Food intake and absorption are affected by dietary lipid level and lipid source in seabream (Sparus aurata L.) larvae

Compared to fish oil alone, a corn and fish oil mixture decreases the lipid requirement of a freshwater fish species, Carassius auratus gibelio

“…However, corn oil can compensate for the deficiency of 18:2n− 6 or 20:4n−6 if fish oil was partially replaced by corn oil in the diet. On the other hand, different dietary FA compositions may exert different effects on fish lipid metabolism, such as FA digestibility, catabolism, lipid transport and uptake, and so on (Morais et al, 2006;Turchini et al, 2009). In rainbow trout Oncorhynchus mykiss, Ng et al (2010) reported that FA digestibility was improved when dietary fish oil was partially replaced by palm FA distillate.…”

Lack of essential fatty acids in live feed during larval and post-larval rearing: effect on the performance of juvenile Solea senegalensis

“…Furthermore, no significant differences were found in terms of survival, growth, activity of the assayed digestive enzymes and incidence of malpigmentations or malformations (see ''Discussion'' below). It has been shown that dietary FA composition may affect seabream larval food intake and absorption efficiency (Morais et al 2006) but we have no knowledge of studies on larval feeding selectivity and prey attractability in relation to the HUFA content of the prey, when preys differing in their FA composition are presented simultaneously. However, if we assume that Senegalese sole larvae do not selectively ingest EA, in detriment of NEA, we might hypothesize that the dietary supply of (n-3) HUFA that, in the present study was 6.3 mg DHA g -1 DW and 12.8 mg EPA g -1 DW in EA, can be greatly reduced (up to half, in the case of DHA), without deleterious effects on larval and juvenile performance and quality.…”

Avanços recentes em nutrição de larvas de peixes

“…A metodologia de incorporação de marcadores isotópicos em presas vivas tem sido utilizada em vários estudos larvares de modo a quantificar a ingestão de alimento, permitindo também uma melhor compreensão do metabolismo proteico e lipídico (Govoni et al, 1982;Conceição et al, 1998;Morais et al, 2006). A metodologia base implica a incorporação de AA marcados com 14 Carbono ( 14 C)na proteína de Artemia (Morais et al, 2004a) e se a mesma for conjugada com o método das câmaras metabólicas (Rønnestad et al, 2001a), como descrito na secção anterior, é possível determinar a ingestão de alimento e como o nutriente marcado é digerido, retido e catabolizado pela larva.…”

“…Conjuntamente, a incorporação de marcadores isotópicos nas pequenas partículas das dietas para larvas, de modo a ser possível determinar a escolha de dietas (ingestão de alimento) e consequente utilização metabólica, é extremamente difícil, além de que devido às reduzidas dimensões das partículas a lixiviação de nutrientes é muito elevada (López-Alvarado et al, 1994;Yúfera et al, 2002;Kvåle et al, 2006;Nordgreen et al, 2007). Por conseguinte, para que seja possível determinar que dieta (presa viva ou dieta inerte) uma larva prefere e como os seus nutrientes são utilizados é necessário desenvolver novas metodologias que sejam adaptadas a fases larvares de peixes.…”