ALBERT

Notes: Abstract— The present research was conducted to evaluate if there is an interrelationship between methionhe and choline as well as between betaine and choline in feed formulations for channel catfish. A semi-purified basal diet was formulated to contain 28-g crude protein/100-g diet. DL-methionine was added to the basal diet to produce deplete, sufficient, and replete levels of methionine (0.35%, 0.39%, and 0.43%); choline chloride (200, 400, and 600-mg cholinentg diet) was added to the basal diet to produce low, median, and high levels of choline; and free base betaine (0 and 1,000-mg betainelkg diet) was added to the basal diet to produce sufficient and replete levels of betaine in eight experimental diets. Each diet was randomly fed to triplicate groups of fish (15 fishleach group) over a 13-wk growth trial. Added choline in the diets containing 0.35% (deplete) methionine had a significant linear effect on weight gain and feed consumption. There were no significant differences in weight gain, FCR, survival, HIS, and liver lipid between diet 3 (deplete methionhe and high choline) and diet 6 (sufficient methionine and median choline). Both added choline and betaine in the diets containing 0.39% (sufficient) methionine had significant effects on weight gain, feed consumption, and FCR. There were no significant differences in the measured parameters between diet 7 (low choline and excess betaine) and diet 6 (median choline and no betaine). Methionine had no significant Linear effect on weight gain and feed consumption when choline was low. Therefore, in the absence of sufficient methionine, choline or betaine can spare a portion of methionine requirement of channel catfish. In the absence of sufficient choline, methionine cannot spare choline requirement of channel catfish. Further, in the absence of sufficient choline, betaine can spare at least a portion of choline requirement of channel catfish.

Notes: Abstract— The production of Litopenaeus vannamei in inland low-salinity well water is a growing industry in several regions of the world. The state of Alabama in the southeastern USA is one such region with a large saline aquifer that could be utilized for shrimp culture. However, some farmers are experiencing problems rearing marine shrimp while others are having considerable success. Previous work has correlated low levels of potassium andor magnesium to poor shrimp survival. The problem is further complicated by the fact that the age at acclimation may also influence survival. In our present study, we evaluated the effects of potassium, magnesium, and the age of acclimation on growth and survival of PL at two farms. The first experiment was run in a static system utilizing four replicate tanks per treatment. Fifty PL17 (0.0066 g) that had been acclimated to 4 ppt seawater were stocked into each tank and the following treatments evaluated: low salinity well water (LSWW) without mineral supplements, LSWW with KCl, LSWW with MgCl2, and LSWW with KCl and MgCl, added to the water. Shrimp were harvested, counted and weighed after 4 wk. Survival was significantly higher in treatments receiving mineral supplements whereas biomass was only higher in the two treatments with potassium supplements. The second experiment was set up initially as a static system filled with 8.5-ppt reconstituted sea water that was then converted to a flow-through system using LSWW. This experiment evaluated the effect of PL age at acclimation on survival and growth at four different ages (PL15, PL19, PL23, and PL27). All tanks were stocked with 50 PL13L. vannarnei. Two days after stocking, and then at 4-d intervals, a series of four tanks were converted to flow through (rate of 40 Lhr) using LSWW. After acclimation, water flow was maintained in all tanks until 28 d after stocking when tanks were harvested and surviving shrimp were counted and weighed.Survival and growth increased with PL age when shrimp were acclimated to inland low salinity well water.

Notes: To allow for the initial identification of practical diet formulations for red snapper culture, the present study was conducted to evaluate the effects of feeding varying levels of dietary protein and lipid on growth and body composition of juvenile and sub-adult red snapper. Twelve diets were formulated to contain varying levels of dietary protein and lipid. In trial 1, juvenile red snapper (initial mean weight 5.9 g) were offered diets with graded levels of dietary protein (32%, 36%, 40%, 44%) and practical energy to protein ratios. In trial 2, juvenile red snapper (initial mean weight 8.64 g) were offered isonitrogenous diets (44% protein) containing graded levels of dietary lipid (8%, 10%, 12%, 14%). Sub-adult fish (initial mean weight 151.5 g) were used in trial 3 and maintained on diets similar to those of trial 1 (32–44% protein). Sub-adult fish (initial mean weight 178.3 g) in trial 4 were offered isonitrogenous diets containing 32% dietary protein and graded levels of dietary lipid (6%, 8%, 10%, 12%). There were no significant differences in growth, feed efficiency ratio (FER) or survival in juvenile fish. Juvenile fish offered 32% dietary protein exhibited a significantly greater (P=0.0497) protein conversion efficiency (PCE) than fish offered a diet containing 44% dietary protein. Juvenile fish in trial 2 also had significantly higher (P=0.005) intraperitoneal fat ratios (IPFRs) at 14% dietary lipid than fish offered diets containing 8–10% dietary lipid, and displayed trends towards greater protein as a percent of whole-body composition at 8–10% dietary lipid. Sub-adult snapper in trials 3 and 4 showed no significant differences in growth, FER or survival. However, in trial 4 there was a general trend towards increased % weight gain (P=0.0615), FER (P=0.0601) and final mean weight (P=0.0596) with increasing levels of dietary lipid. Fish in trial 4 offered 6% dietary lipid also had significantly lower (P=0.0439) IPFR and PCE (P=0.0188) than fish offered 12% dietary lipid. Based on data obtained from these trials, inclusion of dietary protein at levels of 32–36% appears sufficient to support growth. For this level of protein, dietary lipid should be ∼10% in order to meet the energetic demands of the fish and to spare dietary protein for growth.

Notes: Abstract— The purpose of this study was to examine the effect of varying dietary levels of highly unsaturated fatty acids (HUFA) in Live prey on the standard length, specific growth rate, survival, and fatty acid composition of yellowtail snapper Ocyurus chrysurus larvae. Two experiments were conducted utilizing rotifers and Artemiu enriched with live algae (Isochrysis galbana or Nannochloris oculata) or commercial preparations (Aquagrow Advantage, Aquagrow Advantage plus Aquagrow arachidonic acid, and Algarnac 2000). Larval growth and fatty acid composition were evaluated during the rotifer, Brachionus plicatilis, and Artemia feeding periods and survival rates were calculated at the termination of each trial (18 or 20 d after hatching). In general, prey enriched with the commercial products contained higher levels of docosahexaenoic acid, eicosapentaenoic acid, n-3 HUFA, and × HUFA than those enriched with live algae. The addition of arachidonic acid to the Aquagrow Advantage enrichment medium significantly increased the amount of this fatty acid in rotifers but not in Artemia. At the end of the growth trials, larval standard length was highest when larvae were fed prey enriched with I. galbanu (6.4 mm) or commercial preparations (6.7–7.1 mm) versus N. oculatu (5.2 mm). Furthermore, larvae fed prey enriched with commercial preparations had significantly (P 〈 0.05) higher survival rates (2.2-5.9%) than those fed prey enriched with live algae (1.1-1.4%). These results suggest that yellowtail snapper larvae require dietary levels of HUFA beyond those achieved by enriching prey with live N. oculata or I. galbana

Notes: The replacement of fish meal with soybean meal in fish diets has met with varying degrees of success. Quite often, poor responses to high soybean meal diets are either due to shifts in the nutrient profile or a reduced palatability of the diet when fish meal is removed. The present research was designed to evaluate the replacement of menhaden fish meal with solvent-extracted soybean meal in practical diets containing 10% poultry by-product meal and formulated to contain 40% protein, 8% lipid, and a total sulfur amino acid content of 〉 3.0% of the protein. The response of red snapper (mean initial weight 10.9 g) to diets containing graded levels of fish meal (30,20, 10, 0%) as well as the response to a low fish meal diet (10%) without poultry by-product meal were evaluated over a 6-wk growth period. Significant (P± 0.05) differences in final mean weight, percent weight gain, and feed conversion were observed. Final weights (percent gain) ranged from 30.9 g (185.5%) for fish offered diets with 30% fish meal to 12.6 g (16.3%) for fish offered diets with 0% fish meal. Corresponding feed conversion efficiencies ranged from 60.1% to 7.7%. No significant differences were observed for survival between treatment means. Although there was a clear reduction in performance as the fish meal was replaced with soybean meal, the use of 10% poultry by-product meal or 10% fish meal resulted in similar performance of the fish. This is a good indication that poultry by-product meal does not have palatability problems and could be used as a substitute. The present findings suggest that replacing fish meal with high levels of soybean meal appears to reduce the palatability of the diet. While the cost reducing benefit, with respect to the replacement of fish meal, has been shown with other species, before high levels of inclusion can be efficiently utilized further research is needed to address the palatability problems observed with red snapper.