Protein/lipid ratios in extruded diets for Atlantic cod (Gadus morhua L.): effects on growth, feed utilisation, muscle composition and liver histology

Energy dilution with α-cellulose in diets for Atlantic cod (Gadus morhua L.) juveniles — Effects on growth, feed intake, liver size and digestibility of nutrients

“…Feed conversion ratio (FCR) and feed intake were in accordance with other juvenile cod trials Morais et al, 2001;Hansen et al, 2006;Hansen et al, 2007a). In our trial, FCR during the first 7 weeks increased significantly with increased α-cellulose inclusions, in both FM and PP diet groups.…”

“…SGR in this trial was higher than predicted by growth models for cod at the same size and held at 8°C (Björnsson and Steinarsson, 2002). In addition, growth in this trial was good compared to previous studies with good growth for cod juveniles Hemre et al, 1989;Morais et al, 2001;Rosenlund et al, 2004;Hansen et al, 2007b). Growth was not significantly influenced by the increased α-cellulose, in either FM or PP diets, in the total experiment.…”

“…The same strategy will however not function for cod, as this species stores all surplus energy in the liver. Researchers have shown that a high fat content in cod feed gives enlarged liver Lie et al, 1988;Jobling et al, 1991;Hemre et al, 1992;Jobling et al, 1994;Morais et al, 2001;Rosenlund et al, 2004;Karlsen et al, 2006). Also increased dietary starch seems to increase fat and glycogen deposition in liver (Hemre et al, 1989).…”

“…Growth Growth can be affected by environmental factors like water temperature (Howell, 1984), light , fish size (Braaten, 1984;Jobling, 1992), sexual maturation (Braaten, 1984;Hansen et al, 2001;Hemre et al, 2002), health, nutrition (Morais et al, 2001;Rosenlund et al, 2004) and heritage (Gjerde et al, 2004). Specific growth rate (SGR) was higher in the first 7 weeks (1.00 ±0.09) than in the last 7 weeks (0.76 ±0.08), which was expected, since smaller cod have higher feed intake per weight unit than larger cod (Braaten, 1984).…”

Transcriptomic analyses of intestinal gene expression of juvenile Atlantic cod (Gadus morhua) fed diets with Camelina oil as replacement for fish oil

“…There were no significant differences between treatments for any of the growth and 254 feeding performance parameters although there was a trend for growth performance to increase 255 with CO inclusion up to 66% with fish fed diet C66 showing highest final weight, SGR and TGC 256 and lowest FCR. In general, very high and variable lipid content was observed in liver, as is 257 typical of farmed cod which normally present enlarged fatty livers (Morais et al, 2001). There 258 were also trends for increased HSI and VSI, as well as liver lipid contents with CO inclusion but 259 only intestinal lipid content was significantly higher in fish fed diet C66 compared to fish fed diet 260 C0 (Table 4).…”