High dietary lipids elevate carbon loss without sparing protein in adequate protein-fed juvenile turbot (Psetta maxima)

Untitled

“…This may due to the intake of different types of diet in captivity compared to the food resources in a natural habitat (Karapangiotidis et al, 2006;Karapangiotidis et al, 2010). In the present study, the body lipids and dry matter increased significantly with the increase of dietary lipid levels being in agreement with astudy on turbot that showed an increase of body lipid and dry matter when fed with diets containing 10% to 19% of dietary lipid (Sevgili et al, 2014). On the contrary, the body protein and ash contents of O. marmorata declined significantly with an increase in dietary lipid levels.…”

“…The decline of growth in O. marmorata when fed with high dietary lipid diets indicates a limited or absence of protein sparing effect of lipid. This result is in agreement with those in other fish species including turbot Psetta maxima (Sevgili et al, 2014) and blunt snout bream Megabrama amblycephal (Li et al,2010). However, protein sparing effect was reported in rockfish juvenile Sebates schlegeli by (Lee et al, 2002) who recorded significantly better protein utilization, weight gain, feed efficiency, ADC of protein and lipid in fish fed with 42% protein and 14% lipid compared to those fed with 49% protein and 7% lipid.…”

“…Another reason of the increase in body lipid and deposition of fat in the peritoneal in the present study may be that the fish have limited ability to utilize high dietary lipid levels (Schulz et al, 2008).In general, high energy diet should be avoided for lean fish species such as white grouper Epinephelus aeneus (Lupatsch and Kissil, 2005), mouse grouper Cromileptes altiveles (Williams et al, 2004), and turbot (Sevgili et al, 2014), since these fish species do not appear to require high energy diets per unit of body weight gain compared to relatively energy-dense fish such as European seabass and gilthead sea bream (Lupatsch et al, 2003). O. marmorata can also be considered as a lean fish with low body lipid content and have limited ability to utilize high dietary lipid diets.…”

“…The protein and ash content showed an inverse relationship with the body lipid and dry matter. However, in turbot no significant change on the body protein with the increase of dietary lipid levels (Sevgili et al, 2014). A study on gilthead sea bream Sparus aurata suggested that at higher protein-energy intake, the energy retained in the form of protein declined and that protein energy may be utilized for protein and lipid deposition (Lupatsch et al, 2003).…”

“…Feeding fish with high dietary lipid that have limited ability to utilize the high dietary lipid efficiently not only results in low growth, feed utilization, but it also reduces the commercial value of the final product of fish by affecting the processing yield, product quality and the storage stability (Cowey, 1993). The high dietary lipid that is poorly utilized by fish has also been reported lead to high loads of carbon (mainly contributed by the carbon in dietary lipid) in the environment (Sevgili et al, 2014).…”