Effects of β-Alanine Dietary Supplementation on Concentration of Carnosine and Quality of Broiler Muscle Tissue

Chromosome-level genome provides insights into evolution and diving adaptability in the vulnerable common pochard (Aythya ferina)

The common pochard (Aythya ferina) is a freshwater diving duck found in the Palearctic region that has been classified as vulnerable by the IUCN due to continuous and rapid population declines across their distribution. To gain a better understanding of its genetic mechanism of adaptive evolution, we successfully sequenced and assembled the first high-quality chromosome-level genome of A. ferina using Illumina, Nanopore and Hi-C sequencing technologies. A total assembly length of 1,130.78 Mbp was obtained, with over 98.81% (1,117.37Mbp) of sequence anchored to 35 pseudo-chromosomes. We predicted 17,232 protein-coding genes, 95.9% of which were functionally annotated. We identified 339 expanded and 937 contracted gene families in the genome of A. ferina, and detected 95 genes that have been positively selected. The significantly enriched Gene Ontology and enriched pathways were related to energy metabolism, immune, nervous, and sensory systems, suggests that these factors likely played an important role in its evolution. Importantly, we recovered signatures of positive selection on genes related to vasoconstriction that may be associated with thermoregulatory adaptations of A. ferina for underwater diving. Overall, the high-quality genome assembly and annotation in this study provides valuable genomic resources for ecological and evolutionary studies, as well as toward the conservation of A. ferina.

Effect of β-Alanine Metabolite on Gut Integrity and Immunity in Commercial Broiler Chickens Infected with Eimeria maxima

(1) Background: In a metabolomics analysis conducted to investigate the mechanisms behind the growth-promoting effects of probiotics in broilers, β-alanine was found to be significantly elevated. This led to the hypothesis that β-alanine could also contribute to growth-promoting effects in infected broilers. (2) Methods: An in vitro culture system was developed to assess β-alanine's impact on proinflammatory cytokine response in chicken macrophage cells, gut integrity in chicken intestinal epithelial cells, and muscle differentiation in quail muscle cells and primary chicken embryonic muscle cells. In vivo animal feeding studies were then conducted to investigate the effects of dietary β-alanine on various disease parameters in Eimeria maxima-infected broiler chickens. (3) Results: In vitro, β-alanine treatment significantly decreased the gene expression of cytokines in chicken macrophage cells and increased occuldin expression in chicken intestinal epithelial cells. Dietary β-alanine increased the body weight of chickens following Eimeria maxima infection in the H-ALA group. Dietary β-alanine also suppressed cytokines and increased JAM-2 and occludin expression in the H-ALA group compared to the infected group without β-alanine supplementation. (4) Conclusions: These results strongly support the positive effects of dietary β-alanine on intestinal immune responses and gut barrier function in broiler chickens infected with Eimeria maxima.

High-quality chromosome-level genome assembly of the Northern Pacific sea star Asterias amurensis

Asterias amurensis, a starfish species that is native to countries such as China and Japan, as well as non-native regions like Australia, has raised serious concerns in terms of its impact on ecology and economy. To gain a better understanding of its population genomics and dynamics, we successfully assembled a high-quality chromosome-level genome of A. amurensis using PacBio and Hi-C sequencing technologies. A total of 87 scaffolds assembly with contig N50 length of 10.85 Mb and scaffold N50 length of 23.34 Mb were obtained, with over 98.80% (0.48 Gb) of them anchored to 22 pseudochromosomes. We predicted 16,673 protein-coding genes, 95.19% of which were functionally annotated. Our phylogenetic analysis revealed that A. amurensis and Asterias rubens formed a clade, and their divergence time was estimated ~ 28 million years ago (Mya). The significantly enriched pathways and Gene Ontology terms related to the amplified gene family were mainly associated with immune response and energy metabolism, suggesting that these factors might have contributed to the adaptability of A. amurensis to its environment. This study provides valuable genomic resources for comprehending the genetics, dynamics, and evolution of A. amurensis, especially when population outbreaks or invasions occur.

Effects of dietary β-alanine supplementation on growth performance, meat quality, carnosine content, amino acid composition and muscular antioxidant capacity in Chinese indigenous Ningxiang pig

β-alanine has been demonstrated to improve carcass traits and meat quality of animals. However, no research has been found on the effects of dietary β-alanine in the meat quality control of finishing pigs, which are among the research focus. Therefore, this study aimed to evaluate the effects of dietary β-alanine supplementation on growth performance, meat quality, carnosine content, amino acid composition and muscular antioxidant capacity of Chinese indigenous Ningxiang pigs. The treatments contained a basal diet (control, CON) and a basal diet supplemented with 600 mg/kg β-alanine. Each treatment group consisted of five pens, with five pigs per pen. Results showed that compared with CON, supplemental β-alanine did not affect the final body weight, average daily gain, average daily feed intake and the feed-to-gain ratio of pigs. Dietary β-alanine supplementation tended to increase the pH_45 min (p = 0.071) while decreasing the shear force (p = 0.085) and the drip loss (p = 0.091). Moreover, it improved (p < 0.05) the activities of glutathione peroxidase and catalase and lessened (p < 0.05) malondialdehyde concentration. Added β-alanine in diets of finishing pigs could enhance the concentrations of arginine, alanine, and glutamate (p < 0.05) in the longissimus dorsi muscle and tended to raise the levels of cysteine, glycine and anserine (p = 0.060, p = 0.098 and p = 0.091 respectively). Taken together, our results showed that dietary β-alanine supplementation contributed to the improvement of the carcass traits, meat quality and anserine content, the amelioration of muscle antioxidant capacity and the regulation of amino acid composition in Chinese indigenous Ningxiang pigs.

RNA Profiles of the Korat Chicken Breast Muscle with Increased Carnosine Content Produced through Dietary Supplementation with β-Alanine or L-Histidine

Simple Summary

Carnosine is a bioactive food component with several potential health benefits for humans due to its physiological functions. Dietary supplementation with β-alanine or L-histidine can increase the carnosine content of skeletal muscles in chickens. Dietary supplementation with β-alanine or L-histidine has produced a slow-growing chicken variety with high carnosine content in the breast meat; however, the supplementation with L-histidine alone softens the meat toughness, which may affect consumers’ willingness to buy the meat. Gene expression is a key factor that influences meat quality. Understanding the molecular mechanisms that affect carnosine content and meat toughness would allow the production of more value-added slow-growing chickens. We compared global gene expression in chicken breast muscles with differing carnosine contents and meat toughness produced through dietary supplementation with β-alanine or L-histidine. We identified differentially expressed genes involved in regulating myosin, collagen, intramuscular fat, and calpain—factors that may affect meat tenderness. Pathway enrichment analysis indicated that the insulin-related and adipocytokine signaling pathways were altered by dietary supplementation with β-alanine or L-histidine. These data will be useful for future studies on carnosine content and meat toughness in slow-growing chickens.

Abstract

Korat chicken (KRC) is a slow-growing chicken bred in Thailand, whose meat exhibits a unique toughness. A previous study produced KRC breast meat containing high carnosine content through dietary supplementation with β-alanine or L-histidine; however, the KRC that were fed an L-histidine-supplemented diet produced meat that was significantly more tender. Herein, we performed RNA-Seq to identify candidate genes involved in the regulation of carnosine content and meat toughness. Total RNA was isolated from five female KRC breast muscles in each treatment group that KRC fed diets without supplementation, supplemented with β-alanine or L-histidine. Compared to the non-supplemented group, we identified 118 and 198 differentially expressed genes (DEGs) in the β-alanine or L-histidine supplementation groups, respectively. Genes potentially related to meat tenderness—i.e., those regulating myosin, collagen, intramuscular fat, and calpain—were upregulated (LOC107051274, ACSBG1, and CAPNS2) and downregulated (MYO7B, MYBPH, SERPINH1, and PGAM1). However, carnosine synthase gene was not identified. Functional enrichment analysis identified pathways affected by dietary supplementation, including the insulin signaling pathway (β-alanine supplementation) and the insulin resistance and adipocytokine signaling pathways (L-histidine supplementation). The FoxO signaling pathway was identified as a regulatory network for both supplementation groups. The identified genes can be used as molecular markers of meat tenderness in slow-growing chickens.

Influences of Beta-Alanine and l-Histidine Supplementation on Growth Performance, Meat Quality, Carnosine Content, and mRNA Expression of Carnosine-Related Enzymes in Broilers

Simple Summary

In recent years, much attention has been paid to developing functional meat, which contains more functional peptides to impart health benefits. Poultry meat is a good source of imidazole dipeptides (carnosine and its derivative anserine), which are active endogenous constituents and may convey versatile physiological functions to promote health conditions. Carnosine is synthesized from l-histidine and beta-alanine. Dietary addition of histidine and/or beta-alanine may elevate the carnosine content in broiler meat. The current study further investigated the interaction of l-histidine and beta-alanine supplementation on carnosine content, meat quality, and gene expression of carnosine-related enzymes in broilers, which can facilitate a better understanding of the relationship between l-histidine and beta-alanine in carnosine synthesis.

Abstract

The current study investigated the effect of dietary l-histidine and beta-alanine supplementation on growth performance, meat quality, carnosine content, and gene expression of carnosine-related enzymes in broilers. A two-factor design was adopted in this study. A total of 640 1-day-old male broilers were assigned to eight treatments with factorial arrangement containing four levels of l-histidine (0, 650, 1300, or 1950 mg/kg) and two levels of beta-alanine (0 or 1200 mg/kg) supplementation; 0 mg/kg histidine and/or 0 mg/kg were treated as control groups. Each treatment including eight replicates with 10 birds each and the feeding trial lasted for 42 days. Dietary supplementation with l-histidine and beta-alanine did not affect average daily gain (ADG), average daily feed intake (ADFI), and feed conversion ratio (FCR) of broilers during the grower (22–42 days) and the entire phase (1–42 days), compared with the control group (p > 0.05). The only exception was a significantly reduced ADG in the 1950 mg/kg l-histidine group in the starter period (1–21 days, p < 0.05). l-Histidine at 1950 mg/kg significantly decreased redness (a*) and yellowness (b*) values of the meat at 45 min postmortem (p < 0.05), whereas it increased b* value and pH in breast muscle at 24 h postmortem. Moreover, dietary supplementation with beta-alanine alone or combination with l-histidine significantly increased ΔpH in breast muscle (p < 0.01). Dietary l-histidine markedly increased total superoxide dismutase activity and total antioxidant capacity (T-AOC) both in breast muscle (p < 0.01) and in plasma (p < 0.01), and it decreased malondialdehyde (MDA) concentration in breast muscle (p < 0.01). Dietary addition of beta-alanine, alone or combination, significantly increased T-AOC in breast muscle (p < 0.01) and markedly decreased MDA content both in breast muscle and in plasma (p < 0.01). Addition of l-histidine and beta-alanine significantly increased muscle peptide (carnosine and anserine) content (p < 0.05) and upregulated the expression of carnosine synthase, transporter of carnosine/ l-histidine, and l-histidine decarboxylase genes (p < 0.05), with greater change occurring in the combination group of 1300 mg/kg l-histidine and 1200 mg/kg beta-alanine. Overall, dietary l-histidine and beta-alanine could improve meat quality and antioxidant capacity, enhance the carnosine and anserine content, and upregulate the gene expression of carnosine synthesis-related enzymes in broilers.

Antioxidative Characteristics of Chicken Breast Meat and Blood after Diet Supplementation with Carnosine, L-histidine, and β-alanine

The objective of the study was to test the effect of diets supplemented with β-alanine, L-histidine, and carnosine on the histidine dipeptide content and the antioxidative status of chicken breast muscles and blood. One-day-old Hubbard Flex male chickens were assigned to five treatments: control diet (C) and control diet supplemented with 0.18% L-histidine (ExpH), 0.3% β-alanine (ExpA), a mix of L-histidine\β-alanine (ExpH+A), and 0.27% carnosine (ExpCar). After 28 days, chicken breast muscles and blood samples were analyzed for the antioxidant enzyme activity (catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD)), carnosine and anserine content, amino acid profile, and anti-radical activity (ABTS, DPPH, ferric reducing antioxidant power (FRAP)). The results of the study showed that carnosine supplementation effectively increased body weight and breast muscle share in chicken carcasses. Carnosine and L-histidine supplementation with or without β-alanine increased carnosine content in chicken breast muscles up to 20% (p = 0.003), but the boost seems to be too low to affect the potential antioxidant capacity and amino acid content. The β-alanine-enriched diet lowered dipeptide concentration in chicken blood serum (p = 0.002) and activated catalase in chicken breast muscles in relation to the control group (p = 0.003). It can be concluded that histidine or dipeptide supplementation of chicken diets differently affected the total antioxidant potential: in breast muscles, it increased dipeptide content, while in blood cell sediment (rich in erythrocytes), increased SOD and GPx activities were observed.

Differences in muscle histidine-containing dipeptides in broilers

BACKGROUND

Poultry meat has high levels of histidine-containing dipeptides (HCD) and consumption of meat rich in HCD may elicit certain health benefits. The aim of this work was to compare the HCD content (anserine and carnosine) in the breast and thigh muscles of two broiler strains differing in growth rate, feeding regime, and age at slaughter. A 3 (production system) × 2 (sex) × 2 (age at slaughter) full factorial arrangement was applied with fast-growing Ross 308 chicks fed ad libitum (ROSS-AL), slow-growing Sasso T451 chicks fed ad libitum (SASSO-AL), and Ross 308 chicks given limited feeding (ROSS-LIM). At the age of 40 and 62 days, eight birds per production system × sex combination were randomly selected for sampling of the breast and thigh muscle. Muscle HCD content was determined by high-performance liquid chromatography (HPLC).

RESULTS

Across treatments, levels of anserine were 2.5- and 1.9-fold higher than carnosine in breast and thigh muscle respectively (P < 0.001), and levels of anserine and carnosine were 2.2- and 2.8-fold higher respectively in breast versus thigh muscle (P < 0.001). In breast muscle, SASSO-AL had higher levels of HCD than ROSS-AL and ROSS-LIM (P < 0.001). Considering different market meat types, breast muscle of 62-day-old SASSO-AL birds had more than threefold higher content of HCD compared to thigh muscle of 40-day-old ROSS-AL birds (P < 0.001).

CONCLUSION

Large differences in muscle HCD content were found, varying according to type of muscle and broiler. © 2019 Society of Chemical Industry.

Effect of dietary β-alanine supplementation on growth performance, meat quality, carnosine content, and gene expression of carnosine-related enzymes in broilers

The objective of the current study was to investigate the effect of dietary β-alanine supplementation on growth performance, meat quality, antioxidant ability, carnosine content, and gene expression of carnosine-related enzymes in broiler chicks. We randomly assigned 540 1-day-old Arbor Acres broilers to 5 dietary treatments supplemented with 0 (control group), 250, 500, 1,000, or 2,000 mg/kg of β-alanine (mg β-alanine per kg feed). Each treatment included 6 replicates of 18 birds. The feeding trial lasted for 42 d. Dietary β-alanine supplementation linearly and quadratically increased the average daily gain (ADG) during the starting period (d 1 to 21, P = 0.02 and P = 0.002). The feed conversion ratio (FCR) decreased quadratically in response to dietary β-alanine supplementation during the starting and entire periods (P < 0.001 and P = 0.003, respectively). For the entire period, the predicted best FCR would be achieved when β-alanine was fed at a level of 1,100 mg/kg from quadratic regression. The concentrations of carnosine and β-alanine in breast muscle increased quadratically with dietary β-alanine supplementation (d 42, P < 0.001 and P = 0.001, respectively). The predicted dietary β-alanine level for highest breast carnosine content was 1,196 mg/kg. Dietary supplementation with β-alanine reduced the taurine concentrations in plasma (d 42, linear and quadratic, P < 0.001). Breast muscle yield increased linearly and quadratically in response to dietary β-alanine addition (d 21, P = 0.017 and P = 0.007). Dietary supplementation with β-alanine quadratically reduced the shear force (P = 0.003), whereas a*45 min and a*24 h values increased quadratically in response to dietary β-alanine supplementation (d 42, P = 0.020 and P = 0.021, respectively). Dietary β-alanine addition quadratically enhanced the expression of carnosine synthase and taurine transporter mRNAs (P < 0.05). Overall, dietary β-alanine supplementation improved growth performance and carnosine content, ameliorated antioxidant capacity and meat quality, and upregulated the gene expression of carnosine synthesis-related enzymes in broiler chicks.

Effect of Amino Acids on Growth Performance, Carcass Characteristics, Meat Quality, and Carnosine Concentration in Broiler Chickens

The aim of this research was to investigate the deposition of carnosine in broiler muscles by feeding treatments comprising β-alanine, L-histidine, and magnesium oxide in various concentrations. The research was carried out on 120 Cobb 500 broilers divided into four groups. From weeks four to six, broilers were fed finisher mixtures as follows: P1, control group; P2, 0.5% β-alanine + 0.24% MgO; P3, 0.25% L-histidine + 0.24% MgO; and P4, 0.20% β-alanine + 0.10% L-histidine + 0.24% MgO. This paper presents the weights of broilers and their carcasses, portions of main parts of carcasses, technological quality of breast muscles, and concentrations of carnosine in breast and thigh muscles. The following traits of muscle tissue quality were measured: initial and final pH value (45 min after slaughtering pH₁, and 24 h after cooling pH₂), drip loss, color (Minolta colorimeter, expressed as CIE L*, CIE a*, and CIE b* values), meat softness, and cooking loss. Data on relative concentration of protein carbonyl (nmol/mg protein) in the muscles of breasts and thighs and levels of thiobarbituric acid-reactive substances (TBARS) in fresh and frozen breasts muscles (nmol/mg of tissue) are presented. Statistical analysis proved that feeding treatments had an effect on the live weight of broilers in the 4th, 5th, and 6th weeks of fattening (P<0.05), as well as on the carcass quality at slaughter (P<0.05; except the portion of wings), pH₁ value (P=0.035), CIE a* indicator (P=0.007), drip loss (P=0.002), and meat texture (P=0.008). Compared to the control group, synthesis and deposition of carnosine were increased in breast muscles in groups P2, P3, and P4 by 7.51%, 10.62%, and 62.93%, respectively, and in thigh muscles by 61.05%, 78.95%, and 89.52%, respectively. It was also confirmed that feeding treatments influenced the level of TBARS in frozen broiler breast muscles (P=0.014).

Determination of anti-oxidative histidine dipeptides in poultry by microchip capillary electrophoresis with contactless conductivity detection

A home-made microchip electrophoresis (MCE) device was used to quantitate two biologically important histidine dipeptides, carnosine and anserine, using capacitively coupled contactless conductivity detection (C⁴D), at pH 2.7. The C⁴D detector exhibited a linear response to both carnosine and anserine in the range of 0-200μM for the individual dipeptides and in the range of 0-100μM for each dipeptide when both were present as a mixture. The limit of detections (LOD) for the dipeptides in the mixture were 0.10μM for carnosine and 0.16μM for anserine. Standard addition was used to detemine the accuracy of the method. For carnosine and anserine the recoveries were in the range of 96.7±4.9-106.0±7.5% and 95.3±4.5-105.0±5.1% in thigh muscle and 97.5±5.1-105.0±7.5% and 95.3±5.4-97.3±5.6% in breast muscle, respectively.

Influence of dietary replacement of sunflower oil with milk thistle (Silybum marianum) oil on chicken meat quality and antioxidant status of liver

The research focused on the effects of dietary replacement of 3% sunflower oil (SO group) with 3% milk thistle oil (MTO group) on the technological quality of meat, such as pH value, colour (CIE L*, CIE a*, CIE b*), drip loss (%), shear force (N), and cooking loss (%), as well as on the content of fatty acid lipids in broiler breast and thigh muscles. Significant difference (P < 0.05) was determined for pHi, pHu, CIE a*, CIE b* values between groups, although the values for the stated indicators were within the standard range. Lipids of breast meat of the MTO group contained more arachidic acid (P < 0.001), octadecenoic acid isomer B (P = 0.047) and eicosatrienoic acid (P = 0.041), and less α-linolenic acid (P < 0.001) and Σn-3PUFA. Lipids of thigh meat of the MTO group contained more ΣSFA, myristoleic acid, eicosatrienoic acid (P < 0.05) and eicosenoic acid (P < 0.001), and less α-linolenic acid, and had narrower Σn-3/n-6 PUFA ratio than the SO group. According to the antioxidant status of broiler liver, there was significantly higher catalase activity determined in the MTO group.