Home About us Contact
|
Home About us Contact | ||
|
|
||
G Initial Weight (g + initial_weight)
Selected AbstractsOptimum dietary soybean meal level for maximizing growth and nutrient utilization of on-growing gilthead sea bream (Sparus aurata)AQUACULTURE NUTRITION, Issue 3 2009SILVIA MARTÍNEZ-LLORENS Abstract Six isonitrogenous [450 g kg,1 crude protein (CP)] and isoenergetic diets (23 kJ g,1) with six levels of defatted soybean meal inclusion (0, 132, 263, 395, 526 and 658 g kg,1) in substitution of fish meal were evaluated in gilthead sea bream of 242 g initial weight for 134 days. Fish fed diets S0, S13, S26 and S39 had a similar live weight (422, 422, 438 and 422 g, respectively) but fish fed diets S53 and S66 obtained the lowest final weight (385 and 333g, respectively), and similar results were presented in specific growth rate (SGR). Fish fed diets S53 and S66 also obtained the highest feed conversion ratio (FCR). Quadratic multiple regression equations were developed for SGR and FCR which were closely related to dietary soybean level. The optimum dietary soybean levels were 205 g kg,1 for maximum SGR and 10 g kg,1 for minimum FCR. Sensorial differences were appreciated by judges between fish fed S0 and S39 soybean level, but after a re-feeding period of 28 days with diet S0, these differences disappeared. [source] Dietary lysine requirement of juvenile gilthead seabream Sparus aurata L.,AQUACULTURE NUTRITION, Issue 1 2006P.A. MARCOULI Abstract The dietary lysine requirement of juvenile gilthead seabream was determined by the growth response of duplicate groups of fish (3.5 g initial weight) fed on six isonitrogenous (427 g kg,1) and isolipidic (135 g kg,1) diets containing graded levels of crystalline l -lysine HCl, with dietary lysine content ranging from 36.3 to 79.7 g kg,1 of protein. The final indispensable amino acid profile of the diets except for lysine was formulated so as to resemble that of wild seabream whole body. Except for the reduced growth performance of fish groups fed the lysine-deficient diets no other deficiency signs were apparent. Survival observed throughout the feeding period of 6 weeks was excellent. Weight gain (in %), specific growth rate, feed efficiency and daily protein deposition (DPD) were significantly improved in response to the increasing levels of dietary lysine up to 52.7 g kg,1 of protein and remained nearly constant thereafter. Whole-body protein content followed a similar pattern as growth parameters in relation to dietary lysine level. Non-linear regression analysis of DPD against dietary lysine level using the four-parameter saturation kinetic model indicated a lysine requirement of 50.4 g kg,1 of protein for this species to support growth. [source] Effect of stocking density and protein/fat ratio of the diet on the growth of Dover sole (Solea solea)AQUACULTURE RESEARCH, Issue 16 2008Giovanni Piccolo Abstract Two hundred and fifty soles (30 g initial weight) were randomly stocked in 12 tanks (recirculation system) at two different stocking densities (2.3 and 1.3 kg m,2) and fed on two different diets (50% and 54% of crude protein and 21% and 18% of total lipid, respectively, for diets A and B) with triplicate tanks for treatment. The trial lasted for 300 days. Fish stocked at low density showed a significantly higher weight gain than the fish reared at 2.3 kg m,2 density (94.1±7.4 vs. 78.9±8.2 g, P<0.01) with a specific growth rate (SGR) of 0.46±0.11 and 0.43±0.16 (P<0.01) respectively. Feed conversion ratio (FCR) was more favourable for lower density groups (2.50 vs. 2.64, P<0.01). Diet B led to a higher final weight (124.1 vs. 110.2 g, P<0.01) and a better feed utilization (FCR: 2.49 vs. 2.65, P<0.01). Except for the lipid content, which was higher in the low-density group (2.6% vs. 2.3%, P<0.05), proximate composition of sole's muscle was not influenced by treatments. Dover sole reared at low stocking density showed higher monounsaturated fatty acid (35.27% vs. 34.40%, P<0.01) and lower saturated fatty acid (24.36 vs. 26.13%, P<0.01) contents, and lower atherogenic (0.67 vs. 0.75, P<0.01) and thrombogenic (0.28 vs. 0.32, P<0.01) indexes. [source] Utilization of waste material resulting from trout processing in gilthead bream (Sparus aurata L.) dietsAQUACULTURE RESEARCH, Issue 2001Y P Kotzamanis Abstract Fish processing creates a large amount of waste of high nutrient content which, if not properly processed for use in human or animal nutrition, is likely to be deposited in the environment creating pollution problems. Waste parts from rainbow trout processing for smoking, consisting of heads, bones, tails and intestines, were used as feed ingredients for gilthead bream diets. Heads, bones and tails had similar compositions, their weighed mean indicating about 700 g kg,1 moisture, 150 g kg,1 protein and 110 g kg,1 fat. Intestines contained higher lipid (350 g kg,1) and lower moisture (560 g kg,1) and protein content (80 g kg,1). Seasonal changes in composition indicated significant differences. Three experimental diets were formulated having the same proximate composition on a dry weight basis. The control diet (A) contained fish meal as the main protein source and fish oil as the oil supplement. In diet B part of the protein and most of lipid was provided by trout waste and in diet C most of the lipid was provided by trout intestines. Gilthead bream fingerlings of 4 g initial weight were fed to apparent satiation for 72 days, at a temperature of 20 °C, to an average final weight of 19 g. All diets were fed in a dry form. The experiment was performed in duplicate. Growth and feed utilization data were high and similar among groups. The body composition of the resulting fish did not show any difference among dietary treatments. Differences in liver lipid and fatty acid content were found between all dietary treatments. The growth and body composition data from this preliminary experiment indicated that trout waste could be used successfully as a dietary ingredient of sea bream diets. [source] | ||||||||||