limited ability for phospholipid biosynthesis (Geurden et al., 1995, 1999; Fontagné et de novo al., 1998). Thus, dietary phospholipids increase the efficiency of transport of dietary fatty acids and lipids from the gut to the rest of the body possibly through enhanced lipoprotein synthesis (Tocher et al., 2008). Our overall aim is to determine the precise molecular mechanism(s) underpinning the requirement for dietary intact phospholipid in fish and so one objective of the present study was to provide experimental material for mechanistic studies. Our target species was Atlantic salmon due to the fact that, despite the huge commercial importance of this species, its dietary requirements are generally poorly studied and largely extrapolated from rainbow trout data (NRC, 2011). Dietary phospholipid requirements in Atlantic salmon were last investigated a quarter of a century ago in relatively short-term studies (12-16 weeks), using lecithin preparations with rather undefined phospholipid content and class composition. Therefore, the particular aims of the present study were to a) confirm the requirement for dietary phospholipid in Atlantic salmon; b) better define the level of requirement; c) determine the relative importance of individual phospholipid classes, especially PC and d) further establish the period of requirement. To this end, Atlantic salmon fry were fed diets containing either krill oil (a rich source of PC) or soybean lecithin (a source of PC and PI) in a regression design at five levels, 1.5 (low/unsupplemented), 2.6, 3.2, 3.6 and 4.2 % total phospholipid, from first feeding through to parr-smolt transformation. Fish were sampled at approximately 1 g, 2.5 g, 5 g, 10-20 g and smolt, and growth, mortality, vertebral malformation and intestinal histology (steatosis) assessed. 2. Methods & Materials To be consistent with previous studies on phospholipid requirements of fish, the term in the present paper will specifically refer to the glycerophospholipids, the “phospholipid” major classes being PC, PE, PS and PI.
limited ability for de novo phospholipid biosynthesis (Geurden et al., 1995, 1999; Fontagné et al., 1998). Thus, dietary phospholipids increase the efficiency of transport of dietary fatty acids and lipids from the gut to the rest of the body possibly through enhanced lipoprotein synthesis (Tocher et al., 2008). Our overall aim is to determine the precise molecular mechanism(s) underpinning the requirement for dietary intact phospholipid in fish and so one objective of the present study was to provide experimental material for mechanistic studies. Our target species was Atlantic salmon due to the fact that, despite the huge commercial importance of this species, its dietary requirements are generally poorly studied and largely extrapolated from rainbow trout data (NRC, 2011). Dietary phospholipid requirements in Atlantic salmon were last investigated a quarter of a century ago in relatively short-term studies (12-16 weeks), using lecithin preparations with rather undefined phospholipid content and class composition. Therefore, the particular aims of the present study were to a) confirm the requirement for dietary phospholipid in Atlantic salmon; b) better define the level of requirement; c) determine the relative importance of individual phospholipid classes, especially PC and d) further establish the period of requirement. To this end, Atlantic salmon fry were fed diets containing either krill oil (a rich source of PC) or soybean lecithin (a source of PC and PI) in a regression design at five levels, 1.5 (low/unsupplemented), 2.6, 3.2, 3.6 and 4.2 % total phospholipid, from first feeding through to parr-smolt transformation. Fish were sampled at approximately 1 g, 2.5 g, 5 g, 10-20 g and smolt, and growth, mortality, vertebral malformation and intestinal histology (steatosis) assessed. 2. Methods & Materials To be consistent with previous studies on phospholipid requirements of fish, the term “phospholipid” in the present paper will specifically refer to the glycerophospholipids, the major classes being PC, PE, PS and PI.
Tayloretal_Influence_of_dietary_phospholipid_on_early_development_and_performance_of_Atlantic_salmon_Salmo_salar_.docx