Amino acids composition difference and nutritive evaluation of the muscle of five species of marine fish, Pseudosciaena crocea (large yellow croaker), Lateolabrax japonicus (common sea perch), Pagrosomus major (red seabream), Seriola dumerili (Dumeril's amberjack) and Hapalogenys nitens (black grunt) from Xiamen Bay of China

A study was conducted to investigate the muscle amino acid profiles of five species of marine fish, Pseudosciaena crocea (large yellow), Lateolabrax japonicus (common sea perch), Pagrosomus major (red seabream), Seriola dumerili (Dumeril's amberjack) and Hapalogenys nitens (black grunt). These carnivorous fishes, all of which belong to the Perciforms, were sampled from Xiamen Bay. Chemical analysis shows significant difference (P < 0.01) among the five species in the muscle total amino acids (TAA). Lateolabrax japonicus has the highest level of TAA in muscle tissues. Significant difference in muscle total essential amino acid (TEAA) and total non‐essential amino acid (TNEAA) were also found among the five species. Lateolabrax japonicus has the highest TEAA level, and H. nitens has the highest level of TNEAA level. Significant difference (P < 0.01) existed in specific EAA except for lysine (P > 0.05). The significant difference (P < 0.05) of the A/E ratios [(each essential amino acid content/total essential amino acid content including cystine and tyrosine) ×1000] based on the essential amino acid composition of muscle tissue from the five species were found in lysine, histidine, methionine, cystine, valine, leucine, isoleucine, and arginine, except for threonine, phenylalanine and tyrosine. These differences indicate that the amino acids profile is species specific for the five species and their essential amino acid requirements are greatly different although they were fed similar feed. In contrast to the reference amino acid profile recommended by FAO/WHO, muscle proteins of each fish were all rich in lysine, the S‐containing amino acids and threonine, but histidine, valine, leucine, isoleucine, phenylalanine and tyrosine were deficient for children's diets. The first limiting amino acid was histidine for P. crocea and L. japonicus, valine for P. major and H. nitens, leucine for S. dumerili. The amino acid score was 66.8, 76.7, 78.4, 84.0 and 95.7 for P. crocea, L. japonicus, P. major, H. nitens and S. dumerili, respectively. In the adult human diet the muscle protein of the five species of marine fish can almost fulfil the requirements of all essential amino acids except for the histidine of P. crocea and L. japonicus and thus can serve as supplemental source of protein in cereal‐based adults diets if we reinforce the histidine correspondingly. Therefore, increasing the proportion of marine fish in the diet of the people in the area where paddy rice and wheat are the main protein sources is an effective way to enhance the nutrition value of food and improve the nutrition status of the developing countries. Moreover, all of five marine fish species contained a comparatively high content of glutamic acid and arginine, which are beneficial to the patients under such conditions as trauma, burn injury, massive small‐bowel resection and renal failure.     

Whole-body amino acid pattern of juvenile,preadult, and adult pacu,Piaractus mesopotamicus,with an estimation of its dietary essential amino acid requirements

In the present study, juvenile (live body weight, 54.3 ± 8.2 g), preadult (live body weight, 822.5 ± 33.9 g), and adult (live body weight, 1,562.8 ± 41.8 g) pacu, Piaractus mesopotamicus, were used to estimate their dietary essential amino acid (EAA) requirements using the whole-body amino acid (AA) pattern. The results showed that whole-body moisture, crude protein, total lipid, and ash contents expressed on a wet weight basis (%) were significantly different among the studied growth phases. No significant differences were observed in the dietary EAA requirements estimated for the three growth phases of pacu. These dietary EAA requirements were found to be different than those previously estimated for the same fish through its muscle AA pattern. Based on whole-body EAA to total EAA ratios {A/E ratios; [(each EAA/total EAA) × 1,000]}, EAA requirements were estimated to be histidine (0.42%), arginine (1.36%), threonine (0.82%), valine (0.90%), methionine (0.45%), isoleucine (0.83%), leucine (1.29%), phenylalanine (0.74%), lysine (1.64%), and tryptophan (0.14%) for pacu. These estimated requirements may serve as a reference line in the formulation of practical and experimental diets until dose–response-based optimum EAA requirements are available for pacu.     

Amino Acid Profile of Various Body Tissues and Eggs of Discus Fish,Symphysodon aequifasciata

Abstract

Amino acid profiles of various body tissues from juvenile and adult discus fish, Symphysodon aequifasciata, were compared. Results from whole-body tissue revealed significant difference (P < 0.05) between the levels of lysine, phenylalanine, alanine, aspartic acid, and serine among the two different fish sizes. Levels of arginine, histidine, leucine, methionine, phenylalanine, and threonine were also higher in muscle tissue of adult fishes. Analysis of gill tissues showed significant difference in levels of histidine, isoleucine, lysine, methionine, threonine, tryptophan, aspartic acid, glutamic acid, proline, and serine were significantly different among the different fish stages. This study also showed that among all ten essential amino acids, muscle had the highest levels of histidine, isoleucine, lysine, and tryptophan; gills had the highest level of arginine; while levels of methionine and threonine were higher in the intestinal tissue. Regression analysis between the calculated whole-body A/E ratio of discus juveniles and with quantitative dietary amino acid requirements of several fish species also showed significant correlation, with highest r values (> 0.90) obtained with tilapia, common carp, channel catfish, and Japanese eel. This profile may be useful as a preliminary reference index to evaluate suitability of various ingredients in terms of amino acid profile for development of economical diet for discus farming.     

Egg and whole-body amino acid profile of African bonytongue (<Emphasis Type="Italic">Heterotis niloticus</Emphasis>) with an estimation of their dietary indispensable amino acids requirements

African bonytongue, Heterotis niloticus, is a river fish from the Central and West Africa basin. The species presents a great potential for fish farming and has been increasingly raised in Central and South Cameroon. The total amino acid and proximate composition of the whole body of egg, larva, juvenile, immature, and adult Heterotis were determined. Ash, moisture, whole-body protein, and lipid contents were significantly affected by size (P < 0.05). On the other hand, the amino acid composition of the whole-body tissue, when expressed as a percentage of dietary protein, was not significantly different among ontogenetic stages (ranging from 0.2 to 400 g mean body mass). The amino acid composition of the eggs was quite different to the one of whole-body tissue with lower levels of methionine, proline, and glycine, and higher levels of arginine, histidine, isoleucine, leucine, threonine, valine, serine, and alanine. The A/E ratios of adult Heterotis muscle tissue are similar to those obtained for other fish species, except for histidine and tryptophan. Based on whole-body or muscle tissue indispensable amino acids (IAA) to A/E ratios, the IAA requirement profiles for Heterotis (from larva to adult) were estimated and are similar to those of other omnivorous fish species, except for tryptophan and histidine.     

Dietary Lysine Requirement as Basis to Estimate the Essential Dietary Amino Acid Profile for Jundiá, Rhamdia quelen

The present study was designed to determine the optimal dietary lysine requirement for jundiá, Rhamdia quelen, fingerlings. Groups of 17 fish (1.4 ± 0.1 g) were stocked in 120‐L tanks and were fed semipurified diets (33% crude protein [CP] and 3500 kcal metabolizable energy) containing increasing concentrations of lysine (3.0, 4.0, 4.5, 5.0, 5.5, 6.0, and 6.5% CP). After 119 d, fish weight gain (WG), specific growth rate (SGR), feed intake and feed conversion (FC), apparent net protein utilization (ANPU), body composition (CP, fat, and ash), and vertebral collagen were determined. WG and SGR increased as dietary lysine concentration in protein increased up to 4.5%, reducing at 6.0 and 6.5% lysine. Fish that were fed the lowest lysine concentration presented the worst feed conversion (FC), which improved for fish fed with 4.5% or more lysine. Feed consumption followed the same trend as FC. The highest ANPU was observed in fish fed with 4.5% lysine. Fish fed diets containing 4.5, 5.0, and 5.5% lysine accumulated more body protein (P < 0.05). Collagen vertebral concentration was significantly higher in fish fed with the 4.5% lysine diet. Dietary requirement for lysine was 4.5 or 5.1% depending on the statistical model used for estimation: broken line or polynomial regression, respectively. The requirements for the other essential amino acids were estimated on the basis of the ideal protein concept and were similar to the requirements for other fish species, except for isoleucine, leucine, treonine, and valine, which were higher for jundiá.     

The optimum dietary essential amino acid pattern for rainbow trout (Oncorhynchus mykiss), to maximize nitrogen retention and minimize nitrogen excretion

The optimum dietary essential amino acid (EAA) pattern for a given animal species is considered to be that EAA pattern which results in maximum nitrogen (N) retention for protein growth and minimum N excretion. In a series of two 8-week experiments, we investigated the optimum dietary EAA pattern for rainbow trout (Oncorhynchus mykiss). Experimental diets were fed to quadruplicate tanks of fish, using the equalized satiation feeding method. In the first experiment, we used the amino acid deletion method to arrive at an estimate of optimum dietary EAA pattern for rainbow trout. There were 11 dietary treatments: 1 diet with a control EAA pattern, and 10 other diets with 40% deletions of a single EAA from the control pattern. Based on N utilization data, an estimate of optimum dietary EAA pattern for rainbow trout was made. In the second experiment, we compared this dietary EAA pattern with three other estimates of optimum dietary EAA pattern for rainbow trout, based on 1) amino acid composition of rainbow trout whole-body protein, 2) EAA requirements for rainbow trout published by the National Research Council, and 3) EAA requirements for rainbow trout based on nonlinear regression analysis. Response variables included growth rate, feed efficiency ratio and N retention and excretion. The EAA pattern associated with EAA requirements as published by the National Research Council was found to result in the highest mean N retention and lowest mean N excretion, and so was considered the best estimate of optimum EAA pattern of those compared.     

Estimating the ideal dietary indispensable amino acid pattern for growth of white sturgeon, Acipenser transmontanus (Richardson)

Juvenile white sturgeon (Acipenser transmontanus, Richardson) were fed or starved for 4 weeks, and their whole body amino acid composition determined at the beginning and the end of the study. The amino acid compositions of muscle, liver, gill and gastrointestinal tract, and the free amino acids in plasma of fed and starved fish were also determined. Very little variation was observed in the amino acid compositions of all the tissues examined after starvation. However, the plasma free amino acids were significantly (P < 0.05) decreased following starvation. On the basis of the amino acid composition and nitrogen retention values of the whole fish, daily indispensable amino acid requirements for protein accretion and obligatory nitrogen losses (mg amino acid 100 g body weighr^?1 day^?1) were estimated. The pattern of indispensable amino acids required for each of these is different, with the pattern for protein accretion containing much higher levels of lysine, but lower levels of tryptophan and sulfur amino acids. Individual amino acid retention rates varied from 33.3% of dietary tryptophan to 80.2% for arginine. The estimated dietary indispensable amino acid pattern for young growing white sturgeon (expressed as a percentage of total indispensable amino acids plus cystine and tyrosine) is: arginine, 14.0; histidine, 6.6; isoleucine, 8.8; leucine, 12.5; lysine, 15.8; methionine (plus cystine), 6.6; phenylalanine (plus tyrosine), 15.5; threonine, 9.7; tryptophan, 0.8; and valine, 9.7.     

Assessment of requirement values for essential amino acids in the prawn, Marsupenaeus japonicus (Bate)

The requirements of juvenile prawn, Marsupenaeus japonicus (Bate), 0.79 g initial body weight, for essential amino acids (EAA) were evaluated based on the daily increase of each EAA in the whole body when the prawn was maintained on a diet with a high nutritive value (a casein‐squid protein‐based diet). The quantities of each EAA needed daily for growth and maintenance of prawn are conceived to correspond to the daily requirements of this prawn species for EAA. Therefore, these requirement values of respective EAA should be supplied from dietary proteins. To determine these values, protein and amino acids of the whole body of the prawn were quantified before and after feeding experiments, and the quantities of respective EAA needed to meet the requirements were estimated based on the EAA profile of the whole body protein of prawn. As a result, the contents of EAA in dietary proteins (%) needed to meet the requirements of the prawn for EAA were assessed to be: threonine (2.3), methionine (1.3), valine (2.4), isoleucine (2.3), leucine (3.4), phenylalanine (2.6), lysine (3.2), histidine (1.1), arginine (2.9) and tryptophan (0.6), respectively, when the prawn are fed 50% protein diet with 90% protein digestibility at a ration size of 2% (% of body weight).     

哲罗鱼稚鱼氨基酸的需要量

采用高生物价的酪蛋白、明胶为蛋白源的蛋白饲料(PD)和无蛋白饲料(FPD)饲养哲罗鱼稚鱼(6.8～7.3g),通过在实验开始和结束时测定鱼体氨基酸的组成,研究氨基酸的增重需要和维持需要,并计算哲罗鱼必需氨基酸的需求量。试验在室内玻璃钢水族箱中进行,分两个处理,每个处理3个重复,每个重复25尾鱼。试验期间水温23～25℃,溶氧为6.4～7.5mg/L,试验共进行28d。试验结果表明,与FPD组相比,PD组鱼成活率、饲料系数、增重率、粗脂肪的含量均显著升高(P<0.05),而FPD组的水分含量显著增加(P<0.05)。PD组和FPD组鱼体粗蛋白的末含量与初始值相比差异不显著(P>0.05)。鱼体必需氨基酸的维持量(除色氨酸外)均占鱼体必需氨基酸的增加量和维持量之和的20%～30%,色氨酸占54.52%,所以在估计鱼体必需氨基酸的需要量时,鱼体必需氨基酸的维持量是不能忽略的。哲罗鱼各种EAA需求量[g/(100g鱼体重)/d]为苏氨酸(Thr)0.040,缬氨酸(Va1)0.041,蛋氨酸(Met)0.027,异亮氨酸(I1e)0.034,亮氨酸(Leu)0.067,苯丙氨酸(Phe)0.035,赖氨酸(Lys)0...     

Estimating maintenance amino acids requirements of fish through a nonlinear mixed modelling approach

Accurate estimates of maintenance requirement of amino acids are important for feed formulation. However, very little is known about maintenance requirements of essential amino acids in fish. A nonlinear mixed modelling approach was employed in this study to estimate maintenance requirements of essential amino acids of fish from published studies. The maintenance requirements of arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine were estimated to be 7.7 (±6.6), 9.8 (±2.4), 6.4 (±24.8), 9.1 (±13.7), 15.6 (±8.2), 18.4 (±1.9), 14.6 (±3.2), 5.4 (±4.4), 0.5 (±1.3) and 9.3 (±26.6) mg/kg BW^0.75/day respectively, whereas the maintenance requirements of these amino acids as a proportion of their total requirements for protein deposition were estimated to be 4.8%, 31.0%, 8.9%, 12.7%, 5.2%, 11.9%, 19.2%, 2.5%, 2.2%, 10.8% respectively. For most of the essential amino acids, the maintenance requirements represent a small proportion of total requirement (below 10%) with notable exceptions for histidine and phenylalanine. Results from this study suggest that maintenance requirements of fish cannot be assumed equal for all amino acids. The results can be used in developing factorial or mechanistic models of amino acid requirement and utilization.     

达里湖高原鳅肌肉营养成分分析与品质评价

采用常规生化分析方法分析和评价内蒙古达里诺尔湖达里湖高原鳅Triplophysa dalaica肌肉的营养成分。结果表明:达里湖高原鳅全鱼和肌肉的水分、粗蛋白、粗脂肪、粗灰分含量分别为:(74.28±1.04)%和(78.30±0.23)%、(14.57±0.02)%和(17.77±0.05)%、(7.15±1.56)%和(1.77±0.03)%、(3.45±0.14)%和(1.14±0.05)%。达里湖高原鳅肌肉中共检测出18种氨基酸,总量(TAA)为(13.80±0.92)%,其中8种必需氨基酸(EAA)总量为(5.72±0.37)%,占氨基酸总量的(41.43±0.69)%,必需氨基酸总量(TEAA)/非必需氨基酸总量(TNEAA)为(70.76±1.99)%,其必需氨基酸比例符合FAO/WTO的理想模式。依据氨基酸评分标准(ASS),达里湖高原鳅的第一、第二限制性氨基酸分别为缬氨酸、色氨酸;依据化学评分标准(CS),达里湖高原鳅的第一、第二限制性氨基酸分别为色氨酸、蛋氨酸+胱氨酸,必需氨基酸指数(EAAI)为55.52。肌肉中鲜味氨基酸(DAA)总量为(5.29±0.24)%,占氨基酸总量的(38.40±1.07)%,支链氨基酸(BCAA)与芳香族氨基酸(AAA)的比值(F)为(2.48±0.16)。肌肉中共检测出22种脂肪酸,多不饱和脂肪酸(PUFA)总含量为(23.50±0.12)%,其中二十二碳六烯酸(DHA)+二十碳五烯酸(EPA)含量为(9.37±0.10)%,必需脂肪酸(EFA)含量为(10.07±0.29)%。分析结果表明,达里湖高原鳅具有合理的氨基酸和脂肪酸组成,是一种味道鲜美、营养价值丰富的淡水鱼类,具有良好的开发利用前景。     

Feeding of juvenile cobia,Rachycentron canadum: Evaluation of practical feeds,comparison of commercial fishmeal replacers,and estimation of essential amino acid requirements

Three studies were conducted with juvenile cobia, Rachycentron canadum: (Study 1) a 10‐week feeding trial within floating net cages to test the nutritional efficacy of different dietary feeding regimes (trash‐fish control diet, a semimoist diet, an in‐house dry formulated diet, and a commercial cobia feed); (Study 2) a 10‐week feeding trial within an indoor water‐recirculating tank‐based system to test the nutritional efficiency of different potential dietary fishmeal replacers (poultry byproduct meal, soy protein concentrate, feather meal), a diet without taurine supplementation, and a commercial cobia feed; and (Study 3) estimation of the essential amino acid (EAA) requirements of cobia based on EAA whole‐body composition in fast‐growing cobia fed a trash‐fish‐based diet. Fish performance in terms of growth and feed efficiency was the greatest within the outdoor net‐cage feeding trial, with fish fed the control trash‐fish‐based diet exhibiting the best performance. Although fish growth was poorer within the indoor feeding trials, fish performance was similar for most diets, with apparent crude protein digestibility coefficients of over 75% being obtained in all experimental diets in both feeding trials. The estimated EAA requirements of cobia obtained during this study were similar to those reported for other similar marine carnivorous fish species.     

Proximate,Fatty Acid,and Amino Acid Compositions of Fish Muscle and Egg Tissue of Hilsa (Tenualosa) ilisha

The total lipid profile including the fatty acid composition and amino acid composition in eggs of Hilsa (Tenualosa) ilisha was studied in comparison with its muscle tissue. The eggs contained 30.4% lipid (on dry basis), which was 1.2 times higher than that of the muscle tissue lipid. The major portion of the egg lipid was composed of wax ester (about 47.6%) followed by triacylglycerol (TAG), phospholipid (PL), and cholesterol. The muscle tissue lipid contained TAG as the major fraction (41.8 ± 1.48%). Total amount of polyunsaturated fatty acids (PUFAs) was about 43 ± 0.05% and 32.4 ± 0.24% in egg PL and body tissue PL fractions, respectively. Among fatty alcohols of egg wax ester, 16:0 alcohol is predominant (56.4 ± 3.02%). Both the egg and muscle tissues are rich in all essential amino acids. The results indicate that muscle and eggs from Hilsa are rich in essential amino acids, PUFA, and phospholipids which are essential for human health and membrane development.     

Dietary lysine requirement of large yellow croaker (Pseudosciaena crocea,Richardson 1846) larvae

A 30‐day feeding experiment was conducted to estimate the lysine requirement of large yellow croaker larvae (2.75 ± 0.11 mg). Six isonitrogenous (509.5–519.7 g kg^?1 crude protein) and isoenergetic (22.3–22.5 kJ g^?1 energy) microdiets containing graded levels of lysine·HCl ranging from 24.8 to 41.0 g kg^?1 diet in placement of glycine and glutamic acid were formulated. Mixture of crystalline amino acids (MAA) was supplemented to simulate the amino acid (AA) profiles of whole body of this larva, except for lysine. The MAA and supplemented lysine for each diet were coated with tripalmitin. Triplicate groups of 3000 fish were fed to apparent satiation by hand eight times per day. The results showed that specific growth rate (SGR), survival, body composition and the specific activity of digestive enzymes were significantly affected by dietary lysine levels (P<0.05). The optimal dietary lysine requirements estimated by second‐order polynomial model based on SGR and survival were 33.7 (65.5 g kg^?1 dietary protein) and 33.4 (64.9 g kg^?1 dietary protein) g kg^?1 dry diet respectively. The estimated requirements for the other essential AAs were calculated by A/E ratios of whole body AA profile of this larva based on lysine requirement.     

Amino acid composition of Arctic charr, Salvelinus alpinus (L.) and the prediction of dietary requirements for essential amino acids

Embryo somatic tissues, non‐somatic yolk‐sac materials, and whole, individual fingerlings (age 0+) of Arctic charr, Salvelinus alpinus (L.), as well as a commercial trout diet, were analysed for a wide spectrum of amino acids. Analytical material consisted of prefeeding swim‐up fry that were separated into discrete yolk sac and somatic embryo tissue samples. Amino acid concentrations in fry somatic tissue and whole fingerlings were generally very similar to each other, but were lower than those measured in yolk materials. Higher correlations were observed between the majority of specific amino acid concentrations in the trout diet when compared with fingerling data (r² = 0.91) and fry somatic tissue data (r² = 0.89), than when correlated with fry yolk sac material (r² = 0.76). These results indicate that the essential amino acid profiles of fry somatic tissue and whole fingerlings are closer to that of a commercial feed than they are to the endogenous profiles found in the embryonic yolk sac material itself. The dietary ratios of individual essential amino acids were also compared with the total essential amino acid concentrations (A/E ratios) in whole fingerling tissues, and these ratios could be used to accurately estimate the apparent essential amino acid requirements of Arctic charr. The rationale for using carcass amino acid composition data to estimate the dietary essential amino acid requirements of Arctic charr is discussed.     

Nutritional quality of amino acid in farmed,farm‐aggregated and wild Axillary seabream (Pagellus acarne) with implications to Human Health

This study evaluated the nutritional quality of farmed and wild axillary seabream (Pagellus acarne R., 1827) focusing on amino acid profiles, with regards to possible interactions with wild fish aggregating around the cage facility. Total amino acids (∑AA), essential amino acids (∑EAA), non‐essential amino acids (∑NEAA) and neutral amino acids (∑NAA) in farmed fish were lower than those in the wild individuals (p > .05). Amino acid pattern in cage‐aggregated fish showed a slight decline from the wild populations, but still higher than the farmed fish. Based on the amino acid scores (AAS), lysine and leucine could be underlined as the ‘first limiting amino acids’, but all other AASs were over ‘1’, in accordance with reference amino acid contents of FAO/WHO (>1.00), showing that farmed axillary seabream provides high nutritional quality and can be considered as a favourable protein source. The ratios of ∑EAA/∑AA (44%–46%) and ∑EAA/∑NEAA (79%–86%) exceeded the minimum recommendation of 40% and >60% by FAO/WHO for all three groups. It can be concluded that axillary seabream either farmed, farm‐aggregated or distant wild fish presented high‐quality protein generating a healthy source for human food.     

Amino Acid Profiles of Bivalve Mollusks from Beibu Gulf,China

Three bivalve mollusks—clam (Meretrix meretrix), oyster (Crassostrea rivularis), and paphia (Paphia papilionacea) from the Beibu Gulf, China—were analyzed for amino acid profile. Essential amino acids were used for nutritional quality evaluation, and free amino acids were used for taste impact evaluation. The amino acid compositions of the mollusks were quite similar; however, the contents of glycine, alanine, and tryptophan were different. Tryptophan seemed to be the limiting amino acid in clam and paphia meat protein. Oyster, on the other hand, seemed to be a source of high quality protein with well-balanced composition in essential amino acid. Glutamic acid, alanine, glycine, and arginine were the major taste-active amino acids found in the mollusks. According to the taste activity values of free amino acids, paphia was assumed to be the best savory food, followed by clam and oyster.     

Amino Acid Availability of Four Practical Feed Ingredients Fed to Striped Bass Morone saxatilis

Four dietary protein sources were bio-assayed for amino acid availability, as estimated by true digestibility, when fed to striped bass Morone saxatilis . Diets were formulated to contain either herring fish meal, soybean meal, corn gluten meal or peanut meal as the sole source of dietary protein. A fifth diet, containing no protein, was fed to estimate the level of endogenous amino acids for calculation of true digestibility. The five dietary treatments were randomly assigned to ten tanks of striped bass having an average weight of 150 g per fish. All fish received the assigned diet fed at a rate 1.5% of the biomass per day for a period of 10 d. Fecal samples were collected from anesthetized fish by gentle, manual stripping of the lower digestive tract. Diets and feces were analyzed for dry matter, chromium, nitrogen and amino acid concentrations. There were no statistical differences (P > 0.05) among the protein sources for apparent dry matter digestibility or availability of arginine, threonine, valine and nonessential amino acids with the exception of cysteine. Corn gluten meal had a significantly lower availability coefficient for lysine, and peanut meal had significantly lower availability coefficients for histidine, isoleucine, leucine, and lysine when compared to herring fish meal and soybean meal. Statistically there were no differences between soybean meal and herring fish meal for any nutrient tested. These data suggest that in terms of amino acid availability and overall protein quality, soybean meal could be used to spare herring fish meal in striped bass diets, with corn gluten meal being equally as useful when supplemented with lysine or complemented with other proteins.     

印尼拟松鲷肌肉营养成分分析与评价

为分析和评价印尼拟松鲷(Datnioides pulcher)的营养价值,采用常规方法检测印尼拟松鲷肌肉的营养成分,并与同科经济鱼类和常见的优质淡水鱼类进行比较。结果显示,印尼拟松鲷肌肉中的水分、粗蛋白质、粗脂肪和粗灰分含量分别为65.6%、19.6%、7.6%和1.3%。在肌肉中共测得16种氨基酸,总含量为18.4%,其中,包含7种人体必需氨基酸(EAA),占氨基酸总量(TAA)的36.09%;必需氨基酸指数(EAAI)为79.46%,符合FAO/WHO所规定的人体必需氨基酸的均衡模式;印尼拟松鲷第一和第二限制性氨基酸分别是蛋氨酸和缬氨酸;特征性鲜味氨基酸(FAA)含量为42.15%。不饱和脂肪酸共16种,总量为68.41%,其中,油酸和亚油酸分别为23.99%和10.56%,并且含有丰富的DHA和鱼油中相对缺乏的DPA,含量分别为8.5%和5.1%。研究表明,印尼拟松鲷氨基酸含量均衡丰富,不饱和脂肪酸含量高,是兼具较高观赏价值和与食用价值于一身的可开发鱼类品种。     

Effects of dietary essential amino acid deficiencies on the growth performance and humoral immune response in silvery‐black porgy (Sparidentex hasta) juveniles

A 6‐week feeding trial was conducted for determining the effects of dietary essential amino acids (EAA) deficiencies on growth performance and non‐specific immune responses in silvery‐black porgy juveniles (4.7 ± 0.1 g initial weight). Eleven isoproteic (ca. 47%) diets were formulated including a control diet containing the optimum quantity of EAA, and ten EAA‐deficient diets. All diets contained 36% fish meal and 18.5% crystalline EAA and non‐essential amino acids (NEAA) as the main source of dietary proteins. All the EAA and NEAA incorporated in the crystalline amino acids mixture of the control diet simulated the amino acids profile of the fish meal. The other 10 EAA‐deficient diets were formulated by the deletion of each of the 10 EAA (crystalline form) from the control diet and replaced by a mixture of NEAA for the adjustment of dietary nitrogen contents. At the end of the experiment, fish fed with threonine‐deficient diet showed the lowest survival rate (p < .05), whereas growth performance decreased in fish fed all EAA‐deficient diets, although the reduction in body growth varied depending on the EAA considered. Plasma total protein decreased in all experimental groups except for fish fed the phenylalanine‐deficient diet. Fish fed with arginine‐ and lysine‐deficient diets had the lowest plasma C3, C4, lysozyme, total immunoglobulin and total superoxide dismutase activity (p < .05). Present results indicated that lysine, methionine and threonine were the most limiting EAA in terms of growth performance; however, arginine, threonine and lysine were the most limiting EAA for innate immunity responses in silvery‐black porgy juveniles.