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This research study is focused on the lipid requirements of Petenia splendida (0.65 ± 0.19 g) juveniles. Fish were fed with trout commercial diet (Silver Cup? - 45% protein and 16% lipids), as control diet - CD (which is usually used to feed this species at commercial scale), and four isoproteic (45% crude protein) diet formulated with different lipid levels (5, 10, 15 and 20%). Diets were administered for 60 days by triplicate per treatment. Our results showed that fish fed with 10, 15 and 20% lipid levels were significantly higher (P < 0.05) in average weight and total length. Same treatments were significantly lower (P < 0.05) in terms of FCR compared to those shown in 5% and CD. However, fish fed 20% lipid level, showed a significant decrease in WG and a significant (P < 0.05) increase in FCR compared to those shown in 15% lipid level. Fish fed with 15% showed the highest weight gain and the lowest FCR compared with the rest of the treatments. Lipid efficiency ratio (LER) showed significant (P < 0.05) differences among experimental groups. Compared to other diets containing lipid levels (5, 10, and 20%) fish fed 15% diet recorded the lowest protein and lipid content in whole body. Additionally, based on second order polynomial regression analysis of WG, it was demonstrated that 16.2% lipid provides an optimal growth for P. splendida. [ABSTRACT FROM AUTHOR]

The present work evaluates the attractant and palatable potential of six ingredients of animal origin in longarm river prawn Macrobrachium tenellum juveniles in a Y type maze system. Ingredients were pelletized for the first bioassay and included in neutral gelatin (in wet base) in the second bioassay. The ingredient to evaluate was placed in one of the Y-maze arms, allowing the free movement of prawn for 15 min. On both bioassays, attractability was evaluated by quantifying the time required for the first prawn to enter the region where the feed was found and the total of prawns which entered that region. In the second bioassay, also evaluated the palatability quantifying the time for the first prawn to have contact with the ingredient, the total of prawns which had contact with it and the time they remained feeding. No significant differences were obtained between treatments in the first bioassay. Significant differences were found in the second bioassay showing that pork meal, fish meal, feather meal and shrimp meal have greater attractability due to the number of prawns attracted, results also show significant differences in palatability, where fishmeal, shrimp meal and pork meal stimulating a higher number of organisms and promoting a longer consumption time. [ABSTRACT FROM AUTHOR]

Due to the cost of raw materials, the need to formulate balanced feeds with highly digestible ingredients is indispensable for the aquaculture feed industry. For this reason, the protein in vitro digestibility, assessed by the pH-stat method, of ingredients with potential of using them on the balanced feed for Macrobrachium tenellum, were evaluated. The relative protein digestibility was assessed in twelve feed ingredients, including animal (pork meal, feather poultry meal, prime poultry meal, turkey meal, fish meal, shrimp meal), vegetal (coconut paste, chickpea meal, soybean meal, wheat gluten) and microbial (yeast and Spirulina meal); casein (Hammerstein grade) was used as the reference protein. The highest relative protein digestibility was found in: Spirulina meal (52.6%); following by pork meal (45.6%), and feather poultry meal (39.6%). The lowest digestibilities were found in soybean meal (15.9%), chickpea meal (12.1%), and fish meal (11.6%). The protein digestibility value should be considered for selecting potential ingredients for the formulation of balanced feeds for M. tenellum. [ABSTRACT FROM AUTHOR]

Total replacement of fishmeal using marine co-product meals in the diets for white shrimp Litopenaeus vannamei and its effects on growth, feed utilization and muscle HUFA and sterol composition were assessed in a 45-day feeding trial with juvenile shrimp (0.32 g mean initial weight). Eight dietary treatments were tested: a control diet containing fishmeal ( FM), a commercial shrimp diet as external reference and six diets where the FM in the control diet was totally replaced by pen shell scallop viscera ( Pinna rugosa), squid viscera ( Dosidicus gigas) or whole chub mackerel ( Scomber japonicus) meals, produced by two methods: (i) cooking followed by grinding and drying and (ii) grinding followed by drying. Survival in all treatments was above 92%, except in the commercial diet (77%). The growth response, feed utilization and chemical composition of shrimp varied among the treatments and were affected in different ways by the by-products and the meals preparation process. Growth and feed intake were significantly higher in shrimp fed diets containing cooked-dried squid and pen shell scallop viscera meals, and whole mackerel meal produced by grinding followed by drying. Muscle fatty acid profiles were improved for human consumption when these ingredients were used, compared with the diets containing FM. [ABSTRACT FROM AUTHOR]

Food production for aquaculture requires finding other protein sources or ingredients as potential alternatives in the formulation of aquaculture feeds, due to the shortage and high price of protein sources that are most commonly used. The aim of this analysis was to evaluate the relationship between the essential amino acids in 13 types of proteins available in the market with the essential amino acids found in the muscle of four of the most important farmed prawn species of the genus Macrobrachium (M. amazonicum, M. rosenbergii, M. americanum and M. tenellum). The results obtained showed the limiting amino acids of each ingredient for each species, thereby allowing for formulation of commercial foods that meet the nutritional needs to support optimal growth of these prawns in culture. In conclusion, there is a difference in the amino acids most often present as first limiting between sources of animal and plant origin. Thereby, it is possible evaluate complementarities between these sources to achieve an amino acids profile close to that of Macrobrachium species. [ABSTRACT FROM AUTHOR]

The effect of dietary protein (31, 41, 45, and 55%) was evaluated in quadruplicate in the yellow snapper (Lutjanus argentiventris). Specimens were kept in sixteen 200 L plastic tanks for 95 days and the values of growth rate, feeding efficiency and proximate composition of yellow snapper (18 g) were examined. Every 15 days were carried out individual weight measurements and standard length of the total population. At the beginning and end of the experiment, liver and muscle samples were taken for proximate analysis of crude protein and ether extract. In general, the highest gain was obtained with fish fed with 55% crude protein in the diet. The best feed conversion ratio (FCR), specific growth rate (SGR), percent weight gain (WG%), average daily gain (ADG), and feed efficiency rate (FER) were obtained with the fish fed 55% of protein (CP). The protein content in liver decreased in fish fed with protein levels and higher energy compared with the initial fish. Finally, the use of practical diets containing 55% CP is appropriate for optimal growth and efficiency of feed utilization of yellow snapper. The results obtained in this study may be due to the early stage of development of yellow snapper where protein and energy requirements are higher. [ABSTRACT FROM AUTHOR]

Two trials were conducted to determine the efficacy of fish fed live yeast Debaryomyces hansenii strain CBS 8339 on immune and antioxidant systems in leopard grouper Mycteroperca rosacea infected with Aeromonas hydrophila. Juveniles (12±0.5 g) were fed with a control diet or a D. hansenii-supplemented diet (106 colony-forming units per gram) for 5 weeks. The live weight of fish was registered on a weekly basis. After 4 weeks, fish from each treatment were immunocompromised with pathogenic A. hydrophila and further fed for 1 week in order to evaluate the effect on immunological and antioxidant parameters. Generally, the results showed enhanced growth performance in fish fed the diet containing yeast compared with the control. Addition of live yeast had no significant effect on the immunological parameters after 4 weeks of feeding. However, post infection with A. hydrophila fish fed the yeast-supplemented diet resulted in a significant increase in the levels of plasmatic immunoglobulin M. Superoxide dismutase and catalase (CAT) activities were significantly higher in the yeast group. In this fish, CAT and heat shock protein 70 genes were up-regulated before and after infection of A. hydrophila. The present study is the first one reporting that yeast ( D. hansenii) can enhance immunity and resistance against A. hydrophila. [ABSTRACT FROM AUTHOR]