Submitted to: Aquaculture Nutrition
Publication Type: Peer reviewed journal
Publication Acceptance Date: 12/16/2008
Publication Date: 8/10/2009
Citation: Riche, M.A., Williams, T.N. 2009. Apparent digestible protein, energy, and amino acid availability of three plant proteins in Florida pompano Trachinotus carolinus L. in seawater and low-salinity. Aquaculture Nutrition. 16:223-230. Interpretive Summary: There is interest in rearing the saltwater Florida pompano in low-salinity. However, insufficient nutrient availability data to formulate well-balanced low-cost diets presents an obstacle to large-scale commercial production. Additionally, most aquaculture feeds are made with fishmeal to supply the dietary protein; however, it is well documented fishmeal production has peaked, so to support expansion of the aquaculture industry alternative sources of protein must be identified. Soy proteins and corn gluten meal appear to be suitable candidates as partial replacements for fishmeal. Therefore the digestibility or availability of protein, energy, and amino acids from soybean meal, soy protein isolate, and corn gluten meal were determined in Florida pompano. Also, there is some evidence that availability of these nutrients may be different in low-salinity relative to the marine environment, so their availability was determined at high and low salinity. This will assist feed manufacturers in producing the most appropriate feeds regardless of the salinity in which the pompano are reared. The trends suggested availability of protein was higher from the soy products at low salinity, but not in seawater and that the difference was likely due to decreased availability from the soy products in seawater relative to low-salinity. This information will allow feed manufacturers to formulate well-balanced low-cost diets addressing one of the obstacles to large-scale commercial production of Florida pompano.
Technical Abstract: There is interest in rearing the marine euryhaline Florida pompano in low-salinity. However, insufficient nutrient availability data to formulate well-balanced low-cost diets presents an obstacle to large-scale commercial production. Evidence also suggests salinity affects nutrient availability in seawater relative to low-salinity adapted individuals. Two experiments were conducted at 3 and 28 g L-1 salinity to determine apparent crude protein digestibility (ACPD), energy digestibility (AED) and amino acid availability (AAAA) from soybean meal (SBM), soy protein isolate (SPI), and corn gluten meal (CGM). Mean AAAA was similar to ACPD. In fish adapted to 3 g L-1 salinity, they were 81.2 and 81.9 % (CGM), 93.6 and 92.2 % (SBM), 93.8 and 93.1 % (SPI) for AAAA and ACPD, respectively. In fish adapted to 28 g L-1, they were 84.5 and 83.4 % (CGM), 86.5 and 87.1 % (SBM), and 83.4 and 85.0 % (SPI) for AAAA and ACPD, respectively. The general trend suggests AAAA were higher from soy products than CGM. The AED was highest for SPI and lowest for SBM and inversely related to carbohydrate. The ACPD, AED, and AAAA of soy products appeared to be lower in high salinity, whereas CGM was unaffected.