Muscle Amino Acid Composition Research Articles

Alpha-linolenic acid/linoleic acid ratio can effectively promote muscle growth and protein deposition in grass carp (Ctenopharyngodon idella)

Polyunsaturated fatty acids (PUFAs) promoted the muscle structure (muscle fiber cross-sectional area and diameter, as well as thickness of the connective tissue surrounding muscle fibers-endomysium) and taste (fishy) of fillets. As members of the omega-3 and omega-6 PUFA family, alpha-linolenic acid (ALA) and linoleic acid (LNA) have important functions. This study explores influences of ALA/LNA ratio on muscle growth and protein deposition and its mechanisms. Six different diets containing ALA/LNA ratios (0.03, 0.47, 0.92, 1.33, 1.69, and 2.15) were fed to grass carp (Ctenopharyngodon idella) for 9 weeks. Results showed that according to the quadratic regression model, the optimal ALA/LNA ratios of grass carp were 1.12 and 1.22 using malondialdehyde content and muscle fiber diameter as indicators, respectively. Optimum ALA/LNA ratio promoted hypertrophy of myofibers, which might be attributed to genes related to myofiber development (myogenic determinant, myogenin, myosin heavy chain, myogenic regulatory factor 4 and myogenic factor 5). Optimum ALA/LNA ratio enhanced protein deposition, which might be associated with the promotion of protein synthesis (insulin-like growth factors-1, phosphoinositide 3-kinase, target of rapamycin), and inhibition of the ubiquitin-proteasome system and autophagy-lysosome system to inhibit protein degradation. In addition, optimum ALA/LNA ratio enhanced muscle amino acid composition and antioxidant capacity of fish.

Effect of the Bacillus subtilis BS20 on physiological and immune parameters in mutant mice Muc2–/–

Introduction. Inflammatory bowel disease (IBD) is a common pathology that cannot be completely cured and requires lifelong therapy. One of the promising and sparing therapeutic strategies is the use of probiotics. Unlike Lactobacillus and Bifidobacterium, which represent the basis of most classical probiotics, Bacillus spp. are spore-forming bacteria that contributes to their resistance to the acidic environment of the stomach. It has been shown that the bacteria Bacillus spp. is an effective therapeutic drug for the relief of intestinal diseases with signs of inflammation and bacterial origin. Since the main factors causing IBD are dysbiosis and inflammation, and strains of Bacillus spp. as probiotics can be potential modulators of immunity and influence the intestinal microbiome, it is necessary to search for new strains of probiotic bacteria, including representatives of Bacillus spp., which have an effect on immunity and physiological indicators in experimental models of IBD. The aim of the scientific research — to study the effect of Bacillus subtilis BS20 spores on the physiological and immune parameters of the mutant mouse line Muc2–/–. Research objectives: Investigate survival of Muc2–/– mice, weight, immune parameters (cytokines and immune cells) and amino acid composition of muscles. Materials and methods. Muc2–/– females were fed spores of Bacillus subtilis BS20 in the amount of 109 CFU for 2 months. Analysis of the amino acid composition of the femoral muscle was performed by capillary electrophoresis. The concentration of cytokines in the supernatant was measured using the Magnetic Luminex assay kit. Determination of the number of lymphocytes was performed by flow cytometry. Results. The addition of Bacillus subtilis BS20 to the diet of mice reduced mortality and body weight loss in Muc2–/– females. We found a decrease in interleukin-6 and an increase in interleukin-17 in the descending colon and an increase in B and T helper lymphocytes in the spleen. Conclusion. B. subtilis BS20 improves the general condition of Muc2–/– mutant mice, has an anti-inflammatory and immunostimulating effect, reducing the level of the cytokine interleukin-6 and increasing the percentage of B cells and T helper cells in the spleen.

Effects of Dietary Fish Meal Replaced by Cottonseed Protein Concentrate on Growth Performance, Antioxidant Capacity, and Liver and Intestinal Health of Juvenile Hybrid Culter

The objective of this study was to assess the impact of concentrated cottonseed protein (CPC) as a substitute for fishmeal (FM) in juvenile hybrid culter (Erythroculter ilishaeformis ♀ × Ancherythroculter nigrocauda ♂). A total of 360 fish with an initial body weight of 10.0 ± 0.5 g were randomly allocated into 12 indoor culture tanks, with each tank containing 30 fish. Four diets were formulated in which fish meal (FM) was replaced by CPC at different inclusion levels: 0% (T0), 15% (T15), 30% (T30), and 45% (T45). The corresponding amounts of CPC included were 0, 61, 122, and 182 g/kg, respectively. At the end of the 10-week feeding trial, the findings revealed an inverse correlation between the proportion of CPC replacing FM and both final body weight (FBW) and weight growth rate (WG) in hybrid culter. Specifically, the T30 and T45 groups exhibited significantly lower FBW and WG compared to the T0 group (p < 0.05). No significant differences in crude protein and ash contents were observed among all groups (p > 0.05). However, the crude lipid content was highest in hybrid culter fed the T45 diet and lowest in the T0 group (p < 0.05). There were no significant differences in muscle amino acid composition among all treatment groups (p > 0.05). The contents of total protein (TP) and albumin (ALB) declined slightly as the proportion of FM substituted by CPC increased, yet this decline did not reach statistical significance (p > 0.05). Serum alanine aminotransferase (ALT) activity elevated with increasing dietary CPC, and the T45 group exhibited significantly higher ALT activity compared to the T0 group (p < 0.05). The hepatic activities of superoxide dismutase (SOD) and catalase (CAT) were significantly lower in the T45 group than in the T0 and T15 groups (p < 0.05). Furthermore, there was a decrease in intestinal villi length with an increasing replacement ratio of FM by CPC, and the villi length in the T45 group exhibited a significant reduction when compared to that in the T0 group (p < 0.05). It is concluded that replacing 15% FM with CPC does not exert obviously detrimental effects on growth performance, serum biochemical indices, intestinal morphology, muscle amino acid profile, or antioxidant performance of juvenile hybrid culter.

Evaluation of fish meal replacement by Methylcoccus capsulatus protein in diets for juvenile Chinese softshell turtle (Pelodiscus sinensis)

The present study was to investigate the effects of Methylococcus capsulatus protein (MCP) replacing fish meal on the growth performance, immunity, and intestinal health of Chinese soft-shelled turtle (Pelodiscus sinensis). Four isonitrogenous (47.00% crude protein) and isolipidic (6.00% crude lipid) diets were formulated for an 8-week feeding trial. The fish meal group (FM) contained 55% fish meal. MCP was used to replace 10%, 15%, and 20% of the fish meal in the FM group to create MCP10, MCP15, and MCP20 treatment groups. No significant differences were observed in the weight gain, feed conversion efficiency, physical indicators, or muscle amino acid composition among all diet treatments (P > 0.05). The MCP15 group showed the best growth performance. There were no significant differences in serum biochemistry among the groups (P > 0.05), except for aspartate aminotransferase, which exhibited a significant linear increase trend with the increase of MCP replacement level (P = 0.049). In the MCP20 group, the complement C3 content, immunoglobulin M content, and lysozyme activity in serum were significantly lower than those in the FM, MCP10, and MCP15 groups (P < 0.05), showing a quadratic relationship characterized by an initial increase followed by a decrease as the MCP level in the feed increased (P < 0.05). The intestinal morphology in all treatment groups appeared normal and the expression levels of intestinal inflammatory cytokines showed no significant differences (P > 0.05). The community structure of the intestinal microbiota, as well as the phylum and genus composition underwent significant alterations in response to the MCP supplementation. The recommended practice for Chinese softshell turtle diet involves substituting 15% MCP for fish meal, which enhances growth, boosts immune response, and does not adversely affect serum biochemistry, amino acid composition, or intestinal health.

Effects of partial replacement of fishmeal with Spirulina platensis powder and addition of Spirulina platensis polysaccharide on growth, nutrition, antioxidant capacity and gut microbiota of Micropterus salmoides

Fish is currently considered a primary protein in the human diet, and the high demand for fish will stimulate the growth of aquaculture. However, a lack of high-quality fish feed (fishmeal) has led to a decline in the quality and yield of aquatic products. Therefore, an alternative high-quality protein source for fish meal is required to sustain the industry. This study assessed the effects of incorporating Spirulina platensis (SP) dried powder as a partial replacement for fishmeal and supplementing with S. platensis purified polysaccharides (PSP) on the growth, nutritional value, and health status of the largemouth bass, Micropterus salmoides, to address the challenges of fishmeal scarcity and promote sustainable development in fish aquaculture. Juveniles were fed four isonitrogenous and isolipidic diets containing SP at 0% (SP0), 3% (SP3) and 6% (SP6) and PSP at 0.3% for 56 days. The results showed that both the SP3 and SP6 groups displayed significantly (P < 0.05) improved growth performance and lower hepatosomatic indices than the control diet (SP0). Whole-body crude protein and protein efficiency significantly increased in both the SP3 and SP6 groups compared with SP0 (P < 0.05). Conversely, crude lipid content notably (P < 0.05) decreased in SP3 (5.96%) and SP6 (5.41%) in contrast to SP0 (6.59%). The muscle amino acid composition of the PSP, SP3, and SP6 groups also improved significantly (P < 0.05) compared to that of the SP0. Liver SOD activity was significantly increased from 1.11 U/mg in SP0 to 1.22–1.24 U/mg in SP3 and SP6 (P < 0.05), while MDA levels declined accordingly. Serum triglyceride levels were significantly lower in SP3 than in SP0 (P < 0.05) but remained stable in the SP6 and PSP groups. Low-density lipoprotein cholesterol decreased significantly in the SP3 and SP6 groups, but no significant effect was observed in the PSP group. Alanine aminotransferase activity was significantly (P < 0.05) lower in the PSP, SP3, and SP6 groups than in SP0. Aspartate aminotransferase activity in PSP and SP3 was significantly lower than in SP0 (P < 0.05), but showed no significant difference with SP6 (P > 0.05). Intestinal trypsin and amylase activities significantly improved in the PSP, SP3, and SP6 groups (P < 0.05), and lipase activities in PSP and SP3 increased significantly compared to those in SP0 (P < 0.05). The intestinal microbiome displayed significantly higher Shannon index scores for SP3 (0.83) and SP6 (0.93) than for SP0 (0.61). The relative abundances of the phylum Fusobacteria and genus Cetobacterium were significantly increased, whereas Proteobacteria and Plesiomonas were significantly decreased in the PSP and SP3 groups compared with that in SP0 (P < 0.05). The present study indicated that the replacement of fishmeal with 3–6% SP and 0.3% PSP addition could improve the growth performance, protein efficiency, muscle nutritional value, liver health, antioxidant capacity, intestinal digestive enzyme activity, and intestinal microbiota diversity of the largemouth bass. Therefore, the partial replacement of SP or the addition of PSP has great potential in promoting healthy aquaculture of largemouth bass.

Polystyrene nanoplastics exposure alters muscle amino acid composition and nutritional quality of Pacific whiteleg shrimp (Litopenaeus vannamei)

Litopenaeus vannamei were exposed to 80-nm polystyrene nanoplastics (NPs) at different concentrations (0, 0.1, 1, 5, and 10 mg/L) for 28 days to study the effects on muscle nutritional quality. Our results showed that with increasing NPs concentrations, the survival rate, specific gain rate, and protein efficiency ratio decreased but the feed conversion ratio increased. There was no significant difference in moisture, ash, and crude lipid content in the muscle, and a general decrease in crude protein content was observed. However, the total amino acid and semi-essential amino acid contents decreased. The spacing between muscle fibers and the melting morphology of muscle increased. The hardness of muscle flesh texture increased, but springiness, cohesiveness, and chewiness decreased. Regarding antioxidant enzyme activity, the activity of catalase decreased, but the total antioxidant capacity, superoxide dismutase activity, and reduced glutathione first increased and then decreased. The expression level of the growth-related genes retinoid X receptor (RXR), chitin synthase (CHS), and calmodulin A (CaM) first increased then decreased, but calcium/calmodulin-dependent protein kinase I (CaMKI), ecdysteroid receptor (EcR), chitinase 5 (CHT5), cell division cycle 2 (Cdc2), and cyclin-dependent kinase 2 (CDK2) decreased. Our results suggest that exposure to NPs can inhibit growth by inducing oxidative stress, which leads to muscle tissue damage and changes in amino acid composition. These results will provide a theoretical reference for the risk assessment of NPs and the ecological health aquaculture of shrimp.

The Effect of Replacing Whole-Plant Corn Silage with Daylily on the Growth Performance, Slaughtering Performance, Muscle Amino Acid Composition, and Blood Composition of Tan Sheep.

The shortage of high-quality coarse feed resources is the main factor that restricts the development of animal husbandry in many developing countries. The present study aimed to investigate the effects of replacing corn silage with daylily silage on the growth performance, slaughter performance, blood biochemical indicators, meat quality, and muscle amino acid composition of Tan sheep. A total of 72 healthy Tan sheep were randomly assigned to four groups. In each group, 0%, 20%, 40%, and 60% of corn silage were replaced with daylily silage (denoted as CON, HC20, HC40, and HC60, respectively). Tan sheep fed with daylily silage showed no significant adverse effects on their growth performance, meat quality, and muscle amino acid composition (p > 0.05). Some increase was observed in the carcass fat content value (GR-value, p < 0.05), thickness of backfat (p < 0.05), and the blood urea level (p < 0.05). These findings indicate that the utilization of daylily silage instead of whole-plant corn silage has no adverse effects on the growth performance and meat quality of Tan sheep, thus indicating that it can partially replace whole-plant corn feed as a feed resource for Tan sheep.

The Effects of Dietary Protein Level on the Growth Performance, Body Composition, Intestinal Digestion and Microbiota of Litopenaeus vannamei Fed Chlorella sorokiniana as the Main Protein Source.

This study investigated the effect of dietary protein levels on Litopenaeus vannamei. Five isolipid diets with protein levels of 32%, 36%, 40%, 44% and 48% were prepared using C. sorokiniana as the main protein source. L. vannamei (initial body weight 0.83 ± 0.02 g) were fed these five diets for 8 weeks and referred to as the CHL32, CHL36, CHL40, CHL44 and CHL48 groups, respectively. When the feeding trial was finished, the growth performance, body composition, intestinal digestion and microbiota of L. vannamei were studied. The results showed that the maximum weight gain rate (WGR) of L. vannamei was in the CHL40 group while the lowest feed conversion ratio (FCR) was in the CHL48 group. According to the regression analysis using WGR as the evaluation index, the best growth performance of L. vannamei was obtained when the dietary protein level was 40.81%. The crude protein content of whole shrimp showed an increasing and then decreasing trend with increasing dietary protein levels. Furthermore, the L. vannamei muscle amino acid composition was relatively stable and, to some extent, independent of dietary protein levels. Trypsin, lipase and amylase (AMS) activity increased and then decreased with increasing dietary protein levels and, significantly, peaked in the CHL44 group. Analysis of the alpha diversity of the intestinal microbiota showed that the Chao1 index peaked in the CHL40 group and was significantly lower in the CHL48 group. Additionally, the relative abundance of pathogenic bacteria decreased significantly while the relative abundance of beneficial bacteria increased significantly in the intestine of L. vannamei as the dietary protein levels increased. The functional prediction of the intestinal microbiota revealed that dietary protein levels may influence the growth of L. vannamei by regulating various metabolic activities, and the highest WGR in the CHL40 group may have been related to the significant enrichment of nicotinate and nicotinamide metabolism and biotin metabolism functions. In summary, the optimal protein requirement for L. vannamei was around 40% when C. sorokiniana was used as the primary protein source. Too high or too low dietary protein levels could adversely affect shrimp body composition, intestinal digestion and microbiota.

Evaluation of probiotic potentiality of GM-Lac (Lactobacillus and Bifidobacterium) in juvenile Asian seabass Lates calcarifer

This study was conducted to evaluate the probiotic potentiality of GM-Lac (a mixture that comprises four lactic acid bacteria (LAB) strains– Limosilactobacillus fermentum GMNL-93, Lactiplantibacillus plantarum GMNL-141, Lacticaseibacillus casei GMNL-277, and Bifidobacterium lactis GMNL-550) applied in fish aquaculture. First, the four LAB isolates (GMNL-93, −141, −277, and −550) constituting GM-Lac were tested individually for antimicrobial activity in vitro. Then, GM-Lac was incorporated in fish feed at a dose of 5 × 106 cfu (g feed)−1 and fed to Asian seabass (Lates calcarifer) juveniles for eight weeks to assess the effects on growth performance, gastrointestinal (GI) histology and microflora, muscle amino acid composition, and disease resistance. According to the result of the zone of inhibition test, each GMNL strain presented noticeable antimicrobial activity against bacterial pathogens common in aquaculture. After the 8-week feeding trial, the fish in the GM-Lac group had higher final weight (p < 0.05), percent weight gain, specific growth rate, and feed intake than the fish in the Ctrl group, along with higher microvillus length in GI tract (p < 0.05) and greater total amino acid concentration in muscle. Furthermore, the relative abundance of microbial phyla in the GI tract of the fish fed with GM-Lac changed significantly, accompanied by increasing probiotic bacteria and decreasing pathogenic bacteria in the intestine and pyloric caeca. In the challenge test, the fish receiving GM-Lac all survived without any clinical symptoms when challenged with Streptococcus iniae. This study concludes that GM-Lac (the combination of L. fermentum GMNL-93, L. plantarum GMNL-141, L. casei GMNL-277, and B. lactis GMNL-550) is recommended as a probiotic supplement with high potential in aquaculture practice, which has antimicrobial activities against aquatic pathogens and benefits in enhancing growth performance, intestinal health, muscle amino acid composition, and disease resistance in juvenile Asian seabass.

Evaluation of fish meal replacement by Clostridium autoethanogenum protein in diets for juvenile red swamp crayfish (Procambarus clarkii)

A study was conducted to investigate the potential use of Clostridium autoethanogenum protein (CAP) replacing fish meal (FM) in the diet of red swamp crayfish (Procambarus clarkia). Crayfish were fed with FM-based diet and diets with graded levels of CAP replacing FM at 25%, 50%, 75%, and 100%, respectively. Compared to the FM group, the growth performance and feed utilization of crayfish were not significantly influenced by CAP inclusion. The best weight gain of crayfish was observed in the 25% CAP replacement group. The content of arginine, histidine, tyrosine, cysteine, and hydroxyproline of muscle increased at first and then decreased, showing a quadratic relationship with CAP level. The activity of serum aspartate aminotransferase (AST) linearly increased, while alanine aminotransferase (ALT) firstly decreased and then increased with the increase of CAP level. The activity of serum phenoloxidase, gene expression of cyclophilin A (cypa), hemocyanin A chain-like (hemB), and hemocyanin B chain-like (hemB) in hepatopancreas of crayfish were increased in the 25 and 50% CAP replacement group, but were decreased at 100% replacement level. Enteritis was not observed among all the diet groups. The average length of longitudinal ridges was linearly decreased with the increment of CAP level, although it was highest in the 25% CAP replacement group. The overall structure of intestinal microbial community was similar among different experiment conditions, but Shannon and Simpson diversity indexes were quadratically influenced by CAP inclusion. Tyzzerella, Sphingomonas, and Weissella were enriched in the intestine of crayfish fed CAP diets. In conclusion, CAP replacing FM at tested levels did not impact growth performance of crayfish. CAP replacing FM at 25% and 50% improved immune response and muscle amino acid composition but depressed immunity at 100% replacement level. CAP tend to compromise intestinal histology and hepatopancreas health, change the α-diversity and genus composition of intestinal microbiota. It is recommended that CAP replacing 25% FM in a diet containing 10% fish meal could achieve the optimal growth performance, immune response, amino acid composition, and intestinal histology for 6 g crayfish.

Microbiota derived butyrate affected the muscle texture of Nile tilapia (Oreochromis niloticus) fed with different protein sources

Flesh quality is influenced by diet components, but the underlying mechanism remains unclear. This study aimed to investigate the effect of replacing soybean meal (SBM) protein with cottonseed protein concentrate (CPC) at different levels (0%, CK; 15%, CPC15; 30%, CPC30 and 45%, CPC45) on the flesh quality of Nile tilapia. The results indicated that different protein sources influenced muscle amino acid composition instead of fatty acid composition. Lower muscle lipid content was found in CPC45, which in turn significantly altered the muscle texture. The hepatic lipid metabolism-related genes were detected and we found that CPC45 significantly suppressed the lipogenesis and promoted lipolysis. Higher content of microbiota-derived butyrate was found in the intestinal content of CPC45 and butyrate could decrease the lipid accumulation in vitro. Replacing SBM with CPC increased the intestinal butyrate to suppress the lipogenesis in the liver which may account for the increased muscle hardness.

Effects of methionine supplementation in plant protein based diet on growth performance and fillet quality of juveniles Yellow River carp (Cyprinus carpio haematopterus)

The 65 days rearing experiment was carried out to investigate the effects of dietary methionine (Met) levels on growth performance and fillet quality of juveniles Yellow River carp, Cyprinus carpio haematopterus . Five diets containing 6.04 g/kg, 9.31 g/kg, 12.09 g/kg, 15.66 g/kg and 18.05 g/kg Met (Met 6.04, Met 9.31, Met 12.09, Met 15.66 and Met 18.05) were respectively fed to experimental carps (initial weight: 21.56 ± 0.46 g) with three replicates per group. The percentage weight gain (PWG), specific growth rate (SGR), feed efficiency (FE), protein efficiency (PE) and condition factor (CF) all elevated at first and then decreased with the increase of dietary Met levels, and all reached the maximum in Met 12.09 group ( P < 0.05). In Met 9.31 group, the shear force, resilience of raw fillet and the firmness, chewiness, cohesiveness, springiness, resilience of cooked fillet all reached the maximum ( P < 0.05), as did the collagen content and the myofiber density in white muscle, and similar trends were observed in the mRNA levels of myogenic differentiation antigen ( MyoD ), Myogenin , myogenic factor 4 ( Mrf4 ) and myosin light chain ( MyLc ) and the protein expression levels of Myogenin, myosin heavy chain (MyHc) and MyLc. The contents of Ile, Leu, Lys, Arg, Asp, Glu, Ala, Tyr, total umami amino acids (UAA, Asp, Glu, Gly and Ala), total essential amino acids (TEAA), total non-essential amino acids (TNEAA) and total amino acids (TAA) reached the maximum in Met 15.66 group ( P < 0.05). In addition, the quadratic regression analysis of PWG, firmness, chewiness and springiness of cooked fillet against dietary Met levels suggested that the appropriate dietary Met levels (crude protein, about 32.5% and crude lipid, about 8.1% in diet) of Yellow River carp (21.5–69.7 g) was estimated to be 12.20 g/kg, 9.54 g/kg, 11.01 g/kg and 13.70 g/kg, respectively. Our study could lay a theoretical and practical foundation for precise nutritional regulation of flesh quality of Yellow River carp. • Dietary methionine levels change the growth and muscle amino acid composition. • Dietary methionine levels change the myofibers diameter and density. • The methionine levels have more obvious effect on cooked than raw fillet in texture.

Utilization of different lysine isomers: A case study on the growth, metabolic enzymes, antioxidant capacity and muscle amino acid composition in Macrobrachium rosenbergii

An 8-week feeding trial was conducted to compare the effects of different lysine isomers on growth performance, amino acid metabolism-related enzyme activities, antioxidant capacity and muscle amino acid composition of giant river prawn (Macrobrachium rosenbergii). The basal diet was formulated to be low in lysine and contained only 10.9 g/kg lysine. The other three experimental diets were supplemented with 12 g/kg D-lysine, L-lysine, and DL-lysine, respectively. Dietary lysine supplementation improved the growth rate and feed utilization of M. rosenbergii, but significant differences were only found between the prawn fed the control diet and the L-lysine diet. L-lysine supplementation significantly improved the intestinal and hepatic trypsin activities, but unaffected the lipase and amylase activities. The highest hepatic aspartate aminotransferase and alanine aminotransferase activities were observed in prawn fed the L-lysine diet, whereas the highest γ-glutamyl transferase activity was found in prawn fed the D-lysine diet. D-lysine supplementation significantly increased the intestinal and hepatic D-amino acid oxidase activities. However, L-lysine supplementation improved the hepatic lysozyme activity and total antioxidant capacity, depressed the hepatic lactate dehydrogenase and alkaline phosphatase activities. Conversely, D-lysine supplementation generally depressed the hepatic superoxide dismutase and peroxidase activities, and nitric oxide content. Furthermore, L-lysine supplementation increased the muscle aspartic acid, serine, glutamic acid, alanine, lysine, arginine, delicious amino (DAA), non-essential amino acids, total amino acids (TAA) contents and DAA/TAA ratio. These results indicate that M. rosenbergii can effectively utilize L-lysine for growth; D-lysine may partly be used but reveal specific toxic effects on antioxidant response.

Genotype and dietary lysine deficiency affect carcass and muscle amino acid composition of pigs growing from 10 to 25 kg body weight.

Amino acid (AA) composition of body protein is considered constant although there are evidences that AA pattern in pigs may be altered by different factors. Pigs with different body composition and protein deposition rates-like fatty and lean pigs-may differ in AA composition, with possible consequences on their AA requirements. This work investigates effects of genotype and dietary lysine deficiency on AA composition of carcass and muscles of Iberian and Landrace×Large White pigs. Twenty-eight barrows (10kg body weight [BW]), 14 from each breed, were used. They were randomly assigned to two experimental diets according to a factorial arrangement (two breeds×two diets). Diets were isonitrogenous and isoenergetic (200±1g CP/kg dry matter (DM); 14.7±0.1MJ ME/kg DM) and with identical chemical composition except for lysine concentration (10.9 and 5.20g lysine/kg DM, for lysine-adequate (AL) diet and lysine-deficient (DL) diet respectively). Pigs were individually housed, and daily feed allowance was adjusted on a weekly basis according to BW. Pigs were slaughtered at 25kg BW. Isoleucine, valine and phenylalanine concentration were higher in carcass protein of Iberian pigs (p<.01). In longissimus muscle, higher concentration of arginine, isoleucine, phenylalanine, lysine and valine (p<.001-p<.05), and lower of methionine (p<.001) were detected in Iberian pigs, whereas phenylalanine, leucine, lysine, threonine and methionine concentration decreased and arginine increased (p<.001-p<.05) when pigs were fed DL diet. Genotype and lysine deficiency effects were moderate in the AA composition of protein of biceps femoris muscle. The results show that AA proportions in protein of carcass and longissimus muscle can be influenced by pig genotype and conditions of lysine shortage. The biceps femoris muscle, with different functional and metabolic properties, shows more constant AA composition than longissimus, which seem to prevail independent from genotype or nutritional challenges.

Effect of Dietary Energy to Protein Ratio on Growth, Biological Indices, Proximate Composition, and Amino Acid Profiles in the Muscle of Varicorhinus macrolepis

AbstractA 150‐d feeding experiment was conducted to assess the effect of the dietary energy to protein ratio (E/P ratio) on growth, biological indices, proximate composition, and amino acid profiles in the muscle of Varicorhinus macrolepis. Six experimental diets were formulated with different E/P ratios (30.51, 33.90, 37.82, 42.34, 47.70, and 54.09 kJ/g). In the experiment, 360 fish with a mean weight of 8.75 g (SD, 0.59) were randomly divided into six groups (three replicates per group, 20 fish per replicate) and fed three times daily with the experimental diet. Results showed that when the dietary E/P ratio was 37.82 kJ/g, Varicorhinus macrolepis tended to gain the highest specific growth rate. With a change in the increment of dietary E/P ratio, the condition factor, intestosomatic index, hepatosomatic index, and viscerosomatic index all changed in the quadric polynomial regression model. Muscle crude lipid content showed a tendency of leveling‐off first and then increased with increasing dietary E/P ratio. Varicorhinus macrolepis gained the highest concentration of total amino acids and essential amino acids when the dietary E/P ratio was 37.82 kJ/g. Except for methionine + cysteine, phenylalanine + tyrosine, and the amino acid score of lysine, the amino acid scores and chemical scores of the other essential amino acids were highest when the dietary E/P ratio was 37.82 kJ/g. These results suggest that Varicorhinus macrolepis obtained optimal growth and muscle amino acid composition when the dietary E/P ratio was 37.82 kJ/g.

250 Muscle amino acid composition of pigs is influenced by the feeding system and amino acid intake

250 Muscle amino acid composition of pigs is influenced by the feeding system and amino acid intake

Nutritional evaluation ofTenebrio molitormeal as fishmeal substitute for tilapia (Oreochromis niloticus) diet

Fishmeal (FM) and soy meal (SM) are the most common protein sources used in fish feed, but they are associated with environmental, economic or production problems. Insects could be an interesting alternative source of protein. This work investigates the nutritive value of Tenebrio molitor meal (TM) and the effect of total replacement of SM by TM (TM/FM diet) or partial replacement of FM by TM (TM/FM/SM diet) versus a diet based in SM and FM (FM/SM diet) for tilapia. We studied the chitin content in TM, the in vitro protein digestibility, protease activity, oxidative stress and antioxidant defences, growth performance and nutrient utilization. The results indicate that an inclusion up to 500 g kg−1 of TM in the diet did not affect feed intake, in vitro protein digestibility, muscle amino acid composition or biometric indexes. However, their inclusion reduced growth performance and affected the muscle fatty acid profile. The lowest values for protease activity, elevated FRAP in digestive tracts and ROS level in muscle and higher SOD activity were observed in fish fed with SM/FM diet. The use of TM requires better understanding of the role of chitin in digestion and the study of toxins that might affect fish growth.

Nutritional Responses of Round Goby (Neogobius melanostomus) caught from Rhine River (Germany) as a Wild Species to Different Fish Oils

This study was aimed to determine the effects of food supplementation with different levels of two types of fish oil (anchovy and menhaden oils), on growth and the composition of fatty acids and essential amino acids in muscle of a wild and alien species. In this study round goby (Neogobius melanostomus) caught from Rhine River (0.95–1.0 g fresh mass) were fed for 47 days diets containing 5% anchovy oil (AO), 5% menhaden oil (MO) or 2.5% AO+2.5% MO. Fish were cultured in indoor 40 L aquaria (12 aquaria in total). The feeding rate was adjusted to 10% of the fish fresh mass per day and water temperature was constantly maintained at 19°C. After 47 days, no differences were observed in weight gain, specific growth rate (SGR), feed conversion ratio (FCR) and condition factor (P>0.05). The lowest FCR was found in AO diet. Muscle fatty acid composition was influenced by dietary fish oils, and fish fed the AO diet have shown slightly higher contents of eicosapentaenoic and docosahexaenoic acid in their muscle. Muscle amino acid composition was not affected by the diet, an except for leucine. The results indicated that addition of fish oil is important in maintaining the content of n-3 fatty acids in fish in aquaculture.

Whole-body and muscle amino acid composition of Plata pompano (Trachinotus marginatus) and prediction of dietary essential amino acid requirements

Summary Background: knowing the essential amino acid (EAA) requirement values is fundamental to formulate good quality and cost-effective fish feeds. However, such requirements have been established for few fish species. The estimation of amino acid requirements based on amino acid composition of fish is a fast and reliable alternative. Objective: to determine whole-body and muscle amino acid composition of Plata pompano (Trachinotus marginatus) and estimate its EAA requirements. Methods: EAA requirements were estimated using A/E ratios [(Individual EAA ⁄ Total EAA) * 1000]. Results: hystidine, leucine, lysine and phenylalanine were present in higher concentrations in muscle tissue in comparison with the whole-body. On the other hand, arginine, isoleucine, methionine, tryptophan and valine concentration were not different between whole-body and muscle. A/E ratios for Plata pompano determined in the present study are similar to those reported in other fish species, although valine A⁄E ratios were slightly smaller. Conclusion: until dose-response experiments are conducted to precisely determine EAA requirements, the estimated EAA values using whole-body EAA-as proposed in this study-could be used to formulate diets for Plata pompano. Key words: A ⁄E ratio, Carangidae, diet formulation, fish nutrition.. Resumen Antecedentes: conocer los requerimientos de aminoácidos esenciales (EAA) es fundamental para la formulación de raciones rentables y de buena calidad para peces. Sin embargo, dichos requerimientos se han establecido solo para unas pocas especies de peces. La determinación de las necesidades de aminoácidos basada en la composición de aminoácidos de los peces es un método alternativo rápido y viable. Objetivo: determinar la composición de aminoácidos del cuerpo completo y del músculo del Pámpano (Trachinotus marginatus) y estimar sus necesidades de EAA. Métodos: el requerimiento de aminoácidos esenciales se calculó utilizando el índice A/E [(Individual EAA⁄Total EAA) * 1000]. Resultados: la histidina, leucina, fenilalanina y lisina estaban en una mayor concentración en el músculo que en el cuerpo. Por otro lado, arginina, isoleucina, metionina, triptófano y valina no mostraron ninguna diferencia significativa entre la composición del músculo y el cuerpo. Los valores de A/E para Pámpano determinados en este estudio son similares a los reportados para otras especies de peces, pero no los de valina, que fue levemente menor. Conclusiones: hasta que no sean realizados experimentos de dosis-respuesta para determinar con precisión los requerimientos de EAA, el cálculo de los requerimientos de aminoácidos esenciales a partir de la concentración de aminoácidos del cuerpo -como se propone en este estudio- puede ser utilizado en la formulación de dietas para pámpano. Palabras clave: Carangidae, formulación de dietas, nutrición de peces, razón A/E. Resumo Antecedentes: estimar as necessidades por aminoácidos essenciais (AAE) é importante para formular dietas de boa qualidade e com bom custo-benefício. No entanto, poucas espécies de peixes possuem suas necessidades por (AAE) estabelecidas. A determinação das necessidades por (AAE) baseada na composição de aminoácidos do peixe é uma alternativa rápida e viável. Objetivo: determinar a composição de aminoácidos da carcaça e do músculo do Pampo prateado (Trachinotus marginatus) e estimar suas necessidades por (AAE). Métodos: as necessidades por AAE foi estimada usando o índice A/E [(AAE individual⁄AAE total) * 1000]. Resultados: histidina, leucina, lisina e fenilalanina estavam em maior concentração no músculo do que na carcaça. Por outro lado, arginina, isoleucina, metionina, triptofano e valina não apresentaram diferenças significativas entre a composição da carcaça e do músculo. O índice A/E determinado no presente estudo para o Pampo prateado é similar ao reportado para outras espécies de peixe, entretanto o valor do índice A/E para a valina foi ligeiramente menor. Conclusão: até que experimentos dose resposta sejam realizados para determinar com exatidão as necessidades por aminoácidos essenciais, os valores estimados para as necessidades por aminoácidos essenciais usando a composição da carcaça como proposto neste estudo pode ser usada na formulação de dietas para o Pampo prateado. Palavras chave: Carangidae, formulación de dietas, nutrição de peixes, razão A/E.

Differences in the amino acid composition of muscles from pheasant and broiler chickens

Abstract. The present paper explores amino acid composition of breast and thigh muscles of common pheasant and compares it with that in broiler chickens. The experimental feeding of both pheasant and broiler chickens proceeded for a period of 42 days at the identical conditions employing the same diet and rearing technology. Muscles were analysed for the content of following amino acids: Asp, Thr, Ser, Glu, Pro, Gly, Ala, Val, Met, Ile, Leu, Tyr, Phe, His, Lys, and Arg. The results show that the levels of most amino acids in thigh and breast muscles of pheasants (related to dry matter content) were significantly higher (P ≤ 0.01) than those in broiler chickens. In 42-day-old birds, the levels of individual amino acids in breast muscles (related to 100% of dry matter content) ranged from 8.02 to 127.32 g . kg-1 in pheasant chickens and from 19.77 to 110.33 g . kg-1 in broiler chickens while the corresponding average values in thigh muscles ranged from 14.77 g . kg-1 to 132.77 g . kg-1 in pheasant chickens and from 14.02 g . kg-1 to 93.53 g . kg-1 in broiler chickens. One interesting finding is that in the case of broiler chickens the levels of most amino acids in breast muscles were significantly higher (P ≤ 0.01) than those in thigh muscles. In the case of pheasant chickens, the difference between breast and thigh muscles was not confirmed which indicates that both muscles have high nutritive value. The results of amino acid composition of pheasant and broiler meat have proven a high nutritive value of pheasant meat in respect to human nutrition.