The effects of supplemental dietary chitosan on broiler performance and myopathic features of white striping

White striping (WS) is a common myopathy seen in fast-growing broilers. Studies have demonstrated that chitosan is effective as an antioxidant and has antiobesity and fat-absorption reduction properties. We hypothesized that the dietary supplementation of chitosan would have similar effects when fed to fast-growing broilers and would thus lower WS incidence and improve meat quality. One hundred twenty-six broilers were fed corn-soy diets. The grower and finisher diets contained either 0, 0.2, or 0.4% chitosan. After a 6 wk growth period, birds were euthanized, and then WS and gross pathology scores were assessed. Pectoralis major tissues were collected to evaluate cook loss, drip loss, histopathology scores, and the gene expression of CCR7, LECT2, CD36, PPARG, and PTGS2. There were no significant differences between the broiler weights, thus chitosan did not appear to compromise the overall growth of the broilers. Female broilers fed 0.4% chitosan had the lowest WS incidence, while male broiler fed 0.4% chitosan had the least cook loss. However, gene expression analyses did not offer insight into any grossly or histologically visualized differences in the muscles. Thus, while we can postulate that chitosan could have some positive effect in reducing WS incidence and improving meat quality, further studies are required to better scrutinize the mechanisms by which chitosan affects WS and other such myopathies in fast-growing broilers.

Effects of Wooden Breast Myopathy on Meat Quality Characteristics of Broiler Pectoralis Major Muscle and Its Changes with Intramuscular Connective Tissue

This study aimed to investigate the effect of wooden breast (WB) myopathy on chemical composition, meat quality attributes and physiochemical characteristics of intramuscular connective tissue (IMCT) of broiler pectoralis major (PM) muscle. Thirty-six fillets were classified into varying degrees of WB condition, including normal, moderate and severe. Results show that WB myopathy altered the collagen profile in PM muscle by increasing total collagen content and decreasing collagen solubility. The composition of macromolecules in IMCT, including hydroxylysyl pyridoxine cross-linking, decorin and glycosaminoglycans, were increased with the severity of WB myopathy. Differential scanning calorimetry analysis indicated higher denaturation temperatures and lower denaturation enthalpy of IMCT for WB. Secondary structures of α-helix and β-sheet in the IMCT of WB were changed to β-turn and random coil. In addition, chemical composition and meat quality attributes showed a correlation with collagen profile and IMCT characteristics. Overall, this study emphasizes the effect of WB myopathy on IMCT and their contributions to meat quality variation.

Effects of genetic selection for fast growth on the development of wooden breast myopathy in broilers

1. This study investigated the physiological and molecular mechanisms leading to wooden breast (WB) by comparing growth parameters, oxygen consumption rate, thyroid hormone and gene expression patterns in fast- versus slow-growing broiler lines (Cobb500 and L1986, respectively).2. WB was observed in Cobb500 broilers only and was first diagnosed on d 21 post-hatch. Compared to the slow-growing L1986, Cobb500 showed a significantly higher growth rate, relative breast weight, breast thickness, meat pH and water-retention capacity (drip loss). Correspondingly, there was significantly lower relative heart weight, relative right ventricular weight, triiodothyronine and thyroxine concentrations and oxygen consumption rate.3. Compared to No-WB Cobb500, the WB-affected samples exhibited higher relative breast weight, breast thickness and drip loss and lower plasma total thyroxine (T4) concentrations.4. Selection for fast growth was associated with differential expression of genes involved in hypoxia (PLOD2), energy metabolism (FABP3, FABP4, CD36, and LPL), endoplasmic reticulum stress, muscle regeneration (CSRP3) and fibre-type switching (ANKRD1). WB-affected samples exhibited an upregulation of CSRP3, PLOD2 and ANKRD1, while CD36 was downregulated. Taken together, selection for fast growth and muscle gain is not matched by adequate cardiac and metabolic support systems.

Physical, chemical, and microbiological evaluation of sausages produced with chicken meat affected by deep pectoral myopathy

The purpose of the present study was to characterize the chemical composition, lipid oxidation, and physical characteristics of fresh sausages produced with meat from the pectoralis major muscle affected by deep pectoral myopathy. For the characterization of myopathy, samples were collected from broiler chickens slaughtered between 42- and 46-days old in a slaughterhouse in the state of São Paulo. The experiment consisted of samples from pectoralis major muscle of birds affected or not by DPM (normal-absence of myopathy and DPM category 3-progressive degeneration of the pectoralis minor with a greenish appearance). After classification of the samples, a part of raw products with the pectoralis minor removed, was submitted to microbiological and physical analyses for the characterization of DPM. Afterward, only the pectoralis major muscle was used to manufacture fresh sausages and 2 groups were established. The evaluated parameters were: color, pH, water-holding capacity (WHC), cooking loss (CL), shear force (SF), water activity (Aw), and chemical composition. Meat pH was higher (P < 0.05) in meats with DPM, however, WHC values were lower (71.92%), which made CL value increase (25.31%). In addition, the coloring increased and the technological characteristics of raw breasts were less favorable with the presence of DPM. All fresh sausages' color (except a* higher control group), pH, and Aw values were higher in DPM group. No effect on SF values was observed between fresh sausages. In chemical composition, only protein content increased in fresh sausages with DPM. Microbiological analyses did not indicate bacterial contamination of raw samples and fresh sausages. Data obtained in the present study suggest fresh sausages produced with breasts affected by DPM are a viable alternative and may confer more favorable qualitative characteristics to sausages than the raw marketed meat.

Effect of freezing on the quality of breast meat from broilers affected by wooden breast myopathy

The objective of the present study was to characterize possible variations in the quality of wooden chicken breast meat during freezing for 12 mo, in order to prove whether the shelf life recommended by the industry allows the storage of that type of meat without compromising its consumption. Three hundred samples of male Cobb 500 broilers slaughtered at 42 d of age were used. Part of the samples (n = 20 normal-control group; n = 20 moderate degree; n = 20 severe degree) were analyzed on the day of collection (beginning), previously kept under refrigeration (4°C). The other samples were stored (-18°C) for up to 12 mo. At the end of each proposed freezing period (3, 6, 9, and 12 mo), physical and chemical analyses were performed (per period: n = 20 normal-control group; n = 20 moderate degree; n = 20 severe degree). Color (L*, a*, and b*), pH, water-holding capacity, cooking losses, tenderness, lipid oxidation, chemical composition, cholesterol concentration, mineral profile, and collagen concentration were evaluated. The physicochemical quality of wooden chicken breast meat is significantly altered during frozen storage for 12 mo, being of inferior quality when compared to normal chicken breast meat, which can negatively affect consumer acceptance. However, it should be noted that even after 12 mo of freezing, the meats did not show oxidative rancidity.

Dietary Supplementation with Putrescine Improves Growth Performance and Meat Quality of Wenchang Chickens

This study was to investigate the effects of dietary supplementation with putrescine on the growth performance and meat quality of chickens. A total of 480 eighty-day-old female Wenchang chickens were randomly assigned into four groups, with 8 replications per group and 15 animals per replicate. The chickens in the control group (Con) were fed a basal diet; the 3 experimental groups were fed a basal diet with 0.01%, 0.03%, and 0.05% putrescine, respectively. The experiment lasted for 40 days. The results showed that dietary supplementation with 0.05% putrescine increased (p < 0.05) the final body weight and average daily weight gain, and decreased the ratio of feed intake to the body weight gain of Wenchang chickens. Dietary supplementation with putrescine decreased the concentrations of putrescine, spermidine, and spermine in serum (p < 0.05). The contents of methionine, phenylalanine, lysine, aspartic acid, tyrosine, total essential amino acids, and total amino acids in breast muscle were higher (p < 0.05) in 0.03% and 0.05% groups than those in Con group. However, the contents of undecanoic acid, lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, arachidic acid, docosanoic acid, tricosanic acid, lignoceric acid, erucic acid, cis-11,14,17-eicosatrienoate, linoleic acid, and total n-6 monounsaturated fatty acids in breast muscle were lower (p < 0.05) in 0.03% and 0.05% groups than those in Con group. In addition, putrescine supplementation decreased (p < 0.05) the ratio of n-6/n-3 polyunsaturated fatty acids in breast meat. Overall, dietary supplementation with 0.05% putrescine enhanced the growth performance and meat quality of Wenchang chickens.

Study of emerging chicken meat quality defects using OMICs: What do we know?

Starting in approximately 2010, broiler breast meat myopathies, specifically woody breast meat, white striping, spaghetti meat, and gaping have increased in prevalence in the broiler meat industry. Omic methods have been used to elucidate compositional, genetic, and biochemical differences between myopathic and normal breast meat and have provided information on the factors that contribute to these myopathies. This review paper focuses on the genomic, transcriptomic, proteomic, metabolomic, and other omics research that has been conducted to unravel the molecular mechanisms involved in the development of these myopathies and their associated factors and potential causes. SIGNIFICANCE: This review manuscript summarizes poultry meat quality defects, also referred to as myopathies, that have been evaluated using omics methods. Genomics, transcriptomics, proteomics, metabolomics and other methodologies have been used to understand the genetic predisposition, the protein expression, and the biochemical pathways that are associated with the expression of woody breast meat, white striping, and other myopathies. This has allowed researchers and the industry to differentiate between chicken breast meat with and without myopathic muscle as well as the environmental and genetic conditions that contribute to differences in biochemical pathways and lead to the phenotypes associate with these different myopathies.

Using TRIS-Buffered Plasma-Activated Water to Reduce Pathogenic Microorganisms on Poultry Carcasses with Evaluation of Physicochemical and Sensory Parameters

Foodborne diseases are mainly caused by the contamination of meat or meat products with pathogenic microorganisms. In this study, we first investigated the in vitro application of TRIS-buffered plasma-activated water (Tb-PAW) on Campylobacter (C.) jejuni and Escherichia (E.) coli, with a reduction of approx. 4.20 ± 0.68 and 5.12 ± 0.46 log₁₀ CFU/mL. Furthermore, chicken and duck thighs (inoculated with C. jejuni or E. coli) and breasts (with natural microflora) with skin were sprayed with Tb-PAW. Samples were packed under a modified atmosphere and stored at 4 °C for 0, 7, and 14 days. The Tb-PAW could reduce C. jejuni on days 7 and 14 (chicken) and E. coli on day 14 (duck) significantly. In chicken, there were no significant differences in sensory, pH-value, color, and antioxidant activity, but %OxyMb levels decreased, whereas %MetMb and %DeoMb increased. In duck, we observed slight differences in pH-value, color, and myoglobin redox forms for the Tb-PAW, which were not perceived by the sensory test persons. With only slight differences in product quality, its application as a spray treatment may be a useful method to reduce C. jejuni and E. coli on chicken and duck carcasses.

Effect of in ovo creatine monohydrate on hatchability, post-hatch performance, breast muscle yield and fiber size in chicks from young breeder flocks

Younger broiler breeder flocks produce smaller eggs containing smaller yolks, with potentially lower energy reserves for the developing chick. Creatine is a naturally occurring energy source and is abundant in metabolically active tissues; providing this to chicks in ovo should provide additional energy to improve hatchability and post-hatch growth. Thus, post-hatch performance of male and female chicks hatched from younger breeder flocks supplemented with creatine monohydrate (CrM) in ovo was investigated. Four hundred eggs from Ross 308 breeder hens aged 27 to 29 wk were collected and at d 14 assigned to a treatment group and received 1) no injection, 2) 0.75% saline injection, or 3) 8.16 mg creatine monohydrate in 0.75% saline. At hatch 72 birds (24/treatment) were euthanized and BW, breast muscle, heart and liver weight were obtained, and breast muscle tissue was placed in 10% buffered formalin. Birds were then placed in raised metal pens (24 pens; 10-11 birds/pen; 8 replicates/treatment) and grown to d 42 with BW and pen feed intake measured once a week. At d 42, ninty-six birds were euthanized (2 male and 2 female/pen) and the process occurred as at hatch. Body composition was obtained for 48 birds (2/pen; 1 male,1 female) with a dual energy X-ray absorptiometry (DXA) scanner. Breast muscle tissue was processed for histological analysis and breast muscle fiber parameters were analyzed by ImageJ. While not statistically significant, the CrM treatment group saw an improved hatch rate (CrM: 93.5%, Saline: 88.6%, Control: 88.8%) and reduced early post hatch mortality. Chicks given in ovo CrM had significantly increased creatine concentrations in both liver and heart tissue at hatch compared to those in the saline and control groups. BW, BW gain, and final body composition parameters were not statistically different between treatments and in ovo CrM did not affect breast muscle fiber number or area. The creatine injection likely improved the energy status of the growing embryo resulting in the improved hatch rate but leaving little reserves for post-hatch growth.

Quality of poultry meat- the practical issues and knowledge based solutions

Animal protein is the most demanded and expensive source of nutritive protein, globally. Taking into account various types of poultry, the broiler (meat-type poultry) is widely accepted by various religious societies and relatively cheap amongst others animal protein sources. In particular, the chicken and turkey product is perceived to be healthier and of better quality due to a low content of fat, cholesterol and sodium compared to red meat. In order to maintain an unabated development and competitiveness of poultry industry, the priority is to focus on quality and safety of meat, during whole production and processing route. Consumers awareness of what should be considered a high quality product is constantly increasing, especially in the light of European and worldwide strategies to meet the common societal and environmental challenges, i.e. addressing the Zero Hunger goals, Green Deal and One Health concept. In this chapter, a common area of interest for a dialogue of poultry scientists and industrial practitioners is drawn from the background given on the consumer (demands and health)-centered issues.

Linking key husbandry factors to the intrinsic quality of broiler meat

Broiler farming is the fastest-growing animal production sector and broiler meat is the second most-consumed meat in the world. The intensification of broiler production often has a negative impact on the meat quality and carcass characteristics. Consumers, however, expect a quality product from animals reared extensively on farms providing good animal welfare, often intuitively associated with extensive farming practices. Therefore, this literature review investigates how the critical factors contributing to the degree of extensiveness of broiler production affect the quality of meat. We used the data from scientific articles published in the years 2012-2021 to analyze the effect of diet (n = 409), genetics (n = 86), enrichment (n = 25), and stocking density (n = 20) on meat quality and carcass characteristics. Minerals and microelements supplementation in the diet improved all the meat quality aspects: sensory, physical, and chemical in most studies. Minerals and enzymes in the diet had beneficial effects on carcass characteristics, unlike feed restriction and ingredient substitutions. The impact of outdoor access on meat quality and carcass characteristics was most frequently examined, in contrast to the use of perches or effects of litter quality. Overall, enrichment did not affect the meat's sensory or physical parameters, but outdoor access improved its lipid composition. Lower stocking density deteriorated intramuscular fat content, decreased tenderness and juiciness, yet lowered cooking and drip loss, and increased carcass and breast muscle yields. When it comes to genetics, in general, slow growing broiler strains have better meat quality parameters, especially regarding yellowness (b*), redness (a*), cooking and drip loss. Our review shows that the factors which contribute to extensiveness of broiler production systems and birds' welfare also affect meat quality and the carcass characteristics.

Synergistic effect of preheating and different power output high-intensity ultrasound on the physicochemical, structural, and gelling properties of myofibrillar protein from chicken wooden breast

The effects of preheating to 50 ℃ and the subsequent application of high-intensity ultrasound (HIU, 20 kHz) at 200, 400, 600, and 800 W on the physicochemical, structural, and gelling properties of wooden breast myofibrillar protein (WBMP) were studied. Results suggested that the WBMP structure expanded to the balanced state at 600 W, and rheological properties exhibit that 600 W HIU (P < 0.05) significantly improved the storage modulus (G') of WBMP. Notably, the WBMP gel (600 W) had the best hardness (65.428 ± 0.33 g), springiness (0.582 ± 0.01), and water-holding capacity (86.11 ± 0.83%). Raman spectra and low-field NMR indicated that 600 W HIU increased the β-fold content (37.94 ± 0.04%) and enlarged the immobilized-water proportion (93.87 ± 0.46%). Scanning electron micrographs confirmed that the gel was uniform and dense at 600 W. Therefore, preheating to 50 ℃ followed by HIU (600 W) helped form a superior WBMP gel.

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

Simple Summary

Consumers 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.

Abstract

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.

Effects of vitamin A on carcass and meat quality of broilers

This study evaluated the level and length of time of vitamin A supplementation and its effects on carcass and cuts yield, meat quality, and myopathies in 42-day-old broilers. A total of 1,920 birds were divided into 6 groups, and each group received a different level of vitamin A: 0; 6,000; 16,000; 26,000; 36,000 and 46,000 IU/ kg. From d 1 to 21, the treatments were distributed among 16 replicates with 20 birds. From the 22nd d on, 8 repetitions remained with the initial treatment and the others received diets with no vitamin A supplementation. Twelve birds were slaughtered per treatment to evaluate carcass and cuts yield, shear force, cooking loss, water holding capacity, and the presence of substances reactive to thiobarbituric acid. The remaining birds were slaughtered and evaluated in loco for Wooden Breast (WB) and White Striping (WS). Wings weight was affected by vitamin A levels. The duration of the vitamin A supplementation process had effects on the weight of breast, legs with a dorsal portion, and meat color in the yellow intensity (b*). Incidence of WB had higher scores in birds supplemented until 42 d of age. WS showed a quadratic response and a lower response with supplementation of 29,700 IU/ kg. Even for WS, a higher occurrence of the normal score was found in birds supplemented until 21 d of age. Minimal quadratic responses were obtained for normal, moderate, and severe scores, in supplementations of 29,301; 29,959, and 29,827 IU/ kg, respectively. WB had lower occurrence rates in birds supplemented until 21 d of age. Consequently, the severe score was more frequent when supplementation was provided until 42 d of age. The level of vitamin A and the length of time during which this supplementation was provided had influence on cuts yield, meat color and the incidence of WB and WS of the 42-day-old birds.

Acceptability of Artificial Intelligence in Poultry Processing and Classification Efficiencies of Different Classification Models in the Categorisation of Breast Fillet Myopathies

Breast meat from modern fast-growing big birds is affected with myopathies such as woody breast (WB), white striping, and spaghetti meat (SM). The detection and separation of the myopathy-affected meat can be carried out at processing plants using technologies such as bioelectrical impedance analysis (BIA). However, BIA raw data from myopathy-affected breast meat are extremely complicated, especially because of the overlap of these myopathies in individual breast fillets and the human error associated with the assignment of fillet categories. Previous research has shown that traditional statistical techniques such as ANOVA and regression, among others, are insufficient in categorising fillets affected with myopathies by BIA. Therefore, more complex data analysis tools can be used, such as support vector machines (SVMs) and backpropagation neural networks (BPNNs), to classify raw poultry breast myopathies using their BIA patterns, such that the technology can be beneficial for the poultry industry in detecting myopathies. Freshly deboned (3–3.5 h post slaughter) breast fillets (n = 100 × 3 flocks) were analysed by hand palpation for WB (0-normal; 1-mild; 2-moderate; 3-Severe) and SM (presence and absence) categorisation. BIA data (resistance and reactance) were collected on each breast fillet; the algorithm of the equipment calculated protein and fat index. The data were analysed by linear discriminant analysis (LDA), and with SVM and BPNN with 70::30: training::test data set. Compared with the LDA analysis, SVM separated WB with a higher accuracy of 71.04% for normal (data for normal and mild merged), 59.99% for moderate, and 81.48% for severe WB. Compared with SVM, the BPNN training model accurately (100%) separated normal WB fillets with and without SM, demonstrating the ability of BIA to detect SM. Supervised learning algorithms, such as SVM and BPNN, can be combined with BIA and successfully implemented in poultry processing to detect breast fillet myopathies.

Effects of Probiotics, Prebiotics and Synbiotics Injected in Ovo on the Microstructure of the Breast Muscle in Different Chicken Genotypes

The aim of the study was to analyse the effect of probiotics, prebiotics and synbiotics injected in ovo on day 12 of embryonic development on the microstructure of the superficial pectoral muscle (musculus pectoralis superficialis) from 42-day-old chickens of different genotypes: broilers (Ross 308) and general-purpose type (green-legged partridge (GP) chickens Zk-11, native chickens). Incubated eggs were divided into four groups (each genotype separately) depending on the substance injected in ovo: normal saline (C, control); Lactococcus lactis subsp. cremoris (PRO); galactooligosaccharides, GOS (PRE) or GOS + L. lactis (SYN). After hatching, chicks were placed in eight replicated pens (four pens/genotype group). There were eight birds per pen. In total, 64 birds were used in the experiment. Birds were slaughtered at the age of 42 days, and samples of superficial pectoral muscles were taken for analysis. The microstructure of the pectoral muscles was evaluated using the cryosectioning (frozen tissue sectioning) technique and staining with haematoxylin and eosin. Statistical analysis revealed that the in ovo injection of probiotics, prebiotics and synbiotics had no significant effect on the diameter of muscle fibres from chickens of the two genotypes. The number of fibres in the muscles from green-legged partridge chickens was about three-fold higher than the fibre density in the muscles from broiler chickens, with the fibre diameter being two-fold smaller. This fact may indicate a greater tenderness of meat from GP chickens compared to the meat from Ross 308 broilers. In the case of broilers, a prebiotic (GOS) was the most effective bioactive substance in reducing the number of histopathological changes. Considering muscles from GP chickens, the number of normal fibres was highest in birds treated with the probiotic. These findings indicate that the microstructural features of pectoral muscles depend not only on the type of the injected bioactive substance but also on the genotype of chickens.

Partial and Total Replacement of Soybean Meal with Full-Fat Black Soldier Fly (Hermetia illucens L.) Larvae Meal in Broiler Chicken Diets: Impact on Growth Performance, Carcass Quality and Meat Quality

The aim of this study was to compare selected growth performance parameters and slaughter characteristics in broiler chickens fed diets with a different content of full-fat Hermetia illucens L. (HI) larvae meal. The experiment was performed on 384 male broiler chickens (Ross 308) reared to 42 d of age and assigned to four dietary treatments (HI0-control diet and diets where soybean meal protein (SBM) was replaced with HI protein in 50%, 75% and 100%, respectively). The final body weights of chickens were as follows: 3010.0 g (HI0), 2650.0 g (HI50), 2590.0 g (HI75) and 2375.0 g (H100, p < 0.05). The carcasses of chickens from the experimental groups contained less meat and more abdominal fat. The feed conversion ratio for the entire experimental period was similar in groups HI0, HI50 and HI75 and more desirable than in group HI100 (p < 0.05). The meat of broiler chickens from groups HI75 and HI100 was characterized by significantly (p < 0.05) lower juiciness and taste intensity than the meat of birds from groups HI0 and HI50. The replacement of SBM protein with full-fat HI larvae meal in broiler diets exceeding 50% significantly compromised the growth performance of birds and the carcass and meat quality.

Review: Production factors affecting poultry carcass and meat quality attributes

Poultry meat mainly comes from standard production system using high growth rate strains reared under indoor intensive conditions. However, it is possible to find also different alternative systems using outdoor extensive rearing conditions and slow-growing lines. These different production systems can affect carcass and meat quality. In this review, quality has been broken down into six properties: commercial, organoleptic, nutritional, technological, sanitary and image, the latter covering the ethical, cultural and environmental dimensions associated with the way the meat is produced, as well as its origin and being particularly valued in many quality labels. The quality of meat is built and can deteriorate along the continuum from the conception of the animal to the fork. Our review details the different factors implicated in the determinism of poultry meat properties and pinpoints critical periods, such as the preslaughter and slaughter periods, and key factors, such as the feeding regimen, via its direct effect on the fatty acid profile, the antioxidant and volatile compound contents, and indirect effects mediated via the growth rate of the bird. Our review also highlights potential antagonisms between different dimensions of quality. The genetic selection for breast meat yield, for example, has been effective in producing carcasses with higher meat yield, but resulting since a decade in the increased occurrence of quality defects and myopathies (white striping, wooden breast, spaghetti meat and deep pectoral disease). Outdoor access has positive effects on the image and nutritional properties (through its effect on the fatty acid profile of meat lipids), but it increases the exposition risk to environmental contaminants and pathologies (parasites, virus, bacteria); it also increases the variability in meat quality linked to the variability of animal performance and slaughter age. The orientation towards more agro-ecological low-input farming systems may present benefits for the image and nutritional properties, but also risks for the commercial (low carcass weight and low breast yield, irregularity in supply), organoleptic (stronger flavour, less tender and darker colour of the meat) and in terms of variability of the different properties that constitute quality. Efforts should be made in the future to better take into account the various dimensions of quality, in consumer information, payment to farmers and genetic selection.

Impact of deep pectoral myopathy on chemical composition and quality parameters of chicken breast fillet

One of the current myopathies affecting the chicken meat industry is deep pectoral myopathy (DPM), also known as green muscle disease or Oregon disease, the condition is considered a major problem in poultry processing lines. Thus, the present study proposes to examine the meat quality of the Pectoralis major muscle (breast fillet) from carcasses of broilers affected by DPM in Pectoralis minor muscle (tender) and from a control group. Breast fillets samples were harvested from Ross AP95 broilers that were slaughtered at 42 days of age and were selected to the occurrence of the myopathy (score 2 and score 3) and from a control group without (score 0) the presence of myopathy. Chemical composition, cholesterol, fatty acid profile, pH, color, water-holding capacity, cooking loss, shear force, sarcomere length, and collagen were analyzed in the breast fillet. And with the results it was observed the samples classified as DPM score 2 had a higher moisture and a lower protein percentage. The higher values lipid was found in the samples from broilers affected by DPM. There was no difference (P > 0.05) fatty acid profile only to C10:0, C15:0, C17:0, C20:0, and C18:2c9,t11. Differences were detected (P < 0.05) for the pH, WHC, SF, and sarcomere length of the samples from broilers affected by DPM. The higher pH observed in the samples from birds classified as DPM score 2 and the higher WHC values were observed in the samples affected by DPM (score 2 and 3). The SF (P < 0.05) among samples, with the most tender samples (lower SF values) being those unaffected by the condition DPM (score 0). The dorsal side surface, where the Pectoralis major muscle is in contact with the Pectoralis minor muscle, higher L* values were found in the meat affected by the myopathy. Although deep pectoral myopathy affects the Pectoralis minor muscle of broilers, it can also alter the qualitative characteristics and chemical composition of the breast fillets (Pectoralis major muscle).

Meat quality traits and Blunt Meullenet-Owens Razor Shear characteristics of broiler breast fillets affected by woody breast condition and post-cooking meat temperature

This study aimed to investigate meat quality attributes, cooking performance, and water properties of woody breast (WB). A total of 48 broiler breast fillets (7 wk, 3 h debone) of 24 normal (NORM) and 24 severe WB (SEV) were collected. Raw meat characteristics (L*, a*, b*, pH, compression force and energy and) along with the blunt blade of the Meullenet-Owens razor shear (BMORS) properties were determined. Cooking time and internal meat temperature were recorded for each fillet every 5 min on each fillet during cooking. Water/moisture properties and shear values of BMORS were determined at different meat temperatures (HOT [68°C], AMBIENT [22°C] and COLD [4°C]) after cooking. SEV fillets showed higher L*, a*, b*, pH, CF, CE, BMORS force, BMORS energy, and peak counts of BMORS values compared to NORM fillets in raw state (P < 0.05). Cooking time was shorter in SEV fillets than NORM fillets (P < 0.0001). Cook loss, total water loss, and moisture loss (HOT, AMBIENT) were greater in SEV fillets than NORM fillets (P < 0.01). PC-BMORS were greater in SEV fillets than NORM fillets (P < 0.05), and all BMORS shear values increased as post-cooking meat temperature decreased (P < 0.05). Positive correlations were observed between WB scores and raw meat characteristics and shear values. There were also significant relationships (P < 0.001) between WB scores and cooking performance measures except moisture loss for COLD treatment. BMORS force and energy were moderately correlated to total water loss, cook loss, and moisture loss (HOT) regardless of meat temperature (P < 0.05); however, PC-BMORS was only correlated to total water loss at COLD and moisture loss (HOT) at all meat temperatures (P < 0.05). These data corroborate the association of WB condition with impaired quality/texture characteristics in raw and cooked fillets; WB also had a significant impact on cooking time, cooking at a faster rate, along with water/moisture loss during and after thermal processing. Results demonstrate that the post-cooking meat temperature plays an important role in shear test values.

Effect of Aging on the Quality of Breast Meat from Broilers Affected by Wooden Breast Myopathy

This study aimed to evaluate the effects of aging on the quality of breast meat from broilers affected of wooden breast. Samples that were classified as normal (control), moderate (hardness verified only in one region of breast fillet), and severe (hardness verified in all the extension of breast fillet) were evaluated fresh and after three and seven days of aging. Normal samples and samples with a moderate degree of myopathy showed greater water-holding capacity, which may benefit the processing industry of poultry meat. During the aging process, increase was observed in total collagen concentration (from 0.41% in normal samples to 0.56% in samples with severe degree). Samples of chicken breast affected by moderate degree showed higher myofibril fragmentation index (MFI = 115) than normal chicken samples (95.65). Although chicken samples affected with severe degree of wooden breast myopathy are more tender than normal chicken breasts, they produce more exudate, which can be detrimental to the processing of poultry meat. The aging process may improve the reduction of cooking weight loss and protein loss in exudation of broilers' breasts affected by wooden breast myopathy.

Biochemical and technological characteristics of wooden breast chicken fillets and their consumer acceptance

The wooden breast (WB) has caused great damages to meat producing industries, being its etiology still not fully understood. Thus, the objective of this work was to investigate biochemistry and technological characteristics of WB chicken fillets and their consumer acceptance. WB fillets were evaluated in regards to color, pH, approximate chemical composition, water holding capacity, cooking loss, shear force, total and soluble collagen, and comparison estimated of pyridinoline. The sensorial analysis used real size images of fillets. The WB showed changes in physical parameters such as an increase in luminosity and shear force. In regards to the chemical parameters, showed an increase in pH value, moisture content, lipids, and mineral, and protein content reduction. There were biochemistry changes in the collagen with an increase of 17.32% in total collage content and a reduction by 30.96% in the estimated pyridinoline content. Technological parameters were negatively altered by a reduction in water holding capacity. WB fillets showed a low acceptance rate and intention to purchase. Results show the WB meat presented biochemistry and technological characteristics compromised besides a low acceptance and purchase intention, leading to economic losses for the poultry sector.

Pathologic characterization of white striping myopathy in broiler chickens

White striping (WS) is an emerging myopathy of broiler chickens characterized by white striation of muscle. Despite the recent advances, the pathomechanism underlying the WS remains elusive. The aim of this study was to characterize morphological and molecular features of WS in broiler chickens. 50 pectoralis muscles were collected from 55 days old ROSS 308 broiler chickens with a mean weight of 3.5 kg. Samples were snap frozen and analyzed by histopathology, immunohistochemistry, and immunofluorescence. Real-time-PCR was used to evaluate the expression of different cytokines. Histological lesions were observed in all examined animals, both with and without macroscopic evidence of WS. WS muscles showed endomysial and perivascular inflammatory infiltrates of macrophages and cluster of differentiation (CD)8-positive T lymphocytes with severe myofiber atrophy, necrosis, fibrosis and replacement by adipose tissue. There was diffuse sarcoplasmic and sarcolemmal overexpression of the major histocompatibility complex class I (MHC I). The severity of the histologic lesions was positively correlated with the macroscopic degree of white striations. IL-6, IL-17 and lipopolysaccharide-induced TNF-α factor (LITAF) were overexpressed in severe lesions of WS. The presence of the CD8/MHC I complexes, together with the higher expression of IL-6, IL-17 and LITAF in severe degree of WS, suggest that the immune response may be involved in the progression of this myopathy and can be consistent with a hypoxia-induced inflammatory myopathy. These results help to understand the pathomechanism of WS contributing to the reduction of economic losses and improving poultry welfare.

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.

Weighted gene co-expression network analysis identifies molecular pathways and hub genes involved in broiler White Striping and Wooden Breast myopathies

In recent years, the poultry industry has experienced an increased incidence of myopathies affecting breasts of fast-growing broilers, such as White Striping (WS) and Wooden Breast (WB) defects. To explore the molecular mechanisms and genes involved in WS and WB onset, we decided to perform a Weighted Gene Co-expression Network Analysis (WGCNA) using the gene expression profile and meat quality parameters of Pectoralis major muscles analysed in our previous study. Among the 212 modules identified by WGCNA, the red, darkred, midnightblue and paleturquoise4 modules were chosen for subsequent analysis. Functional analysis evidenced pathways involved in extracellular matrix (ECM) organization, collagen metabolism, cellular signaling and unfolded protein response. The hub gene analysis showed several genes coding for ECM components as the most interconnected nodes in the gene network (e.g. COL4A1, COL4A2, LAMA2, LAMA4, FBLN5 and FBN1). In this regard, this study suggests that alterations in ECM composition could somehow activate the cascade of biological reactions that result in the growth-related myopathies onset, and the involvement of Collagen IV alterations in activating the endoplasmic reticulum (ER) stress response may be hypothesized. Therefore, our findings provide further and innovative knowledge concerning the molecular mechanisms related to the breast abnormalities occurrence in modern broilers.

Detection of woody breast condition in commercial broiler carcasses using image analysis

Image analysis could be an objective and rapid method to identify woody breast (WB) myopathy and benefit the global poultry industry. The objective of this study was to determine if there are conformational changes that can be used to detect WB characteristics in commercial broiler carcasses across strains, gender, and ages using image analysis. A total of 900 images of male and female broiler carcasses from commercial standard and high breast-yielding strains and 5 ages (6 through 10 wk) were captured before evisceration. These images were processed and analyzed using ImageJ software. Conformational measurements were M0: breast length; M1: breast width in the cranial region; M2: vertical line from the tip of keel to 1/5th of breast length; M3: breast width at the end of M2; M4: angle formed at the tip of keel and extending to outer points of M3; M5: area of the triangle formed by M3 and lines generated by M4; M6: area of the breast above M3; M7: M6 minus M5. Ratios of these measurements were also considered. Intact breast fillets were scored for WB severity based on tactile evaluation. Regardless of strain, sex, and age, M11 (M1/M0), M9 (M3/M2), and M4 had the highest correlation to WB score (r_s ≥ 0.65; P < 0.01). Overall, the best validated model (Gen. R² = 0.61) to predict WB included M1, M2, and M3. Using this model, 91% of broiler carcasses were properly classified as normal or WB along with a sensitivity of 71% to detect affected carcasses. Although the predictive performance of models for detecting the WB condition using these measurements was associated with the broiler strain, sex, and age or live weight, these data also support the feasibility of using image analysis to predict WB defect in broiler carcasses. The possible integration of these image measurements into commercial noncontact, nondestructive, and fast in-line vision grading systems would allow processors to identify broilers with WB and potentially sort, provide large-scale information downstream to further processing operations and upstream to live production.

Prospect of early vascular tone and satellite cell modulations on white striping muscle myopathy

Polyphasic myodegeneration potentially causes severe physiological and metabolic disorders in the breast muscle of fast-growing broiler chickens. To date, the etiology of recent muscle myopathies, such as the white striping (WS) phenotype, is still unknown. White striping–affected breast meats compromise the water holding capacity and predispose muscle to poor vascular tone, leading to the deterioration of meat qualities. Herein, this review article provides insight on the complexities around chicken breast myopathies: (i) the etiologies of WS occurrence in chicken; (ii) the metabolic changes that occur in WS defect in pectoralis major; and (iii) the interactions between breast muscle physiology and vascular tone. It also addressed the effects of nutritional supplements on muscle myopathies on chicken breast meats. Moreover, the review explored breast muscle biology focusing on the early preparation of satellite and vascular cells in fast-growth chicken breeds. Transcriptomics and histological analyses revealed poor vascularity in breast muscle of fast growth chickens. Thus, we suggest in ovo feeding of nutrients promoting vascularization and satellite cells replenishment as a potential strategy to enhance endothelium-derived nitric oxide availability to promote vascularization in the pectoralis major muscle region.

Effect of Woody Breast Condition on Instrumental Texture Characteristics of Poultry Deli Loaves

The use of broiler breast fillets affected by the woody breast (WB) condition in processed poultry products couldbe a feasible solution to this meat quality problem. This study assessed the impact of utilizing broiler breast fillets at differ-ent degrees of WB severity and percentages on instrumental texture characteristics of deli loaves. Breast fillets (n = 270) were collected from broiler carcasses and sorted based on palpation assessment in 3 WB categories (normal [NOR], mild [MIL], and severe [SEV]). Nine treatments of deli loaves were prepared from cubed portions in each of 3 replications: 100% NOR (T1), 67% NOR + 33% MIL (T2), 67% NOR + 33% SEV (T3), 33% NOR + 67% MIL (T4), 33% NOR + 67% SEV (T5), 100% MIL (T6), 67% MIL + 33% SEV (T7), 33% MIL + 67% SEV (T8), and 100% SEV (T9). Cooked deli loaves were subjected to texture profile analysis, cook loss, instrumental color, and dimensional modifications. Hardness of deli loaves increased (P &lt; 0.05), whereas cohesiveness values decreased (P &lt; 0.05), as WB severity increased in the meat added into the product formulation when compared with NOR samples and excluding treatments T2 through T4. The use of SEV fillets at 100% (T9) or mixtures of MIL and SEV fillets (T7 and T8) yielded nonuniform deli loaves with different color parameters and higher levels of cook loss (&gt;13%), coupled with reductions in diameter (&gt;8%) and length (&gt;5%), comparedto NOR samples (P &lt; 0.05). These results suggest that the negative effects of WB on quality and yield characteristics are not minimized by the preparation of this formed product when using high proportions of WB meat. Thus, broiler breast fillets affected by the WB condition may be used at relatively low percentages combined with NOR fillets as an option in commercial chicken deli loaf formulations.

Instrumental texture analysis of chicken patties prepared with broiler breast fillets exhibiting woody breast characteristics

Potential applications of chicken meat with the woody breast (WB) condition in further processed products could provide processors with alternatives to deal with this meat quality problem. The objective of this study was to evaluate the effect of the use of broiler breast fillets at varying degrees of WB severity and proportions on instrumental texture characteristics of chicken patties. A total of 54 breast fillets were collected from broilers processed as per commercial practices, previously classified based on tactile evaluation in 3 WB categories (normal [NOR]; mild [MIL], and severe [SEV]). Instrumental compression analysis was performed to validate subjective scores. Nine treatments with 6 replicates of chicken patties were prepared: 100% NOR (T₁), 67% NOR + 33% MIL (T₂), 67% NOR + 33% SEV (T₃), 33% NOR + 67% MIL (T₄), 33% NOR + 67% SEV (T₅), 100% MIL (T₆), 67% MIL + 33% SEV (T₇), 33% MIL + 67% SEV (T₈), and 100% SEV (T₉). Instrumental texture profile analysis along with cook loss, color, and dimensional changes was evaluated in cooked patties. Compared with normal samples and excluding treatments T₂ and T₄, hardness, springiness, and chewiness values of chicken patties decreased (P < 0.05) as WB severity increased in the meat incorporated into the formulation. Patties prepared using mixtures of MIL and SEV fillets (T₇ and T₈) including T₉ had higher levels of cook loss (>26%, P < 0.05) accompanied by significant reductions in diameter (>16%, P < 0.05) and distinguishable color changes (ΔE∗_ab > 2) than normal patties. These data suggest that the potential use of WB meat in chicken patties is associated with the degree of WB severity and the incorporation rate. The inclusion of WB fillets at high levels into this product is not recommended owing to their poor functionality. However, feasible mixtures of normal breast fillets with those affected by WB myopathy at relatively low proportions could be considered by processors as an alternative in commercial chicken patty formulations.

Effect of Pre-Blended Phosphates on the Freezing Quality Characteristics of Ground Woody Breast Meat Compared to Normal Meat

Woody breast (WB) myopathy affected meat has a tough texture, higher cook loss, and decreased water holding capacity (WHC), and thus lower consumer acceptability. The WB meat can be ground and further converted into further processed products or frozen, stored, and shipped to further processors. Freezing and thawing of ground WB meat may further affect the quality of WB meat products. Hence, research is required to determine the effect of pre-blended phosphates on the quality of ground WB meat as well as its cryoprotective effect during frozen storage. The objective of this experiment was to investigate the effect of pre-blended phosphate levels on meat quality in WB and normal breast (NB) fillets before and after freezing. NB fillets and severely affected WB fillets were procured from a local commercial processor. The meat was separated into various treatment groups according to the sodium tripolyphosphate (STPP) inclusion levels (0, 0.25, and 0.5% w/w). The meat was ground with respective phosphate treatments and subdivided into vacuum-sealed bags (n = 240; 1 kg each). Half of the bags (n = 120) from each treatment were taken for meat quality analysis, while the other bags were placed in a freezer (-18 °C) for 6 days. Fresh samples were analyzed within 6-8 h while the frozen samples were thawed for 18 h at 4°C prior to analysis. Samples (n = 10) were analyzed for gel strength, pH, color (L* a* b*), proximate composition, and randomly selected samples (n = 5) were analyzed for aerobic plate count (APC). Experiments were repeated in two separate replications and the data was analyzed using the Proc Glimmix model procedure in SAS (v. 9.4) (Cary, NC, USA) with LSMeans Separation at p ≤ 0.05. The gel strength (g) of the fresh ground NB meat (883.7 g) was higher than the gel strength of woody meat (720.8 g) with 0% phosphate (p ≤ 0.05). Addition of phosphate (0.25 and 0.5%) significantly increased the gel strength of fresh woody meat but it was significantly lower than NB meat added with 0.25 and 0.5% phosphate treatment. After freezing, ground NB meat samples with 0.25 and 0.5% phosphate had higher gel strength compared to fresh and frozen ground WB meat (p ≤ 0.05). Pre-blended STPP raised the pH in all treatments (p < 0.05). Treatments did not have any clear impact on APC of ground WB or NB meat. Addition of pre-blended sodium tripolyphosphate increases the functionality of fresh and frozen ground WB meat, as well as NB meat.

Effects of reducing dietary amino acid density and stocking density on growth performance, carcass characteristics, meat quality, and occurrence of white striping in broiler chickens

A 49-day trial was conducted to determine the impact of dietary amino acid (AA) density and stocking density (SD) on growth performance, carcass traits, meat quality, and white striping (WS) occurrence in broiler chickens. Two hundred eighty-eight Ross 308 male broilers consisting of 6 replicate cages with 8 broilers per replicate were used. Treatments were arranged in a 3 × 2 factorial and consisted of 3 AA densities (normal, 10, or 20% lower than normal) and 2 different SD (high 35 kg/m² or low 26 kg/m²). Breasts were classified as normal, moderate, and severe for WS. Data were analyzed as a completely randomized design using the GLM procedure. Decreasing AA density decreased overall growth performance, carcass, breast yields, and fillet dimensions linearly, while leg and rib cage yields increased linearly (P < 0.01). High SD decreased hot carcass, breast, wings, and rib cage weights in birds fed normal AA diets (P < 0.05). High SD increased the length of breast fillet (P < 0.05). Cooking loss, breast lightness (L∗), and redness (a∗) at 48 h postmortem increased linearly with decreasing AA density, while ultimate breast pH (pH_u) and nitrogen content decreased linearly (P < 0.05). The occurrence of normal, moderate, and severe WS fillets was 45.3, 49.1, and 5.6%, respectively. As the dietary AA density decreased, the occurrence of no WS breast fillets increased linearly, whereas the occurrence of moderate WS fillets and mean WS score decreased linearly (P < 0.05). SD did not affect the occurrence of WS. Severe WS fillets were heavier and had higher cranial thickness, pH_u, and fat content and lower yellowness (P < 0.05), but water-holding capacity, nitrogen content, L∗, and a∗ value did not differ among different WS scores. Taken together, WS occurrence and severity increased with higher growth rate. Growth depression created by lowering dietary AA density regardless of SD resulted in a decrease in mean WS score, but it also compromised the growth and meat quality.

A review on the woody breast condition, detection methods, and product utilization in the contemporary poultry industry

In recent years, the global poultry industry has been facing increasing and challenging myopathies such as the woody breast (WB) condition that has caused significant economic losses. Even though the etiological causes of WB myopathy are still unknown or partially understood, the intensive genetic selection for rapid-growth rates and high yields in broilers may be the main factor associated with the development of this abnormality. The severity of this anomaly and its incidence rates are associated with fast-growing and heavier broilers, especially with those from high breast yielding strains. Such WB myopathy is primarily characterized by a notorious hardness in broiler breast muscles, which exhibit morphometric and histopathological alterations coupled with physicochemical abnormalities that result in undesired sensory, nutritional, and technological properties. In this negative context, although scientists are trying to solve or reduce the prevalence of this meat quality problem, the poultry industry needs noncontact and rapid in-line methods for WB detection at the fillet and/or carcass level that could help to establish automated objective grading or sorting systems according to its severity. Another need is the development and selection of profitable alternatives for the utilization of WB meat once poultry carcasses or deboned fillets affected by this abnormality are objectively detected and sorted. Indeed, there is a need for studies to expand the industrial applications of WB meat in further processed products, optimizing the incorporation of this affected chicken meat based on sensorial, technological, and nutritional profile evaluations. Even though a better understanding of the contribution of genetic and nongenetic factors to the development of growth-related myopathies can be the main strategy to mitigate their negative effects, the poultry industry could benefit from meeting the aforementioned needs.

Molecular Phenotyping of White Striping and Wooden Breast Myopathies in Chicken

The White Striping (WS) and Wooden Breast (WB) defects are two myopathic syndromes whose occurrence has recently increased in modern fast-growing broilers. The impact of these defects on the quality of breast meat is very important, as they greatly affect its visual aspect, nutritional value, and processing yields. The research conducted to date has improved our knowledge of the biological processes involved in their occurrence, but no solution has been identified so far to significantly reduce their incidence without affecting growing performance of broilers. This study aims to follow the evolution of molecular phenotypes in relation to both fast-growing rate and the occurrence of defects in order to identify potential biomarkers for diagnostic purposes, but also to improve our understanding of physiological dysregulation involved in the occurrence of WS and WB. This has been achieved through enzymatic, histological, and transcriptional approaches by considering breast muscles from a slow- and a fast-growing line, affected or not by WS and WB. Fast-growing muscles produced more reactive oxygen species (ROS) than slow-growing ones, independently of WS and WB occurrence. Within fast-growing muscles, despite higher mitochondria density, muscles affected by WS or WB defects did not show higher cytochrome oxidase activity (COX) activity, suggesting altered mitochondrial function. Among the markers related to muscle remodeling and regeneration, immunohistochemical staining of FN1, NCAM, and MYH15 was higher in fast- compared to slow-growing muscles, and their amount also increased linearly with the presence and severity of WS and WB defects, making them potential biomarkers to assess accurately their presence and severity. Thanks to an innovative histological technique based on fluorescence intensity measurement, they can be rapidly quantified to estimate the injuries induced in case of WS and WB. The muscular expression of several other genes correlates also positively to the presence and severity of the defects like TGFB1 and CTGF, both involved in the development of connective tissue, or Twist1, known as an inhibitor of myogenesis. Finally, our results suggested that a balance between TGFB1 and PPARG would be essential for fibrosis or adiposis induction and therefore for determining WS and WB phenotypes.

Differentiating Breast Myopathies through Color and Texture Analyses in Broiler

Wooden breast (WB), white striping (WS) and spaghetti meat (SM) are breast myopathies of the Pectoralis major that greatly affect meat quality in broilers. To differentiate color and texture characteristics with instrumental methods, some of them applied for the first time in this species, 300 carcasses were randomly chosen from an abattoir from five different flocks from the same farm, at a rate of 60 carcasses from each flock. Twenty-four hours after slaughter, both side breasts were dissected, and yields calculated. Color was measured on the surface of the breast with a spectrocolorimeter and reflectance values obtained. Texture was measured on raw meat with a modified compression test that hinders the fiber from expanding transversally and a texture profile analysis (TPA) and also on cooked meat with a Warner-Bratzler shear and a TPA. Color differs between severity degrees, increasing redness (from -1.77 to -1.32 in WB) and, especially, yellowness (from 5.00 to 6.73 in WS) and chroma (from 5.75 to 7.22 in SM) with the severity of the myopathy. The subtraction R630 minus R580 was found to be a useful index to differentiate breast myopathies degrees. The modified compression test can be considered an effective tool to assess the hardness of different structures in each myopathy. Texture differences in the myopathies are better assessed in raw than in cooked meat.

Pectoralis Major (Breast) Muscle Extracellular Matrix Fibrillar Collagen Modifications Associated With the Wooden Breast Fibrotic Myopathy in Broilers

The poultry industry has placed significant emphasis on the selection of meat-type broilers for increased body weight, increased meat yield especially the pectoralis major (breast) muscle, decreased time to processing, and improved feed conversion_. Although significant improvements have occurred in fast-growing meat-type broilers, myopathies affecting meat quality especially in the pectoralis major muscle have occurred. Many of the broiler breast muscle myopathies are caused by inflammation leading to the necrosis of existing muscle fibers and resulting in replacement of the muscle fibers with extracellular matrix proteins especially fibrillar collagens, fibrosis. This review explores how the fibrotic deposition and organization of extracellular matrix proteins especially the fibrillar collagens, Types I and III, affects the phenotype of the Wooden Breast myopathy, functional properties of the pectoralis major muscle, and meat quality.

Energy metabolism and sources of oxidative stress in wooden breast - a review

Modern broilers show dramatic growth over a short interval and contribute directly to the success of the poultry meat industry. The growth performance of commercial broilers is a result of genetic selection for "performance traits", such as body size, meat yield, and feed conversion rate. However, due to the rapid growth rate of modern commercial broilers, several growth-related conditions have arisen, increasing economic losses and consumer concerns. Among the most economically consequential is the muscle disorder called wooden breast. Together with associated myopathies such as white striping and spaghetti meat, wooden breast is causing losses of $200 million a year in the U.S. alone and occurs worldwide. No causative factors are known for wooden breast to date. Wooden breast can affect over 80% of broilers in a flock, yet no methods of amelioration are currently available. Overall, the evidence suggests that wooden breast is a genetic, age-dependent condition associated with fast growth rate. The primary features of wooden breast are muscle degeneration and fibrosis, high levels of oxidative stress, hypoxia, and altered energy metabolism. Recent work has also implicated reduced pectoral vessel density in the pathogenesis of wooden breast. This review examines the history of myopathies in commercial broilers and the relationship of myopathies to metabolism and oxidative performance. This review summarizes the foundational knowledge of wooden breast and provides a platform for further investigation of wooden breast.

Machine assisted classification of chicken, beef and mutton tissues using optical polarimetry and Bagging model

Optical polarimetry has been used to characterize muscle tissue samples of chicken, beef and mutton, exhibiting statistically significant (p <  0.01) differences in total depolarization and retardance of three tissue groups. Herein, the total depolarization and retardance were utilized to differentiate and classify the three tissue groups. Specifically, the Bagging classification algorithm was employed for this multi-class differentiation. The performance of the optical polarimetry in tandem with the Bagging model for machine-assisted classification of the three tissue groups was assessed in terms of a comprehensive set of evaluation metrics. The Bagging model correctly classified 47/48, 19/20 and 15/18, whereas the sensitivity (Sn = 97.9 %, 82.6 %, 100 %), specificity (Sp = 97.4 %, 98.4 %, 95.8 %), positive predictive values (PPV = 0.97, 0.95, 0.83) and negative predictive values (NPV = 0.97, 0.94, 1.0) were calculated for the chicken, beef and mutton tissue samples, respectively. This automatic classification of the three tissue samples indicates a novel application of the optical polarimetry in the meat industry.

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.

Effect of vitamin E and omega-3 fatty acids early posthatch supplementation on reducing the severity of wooden breast myopathy in broilers

The wooden breast (WB) myopathy is identified by the palpation of a rigid pectoralis major (P. major) muscle and is characterized as a fibrotic, necrotic P. major muscle disorder in broilers resulting in reduced breast meat quality. Breast muscle affected with WB is under severe oxidative stress and inflammation. The objectives were to identify the effects of dietary vitamin E (VE) and omega-3 (n-3) fatty acids independently or in combination when fed during the starter phase (0-10 D) or grower phase (11-24 D) on growth performance, meat yield, meat quality, and severity of WB myopathy and to determine the most beneficial dietary supplementation period. A total of 210 Ross 708 broiler chicks were randomly assigned into 7 experimental groups with 10 replicates of 3 birds each. The control group was fed with corn-soybean meal basal diet with VE (10 IU/kg) and n-3 fatty acids (n-6/n-3 ratio of 30:1) at a standard level during the entire study (0-58 D). Supplementation of VE (200 IU/kg), n-3 fatty acids (n-6/n-3 ratio of 3:1), or combination of both was performed during the starter phase or grower phase. Growth performance, meat yield, meat quality, and WB scores were obtained. There was no significant difference in final body weight and meat yield when VE was increased (P > 0.05). In contrast, n-3 fatty acids supplementation in starter diets significantly decreased final body weight, hot carcass weight, and chilled carcass weight of broilers (P ≤ 0.05). The P. major muscle from broilers supplemented with VE in starter diets had lower shear force than in grower diets (P ≤ 0.05). Supplemental VE reduced the severity of WB and in starter diets showed a more beneficial effect than those fed VE in the grower diets. These data are suggestive that additional supplementation of dietary VE may reduce the severity of WB and promote breast meat quality without adversely affecting growth performance and meat yield.

Research Note: Effect of chicken genotype and white striping-wooden breast condition on breast meat proximate composition and amino acid profile

The present experiment compared the proximate composition, the amino acid content, and profile of the breast meat of a commercial broiler hybrid (Hybrid-Normal) vs. a broiler hybrid affected by the simultaneous presence of white striping (WS) and wooden breast (WB) myopathies (Hybrid-WSWB) vs. the Italian purebred Polverara chicken (Polverara). To this purpose, a total of n = 30 breast meat cuts from male chickens/group were subjected to meat quality evaluations. Chickens were slaughtered at their commercial age. The meat of the Polverara breed showed the highest protein (P < 0.0001) and the lowest lipids (P < 0.0001) contents, whereas that of the Hybrid-WSWB broiler chickens had the lowest protein and ash (P < 0.0001) contents and the highest (P < 0.0001) amount of fat. Meat of Hybrid-Normal chickens displayed intermediate values. Polverara meat was the richest in most amino acids (g/100 g meat), whereas Hybrid-WSWB one had the lowest content (P < 0.0001). Taurine was not detected in the meat of the Polverara chicken. The meat of Hybrid-Normal chickens was the richest in valine and taurine amino acids (P < 0.0001). Results on the amino acids proportions (% of total amino acids) highlighted that lysine, arginine, leucine, glutamic acid, aspartic acid, alanine, and serine were the most representative essential and nonessential amino acids, respectively, in all 3 meat-types chickens. The study confirmed that WS and WB myopathies negatively affect the meat proximate composition and the amino acid content. The meat of the Polverara breed displayed a remarkable meat quality including a high protein content of very good quality. This may represent a tool to promote its meat among consumers and help the survival of this endangered breed. Furthermore, research efforts should be conducted to understand why taurine was absent in the breast meat of Polverara chicken.

Physiochemical properties, protein and metabolite profiles of muscle exudate of chicken meat affected by wooden breast myopathy

The current study was designed to investigate the physiochemical properties, protein and metabolite profiles of muscle exudate obtained from chicken breast fillets affected by wooden breast (WB) myopathy. Twenty-four fillets were categorized into varying degrees of WB condition including normal, moderate and severe. Results indicated that exudate loss, free hemoglobin concentration, protein and lipid oxidation were affected by WB myopathy. Electrophoresis analysis showed eight distinct protein bands of differential relative abundance in WB samples compared with the normal, and the identified proteins were mostly involved in carbohydrate metabolic process. ¹H nuclear magnetic resonance-based metabolomics identified eleven metabolites including amino acids, nucleotides and organic acid as the most influential metabolites affected by WB myopathy. Overall, this study shows differential molecular profiles of myopathic chicken muscle exudate, and provides a valuable resource for further recognition of WB myopathy.

Effect of feed restriction timing on live performance, breast myopathy occurrence, and muscle fiber degeneration in 2 broiler chicken genetic lines

During recent years, research on meat quality in poultry has aimed to evaluate the presence and consequences of breast myopathies as well as the factors which can affect their occurrence by modifying the growth rate. A total of 900 broiler chickens were reared until slaughter (48 D) to evaluate the effect of 2 genetic lines (A vs. B) and feeding plans (ad libitum [AL], early restricted [ER], from 13 to 23 D of age, and late restricted [LR], from 27 to 37 D of age; restriction rate: 80%) on performance, meat quality, and breast muscle myopathies. Calsequestrin and vascular endothelial growth factor (VEGF) expressions, and muscle fiber degeneration (MFD) were recorded at 22, 36, and 48 D. Chickens in the AL treatment had greater final live (P < 0.01) and carcass weights and proportion of pectoralis major muscle (P = 0.04) compared to chickens in the LR treatment, whereas chickens in the ER treatment had intermediate final live (3,454 g) and carcass weights, and proportion of pectoralis major muscle (25.6%). Chickens of line A were heavier than chickens of line B (P < 0.001), and had a greater feed conversion rate. Chickens of line A also had a greater dressing out percentage (P < 0.001), but a lower proportion of pectoralis major muscle (P = 0.04), as well as a greater meat pH (P < 0.001), meat cooking losses (P < 0.01), and shear force of the pectoralis major muscle (P = 0.03). Calsequestrin and VEGF mRNA were significantly lower in ER and LR chickens compared to AL chickens after feed restriction and during refeeding (P < 0.05). MFD scores increased with chicken age (P < 0.001) and differed between genetic lines (P < 0.001). Neither feeding plan nor genetic line affected the occurrence of white striping or wooden breast condition.

Altered expression of lactate dehydrogenase and monocarboxylate transporter involved in lactate metabolism in broiler wooden breast

Wooden breast (WB) results in significant losses to the broiler industry due to reductions in meat quality. While the etiology of WB is unknown, it is believed to be associated with localized hypoxia and decreased lactate levels in skeletal muscles, indicating the presence of altered lactate metabolism in WB. We hypothesized that the expression levels of the major signaling molecules that control lactate metabolism, including lactate dehydrogenases (LDHA and LDHB) and monocarboxylate transporters (MCT1 and MCT4), were altered in WB. Therefore, the objectives of this study were to evaluate whether there were changes in mRNA and protein levels of LDHA, LDHB, MCT1, and MCT4 in WB compared to normal breast (NB) muscles. Biochemical analysis for LDH enzyme activity in NB and WB muscles was studied. MicroRNA375 (miR-375) expression, known to be inversely associated with LDHB protein expression in human cells, was also investigated. The level of LDHA mRNA was 1.7-fold lower in WB tissues than in NB tissues (P < 0.0001). However, the LDHA protein levels were similar in WB and NB tissues. In contrast, the levels of LDHB mRNA and protein were 8.4-fold higher (P < 0.002) and 13.6-fold higher (P < 0.02) in WB than in NB tissues, respectively. The level of miR-375 was not different between WB and NB muscles. The specific LDH isoenzyme activity that converted lactate to pyruvate was 1.8-fold lower in WB compared to NB tissues (P < 0.01). The level of MCT1 mRNA was 2.3-fold higher in WB than those in NB muscles (P < 0.02). However, this upregulation was not observed with MCT1 protein expression levels. The expression levels of MCT4 mRNA and protein were elevated 2.8-fold (P < 0.02) and 3.5-fold (P < 0.004) in WB compared to NB tissues, respectively. Our current findings suggest the potential roles of LDHB and MCT4 on lactate metabolism and provide a unique molecular elucidation for altered lactate homeostasis in WB muscles of broilers.