Effect of arginine, glycine + serine concentrations, and guanidinoacetic acid supplementation in vegetable-based diets for chickens.

The study investigated guanidinoacetic acid (GAA) supplementation with varying dietary digestible arginine (Arg) and glycine+serine (Gly+Ser) concentrations in the starter phase, exploring respective carry-over effects on growth performance, blood chemistry, incidence of pectoral myopathies and proximate composition in broilers. A total of 2,800 one-day-old male broiler chicks were distributed in a central composite design with 2 factors and double experimental mesh, represented by supplementation or omission of 0.6 g per kg of GAA, with a central point represented by 107% of Arg and 147% of Gly+Ser, 4 factorial points (combinations of Arg/Gly+Ser concentrations: 96.4/132.5%; 117.6/132.5%; 96.4/161.5%, and 117.6/132.5%), and 4 axial points (combinations of axial points estimated for Arg and Gly+Ser, with the central points of 92/147%; 122/147%; 107/126.5, and 107/167.5%), totaling 18 treatments, 4 repetitions to factorial and axial points, 24 replicates to the central point, and 25 birds per pen. Feed conversion ratio (FCR) from d 1 to 10 had a linear response (P = 0.009) for the decreasing Arg content and a quadratic response (P = 0.047) for Gly+Ser concentrations. Broilers supplemented GAA had lower FCR compared with nonsupplemented groups from d 1 to 10 (P = 0.048) and d 1 to 42 (P = 0.026). Aspartate aminotransferase (AST) exhibited increasing and decreasing linear effects as a function of Arg (P = 0.008) and Gly+Ser (P = 0.020) concentrations, respectively. Guanidinoacetic acid decreased serum AST (P = 0.028). Guanidinoacetic acid reduced moderate + severe (P = 0.039) and mild (P = 0.015) Wooden Breast scores. The occurrence of normal White Striping increased (P = 0.002), while severe score was reduced (P = 0.029) with GAA supplementation. In conclusion, increased digestible Arg:Lys and 14% and 6% above the recommendations (107% and 147%), respectively, provided improved FCR during the starter phase. Dietary GAA supplementation (0.6 g per kg) improved FCR, reduced severity of breast myopathies and appears to have reduced muscle damage in broilers fed plant-based diets.

Differential expression of miRNAs associated with pectoral myopathies in young broilers: insights from a comparative transcriptome analysis.

INTRODUCTION: White Striping (WS) and Wooden Breast (WB) pectoral myopathies are relevant disorders for contemporary broiler production worldwide. Several studies aimed to elucidate the genetic components associated with the occurrence of these myopathies. However, epigenetic factors that trigger or differentiate these two conditions are still unclear. The aim of this study was to identify miRNAs differentially expressed (DE) between normal and WS and WB-affected broilers, and to verify the possible role of these miRNAs in metabolic pathways related to the manifestation of these pectoral myopathies in 28-day-old broilers. RESULTS: Five miRNAs were DE in the WS vs control (gga-miR-375, gga-miR-200b-3p, gga-miR-429-3p, gga-miR-1769-5p, gga-miR-200a-3p), 82 between WB vs control and 62 between WB vs WS. Several known miRNAs were associated with WB, such as gga-miR-155, gga-miR-146b, gga-miR-222, gga-miR-146-5p, gga-miR- 29, gga-miR-21-5p, gga-miR-133a-3p and gga-miR-133b. Most of them had not previously been associated with the development of this myopathy in broilers. We also have predicted 17 new miRNAs expressed in the broilers pectoral muscle. DE miRNA target gene ontology analysis enriched 6 common pathways for WS and WB compared to control: autophagy, insulin signaling, FoxO signaling, endocytosis, and metabolic pathways. The WS vs control contrast had two unique pathways, ERBB signaling and the mTOR signaling, while WB vs control had 14 unique pathways, with ubiquitin-mediated proteolysis and endoplasmic reticulum protein processing being the most significant. CONCLUSIONS: We found miRNAs DE between normal broilers and those affected with breast myopathies at 28 days of age. Our results also provide novel evidence of the miRNAs role on the regulation of WS and in the differentiation of both WS and WB myopathies. Overall, our study provides insights into miRNA-mediated and pathways involved in the occurrence of WS and WB helping to better understand these chicken growth disorders in an early age. These findings can help developing new approaches to reduce these complex issues in poultry production possibly by adjustments in nutrition and management conditions. Moreover, the miRNAs and target genes associated with the initial stages of WS and WB development could be potential biomarkers to be used in selection to reduce the occurrence of these myopathies in broiler production.

Deciphering the underlying mechanisms of the oxidative perturbations and impaired meat quality in Wooden breast myopathy by label-free quantitative MS-based proteomics.

The study aimed to investigate biochemical mechanisms occurred in Wooden breast (WB) chicken meat, with attention to the impact on meat quality. Commercial chicken breasts were classified as Normal (N, n = 12), WB-M (moderate degree; focal hardness on cranial region, n = 12) and WB-S (severe degree; extreme and diffused hardness over the entire surface, n = 12). Samples were analyzed for physico-chemical properties, oxidative damage to lipids and proteins, and discriminating sarcoplasmic proteins by using a Q-Exactive mass spectrometer. WB meat presented impaired composition and functionality and higher levels of lipid and protein oxidation markers than N meat. The proteomic profile of WB-S presents a dynamic regulation of the relevant proteins involved in redox homeostasis, carbohydrate, protein and lipid metabolisms. Proteomics results demonstrate that the physiological and metabolic processes of muscles affected by WB myopathy are involved in combating the inflammatory process and in repairing the damaged tissue by oxidative stress.

Classification, quality characteristics, sensory perception and texture prediction of wooden breast myopathy in broilers from Argentina.

The objective of this study was to characterize the wooden breast (WB) myopathy in the poultry industry, and establish degrees of severity by analyzing the composition and important characteristics of meat quality. 175 chickens from the COBB-500 commercial line were analyzed, and three WB categories were established: normal, moderate, and severe. The prevalence was: 4.00% severe, 46.29% moderate, and 49.71% normal, and it was affected by sex and weight. The WB characterization was carried out on 7 breasts of each WB degree. A decrease in protein and ashes, an increase in fat and loss of water by dripping, and color changes were observed as the degree of severity advanced. The texture was evaluated by instrumental, sensory, and image analysis techniques. Severe samples showed alterations in compression test, cohesiveness and juiciness, together with significant differences on the parameters, "contrast" and "energy". A characterization of WB myopathy was achieved for the first time in Argentina. The decline in meat quality could lead to industrial losses. Image analysis proved to be a promising technique for differentiating the severity of WB myopathy in raw chicken. Differences between raw and cooked samples were detected, thus both types of meat should be studied in detail. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-022-05608-9.

Effect of wooden breast myopathy on texture and acceptability of emulsified chicken patties.

Wooden breast (WB) condition is a chicken myopathy that causes quality losses and has been shown to negatively affect the sensory acceptance by consumers. In this work, we prepared emulsified chicken patties using WB meat and evaluated their texture profile and acceptability. Three formulations were processed: PN (100% normal breast), PW (100% WB meat) and PNW (50%:50% PN:PW). All the analyzed samples were in accordance with Brazilian legislation parameters for microbiological traits. A marked decrease (P < 0.001) of hardness was noted for PW and PNW samples compared with PN. The sensory ratings were not affected (P > 0.05) by the addition of WB meat in the different treatments. In fact, all samples presented a global sensory acceptance above 70%. The use of WB meat in the formulation of chicken patties is a useful practice to minimize the economic losses in the poultry industry, also helping to support decision-making and improve production performance.

Techniques for in vivo assessment of myopathies in broiler chicken breasts using a biopsy as a support tool.

An experiment was conducted to validate non-invasive evaluation techniques as in vivo evaluation tools for the myopathies wooden breast and white striping that affect broilers, using biopsy as a support tool. It evaluated 30 Cobb 500® broiler chickens in a completely randomized design consisting of two sexes (males and females) and 15 replications per treatment. At 14, 21, 35, 42 and 49 days, the surface temperature of the birds' breasts was recorded using infrared thermography, analysis of fillet depth, and echogenicity by ultrasound imaging. All broiler chickens were sent for biopsy at 21, 35 and 42 days to collect a fragment of the pectoral muscle for descriptive morphological analyses of histological lesions and muscle fibre morphometry. Males had higher echogenicity values at 14, 21 and 42 days. There was no influence of bird sex on the occurrence of the wooden breast and white striping myopathies at 49 days of age in broilers selected and submitted to the biopsy protocol. There was a general trend of decreasing surface temperature for both sexes according to their age. Muscles with less area occupied with fibres had a lower surface temperature. It was concluded that ultrasonography with a 3.5 MHz transducer detects muscle changes after 28 days of age, which is consistent with the myopathic lesions studied. Infrared thermography is a potential method for detecting changes in breast temperature indicating myopathic lesions. A biopsy can be used as an auxiliary tool in the study of myopathies in broiler chicken breasts.RESEARCH HIGHLIGHTS Detection of changes in the breast muscle after 28 days of age with ultrasonography.Changes in the surface temperature range of pectoral muscle with infrared thermography.Use of biopsy as a tool for early diagnostic evaluation in broiler myopathies.

Physical, Chemical and Histological Characterization of Pectoralis major Muscle of Broilers Affected by Wooden Breast Myopathy.

This study aimed to characterize the effects of wooden breast myopathy (WBM) on quality of broiler chicken breast meat. Normal samples (absence of myopathy), moderate-degree samples (hardness only in one area of the breast fillet) and severe-degree samples (hardness throughout the breast fillet) were classified. In macroscopic analysis, the pectoral muscle affected by the WBM showed, in general, pale color with stiff, irregular and reddish regions (suffusions and petechiae), with the presence of white striations. In microscopic analysis, the myopathy was characterized by loss of the polygonal aspect of the muscle fibers. Samples with moderate degree of the myopathy showed greater (p = 0.0266) water retention capacity. There was an increase (p = 0.004) in total collagen concentration in samples from the severe-degree group 0.29% in normal samples to 0.43 and 0.48% in samples from moderate- and severe-degree groups, respectively. Samples of chicken breast affected by the severe-degree WBM showed lower (p < 0.0001) myofibrillar fragmentation index (64.51) and lower (p = 0.0002) fat concentration (2.17%) than normal chicken samples (80.45 and 3.79%, respectively). Samples affected by WBM are larger and heavier and present poorer physical quality when compared to normal chicken meat. Histologically it is possible to observe loss of the polygonal aspect of muscle fibers.

Effects of Storage on Quality Traits of Sausages Made with Chicken Breast Meat Affected by Wooden Breast.

The aim of this study was to examine the effects of storage on the quality of sausages made with breast from chickens affected by wooden breast myopathy (WBM). Breast samples from male broilers slaughtered at 48 days old were used. Normal (absence of myopathy), moderate degree (hardness only in one region of the breast) and severe degree samples (hardness over the entire length of the breast) were processed into sausages and evaluated prior to storage and after being vacuum-packed and stored for 7, 14, 21 and 28 days at 4 °C. There was a decrease (p < 0.001) in pH and an increase (p < 0.001) in cooking weight loss in samples of sausages, regardless of the myopathy, after 28 days of storage. Sausages produced with chicken breast samples affected by wooden breast myopathy presented higher (p < 0.0001) moisture concentration (72% for the severe degree) and higher (p = 0.0224) protein concentration (17.27% and 17.36%, respectively, for the moderate and severe degrees) than sausages made of normal samples (70.72% and 14.32%, respectively). The results indicate that sausages produced with meat from birds moderately and severely affected by the myopathy show higher oxidative stability. Fresh sausages produced with breast meat from birds affected by wooden breast syndrome may be stored (4 °C) for up to 28 days without exhibiting the characteristic rancid taste and smell. In sensory analysis, no differences were observed between the formulations, which suggests that the consumers approved the samples regardless of the disease severity in the meat used for the making of the sausages. The current results show that chicken meat affected by wooden breast myopathy can be used for producing fresh sausages in the industry.

Wooden breast and white striping: comparative occurrence in three poultry companies / Wooden breast e white striping: ocorrência em três empresas avícolas

To increase the amount of meat produced, researchers have promoted intensive genetic selection for growth rate and muscling and have improved nutrition and management conditions. However, there has been an increase in the number of reports of breast muscle myopathies observed in poultry processing plants, including white striping (WS) and wooden breast (WB). This study aimed to evaluate and to compare the occurrence of WS and WB myopathies in three poultry processing plants and to perform an anatomopathological characterization, including macroscopic and microscopic analyses. A total of 408,334 carcasses were condemned or downgraded due to the presence of WB or WS, which represents 0.73% of the total number of slaughtered animals during the evaluated period. WB was more frequent than WS, but the occurrence of each myopathy varied significantly according to each establishment. WB was more frequent in the establishment which includes only male flocks, an average age of 45 days, and an average live weight of 2775g (B). WS was more frequent in establishment with male, female and mixed flocks, average ages ranging from 41 to 44 days, and average live weight 1731g-2830g (A). It is probably related with specific condition of each poultry company, including genetics, age, nutrition and management conditions. Macroscopically, WB and WS lesions are characterized by hypertrophy and stiffness of the pectoralis major muscle. Under microscopy, the myopathies showed similarities regarding the detected histological abnormalities, characterized by a process of myodegeneration, although the connective tissue infiltrate was more severe in the breasts with WB than in those with WS myopathy. The results found in this study demonstrate that the rates of condemnation for these myopathies are high, vary significantly among the analyzed companies and may cause major economic losses for the productive sector in the region.(AU)

Para melhorar a quantidade de carne produzida, os pesquisadores têm promovido ao longo dos anos uma seleção genética intensiva para a taxa de crescimento e desenvolvimento de músculos, além de melhorias nas condições nutricionais, sanitárias e de manejo. No entanto, houve um aumento no número de relatos de miopatias dos músculos do peito observados em abatedouros-frigoríficos de aves, incluindo white striping (WS) e wooden breast (WB). O objetivo deste estudo foi avaliar a ocorrência de WB e WS em três abatedouros-frigoríficos de aves e realizar uma caracterização anatomopatológica, incluindo análises macroscópicas e microscópicas. Um total de 408.334 carcaças foi condenado (total ou parcialmente) devido à presença WB ou WS, o que representou 0,73% do número total de animais abatidos durante o período avaliado. Apesar de a ocorrência de WB ter sido maior do que a de WS, a frequência de cada uma variou significativamente de acordo com o estabelecimento. WB foi mais frequente no estabelecimento que incluía apenas lotes de machos, com média de 45 dias de idade e peso médio ao abate de 2775g (B). WS foi mais frequente no estabelecimento com lotes de machos, fêmeas e mistos, com idade entre 41 e 44 dias e peso médio ao abate entre 1731g-2830g (A). Isto pode ser justificado por condições específicas de cada empresa, incluindo genética, idade das aves, nutrição e condições de manejo. Macroscopicamente, as lesões de WB e de WS foram caracterizadas principalmente por hipertrofia e rigidez do músculo pectoralis major. À microscopia, ambas as miopatias mostraram semelhanças em relação às anormalidades histológicas detectadas, caracterizadas principalmente por um processo de miodegeneração. Nos músculos apresentando WB, o infiltrado de tecido conjuntivo foi mais intenso quando comparado àqueles com WS. Os resultados encontrados neste trabalho demonstram que os índices de condenação por essas miopatias são altos, variam significativamente entre as empresas analisadas e podem causar grandes perdas econômicas para o setor produtivo da região.(AU)

Wooden breast and white striping: comparative occurrence in three poultry companies

ABSTRACT: To increase the amount of meat produced, researchers have promoted intensive genetic selection for growth rate and muscling and have improved nutrition and management conditions. However, there has been an increase in the number of reports of breast muscle myopathies observed in poultry processing plants, including white striping (WS) and wooden breast (WB). This study aimed to evaluate and to compare the occurrence of WS and WB myopathies in three poultry processing plants and to perform an anatomopathological characterization, including macroscopic and microscopic analyses. A total of 408,334 carcasses were condemned or downgraded due to the presence of WB or WS, which represents 0.73% of the total number of slaughtered animals during the evaluated period. WB was more frequent than WS, but the occurrence of each myopathy varied significantly according to each establishment. WB was more frequent in the establishment which includes only male flocks, an average age of 45 days, and an average live weight of 2775g (B). WS was more frequent in establishment with male, female and mixed flocks, average ages ranging from 41 to 44 days, and average live weight 1731g-2830g (A). It is probably related with specific condition of each poultry company, including genetics, age, nutrition and management conditions. Macroscopically, WB and WS lesions are characterized by hypertrophy and stiffness of the pectoralis major muscle. Under microscopy, the myopathies showed similarities regarding the detected histological abnormalities, characterized by a process of myodegeneration, although the connective tissue infiltrate was more severe in the breasts with WB than in those with WS myopathy. The results found in this study demonstrate that the rates of condemnation for these myopathies are high, vary significantly among the analyzed companies and may cause major economic losses for the productive sector in the region.

RESUMO: Para melhorar a quantidade de carne produzida, os pesquisadores têm promovido ao longo dos anos uma seleção genética intensiva para a taxa de crescimento e desenvolvimento de músculos, além de melhorias nas condições nutricionais, sanitárias e de manejo. No entanto, houve um aumento no número de relatos de miopatias dos músculos do peito observados em abatedouros-frigoríficos de aves, incluindo white striping (WS) e wooden breast (WB). O objetivo deste estudo foi avaliar a ocorrência de WB e WS em três abatedouros-frigoríficos de aves e realizar uma caracterização anatomopatológica, incluindo análises macroscópicas e microscópicas. Um total de 408.334 carcaças foi condenado (total ou parcialmente) devido à presença WB ou WS, o que representou 0,73% do número total de animais abatidos durante o período avaliado. Apesar de a ocorrência de WB ter sido maior do que a de WS, a frequência de cada uma variou significativamente de acordo com o estabelecimento. WB foi mais frequente no estabelecimento que incluía apenas lotes de machos, com média de 45 dias de idade e peso médio ao abate de 2775g (B). WS foi mais frequente no estabelecimento com lotes de machos, fêmeas e mistos, com idade entre 41 e 44 dias e peso médio ao abate entre 1731g-2830g (A). Isto pode ser justificado por condições específicas de cada empresa, incluindo genética, idade das aves, nutrição e condições de manejo. Macroscopicamente, as lesões de WB e de WS foram caracterizadas principalmente por hipertrofia e rigidez do músculo pectoralis major. À microscopia, ambas as miopatias mostraram semelhanças em relação às anormalidades histológicas detectadas, caracterizadas principalmente por um processo de miodegeneração. Nos músculos apresentando WB, o infiltrado de tecido conjuntivo foi mais intenso quando comparado àqueles com WS. Os resultados encontrados neste trabalho demonstram que os índices de condenação por essas miopatias são altos, variam significativamente entre as empresas analisadas e podem causar grandes perdas econômicas para o setor produtivo da região.

Wooden breast and white striping: comparative occurrence in three poultry companies / Wooden breast e white striping: ocorrência em três empresas avícolas

To increase the amount of meat produced, researchers have promoted intensive genetic selection for growth rate and muscling and have improved nutrition and management conditions. However, there has been an increase in the number of reports of breast muscle myopathies observed in poultry processing plants, including white striping (WS) and wooden breast (WB). This study aimed to evaluate and to compare the occurrence of WS and WB myopathies in three poultry processing plants and to perform an anatomopathological characterization, including macroscopic and microscopic analyses. A total of 408,334 carcasses were condemned or downgraded due to the presence of WB or WS, which represents 0.73% of the total number of slaughtered animals during the evaluated period. WB was more frequent than WS, but the occurrence of each myopathy varied significantly according to each establishment. WB was more frequent in the establishment which includes only male flocks, an average age of 45 days, and an average live weight of 2775g (B). WS was more frequent in establishment with male, female and mixed flocks, average ages ranging from 41 to 44 days, and average live weight 1731g-2830g (A). It is probably related with specific condition of each poultry company, including genetics, age, nutrition and management conditions. Macroscopically, WB and WS lesions are characterized by hypertrophy and stiffness of the pectoralis major muscle. Under microscopy, the myopathies showed similarities regarding the detected histological abnormalities, characterized by a process of myodegeneration, although the connective tissue infiltrate was more severe in the breasts with WB than in those with WS myopathy. The results found in this study demonstrate that the rates of condemnation for these myopathies are high, vary significantly among the analyzed companies and may cause major economic losses for the productive sector in the region.(AU)

Para melhorar a quantidade de carne produzida, os pesquisadores têm promovido ao longo dos anos uma seleção genética intensiva para a taxa de crescimento e desenvolvimento de músculos, além de melhorias nas condições nutricionais, sanitárias e de manejo. No entanto, houve um aumento no número de relatos de miopatias dos músculos do peito observados em abatedouros-frigoríficos de aves, incluindo white striping (WS) e wooden breast (WB). O objetivo deste estudo foi avaliar a ocorrência de WB e WS em três abatedouros-frigoríficos de aves e realizar uma caracterização anatomopatológica, incluindo análises macroscópicas e microscópicas. Um total de 408.334 carcaças foi condenado (total ou parcialmente) devido à presença WB ou WS, o que representou 0,73% do número total de animais abatidos durante o período avaliado. Apesar de a ocorrência de WB ter sido maior do que a de WS, a frequência de cada uma variou significativamente de acordo com o estabelecimento. WB foi mais frequente no estabelecimento que incluía apenas lotes de machos, com média de 45 dias de idade e peso médio ao abate de 2775g (B). WS foi mais frequente no estabelecimento com lotes de machos, fêmeas e mistos, com idade entre 41 e 44 dias e peso médio ao abate entre 1731g-2830g (A). Isto pode ser justificado por condições específicas de cada empresa, incluindo genética, idade das aves, nutrição e condições de manejo. Macroscopicamente, as lesões de WB e de WS foram caracterizadas principalmente por hipertrofia e rigidez do músculo pectoralis major. À microscopia, ambas as miopatias mostraram semelhanças em relação às anormalidades histológicas detectadas, caracterizadas principalmente por um processo de miodegeneração. Nos músculos apresentando WB, o infiltrado de tecido conjuntivo foi mais intenso quando comparado àqueles com WS. Os resultados encontrados neste trabalho demonstram que os índices de condenação por essas miopatias são altos, variam significativamente entre as empresas analisadas e podem causar grandes perdas econômicas para o setor produtivo da região.(AU)

Physicochemical Properties and Consumer Acceptance of Hamburgers Processed with Chicken Meat Affected by Wooden Breast Myopathy.

Considering the increased incidence of wooden breast myopathy in broilers, the intake involves no threat to human health, indefinite etiology consumer rejection by appearance in such breasts, and the lack of studies on the industrial use of wooden breast. The objective of this study was evaluating the quality of hamburgers made with chicken meat affected by wooden breast. Breast samples from broilers slaughtered at 48-days-old were used. Normal (absence of myopathy), moderate degree (hardness only in one region of the breast) and severe degree (hardness over the entire length of the breast) samples were processed for the manufacture of hamburgers whose quality analyses (color, pH, cooking weight loss, shrinkage percentage, tenderness, storage weight loss, water activity, lipid oxidation, chemical composition and consumer test) were performed on non-stored samples (Day 0), and after storing at 30, 60, 90 and 120 days at -20 °C. There was a reduction (p < 0.05) in tenderness in samples of moderate-grade hamburgers (from 161.45 N to 289.40 N) after 120 days of storage. Hamburgers produced with chicken breast samples affected by wooden breast myopathy presented higher (p < 0.0001) fat concentration (5.32 g/100 g and 5.26 g/100 g, respectively, for the moderate and severe degree) than hamburgers made of normal samples (4.45 g/100 g). Lipid oxidation values increased, which exceeded the limit of rancidity detection, independent of myopathy. The consumers equally appreciated the aroma, flavor, and texture, and rated their overall acceptance as similar regardless of the quality of chicken meat. Chicken breast hamburgers with wooden breast myopathy is a viable alternative for the poultry industry.

Characterization of Pectoralis Major Muscle Satellite Cell Population Heterogeneity, Macrophage Density, and Collagen Infiltration in Broiler Chickens Affected by Wooden Breast.

Muscle satellite cells (MSCs) are myogenic stem cells that play a critical role in post-hatch skeletal muscle growth and regeneration. Activation of regeneration pathways to repair muscle fiber damage requires both the proliferation and differentiation of different MSC populations as well as the function of resident phagocytic cells such as anti-inflammatory and pro-inflammatory macrophages. The Wooden Breast (WB) phenotype in broiler chickens is characterized by myofiber degeneration and extensive fibrosis. Previous work indicates that the resident MSC populations expressing the myogenic regulatory factors, Myf-5 and Pax7 are larger and more proliferative in broilers severely affected with WB vs. unaffected broilers. To further characterize the cellular and molecular changes occurring in WB-affected muscles, samples from pectoralis major (PM) muscles with varying severity of WB (WB score 0 = normal; 1 = mildly affected; 2 = severely affected) were collected at 25 and 43 days post-hatch (n = 8 per score per age) and processed for cryohistological and protein expression analyses. Collagen per field and densities of macrophages and MyoD+, Myf-5+, and Pax7+ MSC populations were quantified on immunofluorescence-stained cryosections. Relative collagen protein expression was quantified by fluorescent Western Blotting. In both 25 and 43-days-old broilers, the proportion of collagen per field (P ≤ 0.021) and macrophage density (P ≤ 0.074) were greater in PM exhibiting severe WB compared with normal. At day 43, populations of MyoD+, Myf-5+:MyoD+ MSC were larger and relative collagen protein expression was greater in WB-affected vs. unaffected broilers (P ≤ 0.05). Pax7+ MSC relative to total cells was also increased as WB severity increased in 43-days-old broilers (P ≤ 0.05). Densities of Myf-5+ (P = 0.092), MyoD+ (P = 0.030), Myf5+:MyoD+ (P = 0.046), and Myf-5+:MyoD+:Pax7+ (P = 0.048) MSC were greater in WB score 1 birds compared with WB score 0 and 2 birds. Overall, alterations in the resident MSC and macrophage populations and collagen protein content were observed in WB-affected muscle. Further investigation will be required to determine how these changes in cell population kinetics and local autocrine and paracrine signaling are involved in the apparent dysregulation of muscle maintenance in WB-affected broilers.

An in vivo evaluation of the effects of feed restriction regimens on wooden breast using ultrasound images as a predictive tool.

1. Gradual feed restriction was applied to broilers in order to reduce growth rate and, as a consequence, gradually impacts wooden breast myopathy occurrence. Ultrasound (US) images of breast muscle in live birds were correlated with breast fillets presenting wooden breast characteristics (WB). 2. A total of 1800 Cobb × Cobb 500 slow-feathering male chicks were fed one of the six feed restriction treatments with 12 replicates of 25 birds each, in a completely randomised design. Birds were fed ad libitum or were pair-fed to 50%, 60%, 70%, 80% or 90% of normal ad libitum intakes from 8 to 49 d to provide a gradual reduction in growth rate. Ultrasound images were obtained weekly from all birds and, in parallel, one bird per pen was weekly slaughtered and the major breast muscle was weighed and WB graded as 0 (normal), 1 (mild hardening in the upper), 2 (moderate hardening in the upper and/or lower), 3 (severe hardening) and 4 (severe hardening with haemorrhagic lesions and yellow fluid). Blood was taken for analysis of enzymes related to muscle cell breakdown. 3. Feed restriction applied at 50%, 60%, 70%, 80% and 90% of the ad libitum feed intake (FI) resulted in decreased body weight gain (BWG; P ≤ 0.05). 4. From 21 to 49 d, the increasing feed restriction led to linear increases (P ≤ 0.05) in WB scores, fibre density as well as breast depth and breast echogenicity. Creatine kinase, lactate dehydrogenase and aspartate aminotransferase concentration decreased linearly when broilers were feed restricted (P ≤ 0.05). 5. Wooden breast was positively correlated with echogenicity at 21 d (r = 0.510), 28 (r = 0.531), 35 (r = 0.470), 42 (r = 0.430) and 49 d (r = 0.548) (P ≤ 0.001). The use of breast echogenicity can be an additional tool to early detect alterations related to wooden breast.

Impact of chicken wooden breast on quality and oxidative stability of raw and cooked sausages subjected to frozen storage.

BACKGROUND: Considering (i) the increased incidence of wooden breast (WB) myopathy in broilers, (ii) the poor meat quality in such breasts and (iii) the lack of studies on the industrial use of WBs; the objective of this study was to investigate the quality of chicken sausages made with WB under frozen conditions. Three formulations of chicken sausage [100% normal (N) breast, 100% WB, and 50% N breast + 50% WB] were considered and raw and cooked (70 °C/10 min) sausages were frozen for 180 days and evaluated for their quality and oxidative stability. RESULTS: WB formulations exhibited higher pH, moisture (%), and shear force (SF), associated with lower water holding capacity (WHC) and fat (%). During the freezing period, there was a decrease in WHC and redness (a*) and an increase in cooking loss (CL) and SF for all formulations. Additionally, during freezing, thiobarbituric acid-reactive substances values were higher in raw sausages made with N breast than in sausage made with WB probably due to the higher fat content in the former. Results showed that the products did not reach noticeable rancid levels (<2 mg malondialdehyde/kg) and that WB sausage presented great resistance to oxidation, which suggests that WB sausage can be kept frozen at -20 °C for up to 198 days. CONCLUSION: Using WBs for the manufacture of chicken sausages subjected to freezing is a viable option given their overall quality and resistance to oxidation. © 2020 Society of Chemical Industry.

Biochemical and technological view of broiler chicken meat with pectoral / Visão bioquímica e tecnológica de carne de frango com anomalias peitorais

There has been a significant advance in the poultry industry, and new technological and biological processes have accompanied the development of animals and inputs. Alongside the new possibilities for growth, there has been an emergence of new paradigms, including the rise of myopathies among which PSE, DFD, deep pectoral myopathy, oregon disease, acid breast, white stripping, wooden breast and spaghetti meat stand out. They cause considerable damage to the industry, as well as to ride hypotheses for studies in an attempt to better describe them. Researches seek to know about the behavior of proteins and specific protein groups in these anomalies. Groups of proteases are determinant to understand what may be occurring in muscle activity and; consequently, to understand the process in a more detailed way. Therefore, proteolytic systems may be acting on abnormal tissues. Proteases act differently in birds and mammals, but how altered they may be is still unknown. Besides, it is essential to relate the activities of these proteases, measures that indicate technological aspects that are relevant to meat quality standards. These quality standards must be directly associated with the consumption of raw meat in the material destined for processing, regardless of the final product. The important thing is to guarantee information that will lead the industry and consumers that will have, even with the anomaly developed, products that are nutritionally safe . This review discusses the biochemical and technological changes in poultry with pectoral anomalies, and how this affectsmeat quality.(AU)

Sabe-se que houve um avanço considerável na indústria de frangos de corte nos últimos sessenta anos, e que consequentemente novos processos tecnológicos e biológicos acompanharam o desenvolvimento tanto de animais quanto de insumos. Com novas possibilidades de crescimento houve também o surgimento de novos paradigmas, sendo um deles o surgimento de diferentes tipos de miopatias. Como o peito é um dos pontos fortes da indústria de aves, muito tem se estudado sobre o assunto, e pode-se destacar PSE, DFD, Miopatia peitoral profunda ou peito verde, Peito ácido, White striping, Wooden breast e Spaghetti meat são as mais comuns. As três ultimas são mais recentes quando comparadas as outras citadas, e ainda há necessidade de compreensão do seu desenvolvimento, mas sabe-se que acarretam prejuízos consideráveis para o setor, além de permear a mente dos pesquisadores com hipóteses para estudos na tentativa de descrever melhor o que ocorre, o porquê de sua ocorrência e, futuramente, compreende-la ao ponto de poder gerar mecanismos para minimiza-las ou até mesmo suprimi-las. Os grupos de pesquisa nos USA, Italia, Brasil, Finlândia, Canadá e Inglaterra estão em busca destas respostas, todavia, até o momento, a Itália é o país que mais tem reportado informações sobre a problemática em torno de White striping e Wooden breast. Mas com todos os artigos até o presente momento, pouco se sabe sobre o comportamento de proteínas e grupos proteicos específicos nestas anomalias. O que há descrito trata-se de diferença entre conteúdo proteico e colágeno e taxa de degradação proteica. Contudo, sabe-se que grupos de proteases são determinantes para compreender o que pode estar ocorrendo na atividade muscular e consequentemtne entender o processo de forma mais detalhada. Logo, uma possibilidade é a compreensão de sistemas preoteolícos como as calpaínas, caspases e como podem estar atuando nos tecidos anômalos. Sabe-se que estas proteases atuam de maneira diferenciada em aves, quando comparada a mamíferos, mas o quão alterada podem estar ainda não se sabe. Além disto, é importante relacionar a atividades destas proteases com medidas que indiquem aspectos tecnológicos que sejam relevantes para padrões de qualidade de carnes. Estes padrões de qualidade devem estar diretamente associados ao consumo da carne in natura quanto ao material destinado à processamento, não importando qual seja o produto final. O mais importante é garantir informações que levem a indústria e os consumidores que terão, mesmo com a anomalia desenvolvida, produtos seguros nos aspectos nutricionais, bioquímicos e tecnológicos. Com base nestas breves informações, foi definido o procedimento metodológico desta proposta que permeia aspectos que incluam o maior número de informações sobre a alteração White striping em carne de aves, e com a reunião destas informações a possibilidade de entender melhor o que ocorre nestas carnes, levando a um conjunto de analises ainda não relatado na atual literatura.(AU)

Biochemical and technological view of broiler chicken meat with pectoral / Visão bioquímica e tecnológica de carne de frango com anomalias peitorais

ABSTRACT: There has been a significant advance in the poultry industry, and new technological and biological processes have accompanied the development of animals and inputs. Alongside the new possibilities for growth, there has been an emergence of new paradigms, including the rise of myopathies among which PSE, DFD, deep pectoral myopathy, oregon disease, acid breast, white stripping, wooden breast and spaghetti meat stand out. They cause considerable damage to the industry, as well as to ride hypotheses for studies in an attempt to better describe them. Researches seek to know about the behavior of proteins and specific protein groups in these anomalies. Groups of proteases are determinant to understand what may be occurring in muscle activity and; consequently, to understand the process in a more detailed way. Therefore, proteolytic systems may be acting on abnormal tissues. Proteases act differently in birds and mammals, but how altered they may be is still unknown. Besides, it is essential to relate the activities of these proteases, measures that indicate technological aspects that are relevant to meat quality standards. These quality standards must be directly associated with the consumption of raw meat in the material destined for processing, regardless of the final product. The important thing is to guarantee information that will lead the industry and consumers that will have, even with the anomaly developed, products that are nutritionally safe . This review discusses the biochemical and technological changes in poultry with pectoral anomalies, and how this affectsmeat quality.

RESUMO: Sabe-se que houve um avanço considerável na indústria de frangos de corte nos últimos sessenta anos, e que consequentemente novos processos tecnológicos e biológicos acompanharam o desenvolvimento tanto de animais quanto de insumos. Com novas possibilidades de crescimento houve também o surgimento de novos paradigmas, sendo um deles o surgimento de diferentes tipos de miopatias. Como o peito é um dos pontos fortes da indústria de aves, muito tem se estudado sobre o assunto, e pode-se destacar PSE, DFD, Miopatia peitoral profunda ou peito verde, Peito ácido, White striping, Wooden breast e Spaghetti meat são as mais comuns. As três ultimas são mais recentes quando comparadas as outras citadas, e ainda há necessidade de compreensão do seu desenvolvimento, mas sabe-se que acarretam prejuízos consideráveis para o setor, além de permear a mente dos pesquisadores com hipóteses para estudos na tentativa de descrever melhor o que ocorre, o porquê de sua ocorrência e, futuramente, compreende-la ao ponto de poder gerar mecanismos para minimiza-las ou até mesmo suprimi-las. Os grupos de pesquisa nos USA, Italia, Brasil, Finlândia, Canadá e Inglaterra estão em busca destas respostas, todavia, até o momento, a Itália é o país que mais tem reportado informações sobre a problemática em torno de White striping e Wooden breast. Mas com todos os artigos até o presente momento, pouco se sabe sobre o comportamento de proteínas e grupos proteicos específicos nestas anomalias. O que há descrito trata-se de diferença entre conteúdo proteico e colágeno e taxa de degradação proteica. Contudo, sabe-se que grupos de proteases são determinantes para compreender o que pode estar ocorrendo na atividade muscular e consequentemtne entender o processo de forma mais detalhada. Logo, uma possibilidade é a compreensão de sistemas preoteolícos como as calpaínas, caspases e como podem estar atuando nos tecidos anômalos. Sabe-se que estas proteases atuam de maneira diferenciada em aves, quando comparada a mamíferos, mas o quão alterada podem estar ainda não se sabe. Além disto, é importante relacionar a atividades destas proteases com medidas que indiquem aspectos tecnológicos que sejam relevantes para padrões de qualidade de carnes. Estes padrões de qualidade devem estar diretamente associados ao consumo da carne in natura quanto ao material destinado à processamento, não importando qual seja o produto final. O mais importante é garantir informações que levem a indústria e os consumidores que terão, mesmo com a anomalia desenvolvida, produtos seguros nos aspectos nutricionais, bioquímicos e tecnológicos. Com base nestas breves informações, foi definido o procedimento metodológico desta proposta que permeia aspectos que incluam o maior número de informações sobre a alteração White striping em carne de aves, e com a reunião destas informações a possibilidade de entender melhor o que ocorre nestas carnes, levando a um conjunto de analises ainda não relatado na atual literatura.

Determinação das características físico-químicas e das miopatias do músculo Pectoralis major em frangos de corte criados em piso de plástico perfurado / Determination of the physical-chemical characteristics and myopathy of the Pectoralis major muscle in broiler chickens raised on perforated plastic floor

Esse estudo teve como objetivo avaliar a influência da criação de frangos de corte em pisos plásticos perfurados sobre a qualidade físico-química da carne e a incidência de miopatias peitorais. Para isso, os animais foram alojados em 14 box, em dois tratamentos, cama e piso, 25 animais por box. Para a capacidade de retenção de água as aves do tratamento piso apresentaram melhores resultados; no entanto, apresentaram maior perda de água por cocção. O músculo Pectoralis major dos animais criados no piso de plástico, apresentou menor valor de força de cisalhamento, entretanto, maior força de deformação. Para as miopatias, o peito dos frangos criados no piso de plástico apresentaram maior incidência de white striping, enquanto os que permaneceram na cama de casca de arroz apresentaram maior incidência de wooden breast. A criação de frangos de corte em pisos de plástico perfurados não influenciou as características físico-químicas da carne, bem como a incidência de miopatias peitorais.(AU)

Determinação das características físico-químicas e das miopatias do músculo Pectoralis major em frangos de corte criados em piso de plástico perfurado / Determination of the physical-chemical characteristics and myopathy of the Pectoralis major muscle in broiler chickens raised on perforated plastic floor

Esse estudo teve como objetivo avaliar a influência da criação de frangos de corte em pisos plásticos perfurados sobre a qualidade físico-química da carne e a incidência de miopatias peitorais. Para isso, os animais foram alojados em 14 box, em dois tratamentos, cama e piso, 25 animais por box. Para a capacidade de retenção de água as aves do tratamento piso apresentaram melhores resultados; no entanto, apresentaram maior perda de água por cocção. O músculo Pectoralis major dos animais criados no piso de plástico, apresentou menor valor de força de cisalhamento, entretanto, maior força de deformação. Para as miopatias, o peito dos frangos criados no piso de plástico apresentaram maior incidência de white striping, enquanto os que permaneceram na cama de casca de arroz apresentaram maior incidência de wooden breast. A criação de frangos de corte em pisos de plástico perfurados não influenciou as características físico-químicas da carne, bem como a incidência de miopatias peitorais.

Occurrence of white striping and wooden breast in broilers fed grower and finisher diets with increasing lysine levels.

Two experiments were conducted to evaluate the prevalence and severity of white striping (WS) and wooden breast (WB) in breast fillets from broilers fed diets with increasing digestible Lysine (dLys) from 12 to 28 d (Exp. 1) and from 28 to 42 d (Exp. 2). Trials were sequentially conducted using one-d-old male, slow-feathering Cobb 500 × Cobb broilers, both with 6 treatments and 8 replicates. Increasing dLys levels were equally spaced from 0.77 to 1.17% in Exp. 1 and from 0.68 to 1.07% in Exp. 2. The lowest dLys diet was not supplemented with L-Lysine (L-Lys) in either one of the studies and all other essential amino acid (AA) met or exceeded current commercial recommendations such that their dietary concentrations did not limit broiler growth. Four birds per pen were randomly selected from each replication and processed at 35 and 42 d in Exp. 1 and Exp. 2, respectively. Deboned breast fillets (Pectoralis major) were submitted to a 3 subject panel evaluation to detect the presence of WS and WB, as well as to provide scores of WS (0-normal, 1-moderate, 2-severe) and WB (0-normal, 1-moderate light, 2-moderate, 3-severe). Increasing the level of dLys had a positive effect on BW, carcass, and breast weight, as well as breast yield. White striping and WB prevalences were 32.3 and 85.9% in Exp. 1 and 87.1 and 89.2% in Exp. 2. Birds fed diets not supplemented with L-Lys had the lowest average WS and WB scores (0.22 and 0.78 in Exp. 1 and 0.61 and 0.68 in Exp. 2). White striping and WB presented linear responses to performance variables in Exp. 1, whereas quadratic responses were observed for all variables in Exp. 2. In conclusion, increasing the level of dLys improved growth performance and carcass traits as well as induced the occurrence and severity of WS and WB lesions.