Partial or total replacement of fish meal in the diets of Florida pompano Trachinotus carolinus

Two trials were conducted to evaluate the efficacy of commercial enzyme‐treated soy (ESBM) to replace the use of fish meal (FM) in practical diets for Florida pompano Trachinotus carolinus. The reference diet which has been run in numerous trials for Florida pompano was formulated using 150, 466 and 80 g/kg of FM, soybean meal and corn protein concentrate respectively. In trial 1, test diets were produced by replacing FM with 30.8, 61.4 and 92.1 g/kg of ESBM. In trial 2, test diets were produced by replacing FM with 28.9, 89.8, 120.1 g/kg of ESBM. Triplicate group of fish in trial 1 (mean weight = 13.05 ± 0.34 g) and trial 2 (mean weight = 18.45 ± 0.49 g) was fed these diets to apparent satiety for 8 weeks. Growth performance was affected as the dietary FM was replaced with ESBM. In trial 1, final weight (FW), percentage weight gain and thermal growth coefficient were lower in 6 g/kg of FM compared to 15 g/kg, while feed conversion ratio significantly higher in fish fed the lowest inclusion level of FM (6 g/kg). In trial 2, FW was significantly lower when FM completely replaced by ESBM and no significant differences in other growth parameters. In all trials, no significant differences were observed in terms of crude protein, moisture, fat, crude fibre, dry matter and ash content of the fish. No significant differences in serum levels of total protein, albumin, alkaline phosphatase, alanine transaminase, aspartate transaminase, glucose and bile acids were observed in either trial. However, in trial 1, serum cholesterol level was higher in fish fed 150 g/kg FM compared to other dietary treatments. The histomorphological structure of liver and distal intestine was slightly affected by lower inclusion level of FM. Overall, there was a decreasing trend in pompano growth performance as the inclusion of FM decreased. All parameters indicated that ESBM could be used to reduce the inclusion of FM from 150 to 90 g/kg.     

Quantitative taurine requirement for juvenile Florida pompano (Trachinotus carolinus) fed soy‐based practical diets

Florida pompano Trachinotus carolinus is an important species in which the essentiality of taurine has been demonstrated, yet a quantitative requirement has not been estimated. Two experiments were conducted where a combined twelve diets were formulated with graded levels of taurine (ranging 1.6–41.6 g/kg dry matter) and fed to juvenile pompano (initial weight 7.73 and 4.37 g in trial 1 and 2, respectively). Dose responses were observed in terms of growth, feed efficiency and whole‐body taurine content, but there was no effect on survival. Several regression models were evaluated to determine the most appropriate one to draw conclusions from. A 4‐parameter saturation kinetic model was selected to model feed efficiency, while a 5‐parameter saturation kinetic model fitted the growth data (as thermal‐unit growth coefficient, TGC). A broken‐quadratic model served to estimate a breaking point in the whole‐body taurine content, although it also showed that whole‐body taurine kept increasing even at dietary levels in far excess of the requirement. The dietary taurine requirement was estimated at 2.5 g/kg (2.0–3.3 g/kg, 95% CI, dry matter basis) based on feed efficiency, while TGC was maximized at levels between 4.9 and 31.4 g/kg dietary taurine.     

Fish meal replacement with solvent‐extracted soybean meal or soy protein isolate in a practical diet formulation for Florida pompano (Trachinotus carolinus,L.) reared in low salinity

Two 8‐week growth trials were conducted with juvenile Florida pompano, Trachinotus carolinus fed 0–1000 g kg^?1 replacement of fish meal (FM) protein with soybean meal (SBM) or soy protein isolate (SPI). Practical‐type diets were formulated with at least 360 g kg^?1 digestible protein and 24 mg kJ^?1 digestible protein/digestible energy. Weight gain and efficiency were not different between 0 and 800 g kg^?1 FM protein replacement with SBM. Regression of weight gain and protein productive value suggested a conservative level of SBM substitution was 380 g kg^?1 FM protein. It appeared that lysine could be limiting beyond 400 g kg^?1 FM replacement. No significant differences were detected in fish fed 0 and 200 g kg^?1 FM protein replacement with SPI. A decrease in weight gain and efficiency parameters occurred at 400 g kg^?1 protein replacement, and fish fed a replacement of 600 g kg^?1 or greater with SPI exhibited signs of starvation. A third trial indicated intake and growth were significantly reduced (P < 0.0001) in fish fed 600 g kg^?1 relative to 0 g kg^?1 FM protein replacement with SPI. Poor palatability of diets containing 400 g kg^?1 or more FM protein replacement with SPI appeared to be the causative factor for poor performance.     

Comparative effect of advanced soy products or corn protein concentrate with porcine meal on growth,body composition,and distal intestine histology of Florida pompano,Trachinotus carolinus

The present study was designed to investigate the effects of diets containing advanced soy products (enzyme‐treated soy and fermented soy) or corn protein concentrate (CPC) in combination with porcine meal (PM) to completely replace poultry byproduct meal (PBM) on growth performance, body composition, and distal intestine histology of Florida pompano, Trachinotus carolinus. Four experimental diets were formulated to be isonitrogenous and isolipidic, to contain 400 g/kg crude protein and 80 g/kg lipid. A reference diet (PBM diet [PBMD]) contained 150 g/kg PBM and 495 g/kg soybean meal (SBM), and three test diets were formulated replacing PBM with 15 g/kg of CPC (CPC diet [CPCD]) or replacing all SBM and PBM with 535 g/kg fermented soy (fermented soybean meal diet [FSBMD]) or 451.3 g/kg enzyme‐treated soy (enzyme‐treated soybean meal diet [ESBMD]). All three test diets were supplemented with 38 g/kg of PM. Diets were fed based on a percentage of bodyweight adjusted after sampling the fish every 2 weeks to triplicate groups of Florida pompano juveniles (mean weight 8.06 ± 0.22 g). After 8 weeks of feeding, fish fed CPCD and ESBMD performed equally well in terms of final body weight, thermal growth coefficient, and percentage weight gain in comparison to fish fed PBMD. In all cases, feeding FSBMD resulted in poor feed conversion and lower feed intake compared to other treatments. Protein retention efficiency, whole‐body proximate composition, phosphorus, sulfur, potassium, magnesium, calcium, sodium, and zinc contents were not significantly influenced by the dietary treatments. The results obtained in the present histological study showed no significant differences in the thickness of serous layer, muscular layer, and submucosal layer of the intestine among treatments. Fish fed CPCD showed a significant widening of the lamina propria with an increase of cellular infiltration and higher presence of goblet cells compared to other dietary treatment. Based on these results, 451 g/kg ESBM or combination of 150 g/kg of CPC and 495 g/kg SBM supplemented with 38 g/kg PM can be utilized to develop a practical diet for juvenile Florida pompano without impacting growth, nutritive parameters, and several distal intestine health parameters.     

Development of plant‐based diets and the evaluation of dietary attractants for juvenile Florida pompano,Trachinotus carolinus L.

Sustainable and profitable commercial aquaculture production of marine fish species is dependent on the development of sustainable protein sources as substitutes for expensive animal meals such as fishmeal (FM). Previous Florida pompano Trachinotus carolinus studies have indicated that poultry by‐product meal (PBM) and meat and bone meal can be used to produce a FM‐free diet if suitable levels of nutrients (such as taurine) are included in the diets. In this study, we attempted to develop an all‐plant protein diet by removing the animal proteins in practical diets for pompano by substituting back select ingredients. A series of eight FM‐free diets were formulated, four systematically replaced soybean meal (SBM) with soy protein concentrate (SPC) and four replaced PBM with SPC. Based on the results, there is no clear disadvantage to the use of SPC as a replacement for SBM. However, the complete removal of PBM resulted in reduced performance. Two additional growth trials were conducted to supplement additional amino acids including glycine, valine and histidine, a proprietary chemical attractant mix, fish protein concentrate and squid hydrolysate to improve the growth of pompano when fed all‐plant protein diets. The only improvement in performance occurred with the squid hydrolysate. These results demonstrate that using soybean meal, soy protein concentrate and corn gluten meal as the primary protein sources, a plant‐based feed formulation can be developed, but the removal of all animal proteins is not yet feasible.     

Apparent digestible protein,energy and amino acid availability of three plant proteins in Florida pompano,Trachinotus carolinus L. in seawater and low‐salinity water

Two experiments were conducted with Florida pompano, Trachinotus carolinus L. 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 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. The data suggest that SBM, SPI and CGM should be further evaluated as partial fishmeal replacements in Florida pompano diets. Application of the generated coefficients can be used to develop well‐balanced, low‐cost diets for Florida pompano reared in low salinity or seawater.     

Heritability estimates for growth‐related traits in the Pacific oyster (Crassostrea gigas) using a molecular pedigree

Pacific oyster is one of the leading species in world aquaculture, but heritability estimation applying mixed‐family approach has not been actively pursued. In this study, heritability for growth‐related traits in the Pacific oyster was first estimated by creating a single cohort of 45 families in a full‐factorial mating design consisting of nine sires and five dams. A total of 270 offspring were analysed and parentage assignment inferred by six microsatellite markers achieved 100% success. All parents contributed to the spawn and a total of 42 full‐sib families were represented. Using an animal model, heritability estimates at 12 months of age were 0.49 ± 0.25 for shell height, 0.36 ± 0.19 for shell length, 0.45 ± 0.23 for shell width and 0.35 ± 0.17 for wet weight. Genetic correlation between shell height and wet weight was quite high (0.79 ± 0.25), suggesting that direct selection of shell height, which is an easily measurable trait, also improves wet weight. The results obtained in this study indicate that growth‐related traits could be improved by exploiting additive genetic effects through selective breeding.     

三角帆蚌紫色选育系1龄阶段内壳色及生长性状的遗传参数估计

采用群体选育辅助种内群体间杂交选育的方法,以内壳色、体质量作为选育性状,经过连续4代的选育获得了紫色选育系F4。本实验以F4为亲本进行繁殖,利用6对微卫星标记,对15个同批繁育的F4母蚌的1龄后代进行亲子鉴定,鉴别出了来自12个父本、15个母本的42个全同胞家系,使用ASREML软件的约束极大似然法对三角帆蚌内壳色及生长性状进行了遗传参数分析。结果显示,内壳色颜色参数L*、a*、b*、dE*的遗传力分别为0.31±0.22、0.11±0.08、0.36±0.18、0.29±0.19,L*、a*、b*之间的遗传相关和表型相关均较低,范围为0.08~0.47和0.04~0.32,L*与dE*相关性最大,遗传相关为-0.94±0.06,表型相关为-0.96±0.01;生长性状壳长、壳高、壳宽、体质量和壳重的遗传力分别为0.24±0.19、0.37±0.27、0.26±0.16、0.26±0.17、0.31±0.19,各性状间遗传相关和表型相关均为正相关,分别为0.71~0.92、0.66~0.94;颜色参数与生长性状的遗传相关和表型相关均很低,为0.02~0.18。三角帆蚌紫色选育系1龄阶段内壳色和生长性状的遗传力多为中高水平,对其继续进行遗传改良预期能够获得良好遗传进展。内壳色与生长性状的相关度很低,无法实现相互选择,体质量与其他生长性状相关均较紧密,表明将内壳色、体质量作为目标性状进行同步选育的方法合理,可实现同时改良壳色及生长性能的目的。