Chicken Muscle Research Articles

Electrochemical determination of dinitolmide in poultry product samples using a highly sensitive Mn2O3/MCNTs-NPs carbon paste electrode aided by greenness assessment tools

In this paper, chemically modified carbon paste Mn2O3/MCNTs-NPs electrode for estimation of dinitolmide (DOM) utilizing square wave voltammetry method (SWV) was developed. The study investigated the electrochemical behavior of DOM, and the morphology of the modified electrode was evaluated by Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM). The voltammetric behavior of DOM at modified electrode was recorded at a scan rate of 100 mVs−1 against Ag/AgCl reference electrode in phosphate buffer pH 4.0 within linearity range 2–12 µM, LOQ, and LOD of 1.8 and 0.594 µM, respectively, with average % recovery of (100.89 ± 0.795). GAPI and Analytical Eco-Scale tools were applied for greenness assessment. Specificity and interference study was valid for the proposed method; allowing DOM to be determined in its acidic degradation and its major interference drug. The proposed method was successfully employed to quantify DOM in bulk powder, egg, and frozen cuts-up chicken muscle samples.

Rapid determination of 2,4-diaminopyrimidine residues through sample pretreatment using immunomagnetic bead purification along with HPLC–UV

To reduce matrix interference and realize simultaneous detection of multiple homologous compounds (trimethoprim (TMP), diaveridine (DVD), ormetoprim (OMP), baquiloprim (BQP), and aditoprim (ADP) in pig, cattle, chicken, and fish muscles), an immunomagnetic bead (IMB)-based sample purification pretreatment with HPLC–UV was developed. A broad-spectrum monoclonal antibody (mAb, named 14C6) was prepared and conjugated with carboxylic-acid-functionalized magnetic nanoparticles using the active ester method to obtain IMBs for sample purification. The extraction solvent was optimized based on the extraction efficiency. Good linearity was observed for all the five analytes (10–200 μg/kg) with the LOD and LOQ of 5 and 10 μg/kg, respectively. The mean recoveries ranged from 62.5% to 76.9%, while the coefficient of variation was <12.2%. The IMB method afforded greater sample purification and enrichment than those achieved with the SPE column-based conventional method. Hence, the IMB-based sample purification is a useful tool to determine 2,4-diaminopyrimidine residues in edible animal tissues.

Double qualitative immunochromatographic test for simultaneous control of chicken muscles and eggs in food

This study presents the development of a qualitative double immunochromatographic analysis (ICA) for the rapid simultaneous determination of ovalbumin (OVA) and immunoglobulins of class Y (IgY) of chicken origin. The latter serve as biomarkers to control the presence of chicken meat and eggs in food products. Polyclonal antibodies against OVA were produced in rabbits. The test system was based on the two-stage sandwich ICA with gold nanoparticles (AuNPs) as a label for anti-OVA and anti-IgY antibodies. Limits of detection (LODs)/cutoffs of IgY and OVA were 24.8/20 ng/mL and 3.6/2 ng/mL, respectively; the assay was performed within 18 min. The analysis allowed for the determination of OVA and IgY in raw meat mixtures containing chicken meat and dry egg white with visual cutoffs of 0.125 % and 0.0001 % (w/w) for chicken and egg white additives. The analysis in foodstuffs—ravioli with known composition—demonstrated that the developed double ICA can reveal IgY in poultry meat. The test system has a great potential for food product analysis when reliable determination and differentiation of chicken egg white and chicken meat as separate components are required.

Study of Freezing and Defrosting Effects on Complex Permittivity of Biological Tissues

In this letter we study the effect of freezing and defrosting on the dielectric properties of biological tissues. The electromagnetic characterization of tissues at microwave frequencies is crucial for the development of microwave-based biomedical devices. These measurements are often not practical, as tissue degradation restricts the time available between tissue excision and dielectric measurements. For this reason, measurement of tissues that underwent freezing and defrosting may provide researchers with more flexibility in setting measurement campaigns, thus speeding up the development of microwave-based biomedical devices. To this end, this letter presents dielectric measurement on frozen and defrosted tissue, which translates into the following objectives: first, investigate if the dielectric properties of defrosted tissues depend on frozen storage time; second, determine if defrosted tissue dielectric properties differ from those of fresh tissues. As a result, we measure the dielectric properties of ten samples of chicken muscle, bovine liver, and bovine fat, each before and after freezing (up to 14 days) and defrosting. The measurements are performed with the open-ended coaxial probe method at the frequency band of 0.5–8.5 GHz. We observe a slight increase—less than 10%—in complex permittivity of high-water-content tissues (muscle and liver) after defrosting, and negligible effect on fat tissues.

Ghrelin is a signal to facilitate the utilization of fatty acids and save glucose by the liver, skeletal muscle, and adipose tissues in chicks

Ghrelin, classically known as a central appetite-stimulating hormone, has recently been recognized to play an important role in peripheral tissue energy metabolism. In chicken, contrary to mammal, ghrelin acts as an anorexia signal, increased by fasting and further elevated after refed. In the present study, the effect of ghrelin on glucose/lipid utilization by peripheral tissues was investigated. Injection of exogenous acyl ghrelin reduced plasma triglyceride and glucose levels of chickens at both fasting and fed status. In the in vitro cultured chicken primary hepatocytes, adipocytes, and myoblasts, ghrelin suppressed glucose uptake, stimulated fatty acids uptake and oxidation, and decreased TG content. In hepatocyte, ghrelin increased the activities of LPL and HL, and upregulated the expression levels of gene ACC, CPT1, and PPARα. Ghrelin treatment markedly increased the protein level of p-ACC, PPARγ, PGC1α, and CPT1 in hepatocytes, adipocytes and myoblasts. Inhibition of AMPK activity by Compound C had no influence on glucose uptake by hepatocyte, adipocyte, and myoblast, but further amplified the stimulated fatty acid uptake of adipocyte by ghrelin. The present result demonstrates that ghrelin facilitates the uptake and oxidation of fatty acid and cut down the utilization of glucose by the liver, muscle, and adipose tissues. The result suggests that ghrelin functions as a signal of fatty acid oxidation. The study provides a vital framework for understanding the intrinsic role of ghrelin as a crucial factor in the concerted regulation of metabolic substrate of hepatocytes, adipocytes, and myoblasts.

Chromatin Interaction Responds to Breast Muscle Development and Intramuscular Fat Deposition Between Chinese Indigenous Chicken and Fast-Growing Broiler.

Skeletal muscle development and intramuscular fat (IMF) content, which positively contribute to meat production and quality, are regulated by precisely orchestrated processes. However, changes in three-dimensional chromatin structure and interaction, a newly emerged mediator of gene expression, during the skeletal muscle development and IMF deposition have remained unclear. In the present study, we analyzed the differences in muscle development and IMF content between one-day-old commercial Arbor Acres broiler (AA) and Chinese indigenous Lushi blue-shelled-egg chicken (LS) and performed Hi-C analysis on their breast muscles. Our results indicated that significantly higher IMF content, however remarkably lower muscle fiber diameter was detected in breast muscle of LS chicken compared to that of AA broiler. The chromatin intra-interaction was prior to inter-interaction in both AA and LS chicken, and chromatin inter-interaction was heavily focused on the small and gene-rich chromosomes. For genomic compartmentalization, no significant difference in the number of B type compartments was found, but AA had more A type compartments versus LS. The A/B compartment switching of AA versus LS showed more A to B switching than B to A switching. There were no significant differences in the average sizes and distributions of topologically associating domains (TAD). Additionally, approximately 50% of TAD boundaries were overlapping. The reforming and disappearing events of TAD boundaries were identified between AA and LS chicken breast muscles. Among these, the HMGCR gene was located in the TAD-boundary regions in AA broilers, but in TAD-interior regions in LS chickens, and the IGF2BP3 gene was located in the AA-unique TAD boundaries. Both HMGCR and IGF2BP3 genes exhibited increased mRNA expression in one-day-old AA broiler breast muscles. It was demonstrated that the IGF2BP3 and HMGCR genes regulated by TAD boundary sliding were potential biomarkers for chicken breast muscle development and IMF deposition. Our data not only provide a valuable understanding of higher-order chromatin dynamics during muscle development and lipid accumulation but also reveal new insights into the regulatory mechanisms of muscle development and IMF deposition in chicken.

Filamin C regulates skeletal muscle atrophy by stabilizing dishevelled-2 to inhibit autophagy and mitophagy

FilaminC (Flnc) is a member of the actin binding protein family, which is preferentially expressed in the cardiac and skeletal muscle tissues. Although it is known to interact with proteins associated with myofibrillar myopathy, its unique role in skeletal muscle remains largely unknown. In this study, we identify the biological functions of Flnc in vitro and in vivo using chicken primary myoblast cells and animal models, respectively. From the results, we observe that the growth rate and mass of the skeletal muscle of fast-growing chickens (broilers) were significantly higher than those in slow-growing chickens (layers). Furthermore, we find that the expression of Flnc in the skeletal muscle of broilers was higher than that in the layers. Our results indicated that Flnc was highly expressed in the skeletal muscle, especially in the skeletal muscle of broilers than in layers. This suggests that Flnc plays a positive regulatory role in myoblast development. Flnc knockdown resulted in muscle atrophy, whereas the overexpression of Flnc promotes muscle hypertrophy in vivo in an animal model. We also found that Flnc interacted with dishevelled-2 (Dvl2), activated the wnt/β-catenin signaling pathway, and controlled skeletal muscle development. Flnc also antagonized the LC3-mediated autophagy system by decreasing Dvl2 ubiquitination. Moreover, Flnc knockdown activated and significantly increased mitophagy. In summary, these results indicate that the absence of Flnc induces autophagy or mitophagy and regulates muscle atrophy.

New Findings on LMO7 Transcripts, Proteins and Regulatory Regions in Human and Vertebrate Model Organisms and the Intracellular Distribution in Skeletal Muscle Cells.

LMO7 is a multifunctional PDZ–LIM protein that can interact with different molecular partners and is found in several intracellular locations. The aim of this work was to shed light on LMO7 evolution, alternative transcripts, protein structure and gene regulation through multiple in silico analyses. We also explored the intracellular distribution of the LMO7 protein in chicken and zebrafish embryonic skeletal muscle cells by means of confocal fluorescence microscopy. Our results revealed a single LMO7 gene in mammals, sauropsids, Xenopus and in the holostean fish spotted gar while two lmo7 genes (lmo7a and lmo7b) were identified in teleost fishes. In addition, several different transcripts were predicted for LMO7 in human and in major vertebrate model organisms (mouse, chicken, Xenopus and zebrafish). Bioinformatics tools revealed several structural features of the LMO7 protein including intrinsically disordered regions. We found the LMO7 protein in multiple intracellular compartments in chicken and zebrafish skeletal muscle cells, such as membrane adhesion sites and the perinuclear region. Curiously, the LMO7 protein was detected within the nuclei of muscle cells in chicken but not in zebrafish. Our data showed that a conserved regulatory element may be related to muscle-specific LMO7 expression. Our findings uncover new and important information about LMO7 and open new challenges to understanding how the diverse regulation, structure and distribution of this protein are integrated into highly complex vertebrate cellular milieux, such as skeletal muscle cells.

Влияние кормовой микробной добавки на мясную продуктивность цыплят-бройлеров и качество мяса птицы

Abstract. The purpose of the research is to study the effect of a probiotic supplement on the productivity of broiler chickens of the fast-growing Cobb 500 cross and the quality of poultry meat. Research methods. To study the parameters of meat productivity of broiler chickens, slaughter and anatomical cutting of poultry carcasses were carried out, the morphological composition of individual parts of carcasses was evaluated, the chemical composition of poultry meat was analyzed by determining moisture (GOST 9793-74), fat (GOST 23042-86), protein (GOST 25011-81), the level of essential amino acids (capillary electrophoresis method), organoleptic parameters of poultry meat and broth were studied. Research results. It was found that the introduction of a fodder additive into the poultry diet contributes to the improvement of meat characteristics of the Cobb 500 cross, improves the quality properties of poultry meat, as well as the bio-value of poultry meat products. When studying meat productivity, it was revealed that in experimental groups the mass of the gutted carcass was higher than in the control by 1.45.3 %, the slaughter yield was higher by 0.31.4 %, the mass of all breast tissues of broiler chickens of experimental groups exceeded this indicator in the control by 1.78.2 %, the mass of all femoral tissues was higher by 2.07.8 %, and the mass of all shin tissues by 1.56.8 %. The results of the chemical analysis of muscles of broiler chickens showed that the protein content was higher in experimental groups compared to the control group by 0.180.60 %, with a decrease in fat by 0.060.16 %, and there was also a decrease in meat quality index in all experimental groups by 4.510.5 %. A positive statistically significant difference was revealed when analyzing the amino acid score in the muscles of birds of experimental groups compared with the control group. The organoleptic evaluation of boiled broiler chicken meat and broth from them in experimental groups showed superiority over the poultry meat of the control group and averaged 4.9 versus 4.8 points. Scientific novelty. For the first time, the meat productivity and meat quality of broiler chickens were evaluated when using a microbial additive based on autochthonous microorganisms of the genus Lactobacillus isolated from the contents of the gastrointestinal tract of wild quails in their diet.

Influence of different level of Camelina presscake on the quality composition of broiler chickens muscle tissue

In Russian market of meat products production of poultry meat occupies more than 47 %. At the same time, the share of poultry products in the total volume of animal protein consumed is 42,1 %, including poultry meat – 27,8 %, eggs – 14,3 %. The quality of the resulting meat is significantly influenced by feeding (feed ingredients, biologically active additives). The purpose of the investigations was to study the influence of compound feed containing Camelina presscake on the chemical composition of broiler muscle tissue. The investigations have been carried out on the basis of the Siberian Scientific and Research Institute of Poultry Farming – a branch of the Federal State Budgetary Scientific Institution “Omsk Agricultural Research Center” (Morozovka village, Omsk region) on broiler chickens of the cross Sibiryak-2. The results of the investigations on the influence of compound feed with Camelina presscake obtained from seeds of the Siberian selection on the qualitative composition of the muscle tissue of broilers have been presented in the article. The research has been conducted on four groups of broiler chickens from 1 to 42 days of age, in each group there were 100 heads. Camelina presscake was introduced instead of another traditional protein feed to the 1st experimental group – 12,5 %, the 2nd – 15 % and the 3rd experimental group – 20 % with the preservation of the total energy and protein nutrition of the compound feed. It has been found that in the muscles of broiler chickens of the experimental groups the protein content was higher by 0,06–0,73 abs.%, fat by 0,03–0,57 abs.%, energy nutrition higher by 0,03–0,29 MJ/kg. When comparing the amount of macro- and microelements in muscle tissue, the advantage has been noted for most of the studied indicators of poultry of experimental groups that received compound feed with Camelina presscake.

Detection and quantification of multiclass antibiotic residues in poultry products using solid-phase extraction and high-performance liquid chromatography with diode array detection

This article describes the initial study on the simultaneous determination of multiclass antibiotic residues in imported and local frozen poultry specimens, including turkey gizzard and muscle tissues, and chicken muscle tissues, commonly consumed in Ogun State, Nigeria. Minced tissues were treated with phosphate buffer adjusted to pH 7 that was cleaned using C18 SPE-column (Supelclean™) cartridge. For the determination of six antibiotic residues including fluoroquinolones, sulfonamides, and macrolides, a solid-phase extraction method was used, followed by extract analysis using high-performance liquid chromatography–diode array detection (HPLC–DAD). The coefficient of determination (R2) for the external standards for all the analytes ranged between 0.963 and 0.999. The limit of detection (LOD) and quantification (LOQ) ranged between 5.37 – 55.4 μg/kg, and 17.9–185 μg/kg, respectively. Enrofloxacin, sulfadimethoxine, sulfamerazine, and tylosin showed high concentration levels in the frozen poultry beyond acceptable maximum residue limits (MRLs). The six drugs considered in this study were present at higher concentrations in domestic chicken tissues than the permissible level. This suggests that farmers do not observe the cessation period before poultry birds previously treated with antibiotics are sold to consumers thus exposing them to potentially hazardous antibiotic residues.

Growth Performance, Carcass Characteristics and Meat Quality of Organically Reared Broiler Chickens Depending on Sex.

Simple SummaryConsumers are increasingly interested in the health and nutritional aspects of meat products, with the result that they are willing to pay more for meat products that have been produced naturally, taking into account high standards and animal welfare. Therefore, we decided to examine in a slightly wider perspective the muscles of Ross 308 chickens kept in an ecological system, taking into consideration an additional factor, i.e., sex. As sexual dimorphism is considered to be a factor in meat quality, we decided to examine this factor in our study. At the same time, we investigated the suitability of these fast-feathering broilers for ecological production. The aim of the study was to investigate the effect of sex on the growth performance, carcass traits, meat quality, fatty acid profile and histological traits of the pectoral muscles in organic Ross 308 broiler chickens. The suitability of these fast-growing broilers for organic production systems was also analyzed. As expected, the study confirmed the influence of sex on the analyzed parameters of the pectoral muscles in chickens reared in the organic system.Given the growing interest of consumers in naturally produced meat, we decided to examine the muscles of Ross 308 broiler chickens kept in an ecological system, with the division into two research groups depending on sex. All the analyses were carried out using the appropriate methods recommended by the AOAC and in accordance with the Polish standards (PN), which are described in detail in the relevant section of the publication. The aim of the experiment was to investigate the effect of sex on the growth performance, carcass traits and meat quality, as well as the fatty acid profile and histological parameters, of the pectoral muscles from organic broiler chickens. A total of 60 one-day-old Ross 308 chickens (half males and half females) were divided into two groups, according to the sex, and reared under organic conditions (Org.) until 82 days of age (ten birds, i.e., five males and five females in each of three pens; replications for experimental groups). Compared with the female group, the male group had a higher final BW and carcass weight (p < 0.05). The males had a better growth and slaughter performance than the females. The meat quality traits and fatty acids content were also affected by sex. The meat from females showed a significantly higher (p < 0.05) protein, dry matter, fiber diameter and shear force and a significantly lower (p < 0.05) fat level than the male group. In this research, the suitability of these fast-growing broilers for natural and organic production systems has been researched with regard to the performance, meat quality and histological characteristics of the muscles.

Development of a Dihydropteroate Synthase-Based Fluorescence Polarization Assay for Detection of Sulfonamides and Studying Its Recognition Mechanism.

In this study, the dihydropteroate synthase of Staphylococcus aureus was obtained, and its recognition mechanisms for 31 sulfonamide drugs were studied. Results showed that their core structure matched well with the binding pocket of para-aminobenzoic acid, and all the sulfonamide side chains were out of the binding pocket. Hydrogen bonds and hydrophobic interactions were the main intermolecular forces, and the key amino acids were Gly171 and Lys203. The binding sites in sulfonamide molecules were mainly around the para-aminobenzenesulfonamide part. This enzyme was used to develop a fluorescence polarization assay for detection of these drugs in chicken muscles. The change trends of half of inhibition concentrations and cross-reactivities for the 31 drugs were identical with the receptor-ligand affinities. The limits of detection were in the range of 2.0-38.5 ng/g, and one assay could be finished within several minutes. Therefore, this method could be used for multiscreening of sulfonamide residues in meat samples.

Telomere Length, Apoptotic, and Inflammatory Genes: Novel Biomarkers of Gastrointestinal Tract Pathology and Meat Quality Traits in Chickens under Chronic Stress (Gallus gallus domesticus).

Simple SummaryThe assessment of poultry’s gastrointestinal (GI) tract and meat quality traits are crucial for sustainable poultry production in the tropics. The search for well-conserved and more reliable biomarkers for the GI tract and meat traits has faced many challenges. In this study, we observed the effect of corticosterone (CORT) and age on body weight, buffy coat telomere length, GI tract, and meat quality traits. The critical evaluation of the GI tract and meat traits in this study revealed that telomere length, mitochondria, and acute phase protein genes were altered by chronic stress and were associated with the traits. This study informed us of the potential of telomere length, mitochondria, and acute phase protein genes in the assessment of GI tract pathological conditions and meat quality in the poultry sector for sustainable production.This study was designed to examine the potentials of telomere length, mitochondria, and acute phase protein genes as novel biomarkers of gastrointestinal (GI) tract pathologies and meat quality traits. Chickens were fed a diet containing corticosterone (CORT) for 4 weeks and records on body weight, telomere length, GI tract and muscle histopathological test, meat quality traits, mitochondria, and acute phase protein genes were obtained at weeks 4 and 6 of age. The body weight of CORT-fed chickens was significantly suppressed (p < 0.05). CORT significantly altered the GI tract and meat quality traits. The interaction effect of CORT and age on body weight, duodenum and ileum crypt depth, pH, and meat color was significant (p < 0.05). CORT significantly (p < 0.05) shortened buffy coat telomere length. UCP3 and COX6A1 were diversely and significantly expressed in the muscle, liver, and heart of the CORT-fed chicken. Significant expression of SAAL1 and CRP in the liver and hypothalamus of the CORT-fed chickens was observed at week 4 and 6. Therefore, telomere lengths, mitochondria, and acute phase protein genes could be used as novel biomarkers for GI tract pathologies and meat quality traits.

Effect of dietary folic acid and energy density on immune response, gut morphology, and oxidative status in blood and breast muscle of broiler chickens

Folic acid (FA) plays essential roles in many metabolic functions and has been reported to have antioxidant effects. Therefore, dietary supplementation with high levels of FA may improve gut health and prevent potential oxidative stress caused by feeding a high energy density diet to broiler chickens. Broiler chickens were assigned into eight treatments, consisting of either a normal energy (NE) or high energy (HE) density diet, and four FA levels (2.2, 5, 10, and 15 ppm). Data were analyzed by SAS 16 GLM procedure. Birds-fed HE diets had increased (P &lt; 0.05) plasma concentrations of calcium and albumin but reduced (P &lt; 0.005) weights of ceca and bursa compared with those fed NE diets. Dietary supplementation with 10 ppm FA significantly increased (P &lt; 0.05) birds’ heart weight and bile acid concentration. Folic acid and energy density interactions were significant for jejunal villus height (VH; P = 0.0226), villus width (VW; P &lt; 0.0001), and crypt depth (CD; P = 0.0332). Among the NE group, birds fed 5–15 ppm FA had reduced (P &lt; .0001) VW, while in the HE groups, 15 ppm FA supplementation resulted in an increased jejunal VH (P = 0.0317) compared with other treatments. In conclusion, dietary supplementation with increased levels of FA in HE diets could be beneficial for the intestinal health of broiler chickens.

Enzymatic probe sonication for quick extraction of total bisphenols from animal-derived foods: Applicability to occurrence and exposure assessment

A high demand exists in bisphenols (BPs) screening studies for quick, reliable and straightforward analytical methods that generate data faster and simultaneously. Herein, we describe a combination of enzymatic probe sonication (EPS) and ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) for quick extraction and simultaneous quantification of eight important BPs in animal-derived foods. Results obtained demonstrated that the ultrasonic probe power could not only enhance the enzymatic hydrolysis efficiency, but also accelerate the liquid-liquid extraction procedure. Under optimized EPS parameters, one sample could be exhaustively extracted within 120 s, as compared with 12 h needed for the conventional enzymatic extraction which is more suitable for high-throughput analysis. The method was successfully applied to analyze residual BPs in animal-derived foods collected from Beijing, China. Widespread occurrence of BPA, BPS, BPF, BPAF, BPP, and BPB were found, with detection frequencies of 65.2%, 42.4%, 33.7%, 29.4%, 28.3%, and 27.2%, respectively. The highest total concentration levels of BPs (sum of the eight BPs analyzed, ΣBPs) were found in chicken liver (mean 12.2 μg/kg), followed by swine liver (6.37 μg/kg), bovine muscle (3.24 μg/kg), egg (2.03 μg/kg), sheep muscle (2.03 μg/kg), chicken muscle (1.45 μg/kg), swine muscle (1.42 μg/kg), and milk (1.17 μg/kg). The estimated daily intake (EDI) of BPs, based on the mean and 95th percentile concentrations and daily food consumptions, was estimated to be 5.687 ng/kg bw/d and 22.71 ng/kg bw/d, respectively. The human health risk assessment in this work suggests that currently BPs do not pose significant risks to the consumers because the hazard index (HI) was <1.

MiR-29b-1-5p regulates the proliferation and differentiation of chicken primary myoblasts and analysis of its effective targets

Several recent studies investigated the role of the miR-29 family in muscle development. However, only a few studies focused on chicken skeletal muscle. In the present study, cell cycle, 5-ethynyl-2’-deoxyuridine (EdU), cell counting kit-8 (CCK-8), and other assays indicated that miR-29b-1-5p can inhibit the proliferation of chicken primary myoblasts (CPMs); the western blot assay and immunofluorescence detection of MYHC demonstrated that miR-29b-1-5p can promote the differentiation of myoblasts. The functional enrichment analysis revealed that the target genes of miR-29b-1-5p may be involved in muscle tissue development, muscle organ development, and striated muscle tissue development, which are biological processes related to muscle development. The correlation analysis showed that these 6 genes, that is, ankyrin repeat domain 9 (ANKRD9), lactate dehydrogenase A (LDHA), transcription factor 12 (TCF12), FAT atypical cadherin 1 (FAT1), lin-9 homolog (LIN9), and integrin beta 3 binding protein (ITGB3BP), can be used as effective candidate target genes of miR-29b-1-5p. Moreover, miR-29b-1-5p inhibits the expression of ANKRD9 by directly binding the 3′UTR of ANKRD9. Overall, these data indicate that miR-29b-1-5p inhibits the proliferation of primary chicken myoblasts, stimulates their differentiation, and is involved in the process of muscle development and that its effective target gene is ANKRD9. This study identified the molecular mechanism of miR-29b-1-5p in chicken muscle development.

Refining the Diagnosis of Growth-Related Muscle Abnormalities in Chickens Based on the Nomenclature Used to Characterise Human Myopathies.

Although worldwide poultry meat consumption is increasing, growth-related muscle abnormalities represent a limitation to the sustainability of chicken meat production due to their significant economic consequences and unfavourable impact on product quality and social acceptability (Kuttappan et al., 2012b). Several abnormalities have already been described in modern broiler strains, but there has been a notable increase in the prevalence of white striping (WS) and wooden breast (WB) syndromes over the past decade. Briefly, the WS defect corresponds to the appearance of white streaks mainly on the Pectoralis Major (PM) muscle of the fillet (Kuttappan et al., 2012b), while the WB defect corresponds to a hard, bulging PM muscle with a slimy appearance and petechiae in the most severe cases (Sihvo et al., 2014). Several studies have shown that rapid growth, high slaughter weight and breast meat yield as well as limited muscle glycogen store contribute to increase the incidence of such breast muscle abnormalities (Kuttappan et al., 2013a; Abasht et al., 2016; Alnahhas et al., 2016; Kawasaki et al., 2018. In recent years, many studies have been carried out to understand the molecular mechanisms underlying the development of breast muscle abnormalities in broiler. Muscle histological characterizations have allowed a detailed description of injuries associated with the abnormalities. Combined with high-throughput molecular studies, they have speed up the understanding of the biological processes involved in their establishment (for review, Soglia et al., 2021). In particular, these studies have shown that WS and WB muscle abnormalities share several histological features with human myopathies (Dubowitz et al., 2020) that could be used for their diagnosis (Praud et al., 2020). The purpose of this opinion paper is to highlight the importance of using current knowledge on human myopathies and existing nomenclature used by muscle pathologists to accurately interpret histological observations of chicken muscle abnormalities and thus improve their diagnosis.

Influence of dietary olive paste flour on the performance and oxidative stress in chickens raised in field conditions

Olive oil contains a variety of antioxidants, including vitamin E. Its consumption protects against oxidative stress, which is involved in many pathological conditions, affecting animals’ development and their general welfare. The present study aimed to investigate the effect of olive paste flour (OPF) on the antioxidant status and performance of broiler chickens raised in field conditions. Total of 18.000 broilers was randomly allocated in equal numbers in two poultry houses. The chickens were grouped according to their diet as follows: Control group: chickens fed commercial poultry feed, and OPF group: chickens fed control dietsin the starter period, but they got a supplement of OPF in grower, and finisher 1 and 2periods, respectively. The birds were raised under identical field conditions (ventilation, vaccination, lighting, etc.). Antioxidant status was assessed by measuring the concentration of vitamin E in plasma, as well as the total antioxidant capacity (TAC) in plasma and muscle tissue. According to the statistical analysis of the results, the addition of OPF to chickens’ diet significantly enhanced plasma α-tocopherol concentration (p≤0.05). TAC did not show any significant differences in chicken plasma nor muscle tissue(p&gt;0.05).Feed intake (FI) was higher in OPF group, while Body weight (BW) was lower. Liveability was similar for the two groups. The feed conversion ratio (FCR) was higher, and the European production efficiency factor (EPEF) was lower in broilers of the OPF group compared to those of the control group.Samples of roasted breast from chickens of both groups were used for organoleptic characteristics evaluation. Results showed that samples of the OPF group smelled more intensely and were more tasteful than those of the control group.However, other organoleptic characteristics did not differ. In conclusion, the results demonstrated that although the addition of OPF to chickens’ diet can cause growth retardation, it can significantly increase the plasma α-tocopherol concentration. Further studies are needed to optimize the concentration of OPF in poultry feed in order to avoid growth retardation or even to promote growth in broiler chicks.

DOXYCYCLINE DETERMINATION IN ANIMAL TISSUES AND BLOOD PLASMA SAMPLES USING SCREENING AND CONFIRMATORY METHODS

The article presents the results of validation of sample preparation method for muscle and parenchymal tissues of animals for further determination of doxycycline residual amounts by enzyme-linked immunosorbent assay using Oxytetracycline ELISA test kits from EuroProxima (Netherlands), initially developed for the analysis of other target matrices, viz. honey and shrimp. The results of modification of shrimp sample preparation method for the analysis of muscle and parenchymal tissue samples are showed. In accordance with the European Commission Decision 2002/657/EC, the proposed method was validated taking into account the maximum residue levels (MRLs) of doxycycline in tissues of productive animals: 100 μg/kg for muscle tissue and 300 μg/kg for liver. The suitability of the technique was confirmed on the basis of the established main validation parameters for screening methods (technical threshold and cut-off factor) using control (pure) and spiked with standard doxycycline solution at the level of ½MRL samples of muscle and parenchymal tissues of broiler chickens by means of “added – found” criterion. It was discovered that this approach to sample preparation makes it possible to determine doxycycline residues in poultry tissues at the level of 5-10 μg/kg with the absolute recovery about 54 %. The main advantages of the developed technique are simplicity of performance, rapidity and cost-effectiveness.&#x0D; The reliability of the results obtained by the screening method was verified using confirmatory UPLC-MS/MS method, viz. a comparative study of blank and spiked samples of muscle and parenchymal tissues of broiler chickens. The method of sample preparation of the studied specimens, the conditions of analysis carrying out, and the main validation parameters of the confirmatory method are also presented. Based on the obtained results, it was concluded that the developed screening method of enzyme-linked immunosorbent assay is suitable for the determination of doxycycline residual amounts in muscle and parenchymal tissues samples, and it is possible to use it for routine laboratory tests, as well as for the establishment of withdrawal periods of veterinary drugs based on doxycycline from the tissues of productive animals. Also using the same test kit, the sample preparation method for blood plasma samples for doxycycline content assay (at the levels of μg/ml) was suggested to study the bioequivalence of veterinary drugs containing doxycycline as an active pharmaceutical ingredient, which was as well confirmed by UPLC-MS/MS.