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Microbound Diets (microbound + diet)
Selected AbstractsThe problem of meeting dietary protein requirements in intensive aquaculture of marine fish larvae, with emphasis on Atlantic halibut (Hippoglossus hippoglossus L.)AQUACULTURE NUTRITION, Issue 3 2007A. KVÅLE Abstract Atlantic halibut (Hippoglossus hippoglossus) achieve a mature gastrointestinal tract approximately 2 months after first feeding (12 °C). The immature digestion may be the reason that compound diets fail to sustain growth and survival in first feeding halibut larvae and in larvae of other marine fish species. On the other hand, larvae fed with live feeds are capable of extraction of sufficient quantities of nutrients to sustain high growth rates. A lower availability of the protein in formulated diets compared with live prey is considered to be an important reason for the low performance of formulated diets. One approach to increase dietary protein availability is supplementation of pre-digested proteins. Experiments using tube fed individual larvae show that halibut larvae are able to utilize hydrolysed protein more efficiently than intact protein. However, Atlantic halibut in culture did not respond well to dietary supplementation of hydrolysed protein, in contrast to some other species. One reason may be extensive leaching of pre-hydrolysed proteins from the microparticulate feed. Atlantic halibut are slow feeders and may thus suffer more from nutrient leaching than species eating more rapidly. Feed formulation techniques affect dietary protein leaching, and in this paper, different techniques and their impact on feed properties are described. Microbound diets are most widely used in larval rearing, but show high rates of nutrient leaching. Lipid-based capsules seem to have the best potential to prevent leaching, however, they are not able to deliver a complete diet. The high need for improvements in larval feed formulation techniques are clearly stated, and some suggestions are given. Among these are production of complex particles, where small lipid-based capsules or liposomes containing the low molecular weight water-soluble nutrients are embedded. In such feed particles the water-soluble molecules are protected from leaching. Techniques for delivery of water-soluble nutrients that are needed in large quantities, i.e. free amino acids or hydrolysed and water-soluble protein, remain to be developed. [source] Effects of Dietary Heat-killed Lactobacillus plantarum on Larval and Post-larval Kuruma Shrimp, Marsupenaeus japonicus BateJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 2010Ha Thanh Tung Two feeding trials were conducted to evaluate the effects of heat-killed Lactobacillus plantarum (HK-LP) on larval and post-larval kuruma shrimp, Marsupenaeus japonicus Bate. Five microbound diets were formulated to contain levels of a preparation containing 20% HK-LP (HK-LP Prep): 0, 0.001, 0.01, 0.1, and 1 g/kg. In the first experiment, zoea1 stage larvae were fed test diets for 8 d. Some parameters such as survival, developmental stage, metamorphosis to post-larvae, and formalin stress resistance were evaluated. In second trial, post-larval shrimp (16 ± 0.04 mg) were fed test diets for 30 d. Survival, body weight gain, specific growth rate, feed efficiency ratio, individual dry weight, total body length, osmotic and formalin stress resistances, and protease activity were evaluated. Results indicated that the larvae that received HK-LP Prep at 0.1 and 1 g/kg diets showed significantly (P < 0.05) higher survival than that of the control group. For the post-larval trial, shrimp that received HK-LP Prep at 1 g/kg diet were significantly higher than the control group in most of the growth parameters and stress resistance. However, shrimp that received HK-LP Prep at 0.1 g/kg diet were significantly higher than the control group in survival only. For protease activity, there was no significant difference detected among groups. [source] Enzyme and acid treatment of fish meal for incorporation into formulated microbound diets for barramundi (Lates calcarifer) larvaeAQUACULTURE NUTRITION, Issue 2 2009L. NANKERVIS Abstract This study reports on two experiments in which the use of enzyme- and acid-treated fish meal were evaluated for incorporation into formulated microbound diets for barramundi (Lates calcarifer) larvae. In the first experiment, partially hydrolysed fish meal was used to determine whether partial hydrolysis increased the dietary value of fish meal used in microbound diets fed to L. calcarifer larvae. Total length and dry weight at the end of the experiment were both higher for larvae fed diets containing untreated fish meal than those fed diets containing any level of hydrolysate. Larval survival ranged from 15.8% to 47.2% but there were no significant differences between treatments (Fig. 3; P > 0.05). Carcass pepsin levels of larvae fed diets containing untreated fish meal were significantly higher than pepsin levels of larvae fed all other diets (P < 0.05). The second experiment determined the effects of incorporating graded levels of denatured fish meal (DF) into microbound diets for L. calcarifer larvae. Acid treatment increased the digestibility of fish meal approximately twofold when compared with intact fish meal. Larvae fed diets containing 45% DF had significantly higher total length and dry weight at the end of the growth trial than those fed a diet containing only intact fish meal. Larval survival ranged from 30.2% to 58.2%, with no significant differences between treatments. Whole homogenate pepsin levels were significantly affected by the level of dietary DF inclusion with larvae fed diets containing a greater proportion of intact fish meal containing higher pepsin levels. There was a significant correlation between dietary DF inclusion level and decreasing pepsin level (r2 = 0.569, P < 0.01); however, larval pepsin level did not correlate to either dry weight or total length (Pearson correlation, P > 0.05). The results of this study are a valuable contribution to our understanding of factors influencing the utilization of ingredients in microbound diets developed for marine fish larvae and will facilitate development of more effective formulated foods for them. Figure 3. ,Mean (±SE) survival of barramundi larvae fed experimental diets containing fish meal hydrolysed for varying period (7.5,60 min), from 14 to 28 days after hatching. Means with different superscripts are significantly different (P < 0.05). [source] Assessment of dietary lecithin and cholesterol requirements of mud crab, Scylla serrata, megalopa using semi-purified microbound dietsAQUACULTURE NUTRITION, Issue 6 2007M.-H. HOLME Abstract The effects of varying dietary lecithin and cholesterol levels on growth, development and survival of mud crab, Scylla serrata, megalopa were evaluated using six semi-purified, microbound diets formulated to be iso-energetic and containing three levels of supplemental lecithin (0, 20 and 40 g kg,1 diet dry weight) and two levels of supplemental cholesterol (0 and 7 g kg,1 diet dry weight). Fifteen megalopa were reared individually in each treatment and the nutritional value of diets was assessed on basis of mean dry weight and mean carapace width of newly settled first crab stage, as well as development time to the first crab stage and overall survival. A significant interaction between supplemental dietary lecithin and supplemental dietary cholesterol was found for final mean dry weight of newly settled crabs, and highest survival (60%) was recorded for megalopa fed diets containing the highest levels of dietary lecithin (39.7,44.1 g kg,1) (diet 5 and 6) regardless of whether diets were supplemented with cholesterol; this rate of survival was identical to that of megalopa fed live Artemia nauplii. The results indicate that supplemental dietary cholesterol may not be essential for mud crab megalopa when fed diets containing sufficient levels of supplemental dietary phospholipids. [source] | ||||||||||