Dietary zinc supplementation in breeding pigeons improves the carcass traits of squabs through regulating antioxidant capacity and myogenic regulatory factor expression

The purpose of this experiment was to explore the effects of zinc supplementation in breeding pigeons diet on carcass traits, meat quality, antioxidant capacity and mRNA expressions of myogenic regulatory factors of squabs. A total of 120 healthy White King pigeons were randomly assigned to 5 treatments, each involving 8 replicates. The experiment lasted for 46 d (18-d incubation period of eggs and 28-d growth period of squabs). The 5 groups were 0, 30, 60, 90, and 120 mg/kg zinc addition. Results showed that the 28-d body weight, breast muscle yield, zinc content in crop milk and myogenic factor 6 (MyF6) abundance of breast muscle were linearly increased (P < 0.050), but the abdominal fat yield linearly decreased (P = 0.040) with increasing dietary zinc supplementation. Both the linear (P < 0.050) and quadratic responses (P < 0.001) were observed in copper zinc superoxide dismutase (Cu-Zn SOD), total antioxidant capacity (T-AOC) and malondialdehyde (MDA) contents in liver and breast muscle. The 28-d body weight was increased by 90 mg/kg zinc supplementation (P < 0.05), and there is no significant difference between 90 and 120 mg/kg zinc addition. The breast muscle yield, Cu-Zn SOD and T-AOC contents in breast muscle and liver, zinc contents in crop milk and breast muscle, MyF6 mRNA expression in breast muscle were higher (P < 0.05) in the group supplemented with 120 mg/kg zinc than the control. The abdominal fat yield was numerically lowest, and MDA contents in breast muscle and liver were significantly lowest in the group fed 120 mg/kg zinc (P < 0.05). However, the meat quality traits were not affected (P > 0.05) by zinc supplementation, except for shear force. It should be stated dietary zinc supplementation at the level of 120 mg/kg for breeding pigeons increased body weight and breast muscle yield of squabs, which may be associated with the up-regulating MyF6 mRNA expression and antioxidant capacity in liver and breast muscle.

Changes of Raw Texture, Intramuscular Connective Tissue Properties and Collagen Profiles in Broiler Wooden Breast during Early Storage

A recently identified broiler myopathy known as wooden breast (WB) is predominantly found in the pectoralis major muscle of fast-growing broiler hybrids and is causing significant losses to the poultry industry. The aim of this study was to investigate the effects of WB syndrome on raw meat texture, purge loss and thermal properties of intramuscular connective tissue of pectoralis major muscle in the early postmortem period (1-3 days). Results showed that the presence of the WB muscles condition at 1 day postmortem was associated with significantly increased stiffness (27.0 N vs. 23.1 N) and significantly increased purge loss (1.8% vs. 1.0%) compared to normal breast (NB). However, on 3 days postmortem, these parameters did not differ between WB and NB groups. Insoluble and total collagen content was significantly higher in WB muscles compared to NB muscles, and the extractability of intramuscular connective tissue (IMCT) of WB was also higher (0.42% vs. 0.37%) compared to NB and remained stable in the early postmortem period. There was significantly lower protein content in the sarcoplasmic protein fraction and myofibrillar protein fraction of WB muscles compared to NB muscles (p < 0.05). The IMCT of these two groups showed different thermal properties, as the enthalpy of denaturation (ΔH) was significantly lower in WB muscles compared to NB muscles. The WB syndrome had a great effect on the texture and connective tissue properties of the meat compared to normal muscle, with a tendency for having a lower purge loss and higher raw meat hardness.

Effects of tannic acid supplementation on growth performance, gut health, and meat production and quality of broiler chickens raised in floor pens for 42 days

A study was conducted to investigate the effects of tannic acid (TA) supplementation on growth performance, gut health, antioxidant capacity, gut microbiota, and meat yield and quality in broilers raised for 42 days. A total of 700 one-day-old male broiler chickens (Cobb500) were allocated into 5 treatments with 7 replicates of 20 birds per pen. There were five treatments: 1) tannic acid 0 (TA0: basal diet without TA); 2) tannic acid 0.25 (TA0.25: basal diet+0.25 g/kg TA); 3) tannic acid 0.5 (TA0.5: basal diet+0.5 g/kg TA); 4) tannic acid 1 (TA1: basal diet+1 g/kg TA); and 5) tannic acid 2 (TA2: basal diet+2 g/kg TA). The dietary phases included starter (D 0 to 18; crumble feed), grower (D 18 to 28; pellet feed), and finisher (D 28 to 42; pellet feed). On D 18, the supplementation of TA linearly reduced body weight (BW) and average daily feed intake (ADFI) (p < 0.05), and on D 28, the supplementation of TA linearly reduced BW, average daily gain (ADG), and feed conversion ratio (FCR) (p < 0.05). Relative mRNA expression of genes related to mucin production (MUC2), tight junction proteins (CLDN2 and JAM2), and nutrient transporters (B0AT1 and SGLT1) was linearly increased by the supplementation of TA (p < 0.05). The supplementation of TA tended to linearly increase the relative abundance of the family Enterobacteriaceae (p = 0.08) and quadratically increased the relative abundance of the families Lachnospiraceae and Ruminococcaceae in the cecal microbial communities (p < 0.05). On D 36, the ratio of the phyla Firmicutes and Bacteroidetes was quadratically reduced by the supplementation of TA (p < 0.05). On D 42, bone mineral density and the lean to fat ratio were linearly decreased by the supplementation of TA (p < 0.05). On D 43, total chilled carcass weight was linearly reduced (p < 0.05), and proportion of leg weight was increased by supplementation of TA (p < 0.05). The supplementation of TA linearly reduced pH of the breast meat (p < 0.05) and linearly increased redness (a*) (p < 0.05). Although the supplementation of TA positively influenced gut health and gut microbiota in the starter/grower phases, it negatively affected overall growth performance, bone health, and meat production in broilers on D 42.

The Effects of Preslaughter Electrical Stunning on Serum Cortisol and Meat Quality Parameters of a Slow-Growing Chinese Chicken Breed

Electrical stunning is widely utilized prior to a neck cut to induce unconsciousness in order to improve animal welfare and slaughter efficiency in the broiler production industry. However, slaughter without stunning is still very commonly used in China, in part because there is a belief that stunning reduces meat quality. The purpose of this study was to determine whether the physical (hemorrhages, pH, drip loss, and shear force) and chemical (inosinic monophosphate concentration and reducing sugar content) properties of broiler meat differed between chickens in preslaughter stunning and nonstunned slaughter groups, and whether the groups differed in their levels of cortisol as an indicator of stress. Serum cortisol levels of the nonstunned group were nearly twice as high as those in the stunned group (p < 0.05). Several meat quality indicators were better in the stunned group than in the nonstunned group. We concluded that electrical stunning prior to slaughter significantly decreases the stress caused by slaughter, resulting in both improved animal welfare and meat quality traits.

Assessment of meat quality distributions of breast fillets with woody breast condition in the raw and cooked state

The objective of this study was to determine meat quality distributions and assess hardness distributions in raw and cooked breast fillets with the woody breast (WB) condition, in addition to evaluating the relationship between water properties and WB severity. A total of 90 breast fillets were collected and categorized as normal (NORM), mild (MILD) and severe (SEV). Breast weight, drip loss, compression measurements, cook loss, shear and texture profile analysis (TPA) values were measured for each sample by fillet location (cranial to caudal) and sampling depth (cranial-superficial, cranial-internal, middle-superficial, and middle-internal) in the raw and cooked meat state. Low-field NMR relaxation measurements were also collected for both the raw and cooked fillets. Results indicate that severe WB expressed increased hardness, a higher water content (bound water and free water) and reduced meat quality attributes in raw and cooked meat. Breast fillet hardness and meat quality distributions were unevenly distributed between fillets, compression measurements were higher mainly in the cranial region, and progressively decreased toward the caudal region for both raw and cooked fillets. Shear force and energy values were higher in the cranial region than in the middle region, and TPA values were higher in superficial regions rather than internal portions. Additionally, low-field NMR could be used to predict WB through variation in water properties as thermal processing reduces water distributing abilities in affected fillets.

Quality properties of chicken meatballs prepared with varying proportions of woody breast meat

The objective of this study was to explore the effect of woody breast (WB) on quality characteristics of chicken meatballs paired with the feasibility of its inclusion. Cook loss (CL), color (CIE L*, a*, b*), texture (hardness, springiness, chewiness and resilience), low-field NMR (bound water, immobilized water, and free water), microstructure, and sensory characteristics of chicken meatballs with different WB inclusion levels (0%, 25%, 50%, 75%, 100%) were analyzed. The results showed that the impairment of product quality traits such as CL, color, texture (hardness, chewiness), free water, microstructure, and sensory scores (appearance, organization, total score) increased as the percentage of WB meat increased in the product formulation, particularly when the WB incorporation level exceeded 25%. Indeed, cook loss, L*, a*, b* parameters, bound water, and immobilized water increased when the WB inclusion level was higher than 25% (P ≤ 0.05). However, free water, sensory characteristics, hardness, and chewiness parameters decreased (P ≤ 0.05). The microstructure of chicken meatballs also changed as the proportion of WB meat increased. Even though data suggest that the inclusion of WB meat up to 30% could be feasible to produce acceptable chicken meatballs, the optimal maximum incorporation rate of WB meat into chicken meatball recipes was 25% based on economic feasibility and final overall quality.

Development of Imaging System for Online Detection of Chicken Meat with Wooden Breast Condition

In recent years, the wooden breast condition has emerged as a major meat quality defect in the poultry industry worldwide. Broiler pectoralis major muscle with the wooden breast condition is characterized by hardness upon human palpation, which can lead to decrease in meat value or even reduced consumer acceptance. The current method of wooden breast detection involves a visual and/or tactile evaluation. In this paper, we present a sideview imaging system for online detection of chicken breast fillets affected by the wooden breast condition. The system can measure a physical deformation (bending) of an individual chicken-breast fillet through high-speed imaging at about 200 frames per second and custom image processing techniques. The developed image processing algorithm shows the over 95% classification performance in detecting wooden breast fillets.

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.

Nutritional Intervention Strategies Using Dietary Antioxidants and Organic Trace Minerals to Reduce the Incidence of Wooden Breast and Other Carcass Quality Defects in Broiler Birds

Wooden breast (WB) is a degenerative myopathy seen in modern broiler birds resulting in quality downgrade of breast fillets. Affected filets show increased toughness both before as well as after cooking and have decreased water holding capacity and marinade pick up compared to normal fillets. Although the exact etiology is unknown, the circulatory insufficiency and increased oxidative stress in the breast muscles of modern broiler birds could be resulting in damage and degeneration of muscle fibers leading to myopathies. Three independent experiments were conducted to evaluate the effect of various dietary interventions on the incidence of WB when birds are exposed to oxidative stress associated with feeding oxidized fat and mild heat stress. Feed additives such as dietary antioxidant [Ethoxyquin (ETX)], mineral methionine hydroxy analog chelate (MMHAC) of Zn, Cu, and Mn, and organic selenium (Org Se) were tested at recommended levels. In experiment 1, ETX reduced (P < 0.05) the incidence of severe WB induced by oxidized fat diet. The magnitude of improvement in percentage of normal (no WB) filets and reduction in muscle lipid peroxidation was greater (P < 0.05) when ETX and MMHAC were fed together as shown by experiment 2. In birds exposed to mild heat stress (Experiment 3), feeding MMHAC by itself reduced (P < 0.05) tissue damage by reducing incidence of tibial head lesions, skin scratches, breast blisters, in addition to increasing the incidence of normal (no WB) fillets. When MMHAC was combined with ETX and Org Se, further improvement (P < 0.05) in normal (no WB) filets was observed. In summary, under different oxidative stress conditions, dietary intervention programs that contain ETX, MMHA-Zn, -Cu, and -Mn and Org Se can improve performance and increase carcass integrity, reducing problems, such as WB, either independently or with additive effect. This effect is most likely attained by simultaneously improving the exogenous and endogenous antioxidant status, reducing oxidative stress, and improving tissue healing process of the bird.

Nutritional Properties and Oxidative Indices of Broiler Breast Meat Affected by Wooden Breast Abnormality

Wooden breast (WB) abnormality adversely impacts the quality of chicken meat and has been linked with oxidative stress. In this study, breast samples were taken from carcasses of 7-week-old Ross 308 broilers 20-min and 24-h postmortem. Five WB and seven non-WB control samples were assigned based on palpatory hardness (non-WB = no unusual characteristics and WB = focal or diffused hardness). WB exhibited lower contents of protein and the amino acids, i.e., isoleucine, leucine and valine, lighter surface color, lower shear force, greater drip loss and altered mineral profiles (p ≤ 0.05). Despite no difference in lipid oxidation, a greater degree of protein oxidation was found in the WB meat (p ≤ 0.05). Absolute transcript abundances of superoxide dismutase, hypoxia inducible factor 1 alpha and pyruvate dehydrogenase kinase 1 were greater in WB (p ≤ 0.05), whereas lactate dehydrogenase A expression was lower in WB (p ≤ 0.05). The findings support an association between oxidative stress and the altered nutritional and technological properties of chicken meat in WB.

Wooden breast myopathy on broiler breast fillets affects quality and consumer preference

INTRODUCTION

The emergence of myopathies such as wooden breast in the poultry industry generally associated with the fast development of the breast muscle of broilers has provided changes in the morphological structure of muscle tissues, as well as problems of meat qualitative attributes. The aim of this study was to evaluate physical, chemical, qualitative, and sensorial attributes of broiler fillets associated with severity levels of wooden breast (WB) myopathy in a poultry slaughterhouse.

MATERIALS AND METHODS

Three hundred fillets in a poultry slaughterhouse were classified into three severity levels: normal (100 samples), moderate (100 samples), and severe (100 samples).

RESULTS

After identification, classification, and description of changes, fillets with a severe WB level presented higher levels of red (a*), yellow (b*), and final pH. The lowest shear force and the highest myofibrillar fragmentation index were observed in fillets with a severe level when compared with normal fillets. The collagen content increased according to severity level. Tasters better evidenced the characteristic taste of chicken meat when tasting fillets with a severe WB level when compared with normal and moderate fillets. The succulence and preference of the Brazilian testers increased according to the severity level of the myopathy.

CONCLUSION

In general, fillets with moderate and severe WB myopathy were affected not only in appearance but also in qualitative, physical, chemical, and sensory characteristics.

Muscle water properties in raw intact broiler breast fillets with the woody breast condition

The purpose of this study was to investigate the relationships between muscle water properties, water-holding capacity (WHC), and woody breast (WB) severity in intact raw broiler breast fillets. Broiler pectoralis major deboned at 3 h postmortem was collected from a commercial plant and categorized as normal (NORM), moderate WB, or severe WB (SEV). Meat drip loss was calculated based on weight loss during overnight storage at 4°C. Water properties of the intact fillets were determined with time domain nuclear magnetic resonance and the T2 relaxation times were determined using an inverse Laplace algorithm (CONTIN). Three T2 water components, hydration water (T2b), intra-myofibrillar water (T21), and extra-myofibrillar water (T22), were identified. With increasing WB severity, the time constant of each water component and the relative content of T22 (P22) increased while the relative areas of T2b and T21 (P2b and P21, respectively) decreased. Spearman correlation analysis showed that there were significant correlations between the WB condition score and either the time constant or normalized area for each T2 component. T22 normalized areas (A22) were most strongly correlated with the WB score (r = 0.75); however, the weakest correlation was found between the WB score and T21 areas (A21). Pearson correlation analysis revealed that the strongest correlation (r = 0.64) was found between A22 and drip loss; however, there was no correlation between A21 and drip loss. Within the NORM group, drip loss was significantly correlated to the time constants for both T2b and T21. Within the SEV group, only A22 was significantly correlated to drip loss. These data indicate that the WB condition has a significant impact on the distribution of water within the intact muscle tissue. The content of extra-myofibrillar water in broiler breast fillets may be a key factor responsible for the poor WHC measurements in WB meat.

Research Note: Texture characteristics of wooden breast fillets deboned at different postmortem times

The study aimed to understand whether deboning time contributes to the altered texture attributes of wooden breast (WB) fillets. To this purpose, 30 unaffected (NORM) and 30 severely affected (WB) carcasses were selected at 15 min postmortem (PM) and allotted into treatments with different deboning times: A (5 NORM + 5 WB; right fillets deboned at 15 min PM), B (5 NORM + 5 WB; right fillets deboned at 3 h PM), and C (5 NORM + 5 WB; right fillets deboned at 6 h PM). Left fillets from each carcass were deboned at 24 h PM. Multiple instrumental texture analyses were performed on the cranial-middle portion of the Pectoralis major muscles. Irrespective of deboning time, all fillets were subjected to a single 30% compression in the raw state at 24 h PM. All fillets were cooked at 24 h PM and subjected to shear force assessments at 48 h PM using blunt Meullenet-Owens razor shear, Meullenet-Owens razor shear, and Warner-Bratzler shear force. Using an ANOVA mixed model, deboning time was evaluated as a fixed effect within muscle condition (sampling session and carcass ID as random effects). Compression force assessment of raw meat at 24 h PM showed that WB fillets exhibited the greatest hardness when they were deboned at 6 h PM (15 min = 35.4 N; 3 h = 30.9 N; 6 h = 48.0 N; 24 h = 30.6 N; P < 0.05). Differently, deboning time had no effect (P > 0.05) on raw compression force values in NORM fillets. In cooked NORM fillets, shear force values were the greatest in fillets deboned at 15 min, and shear force gradually declined with deboning time through 24 h PM. On the contrary, no changes (P > 0.05) in shear values due to different deboning times were observed in cooked WB meat regardless of shear method. These results suggest that early PM changes in breast muscles and their influence on meat texture are different between normal and WB fillets.

Quality Differences in Wooden and Normal Broiler Breast Meat Marinated with Traditional and Clean Label Marinades

Wooden breast (WB) is a Pectoralis major muscle myopathy in broilers that negatively impacts breast meat quality. The objective of this research was to evaluate quality differences between normal (NOR), moderately woody (MOD), and severely woody (SEV) broiler breast that were marinated with water (control); water, sodium phosphate, and salt (traditional); or water, potassium carbonate, and salt (clean label). Treatments were vacuum tumbled for 30 min and then frozen in a CO2 cabinet. A 3 × 3 factorial structure within a randomized complete block design with 3 replications was used to evaluate the effects of marinade (control, traditional, clean label) and WB severity (NOR, MOD, SEV) on tumble and cook loss, shear force, and texture profile analysis. For sensory analysis, a 2 × 3 factorial structure was used because the control was not evaluated. When averaged over WB severity, clean label marinade had less tumble loss (P &lt; 0.05) than traditional. When averaged over marinade, NOR had less tumble loss (P &lt; 0.05) than MOD and SEV. Marinated SEV were crunchier and less tender (P &lt; 0.05) than MOD and NOR, and MOD was less tender (P &lt; 0.05) than NOR. Similarly, the clean SEV was chewier (P &lt; 0.05) than MOD and NOR, but traditional SEV was only chewier (P &lt; 0.05) than NOR. Clean and traditional SEV were less acceptable (P &lt; 0.05) than MOD and traditional NOR, but no difference (P &gt; 0.05) existed in acceptability between MOD and NOR for both marinades. In addition, when averaging over WB severity, the traditional marinade was preferred (P &lt; 0.05) over the clean label marinade. Although the clean marinade samples were tender, the clean label formulation was not interchangeable with the traditional marinade when SEV was marinated. The use of salt and sodium phosphate or potassium carbonate improved the eating quality of MOD and SEV WB. However, differences remain between NOR and SEV in tenderness, gumminess, and crunchiness that negatively impact consumer acceptability.

The impaired redox status and activated nuclear factor-erythroid 2-related factor 2/antioxidant response element pathway in wooden breast myopathy in broiler chickens

OBJECTIVE

Wooden breast (WB) is a novel myopathy affecting modern broiler chickens, which causes substantial economic losses in the poultry industry. The objective of this study was to evaluate the effect of WB abnormality on meat quality, redox status, as well as the expression of genes of the nuclear factor-erythroid 2-related factor 2 (Nrf2) pathway.

METHODS

A total of 80 broilers (Ross 308, 42 days of age, about 2.6 kg body weight) raised at Jiujin farm (Suqian, Jiangsu, China) were used. Twelve unaffected (no detectable hardness of the breast area) and twelve WB-affected (diffuse remarkable hardness in the breast muscle) birds were selected from the commercial broiler farm according to the criteria proposed by previous studies.

RESULTS

The results indicated that WB showed histological lesions characterized by fiber degeneration and fibrosis, along with an increase of muscle fiber diameter (p<0.05). Moreover, higher pH value, lightness, yellowness, drip loss and cooking loss were observed in the WB group (p<0.05). Compared with the normal breast (NOR) group, the WB group showed higher formation of reactive oxygen species (p<0.05), increased level of oxidation products and antioxidant activities (p<0.05), accompanied with mitochondrial damages and lower mitochondrial membrane potential (p<0.05). Meanwhile, the relative mRNA expressions of Nrf2 and its downstream antioxidant genes including heme oxygenase-1, NAD(P)H qui none dehydrogenase 1, glutathione peroxidase, superoxide dismutase, and glutamate-cysteine ligase were higher than those of the NOR group (p<0.05).

CONCLUSION

In conclusion, WB myopathy impairs meat quality by causing oxidative damages and mitochondrial dysfunction in broilers, even though the activated Nrf2/antioxidant response element pathway provides protection for the birds.

Relationships between instrumental texture measurements and subjective woody breast condition scores in raw broiler breast fillets

The objective of this study was to compare the relationships between instrumental texture measurements and subjective woody breast (WB) scores in raw broiler breast fillets. A total of 181 broiler breast fillets were scored based on palpable hardness and rigidity ranging from 1.0 to 3.0 in 0.5 increments. Texture properties of raw fillets were measured with 3 different instrumental methods: compression force, blunt Meullenet-Owens Razor Shear (BMORS), and Meullenet-Owens Razor Shear (MORS). Compression force was measured based on % of fillet height (30%) and distance (10 mm). Blunt Meullenet-Owens Razor Shear and MORS measurements included peak force, energy, and peak counts. One-way ANOVA of instrumental texture measurements were performed. Spearman correlations between WB scores and instrumental texture measurements and Pearson correlations between 3 instrumental measurements were analyzed. ANOVA results showed that the best means separations between WB scores were found with the compression method. The weakest means separations were observed with MORS force and BMORS peak counts. Spearman correlation coefficients showed that there were significant relationships between WB scores and instrumental measurements. The strongest correlations were found between subjective WB scores and compression force measurements (r = 0.58–0.73, P < 0.0001), followed by BMORS force and energy (r = 0.55–0.56, P < 0 0.0001), MORS energy and peak count (r = 0.47–0.50, P < 0 0.0001), and BMORS peak count (r = −0.18, P = 0.015). The weakest correlation was found between the WB scores and MORS force (r = 0.17, P = 0.023). Pearson correlation coefficients between 3 different instrumental texture methods were also significant (P < 0.0001). These results demonstrate that there are significant correlations between subjective WB scores and instrumental texture measurements but that correlation strength varies with the instrumental method. Instrumental texture measurements can be used as references for subjective WB scores. Compression force method has the best potential for assessing subjective WB condition scores.

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.

Detection of razor shear force differences in broiler breast meat due to the woody breast condition depends on measurement technique and meat state1

Broiler breast meat with the woody breast (WB) myopathy exhibits abnormal tissue hardness and muscle rigidity in the raw state. The effectiveness of using instrumental shear measurements to characterize texture in WB fillets before and after cooking is not well understood. The objective of this study was to determine the influence of WB on razor shear force measurements in fresh never-frozen and frozen-thawed broiler breast fillets in both the raw and cooked state. Deboned breast fillets (n = 234) were collected from a commercial processing plant and categorized as normal (n = 78), moderate WB (n = 86), or severe WB (n = 70). At 24 h postmortem fillets were either used for texture analysis directly or frozen-thawed prior to analysis. Each fillet was measured before and after cooking using either the blunt blade (BMORS) or sharpened blade (MORS) versions of the Meullenet-Owens razor shear test. The ability of BMORS to distinguish between normal and WB fillets was different between raw and cooked fillets. In both fresh and frozen-thawed fillets, raw BMORS shear values (peak shear force and shear energy) increased (P < 0.0001) with WB severity. In fresh fillets, cooked BMORS values were similar between normal, moderate WB, and severe WB fillets. In frozen-thawed fillets, cooked BMORS values were greater (P < 0.001) in severe WB compared to normal fillets but were similar between normal and moderate WB fillets. Cooking had less impact on the ability of MORS to distinguish between normal and WB fillets. For both fresh and frozen-thawed fillets, MORS shear values (peak shear force and shear energy) were greater (P < 0.05) in WB fillets than normals in both the raw and cooked states. Data from this study demonstrate that the WB myopathy influences razor shear measurements in raw broiler breast fillets, but suggest that the ability to objectively detect texture differences in cooked WB meat is strongly dependent upon razor shear technique.

Characteristics and incidence of broiler chicken wooden breast meat under commercial conditions in China

Wooden breast (WB) has emerged as a dramatically increasing myopathy in the poultry industry over the past few years. The objective of this study was to investigate the incidence of WB in a Chinese commercial broiler processing plant, and the consequences on quality attributes, textural properties, and sensory traits. A total of 1,135 breast fillets were collected at the deboning line and assigned to normal, mild, moderate, and severe WB categories by tactile evaluation. The proportion affected by WB was approximately 61.9%. WB fillets appeared heavier and thicker than normal fillets. The degree of WB myopathy was highly correlated with fillet weight and thickness. The meat quality characteristics of cooking loss and purge loss increased along with increasing severity of WB myopathy. Compression tests of raw meat revealed higher cutting strength and shear values for WB. In cooked meat, only severe WB fillets exhibited elevated hardness and chewiness. Finally, moderate and severe WB fillets affected the sensory evaluation by consumers owing to their impaired general appearance, texture, and drip loss. The results suggested that a high proportion of WB broiler fillets would cause detrimental losses to the poultry meat retailing and processing industry.

Wooden-Breast, White Striping, and Spaghetti Meat: Causes, Consequences and Consumer Perception of Emerging Broiler Meat Abnormalities

Ten years ago, the occurrence of macroscopic defects in breasts muscles from fast-growing broilers challenged producers and animal scientists to label and characterize myopathies wholly unknown. The distinctive white striations in breasts affected by white striping disorder, the presence of out-bulging and pale areas of hardened consistency in the so-called wooden breast, and the separation of the fiber bundles in breasts labelled as spaghetti meat, made these myopathies easily identified in chicken carcasses. Yet, the high incidence of these myopathies and the increasing concern by producers and retailers led to an unprecedented flood of questions on the causes and consequences of these abnormal chicken breasts. This review comprehensively collects the most relevant information from studies aimed to understand the pathological mechanisms of these myopathies, their physicochemical and histological characterization and their impact on meat quality and consumer's preferences. Today, it is known that the occurrence is linked to fast-growth rates of the birds and their large breast muscles. The muscle hypertrophy along with an unbalanced growth of supportive connective tissue leads to a compromised blood supply and hypoxia. The occurrence of oxidative stress and mitochondrial dysfunction leads to lipidosis, fibrosis, and overall myodegeneration. Along with the altered appearance, breast muscles affected by the myopathies display poor technological properties, impaired texture properties, and reduced nutritional value. As consumer's awareness on the occurrence of these abnormalities and the concerns on animal welfare arise, efforts are made to inhibit the onset of the myopathies or alleviate the severity of the symptoms. The lack of fully effective dietary strategies leads scientists to propose whether "slow" production systems may alternatively provide with poultry meat free of these myopathies.