Improving the biological efficacy and cost-effectiveness of a premium weaning diet for Senegalese sole (Solea senegalensis)

• Autor(a) principal: Pereira, Leila dos Reis
• Data de Publicação: 2016
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.1/9950
• topic: Linguado senegalês; Solea senegalensis; Desmame; Ração; Taxa de alimento ingerido; Winflatplus

This Thesis aims to optimize the cost/benefit of a novel premium weaning diet for Senegalese sole - Winflatplus, developed by Sparos Lda. This objective should be reached through: 1) selecting a new prototype with minor changes on diet ingredient formulation with benefits on fish performance; 2) validate its cost-effectiveness; 3) implement a feed intake assessment method using a new dye added to the fish feeds. Two trials were done where fish performance was determined by analysing dry weight, total length, relative growth rate, feed conversion rate and feed intake. The first trial tested five diets variants of Winflatplus with similar proximal composition, where seven treatments were performed. A sudden weaning was done at 27 DAH. At the end of the trial, the growth performance of treatments with Winflatplus+F3, F1, F2, F3 and P1 were higher that the remaining treatments. The diet F3 was the diet chosen to be used in trial 2. This choice was based on costs-benefit relationship, being the F3 diet the one with the lowest cost formulation. In the second trial, first-feeding larvae were initially separated into three different feeding regimes. Larvae groups were submitted to a same co-feeding strategy, each with a different inert diet. At 19 DAH each larvae group was split into two co-fed regimes, each with two new different inert diets. Hence, 6 experimental treatments were considered. The weaning was performed at 35 DAH. At the end of the trial the treatments with F3 diet obtained higher growth performance than those treatments with Winflatplus. Feed intake results were used to verify if it would be possible to predict in advance which diets would provide better results. This method was more efficient in predicting the final results when applied a few days after weaning. At the end, all proposed goals were achieved. In conclusion, it was possible to verify that with diets with the same proximate nutritional composition but with lower production costs, it is possible to improve Senegalese sole growth performance and survival.