Robert C. Reigh

Apparent digestibility of selected ingredients in red drum (Sciaenops ocellatus) diets

Abstract Production of cultured red drum requires use of formulated diets for grow-out to marketable size. However, insufficient information is available regarding the nutrition of this species to make least-cost feed formulation practical. Knowledge of the digestibility of ingredients used in red drum diets could facilitate least-cost formulation and reduce feed costs. The objective of this study was to determine apparent digestibility of dry matter, crude protein, and energy in blood meal, corn grain, cottonseed meal, grain sorghum, meat and bone meal, menhaden fish meal, rice bran, soybean meal, and wheat middlings in formulated red drum diets. Digestibility coefficients were determined using a reference diet and test diets that contained 70% of the reference diet mixture and 30% test ingredient. All diets contained 1% chromic oxide as a digestibility indicator. Fecal samples were manually stripped from anesthetized fish to prevent contact with water. Apparent digestibility coefficients for dry matter, crude protein, and energy in the reference and test diets were determined, and digestibility coefficients for the test ingredients were calculated based on differences in the digestibility of test diets relative to the reference diet. Apparent crude protein digestibility coefficients ranged from 74 to 100% for all feedstuffs tested, indicating that red drum utilized dietary protein efficiently regardless of source. Protein digestibility was highest in feedstuffs with high protein content (> 60%) and low fiber content (

Apparent digestibility of selected feedstuffs in diets for hybrid striped bass (Morone saxatilis ♀ X Morone chrysops ♂)

Abstract Hybrid striped bass were fed a reference diet or one of nine test diets containing selected protein and energy supplements: menhaden fish meal, meat and bone meal, blood meal, soybean meal, cottonseed meal, corn grain, wheat flour, wheat middlings, and rice bran. Test diets contained 70% reference diet mixture and 30% test ingredient. All diets contained 1 % chromic oxide indicator. Fecal samples were manually stripped from anaesthetized fish to prevent contact with water. Apparent digestibility coefficients for dry matter, crude protein, and energy in the reference and test diets were determined, and digestibility coefficients for the test ingredients were calculated based on differences in the digestibility of test diets relative to the reference diet. Apparent crude protein digestibility was high (71–93%) for all ingredients tested. Apparent energy digestibility (AED) was significantly higher for ingredients of animal origin (fish meal and meat and bone meal; 80–95%) than for those of plant origin (soybean meal, corn, wheat flour, wheat middlings, and rice bran; 41–73%) with one exception—AED of meat and bone meal and cottonseed meal did not differ. Apparent dry matter digestibility (27–84%) varied significantly among ingredients of both plant and animal origin and appeared to be negatively related to fiber and starch content of the ingredient. Results indicated that hybrid striped bass utilized high-protein and high-lipid feedstuffs better than high-carbohydrate or high-fiber feedstuffs.

Effects of dietary lipid and carbohydrate levels on growth and body composition of juvenile red drum, Sciaenops ocellatus.

Juvenile red drum (2.9 ± 0.3 g) were led one of six experimental diets (containing fish meal, crab meal, fish oil, wheat middlings, mineral and vitamin supplements, cellulose filler and binder) that provided 32% crude protein and 6 or 10% lipid, at three gross-energy (GE) levels ( 15.8 ± 0.3,17.1 ± 0.2 and 18.7± 0.3 kJ/g). Dietary carbohydrate (NFE) levels ranged from 24 to 39%. Significantly (P < 0.05) higher weight gain (481%), feed efficiency (FE: 0.375), apparent net protein retention (ANPR: 19.77%) and apparent net energy retention (ANER: 10.81%) were associated with a diet containing 16.1 kJ GE/g, 10% lipid and 24% NFE. Survival (71–88%) did not differ significantly among dietary treatments. Weight gain, FE, ANPR and ANER of red drum was inversely related to dietary energy level and dietary carbohydrate content. Body lipid levels were significantly (P < 0.05) higher in fish fed 10% lipid diets than in those fed 6% lipid. Dietary lipid exhibhted greater proteinsparing action than dietary carbohydrate, at all energy levels tested. The ability of juvenile red drum to utilize dietary carbohydrate as an energy source may be limited in comparison with warnwater omnivorous species like channel catfish and common carp.

Effects of dietary soybean and fish-protein ratios on growth and body composition of red drum (Sciaenops ocellatus) fed isonitrogenous diets.

An 8-week growth trial was conducted with red drum (Sciaenops ocellatus) to determine the amount of soybean protein that could be substituted for fish protein in formulated diets without reducing growth. In the laboratory, juvenile red drum (7.4 ± 0.1 g) were fed 34%-crude-protein diets in which dietary protein was supplied by soybean (soy) meal, menhaden fish meal or an isonitrogenous mixture of soybean and fish meal calculated to provide graded levels of each protein source. Dietary protein was provided as: (1) 100% soy protein; (2) 100% soy protein with a methionine supplement (calculated to approximate the methionine content of menhaden fish meal); (3) 75% soy protein: 25% fish protein; (4) 50% soy protein: 50% fish protein, (5) 25% soy protein: 75% fish protein; and (6) 100% fish protein. Diets containing only soy protein or soy protein plus a methionine supplement were poorly consumed by red drum. Approximately half of the fish that received these diets died during the first 4 weeks of the growth trial and the remainder lost weight. The 100%-soy and 100%-soy + methionine diets were therefore considered unacceptable for practical use and both treatments were terminated after 4 weeks. Among the remaining treatment groups, red drum fed diets containing only fish protein (100 FP), or soy-protein: fish-protein (SP: FP) ratios of 1: 3 (25 SP: 75 FP) and 1: 1 (50 SP: 50 FP) had higher (P 0.05) from that of fish fed the diets with higher levels of fish protein. This indicated a superior cost: benefit ratio for the 1:1 soy-protein: fish-protein mixture in a 34%-crudeprotein diet for fingerling red drum.

Apparent digestibility coefficients for common feedstuffs in formulated diets for red swamp crayfish, Procambarus clarkii

Abstract Apparent digestibility coefficients were determined for 15 feedstuffs in formulated diets for red swamp crayfish (P. clarkii) using a reference diet and test diets composed of 70% reference diet and 30% test ingredient. Digestibility coefficients for dry matter (DM), protein (P) and energy (E) were: (1) alfalfa meal: 34.7% DM, 75.6% P, 35.6% E; (2) corn grain: 100% DM 97.3% P, 100% E; (3) cottonseed meal: 64.8% DM, 83.7% P, 67.9% E; (4) crab meal: 61.9% DM, 81.1% P, 68.1% E; (5) meat and bone meal: 61.3% DM, 76.5% P, 78.1% E; (6) menhaden fish meal: 71.6% DM, 80.7% P, 82.5% E; (7) milo (grain sorghum): 87.5% DM, 86% P, 82.7% E; (8) rice bran: 71% DM, 93.5% P, 73.7% E; (9) rice grain: 70.8% DM, 87.7% P, 70.8% E; (10) soybean meal: 78.6% DM, 94.8% P, 83.1% E; (11) wheat flour: 100% DM, 96.4% P, 99.5% E; (12) wheat gluten: 100% DM, 100% P, 100% E; (13) wheat middlings: 74.8% DM, 92.5% P, 75.3% E; (14) wheat shorts: 81.6% DM, 92.2% P, 79.5% E; and (15) dried yeast: 61.6% DM, 69.8% P, 55.3% E. Dry matter, crude protein and energy digestibility coefficients indicated starchy seed meals and grain by-products were more digestible for crayfish than high-fiber roughage or animal protein products containing high levels of chitin and ash. Dry matter and energy digestibility of feedstuffs varied inversely with fiber and ash content, indicating that high-fiber roughages may be of little value as crayfish feeds. High-starch feedstuffs, however, appeared to be excellent sources of dietary energy for crayfish. Dry matter digestibility of animal protein products was generally lower than that of non-fibrous plant meals. However, protein and energy (lipid and nitrogen-free extract) components of animal protein products were well digested by crayfish, indicating that animal protein products may be used effectively as protein supplements in formulated crayfish feeds, and may be selected primarily on the basis of crude protein content and amino acid composition, since protein digestibility coefficients for most available supplements are adequate.

Plant Products Affect Growth and Digestive Efficiency of Cultured Florida Pompano (Trachinotus carolinus) Fed Compounded Diets

Costs of compounded diets containing fish meal as a primary protein source can be expected to rise as fish meal prices increase in response to static supply and growing demand. Alternatives to fish meal are needed to reduce production costs in many aquaculture enterprises. Some plant proteins are potential replacements for fish meal because of their amino acid composition, lower cost and wide availability. In this study, we measured utilization of soybean meal (SBM) and soy protein concentrate (SPC) by Florida pompano fed compounded diets, to determine the efficacy of these products as fish meal replacements. We also calculated apparent digestibility coefficients (ADCs) for canola meal (CM), corn gluten meal (CGM), and distillers dried grains with solubles (DDGS), following typical methods for digestibility trials. Juvenile Florida pompano were fed fish-meal-free diets containing graded levels of SBM and SPC, and weight gain was compared to a control diet that contained SBM, SPC, and fish meal. Fish fed diets that contained 25–30 percent SBM in combination with 43–39 percent SPC had weight gain equivalent to fish fed the control diet with fish meal, while weight gain of fish fed other soy combinations was significantly less than that of the control group. Apparent crude protein digestibility of CGM was significantly higher than that of DDGS but not significantly different from CM. Apparent energy digestibility of DDGS was significantly lower than CGM but significantly higher than CM. Findings suggested that composition of the reference diet used in a digestibility trial affects the values of calculated ADCs, in addition to the chemical and physical attributes of the test ingredient.

Effect of Feeding Strategies on Production Characteristics and Body Composition of Florida Pompano Reared in Marine Recirculating Systems

Abstract The effect of feeding strategies on production characteristics and body composition of Florida pompano Trachinotus carolinus reared using marine recirculating systems was evaluated in three growth trials (water temperature, 27–29°C; salinity, 23–28‰). A commercial diet (53% protein, 13% lipid) was fed in each trial. In trial 1, mean final weight of juveniles fed 5% of body weight per day (bw/d) in two, three, or six feedings for 38 d was significantly greater than that of Florida pompano fed once daily. In trial 2, Florida pompano that were fed twice daily to apparent satiation (AS) were significantly larger after 54 d than fish fed a fixed ration of 5% bw/d, regardless of initial stocking density (1.3 or 2.6 kg/m3). In trial 3, mean final weight of Florida pompano fed to AS four times daily for 133 d was significantly greater than that of fish fed to AS twice daily. Feeding rate and frequency did not affect feed conversion efficiency or body composition and had minimal effects on specific growth...

Growth and body composition of pond-raised hybrid striped basses, Morone saxatilis × M. chrysops and M. saxatilis × M. mississippiensis, fed low and moderate levels of dietary lipid

Abstract Differences in growth of original-cross hybrid striped bass and striped bass × yellow bass hybrids have been documented in tank-reared fish. This experiment was conducted to compare growth and body composition of hybrids raised in ponds, and determine the extent to which growth and body lipid content was influenced by addition of a fish oil top-spray to the diet. Sixteen 0.04-ha earthen ponds were stocked with 300 fingerling striped bass hybrids per pond-8 ponds with a striped bass female × white bass male hybrid (SB × WB) and 8 with a striped bass female × yellow bass male hybrid (SB × YB). The two hybrids were hand-fed to apparent satiation, once daily, with either a menhaden-oil-supplemented diet (OSD; 6.78% total lipid) or a diet with no oil supplement (USD; 4.12% total lipid). Fish were harvested after 295 days. Mean production yields were 3974 kg/ha for SB × WB hybrids fed OSD; 3629 kg/ha for SB × WB hybrids fed USD; 2462 kg/ha for SB × YB hybrids fed OSD; and 2048 kg/ha for SB × YB hybrids fed USD. Weight gains of SB × WB hybrids fed oil-supplemented and unsupplemented diets were higher than weight gains of SB × YB hybrids fed either diet. Weight gain, feed efficiency ratio, and dietary protein and energy retention of SB × WB hybrids did not differ significantly among fish fed oil-supplemented or unsupplemented diets. However, SB × YB hybrids fed OSD had lower dietary protein and energy retention than those fed USD. Percentages of lipid in whole body and fillets of both hybrids increased with time, regardless of diet fed, but lipid content of fish did not differ among treatments. Fillet yield did not differ between SB × WB and SB × YB hybrids or among fish fed either diet. Results indicated that (1) SB × WB hybrids produced higher yields in ponds than SB × YB hybrids, and (2) increasing the dietary lipid level above 4% had no beneficial effect on production, feed efficiency, or body composition of either hybrid. A low-lipid practical diet of the type used in this study was suitable for production of SB × WB and SB × YB hybrids in ponds.

Amino Acid Availability of Soybean Meal for Florida Pompano

Abstract Availability of amino acids in soybean meal was determined in a feeding trial with Florida pompano Trachinotus carolinus by using a standard digestibility marker method. Fecal samples were manually stripped from anesthetized fish to avoid contact with water and resultant leaching losses. Apparent amino acid availability coefficients (mean ± SD) for dehulled, solvent-extracted soybean meal ranged from 78.4 ± 2.2% to 96.5 ± 1.0%. Apparent energy digestibility was 67.4 ± 0.8%. Apparent crude protein digestibility was 84.3 ± 0.5%.

Growth Performance and Body Composition of Palmetto Bass Fed Five Levels of Dietary Protein at Two Energy-to-Protein Ratios

Abstract A feeding trial was conducted to determine the effects of dietary crude protein (CP) level and digestible energy-to-protein (DE:P) ratio on the growth performance and body composition of palmetto bass (female striped bass Morone saxatilis × male white bass M. chrysops). Ten soybean-meal-based diets were prepared to contain 30, 35, 40, 45, or 50% CP at DE:P ratios of 33.48 or 41.85 kJ/g CP. The diets contained lyophilized palmetto bass muscle as the sole animal protein source to improve dietary amino acid composition. Wheat middlings and corn grain were the major sources of carbohydrates, and the diets were formulated to meet the known nutritional requirements of palmetto bass. Fish fed 35% or 40% CP at 33.48 or 41.85 kJ/g CP had significantly (P ≤ 0.05) greater weight gains and higher feed efficiency ratios than fish fed the other diets. The protein efficiency ratio (g weight gain/g CP consumed) decreased and visceral fat ([g visceral fat × 100]/g body weight) increased as the dietary protein lev...