Libya, Portugal, France, Italy, Spain, Belgium and Sweden) attended the meeting; the list of participants is given in annex 1.
The workshop was envisaged for senior scientists, researchers managers in charge of planning investigation or developing programme in the field of aquaculture-nutrition.
According to its new strategy, MEDRAP offered to private food producers an opportunity to join this workshop in order to update participants, exchange information with researchers and to enrich debate and discussion through their knowledge and experiments in the relevant field
On behalf of Mr. Hassen Akrout, the project coordinator, Mr. Belkhir Mohieddine, the MEDRAP expert, welcomed all participants and wished to them good stay and full success to the workshop just opened by Mr. A. Oliva Teles, Professor at the “Instituto de Zoologia de Porto” and meeting activities organiser in Porto.
Participants elected the following bureau for the workshop composed as follwos:
| Chairman: | Mr. A. Oliva Teles (Portugal) |
| Reporters: | Mr. A. Aboudala (Morocco) |
| Mr M. Belkhir (MEDRAP) | |
| Mr. O. Beji (MEDRAP) |
The workshop agenda (annex 2) was introduced, discussed and adopted by participants
General discussion were oriented along the following lines:
manufacturing and appropriate processing technology.
The main relevant remarks and suggestions formulated during the general comments on food production and feeding techniques are reported below.
The chapter on nutritional requirements and processing brought into focus a number of uncertainties concerning, particularly the methodology accuarcy and raised the need for a permanent monitoring and research to be undertaken in collaborative activities. Indeed, despite increasing interest for aquaculture of marine finfish within the Mediterranean region, there is little quantitative data on the essential nutrient requirements of species such as seabream, seabass and turbot. It was recognised that basic research should be promoted to help create a viable feed industry and to ensure sustained development of aquaculture; besides the optimisation of production criteria, specific attention should be paid to the effects of health and quality in respect to bot flesh and environment
Reliance of member countries upon imported feed ingredient sources and ready-made aquafeeds was highlighted as a major limitation to the development of the sector. In order to reduce this reliance, there is a need to develop appropriate feeding technology and to maximise the utilisation of locally available feed ingredient sources. Towards this end, national agricultural feed surveys have to be conducted within member countries and this lack of knowledge on requirements of marine fishes of interest to the region be fullfilled at national and regional levels. It was suggested that the urgent establishment of a data bank would provide a useful tool to facilitate the work in this important subject area.
The session on diet formulation and manufacturing addressed the problems and issues of developping more specific diets, profitable and well adapted to the Mediterranean culture conditions. It also offered an outline of collaboration and exchange of idea between technicians, farming producers and food manufacturing managers which is vital for future development of the Mediterranean aquaculture.
It was recorded that three main parameters are of a great concern to the farmer:
the digestibility of the feed.
For appropriate food, these parameters may lead, to optimum fat deposit according to market or processing and to maximum protein efficiency with minimum nitrogen discharge.
Field results achieved on large-scale production permitted to rise comparison between different commercial feed with different formulation and recipes. Participants noted that protein efficiency was varying according to ecological conditions of fish growth speed and fish retention amount of protein. Despite the interest of farmer to improve the feed composition, its efficiency, the risk for fatty fish, remains as main risk. Indeed, when rising feed energy, flesh quality could be affected and gut loss will increase and so will the production cost. Particular attention has been paid to the necessity of having good feed quality. Also, the selection of adequate raw material would conduct to new diets with better performance and growth period reduction. Specific diets enable farming efficiency improves feed digestion and decreases the large amount of phosphorus-nitrogen discharges in the environment and therefore increases profit.
The session on feeding techniques and strategies was sealing with the main areas of enrichment techniques
and larval feeding strategy. It attempted to identify the main problems and issues associated to
the early feeding and weaning procedures in marine fish larvae.
Participants noted that feeding performance of larvae might be studied using a simple tool such as gut
content analysis. On the other hand, the bio-encapsulation technique seems also a good enrichment
method for larvae rearing, it allows to incorporate other nutritional compounds such as vitamins, drugs,
etc. Furthermore, the delivery of essential nutrients through liposom encapsulation is considered as an
alternative to the present techniques. Relevant results obtained so far permitted to foresee interesting
perspectives for this technique due to several advantages that liposom use provides.
During the general discussion, it was pointed out that the first feeding must be quickly undertaken and care should be taken in the case of species with yolk reserve almost used when opens. It was also retained that the transition from endogenous to exogenous feeding is an important problem that may affect larvae survival and growth rate.
Whilst feeding amount was considered well adapted to different feed energy, the hatchery feed needs to be of high and balanced energy, very digestible and quality consistent since weaning and metabolism processes occur rapidly. Attention should however be paid to the lipid content of the live food enrichment that differs according to species, the nutritional status of eggs, larvae age and the rearing condition. It was indicated that the optimisation of the feeding performance relied on the maintenance of the level of several variable (physical, biological, etc.) within the most appropriate range. It was noted that conventional weaning diets constitutes the usable diets in case of juveniles that show a well developed digestive system. High quality juveniles and reliable results could be reached when the right diets are used in right wearing time.
The workshop also provided also a broad review on nutritional trials within MEDRAP II members and respective delegates presented their national nutrition statement. All stressed the existing problems and conflicts with the use of the local raw material sources and read-made aquafeed. Participants recognised a number of uncertainties concerning the analytical methodology used for feed quality and digestibility. Once more, they raised the need for a permanent and collaborative research to help describing various economic aquaculture aspects and identifying their impact on the overall development of the sector.
Recommendations On the basis of papers presented and discussion held during the sessions on food production and feeding techniques, the following recommendations were made:
The need for the establishment of a data base concerning the national agricultural feed resources of members countries, (public and private sectors, institutions/ companies, engaged in aquaculture nutrition and feed development,) and also published information on nutrition and feeding of species cultured within the Mediterranean region.
The need for strengthening national expertise in aquaculture nutrition and feed technology within MEDRAP members countries by conducting specialised training courses within the region at technical and higher scientific level.
The need to review and harmonise experimental methodologies employed by researchers in aquaculture nutrition and feeding studies, especially the one concerning chemical feed analytical techniques and diet digestibility measurements.
The need to conduct joint research studies within MEDRAP members countries for short and long term duration on aspects of fish-shrimp nutrition and feed development of practical relevance to the region, to set up efficient aquafeeds and feeding regimes and reduce the reliance of members against imported feed ingredient and ready made aquafeeds. Such joint research studies should focus on larval feeding and weaning techniques for marine finfish species.
The need to evaluate the effect of changes in dietary feeding strategies (ie. utilisation of local by-products, home produced instead of imported feed, integrated farming methods) on the economic viability of aquaculture production systems and their environment quality.
