Three trials, with classical experimental designs for in vivo digestibility studies, were conducted to determine the apparent digestibility coe⁄cient (ADC) of protein (ADCp), lipid (ADCl), energy (ADCe) and amino acids (AA) in selected animal by-products fed to European sea bass, Dicentrarchus labrax (Trial 1), gilthead sea bream, Sparus aurata (Trial 2), and turbot, Psetta maxima (Trial 3). In each trial, ¢ve experimental diets [including a reference diet (RD)] where ¢sh meal (FM) was used as the sole protein source were fed ad libitum to the ¢sh for a period of 4 weeks. Test diets were based on the FM RD and obtained by replacing 30% of the RD with a category III designated European animal by-products (¢t for human consumption), namely: steam hydrolysed feather meal (HFM), enzyme-treated feather meal (EFM), poultry meat meal (PMM) and spray-dried haemoglobin meal (SDHM). Faecal material was collected using the 'Guelph system' , and nutrient and energy digestibility coe⁄cients were related to the measurement of chromic oxide (Cr 2 O 3 ) incorporated into the diet at a rate of 0.5%. Without any exception, FM diets yielded the best digestibility values for all macro-nutrients and by all ¢sh. Among the test ingredients, ADCp was consistently higher for PMM and SDHM in the three species (85.5%, 91.1% in sea bass;79.2%, 82.8% in sea bream; and 78.4%, 74.8% in turbot). Conversely, ADCp of HFM and EFM were less e⁄ciently digested (67.2%, 68.2% in sea bass; 21.5%, 21.7% in sea bream; and 46.6%, 36.0% in turbot). However, the novel processing method applied to feather meal did not considerably in£uence the digestibility of most of the nutrients in this feedstu¡. The current investigation yielded valuable numerical ADC for EAA considered to be of prime importance in generating balanced diet formulations.

As a marine carnivore exhibiting exceptionally high growth rates, cobia are considered a species for which fish oil (FO) replacement may be difficult. However, partial, if not complete, FO replacement is necessary to ensure sustainability. We evaluated the effects of graded substitution of dietary FO with soybean oil (SO) in cobia culture. Feeds contained FO (100% FO), SO (0% FO) or blends of the two (67% FO, 33% FO) as the supplemental lipid source. Production performance was largely unaffected by partial replacement of FO with SO: feed intake and final weight were reduced only in the 0% FO dietary treatment. Fillet total lipid fatty acid (FA) composition differed among the dietary treatments, closely approximating dietary FA profile. As increasing amounts of FO were replaced, SO‐associated FA became enriched within the fillet lipid at the expense of FO‐associated FA. Fillet lipid classes were associated with a particular FA signature, regardless of dietary FA profile. SO can replace a substantial amount of dietary FO; however, juvenile cobia appear to exhibit a nominal requirement for intact long‐chain polyunsaturated FA. Therefore, aggressive FO replacement may result in essential fatty acid deficiencies unless the feeds can be amended with alternative sources of these essential nutrients.

Intracellular pathogenic microorganisms and toxins exploit host cell mechanisms to enter, exert their deleterious effects as well as hijack host nutrition for their development. A potential approach to treat multiple pathogen infections and that should not induce drug resistance is the use of small molecules that target host components. We identified the compound 1-adamantyl (5-bromo-2-methoxybenzyl) amine (ABMA) from a cell-based high throughput screening for its capacity to protect human cells and mice against ricin toxin without toxicity. This compound efficiently protects cells against various toxins and pathogens including viruses, intracellular bacteria and parasite. ABMA provokes Rab7-positive late endosomal compartment accumulation in mammalian cells without affecting other organelles (early endosomes, lysosomes, the Golgi apparatus, the endoplasmic reticulum or the nucleus). As the mechanism of action of ABMA is restricted to host-endosomal compartments, it reduces cell infection by pathogens that depend on this pathway to invade cells. ABMA may represent a novel class of broad-spectrum compounds with therapeutic potential against diverse severe infectious diseases.

Soybean meal (SBM) is perhaps the most common fish meal (FM) alternative used in aquafeeds; however, SBM cannot fully replace FM in sunshine bass Morone chrysops × M. saxatilis feeds without impacting growth. Reduced production performance may be the result of subtle changes in morphology and/or physiological status. Accordingly, our objective was to assess growth, gastrointestinal integrity and stress tolerance of sunshine bass fed increasing amounts of SBM. Fish (approximately 14.5 g) were fed diets (14% lipid and 40% protein) containing increasing amounts of SBM at the expense of FM (30% FM, 20% FM, 15% FM, 10% FM, 5% FM and 0% FM) for 8 weeks. As expected, complete replacement of FM reduced growth. Although some signs of enteritis were noted, no significant differences in gut integrity were observed. Following 15-min low-water stress challenge, plasma glucose levels were elevated, particularly among fish fed increasing amounts of SBM. Cortisol response was similar, but statistical differences were not resolved for this parameter. Completely replacing FM in feeds for sunshine bass elicits overt reductions in growth. More subtle physiological changes may also result from FM replacement, including alterations in stress tolerance, and these may be important to consider in terms of the suitability of aquafeed formulations and optimal nutrition of sunshine bass.

Fish oil (FO) sparing is common in aquafeed formulation; however, some alternative lipids have proven to be more successful than others in ensuring adequate growth and maintenance of desirable fillet fatty acid (FA) composition. Depending on the lipids used, grow‐out feeds influence the FA composition of the tissues of “lean‐fleshed” fishes and their responsiveness to subsequent tailoring during finishing. To address whether different lipid sources similarly influence growth performance and tissue composition of a “fat‐fleshed” fish, rainbow trout Oncorhynchus mykiss were reared on feeds containing FO or a 50:50 blend of FO and coconut oil (COCONUT), palm oil (PALM), standard soybean oil (STD‐SBO), hydrogenated soybean oil (HYD‐SBO), low‐18:3(n‐3) (alpha‐linolenic acid) soybean oil (LO‐ALA‐SBO), or low‐18:3(n‐3) canola oil (LO‐ALA‐CAN). Two saturated FA (SFA)‐enriched lipids derived from the processing of cottonseed (SFA‐COT) or soybean (SFA‐SBO) were also evaluated as 50% FO substitutes. After 7 weeks, growth performance was largely unaffected by dietary lipid source. Fillet levels of long‐chain (LC) polyunsaturated FAs (PUFAs) among fish that received the HYD‐SBO, LO‐ALA‐SBO, SFA‐SBO, and SFA‐COT feeds were equivalent to levels in fish that received the FO feed, despite an approximate 50% reduction in dietary LC‐PUFA intake. Our results indicate that feeds containing a blend of FO and novel soy‐ or cottonseed‐derived lipids yielded equivalent growth performance and fillet LC‐PUFA content in rainbow trout. The use of STD‐SBO, COCONUT, PALM, or LO‐ALA‐CAN did not impair growth or efficiency but did alter the fillet FA profile. Rainbow trout appeared to differ somewhat from other fishes in terms of dietary influence on tissue FA profile; however, the pattern of greater LC‐PUFA retention in fish reared on SFA‐rich feeds appears to be largely consistent among the fish taxa we have assessed.Received January 19, 2010; accepted July 25, 2010