Incidence of broiler breast myopathies at 2 different ages and its impact on selected raw meat quality parameters

Polyphenol blend enhances zootechnical performance, improves meat quality, and reduces the severity of wooden breast in broiler chickens

This study investigated the effects of a commercial polyphenol blend on broiler performance, meat quality, carcass traits, and the incidence of pectoral myopathies. Broilers (1-42 days old) were allocated to four treatments: T1 (control, basal diet), T2 (250 g/ton polyphenol blend), T3 (500 g/ton), and T4 (1,000 g/ton), with eight replicates of 40 birds each. All diets were corn-soy based, isonutritional, and formulated to meet age-specific nutritional requirements. Parameters assessed at 21, 28, 35, and 42 days included antioxidant potential, growth performance, myopathy incidence, carcass yield, allometric growth, muscle morphometry, meat quality, and lipid profile. Optimal performance was observed at a supplementation level of 514 g/ton of polyphenols. While carcass yield remained unaffected, birds fed 500 g/ton exhibited delayed breast growth relative to other body parts, suggesting modulated allometric growth. Polyphenol supplementation reduced breast muscle fiber size, increased fiber density, and lowered the severity of wooden breast without influencing the incidence of white striping. Improved meat tenderness was evident through reduced cooking weight loss and enhanced shear force. Antioxidant status improved in plasma, muscle, and liver tissues, and the muscle lipid profile was favorably altered. In conclusion, the polyphenol blend enhanced broiler zootechnical performance, alleviated wooden breast severity, and improved meat quality and tenderness.

Gaping conditions of the Pectoralis minor (tenders) in commercial broilers: Prevalence, histology, and gene expression

Gaping is a recently described condition that affects the Pectoralis minor (tender) muscle of broiler chickens, characterized by post-mortem separation of myofiber that leads to meat depreciation and economic losses. In this study, we aimed at understanding prevalence, morphological features, and transcriptomics signatures of this poorly understood myopathy. Between July 2022 and January 2023, a total of 5,180 chicken tenders were collected from 32 flocks across two plants in the USA, handling light (2.7 kg) and heavy (4.1 kg) birds. The prevalence of moderate and severe gaping was 24.8 % and 53.7 %, respectively. The light bird plant had a lower prevalence of moderate gaping (P < 0.001), while the heavy bird plant had a lower prevalence of severe gaping (P < 0.001). Spaghetti meat prevalence from 8,000 fillets was 46.9 % for moderate and 8.3 % for severe cases, with no significant inter-plant differences. Use of peracetic acid treatment at the poultry plants significantly increased the prevalence of severe gaping. Physical and histological features, along with gene expression, were evaluated in 120 samples representative of three gaping severity tiers. Severely gaped tenders showed greater width compared to normal and moderately gaped tenders in both light and heavy birds (P < 0.05). An increase of 1 cm in tender width was associated with a 1.99-fold increase in the odds of classification into a more severe gaping category (95 % CI: 1.15 - 3.46). Affected muscles revealed histological evidence of myodegeneration, inflammation, and lipidosis with fibrosis. For one-unit increase in the myodegeneration score, samples had a 1.75-fold increase in the odds of being classified into a more severe gaping category (95 % CI: 1.37 - 2.23). Gene expression analysis using droplet digital PCR showed differential expression of 19 genes involved in oxidative stress response, cellular signaling, muscle development, and collagen formation between weight groups and myopathy categories. Notably, 21 out of 22 differentially expressed genes showed higher expression in light birds. This study provides the comprehensive description of gaping in broiler chickens and lays a crucial benchmark for assessment of future mitigating strategies.

Breast myopathy co-occurrence and its impact on carcass and meat quality attributes in broiler chickens

Wooden breast (WB), spaghetti meat (SM) and white striping (WS) are significant research focuses due to their impact on meat quality. This study examines the relationship between different myopathies in chickens from a commercial slaughterhouse and compares physicochemical traits between breasts with single and multiple myopathies and control (CO-no apparent myopathy). A total of 240 breasts were evaluated for myopathy presence, severity and location, and physicochemical parameters (i.e. carcass weight and color; breast color, pH, electrical conductivity, drip, thaw and cooking loss, Warner-Brazler texture, moisture, protein, fat and collagen content). A 54.8 % of the affected breasts presented multiple myopathies, and within them, a correlation between WB and WS was found (Kendall's tau = 0.24; P < 0.01). Additionally, myopathies were more prevalent in the breast cranial region (P < 0.05). Most physicochemical parameters varied significantly across myopathy classes. Breasts presenting WB, alone or in combination, were the most altered, showing: heavier carcasses with higher breast yield and redder and yellower skin; breasts with higher L*, b* and Hue, higher moisture, fat and collagen and lower protein content, and with higher cooking loss and lower resistance to shear (P < 0.05). SM, WS and their combination often had intermediate values between CO and WB breasts, with a few exceptions in carcass color and breast fat content. The principal component discriminant analysis revealed a proximity of CO to WS, SM, and their combinations, and a clear separation to WB and WB-SM. Breast yield, pH, cooking and thaw loss, and protein and fat content were the most discriminative parameters between categories. The partial least squares discriminant analysis could not differentiate between single, multiple myopathies and CO (accuracy = 42.6 %), but showed 80.63 % balanced accuracy for WB-SM, 74.26 % for SM and 74.61 % for CO. These findings confirm most previously reported data on meat quality, and provide a thorough analysis that can help industries to improve breast myopathies postmortem classification and identification.

Nutritional Composition, Technological Quality, and Sensory Attributes of Chicken Breast Meat Affected by White Striping, Wooden Breast, and Spaghetti Meat: A Comprehensive Evaluation

This study assessed the impact of growth-related myopathies-white striping (WS), wooden breast (WB), and spaghetti meat (SM)-on the technological properties, lipid and protein oxidation, chemical composition, and profiles of fatty acids (FAs), amino acids, minerals, and sensory attributes of pectoralis major muscles in broiler chickens. Breasts with myopathies had similar pH and lightness but exhibited lower redness and yellowness in the case of WB defect compared to normal meat (p < 0.05). The WB samples also showed higher cooking losses than normal meat and increased shear force compared to the SM samples (p < 0.01). Moreover, WB meat showed lower protein content (p < 0.001) than the normal and SM samples but the highest glycine content (p < 0.05). The WB meat also exhibited significant alterations in FA composition, with higher levels (p< 0.05) of C18:2n6, C22:6n3, n3 PUFA, n6 PUFA, and total PUFA compared to the normal and SM samples. The presence of myopathies did not influence the meat mineral composition, oxidative pattern, or sensory properties. In conclusion, growth-related myopathies in broiler chickens impact the technological quality and chemical composition of their breast meat, with WB showing the most significant alterations in protein content and FA composition. These changes indicate potential challenges to processing and nutritional quality, though sensory attributes remain largely unaffected.

Increased activity reduces the prevalence of woody breast in Ross 708 and Ranger Gold broilers

Woody or wooden breast (WB) is characterized by hardening and paleness of the Pectoralis major muscle and can affect up to 85% of broilers. We hypothesized that increased locomotor activity would lead to a lower prevalence of WB and increased tibia bone quality, with a greater effect on a faster growing than a slower growing broiler strain. Ross 708 (N = 188) and Ranger Gold (N = 213) broilers were raised in 3.05×3.05 m2 pens in groups of 23 to 24 and 26 to 27, respectively. Target ages for the Ross 708 and Ranger Gold birds were 42 and 56 d. There were 8 pens per strain: 4 assigned to an exercise treatment and 4 unexercised controls. An exercise regimen was applied for 10 min every hour for 6 h during each weekday with the goal of increasing frequency of standing and walking. A perch was placed between the feeder and drinker line in the exercise treatment pens to further promote broiler activity. WB severity was determined by palpation for all birds at the target age. Tibial bone mineral content (BMC) and bone mineral density (BMD) were measured using a dual-energy x-ray absorptiometry. The Fisher's Exact Test was used to determine treatment effects on the prevalence and severity of WB. Both prevalence (Ross 708: 77.5 vs. 90.5% control, P = 0.013; Ranger Gold: 57.9 vs. 76.4% control, P = 0.005) and severity (Ross 708: 12.9 vs. 24.2% control, P = 0.02; Ranger Gold: 4.7 vs. 0.02% control, P = 0.01) were reduced by treatment. The effects of strain, treatment and their interaction on tibial BMC and BMD were analyzed using linear mixed models. Only strain affected BMC (P = 0.003) and BMD (P = 0.03), with Ross 708 broilers having higher BMC (control: 3.246 g ± 0.061; treatment: 3.251 g ± 0.058) and BMD (control: 0.177 g/cm2 ± 0.002; treatment: 0.174 g/cm2 ± 0.002) values compared to Ranger Gold's BMC (control: 2.966 g ± 0.067; treatment: 2.987 g ± 0.064) and BMD (control: 0.168 g/cm2 ± 0.002; treatment: 0.168 g/cm2 ± 0.002) values. However, per unit of final body weight, Ranger Gold birds had a significantly higher BMC (P = 0.006) and BMD (P = 0.01) than Ross 708 broilers. Promoting broiler activity can reduce the prevalence and severity of WB prevalence in fast and slow growing broilers.

Rapid detection of poultry meat quality using S-band to KU-band radio-frequency waves combined with machine learning-A proof of concept

Rapid changes in consumer preferences for high-quality animal-based protein have driven the poultry industry to identify non-invasive, in-line processing technologies for rapid detection of muscle meat quality defects. At production plants, technologies like radio-frequency waves (RF waves) can identify and separate myopathy-conditioned meat, reducing misclassification errors due to human fatigue and inexperience. Previous studies have shown that advanced diagnostic tools combined with complex data analytics, such as support vector machines (SVMs) and backpropagation neural networks (BPNNs), can classify chicken breast myopathies post-deboning. This study demonstrates RF wave use for myopathy detection at four processing stages. Using 107 (48-day old) broilers, RF wave data in amplitude and phase were collected from live birds, pre-chilled without giblets (WOGs), post-chilled WOGs, and freshly deboned fillets (3-3.5 h post-slaughter) and examined by hand-palpation for woody breast categories (1-normal; 2-moderate; 3-severe). Data preprocessing involved false discovery rate and predictor analysis to identify specific signature frequencies and develop classification models using supervised machine learning (ML) algorithms. Variable clustering analysis identified seven to eight different frequencies at various processing stages. Preprocessed data with identified signature frequencies were used to develop classification models using BPNN and SVM. BPNN demonstrated superior classification accuracy compared to SVM, with accuracy ranges from 90.0% to 96.1% for live birds, 78.9% to 97.1% for pre-chilled WOGs, 82.1% to 95.9% for post-chilled WOGs, and 94.2% to 98.2% for deboned fillets. Integrating specific RF range devices or sensors with supervised ML algorithms like SVM and BPNN in poultry processing can effectively detect muscle myopathies at different processing steps during in-line processing.

Different dietary branched-chain amino acid ratios, crude protein levels, and protein sources can affect the growth performance and meat yield in broilers

Balanced ratios of branched-chain amino acids (BCAAs) can enhance chicken growth, immunity, and muscle synthesis. However, these ratios can be affected by changes in crude protein (CP) levels or the substitution of protein sources, leading to BCAA antagonism. This, in turn, can have a negative impact on chicken growth. In Experiment 1, a total of 960 0-d-old male Cobb 500 broilers were divided into 6 treatments with 8 replicates. Three different BCAA ratios were used in High or Low CP diets as follows: 1) Low Leu group (Low level of leucine with increased valine and isoleucine levels), 2) Med Leu group, and 3) High Leu group (High level of leucine with reduced valine and isoleucine levels) for a total of 6 diets. In Experiment 2, a total of 640 0-d-old male Cobb 500 broilers were divided into 4 treatments with 8 replicates. The four diets had either High or Low CP and one of two protein sources with the same medium levels of BCAAs: 1) the soybean meal (SBM) group, which had SBM as the main protein source (protein bound AA), and 2) the wheat middlings with non-bound AAs (WM+AA) group (non-bound AA), which had additional non-bound AAs to replace SBM. The High Leu diet had a negative effect on overall growth performance, carcass weight, breast muscle weight, and body mineral composition compared to the Low Leu and Med Leu groups, particularly in the High CP diet (P < 0.05). The SBM group showed increased growth performance, breast muscle weight, expression levels of genes promoting muscle growth, and improved bone mineral composition compared to the WM+AA group, and the High CP group intensified the negative effect of the WM+AA diet (P < 0.05). In summary, balanced BCAA ratios and SBM-based diets have positive effects on chicken growth and muscle accretion, whereas excessive leucine and non-bound AA levels in the diets may negatively affect growth performance and meat yield in chickens.

Skeletal muscle metabolic characteristics and fresh meat quality defects associated with wooden breast

Wooden breast (WB) is a myopathy that occurs in pectoralis major (PM) muscles, predominately affecting large, fast-growing broilers. Severe myodegeneration, increased hypoxia, reduced blood flow, and increased collagen deposition are hallmark characteristics of WB that culminate in unsatisfactory fresh meat quality attributes, such as poor water-holding capacity, tenderness, and processing characteristics. Therefore, WB meat is often downgraded resulting in economic losses for the United States poultry industry. Although WB has been well characterized, its etiology remains undefined. As the scientific community continues to resolve mechanisms responsible for WB onset, understanding biochemical changes associated with WB may facilitate solutions to negate its poor meat quality attributes. Given changes in metabolism of living muscle can alter biochemical processes during the conversion of muscle to meat, this review aims to summarize and discuss the current knowledge of WB muscle and meat biochemistry. For example, it appears metabolic pathways that support combating stress are upregulated in WB muscle at the expense of glycolytic flux, which presumably contributes to the high ultimate pH of WB meat. Further, perturbed function of WB mitochondria, such as altered calcium handling, impacts aspects of postmortem metabolism and proteolysis. Collectively, metabolic dysfunction of WB muscle alters the biochemical processes that occur during the conversion of muscle to meat, and thus contributes to the poor WB meat quality.

Endoplasmic reticulum stress and associated apoptosis are linked with the pathogenesis of white striping in broiler breast muscles

White striping (WS) that appears as white stripes parallel to the muscle fibrils is an emerging growth-related abnormality of broiler breast meat. The pathomechanism of this defect has not been fully understood despite intensive studies over the past decade. In the present study, endoplasmic reticulum (ER) stress and its associated apoptotic pathways were investigated to elucidate the potential role of these pathways in the development of WS. To this end, a total of 60 Pectoralis major (Pm) muscle samples were collected from 55-d-old Ross 308 male broiler chickens according to the severity of gross WS lesions (normal, mild, and severe). Histopathological and molecular analyses were conducted to evaluate the lesions and genes involved in the ER stress and related apoptosis. All the Pm samples, both with and without macroscopic WS lesions, showed varying degrees of myodegenerative lesions. Molecular analysis revealed that the transcript abundances of many components related to protein kinase R-like ER kinase (PERK) and inositol-requiring enzyme type 1 (IRE-1) signals of the ER stress response were significantly greater in severely WS-affected breast tissues compared to their mildly affected and normal counterparts. Similarly, the transcript abundances of apoptotic markers related to both signaling pathways were significantly greater in severe WS lesions than those of mildly affected and normal Pm tissues. Besides these, a significant increase in caspase-3 transcript abundance was seen in severe WS lesions in comparison with mild WS and normal breast muscles. Findings of this study suggest that ER stress response and its related apoptotic pathways are possibly activated in the breast muscle of broiler chickens with severe WS lesions. Based on these findings, it is speculated that ER stress-mediated apoptosis occupies a central role in the progression of WS in broiler chickens.

Effect of Age, Deboning Time of Carcass, and Different Cooking Conditions on the Woody Breast Myopathies in Chicken: A Meta-Analysis

This meta-analysis review undertakes a comprehensive examination of various approaches for identifying myopathic fillets and meticulously evaluates the effects of bird age, deboning time, and different cooking and storage conditions on woody breast (WB) myopathic conditions in broiler deboned fillets. The data, meticulously collected from 20 articles based on predefined inclusion criteria sourced from various databases and online resources, reveal significant insights. For instance, the analysis uncovers that deboning time significantly affects Meullenet-Owens Razor Shear (MORS), Blunt Meullenet-Owens Razor Shear (BMORS), and descriptive analysis values (p < 0.001). Instrumentation techniques, such as compression force and shear force, along with different cooking conditions, strongly impact BMORS shear force values (R2 = 86.80%), with significance levels ranging from 0.01 to 0.001. Deboning time also substantially impacts MORS shear force values (R = 64.03%). In contrast, the effects of deboning time, bird age, and cooking conditions on descriptive sensory evaluation are minimal when compared to woody breast fillets (age of birds: R2 = 26.53%; cooking conditions: R2 = 32.57%; deboning time: R2 = 10.06%). The overall effect of bird age on chicken breast meat quality shows significant differences for the evaluated parameters (Hedges' g [95% CI] = -0.72 [0.17, 1.26], I2 = 93%, p < 0.01). The sous vide cooking method significantly affects shear force energies and sensory descriptive evaluation for woody breast fillets (Hedges' g [95% CI] = 5.30 [-50.30, 83.40], I2 = 98%, p < 0.01). These findings, with their significant implications, provide valuable insights for optimizing processing conditions in the poultry industry to reduce woody breast occurrences and enhance meat quality, instilling confidence in the robustness of the research.

Assessing meat quality and textural properties of broiler chickens: the impact of voltage and frequency in reversible electrical water-bath stunning

The implementation of the head-only electrical stunning procedure in poultry processing has been aimed at enhancing eating, ethical, and religious quality. However, inconsistencies in voltage and frequency standardization, along with variations in previous research outcomes, have led to numerous cases of both under-stunned and over-stunned birds. Thus, this study aimed to comprehensively evaluate the effects of varying voltages and frequencies during electrical water bath stunning on carcass quality, meat attributes, and textural properties in broiler chickens. A cohort of 240 healthy female broilers (Cobb 500, 42-days-old, 2 kg ± 0.1 kg) was meticulously selected from a commercial farm. The birds underwent exposure to different stunning voltages (2.5, 10.5, 30, and 40 V) and frequencies (50 and 300 Hz). Subsequent analyses were conducted on meat samples to assess physicochemical properties, carcass quality, and textural attributes. The findings revealed a higher incidence of petechial hemorrhage (P < 0.05) in birds stunned at 10.5 V compared to other voltage. Notably, no broken bones were recorded in birds subjected to high voltages (30 and 40 V). Low frequency (50 Hz) significantly increased the occurrence of petechial hemorrhage and simultaneously resulted in pectoralis major muscle with decreased redness (a*). Birds subjected to the 10.5 V stunning treatment exhibited a lower cooking loss percentage. Significant interactions between voltage and ageing (V × A) were observed. Birds stunned at 30 V and aged for 7 d displayed highest drip loss compared to a one-day ageing period across different voltage levels. This interaction also impacted pH values, with birds subjected to 10.5 V showing significantly lower (P < 0.05) pH at d 7 of ageing. The meat hardness was influenced by the V × A interaction, wherein birds stunned at 10.5 V exhibited lower hardness after one day of ageing compared to other voltage levels. Red wing tips, lightness (L*), adhesiveness, and resilience were also significantly impacted (P < 0.05) by the interaction between frequency and voltage. A notable 3-way interaction was observed for gumminess and chewiness (F × V × A), where the 2-way interaction between frequency and voltage (F × V) affected both parameters differently at various ageing periods. Additionally, there was a significant interaction (P < 0.05) between frequency and voltage influencing shear strength and yellowness.

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.

Estimating In Vitro Protein Digestion and Protein Digestibility Corrected Amino Acid Score of Chicken Breasts Affected by White Striping and Wooden Breast Abnormalities

An understanding regarding impacts of growth-related myopathies, i.e., white striping (WS) and wooden breast (WB), on the quality of dietary protein from cooked chicken breast is still limited. This study aimed at comparing protein content and in vitro protein digestion and estimating the in vitro protein digestibility corrected amino acid score (PDCAAS) of cooked chicken meat exhibiting different abnormality levels (i.e., normal, WS, and WS + WB). The results show that the WS + WB samples exhibited lower protein content, greater cooking loss, and greater lipid oxidation than those of normal samples (p < 0.05). No differences in protein carbonyls or the myofibril fragmentation index were found (p ≥ 0.05). Cooked samples were hydrolyzed in vitro using digestive enzyme mixtures that subsequently mimicked the enzymatic reactions in oral, gastric, and intestinal routes. The WS + WB samples exhibited greater values of free NH2 and degree of hydrolysis than the others at all digestion phases (p < 0.05), suggesting a greater proteolytic susceptibility. The in vitro PDCAAS of the WS + WB samples was greater than that of the other samples for pre-school children, school children, and adults (p < 0.05). Overall, the findings suggest that the cooked chicken breast with the WS + WB condition might provide greater protein digestibility and availability than WS and normal chicken breasts.

Effect of light restriction on productive results and behavior of broiler chickens

The study aimed to evaluate the effect of light restriction (18L:6D vs. 14L:10D), genotype (A vs. B), and sex on performance, behavior, and meat quality, and the occurrence of wooden breast (WB) and white striping (WS) in broiler chickens. To this purpose 704 one-day-old chickens of 2 genotypes, half males and half females, were reared from hatching until slaughtering at 45 d of age in 32 collective pens (22 chickens per pen). Light restriction reduced growth rate and final live weight (LW), but improved feed conversion ratio (FCR) (P < 0.01) and reduced inactive behaviors of chickens (P < 0.001). Light restriction also reduced WS occurrence in breasts (89.5 to 64.6%; P < 0.001) and reduced meat shear force (2.64 to 2.20 kg/g; P < 0.05) and ether extract content (2.29 to 1.87%; P < 0.05). Regarding genotype, compared to genotype B, chickens of genotype A were heavier (3,242 g vs. 3,124 g; P < 0.01) with higher cold carcass weight and Pectoralis major muscle yield (12.9 vs. 12.0%; P < 0.001) and a higher FCR (1.63 vs. 1.61; P < 0.01). Finally, females had lower final LW (2,852 g vs. 3,513 g) and higher FCR (1.64 vs. 1.59) than males (P < 0.001), but a higher proportion of breast and P. major (P < 0.001), lower cooking losses (P < 0.001) and shear force (P < 0.01), and higher protein content (21.6 vs. 20.7%; P < 0.001). In conclusion, light restriction depressed growth, but was effective in decreasing WS occurrence and improved feed conversion. The decrease in inactive behaviors (sitting/laying) of light-restricted chickens can be positively considered in view of animal welfare.

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.

Oxidative stability of white striping chicken breasts: effect of cold storage and heat treatments

This study aimed to investigate the level of lipid and protein oxidation in poultry breasts with severe white striping (WS; striation thickness > 1 mm) and nonaffected meats (N; normal breast) during storage under refrigeration (1°C for 14 d) and freezing (-18°C for 90 d). WS presented higher lipid content, although no difference in protein content was detected, compared to normal broiler breast (N). Regarding oxidative damages, a reduction in malondialdehyde and carbonyl protein, hexanal, octanal and nonanal levels, alongside the interaction of these compounds with other compounds in raw, roasted, and reheated breasts was observed under refrigerated storage (14 d). Freezing storage promotes an increase in carbonyls proteins, hexanal, octanal and nonanal levels at 45 d of storage in poultry meats and subsequent decrease, indicating the evolution of oxidative reactions. Regardless of the type of storage, in general, breasts with WS myopathy have higher levels of lipid and protein oxidation.

Meat quality attributes of male and female broilers from 4 commercial strains processed for 2 market programs

In recent times, meat quality has become a key aspect of poultry production. In the current study, 2,400 sex separate broilers from 4 commercial strains were placed in 6 replications to evaluate various meat quality characteristics when grown to 2 market weights. Broilers were fed 1 of 2 diets with varying degrees of amino acid inclusion to evaluate meat quality of broiler raised on varying planes of nutrition. Birds were processed to meet 2 specified target weights (2.5 and 3.8 kg) representing small bird and big bird debone markets in the United States, respectively. Birds were processed using commercial methods, deboned at 3-h postmortem, and meat quality was assessed. Myopathies (woody breast, white striping, spaghetti meat, along with tenderloin quality), fillet dimensions, color, water-holding capacity (e.g., drip loss, cook loss), and Meullenet Owens Razor Shear was determined. Data were analyzed using the Mixed Model platform of JMP Pro 15.2 (SAS Institute, Cary, NC). Diet had no effect (P > 0.05) on the key quality responses; data were then pooled resulting in main effects of sex, strain, and target weight (noted as carcass size). On the day of processing, high yielding (HY) strains produced higher breast and tender yields (P < 0.05) when compared to standard yielding (SY) strains. In addition, and as expected, females exhibited higher breast and tender yields (P < 0.05) than males. However, males had significantly thicker (P < 0.05) and longer (P < 0.05) fillets, higher incidences (P < 0.05) of white striping, and higher (P < 0.05) cook loss when compared to females. Differences were also observed in tenderness as SY strain A produced the lowest shear values, whereas SY strain B produced the highest shear values across parameters (P < 0.05). SY strains in the small bird (SB) market performed better than SY strains in the big bird (BB) market as indicated by lower incidences of breast and tender myopathies white striping, woody breast, spaghetti meat, woody-like tender, and tender feathering and improved quality attributes (P < 0.05). Similar trends were observed (P < 0.05) in HY strains as SB carcasses produced a better overall product than BB. Differences in carcass size directly impacted quality (P < 0.05) as SB markets showed improvements in most parameters assessed, but broilers representing BB markets had greater breast yield. Although strain had minimal impacts on quality measures, carcass size, and sex had a greater impact on muscle myopathies, water-holding capacity, and shear properties.

Precision technologies for predictive diagnosis and study of the allometric growth of broiler chickens with breast myopathies

1. An experiment was carried out to validate techniques as predictive diagnostic tools for breast myopathies and to study the allometric growth of distinct parts of the body and meat quality of broilers.2. Infrared thermography was performed at 35 d of age. The surface temperatures of breasts of 300 birds were recorded, followed by ultrasound imaging.3. The birds were slaughtered and the cuts were made to weigh the body parts. Then, the breasts were evaluated as for the presence and severity of myopathies, from which nine treatments were established represented by the associated degrees of the myopathies white striping and wooden breast and breasts classified as normal.4. There was no difference in surface temperatures and echogenicity values between normal breasts and breasts affected by myopathies. At 35 d of age few fillets classified as normal were found.5. The breast showed late growth in relation to the body, regardless of characteristic lesions of myopathies. The most severe score of wooden breast affected meat quality variables.

Dietary inositol-stabilized arginine silicate numerically reduced woody breast severity in male Ross 708 broilers without altering growth

The woody breast (WB) myopathy is an unintended outcome of fast broiler chicken growth and high breast muscle yields. Myodegeneration and fibrosis in the living tissue are results of hypoxia and oxidative stress driven by lack of blood supply to muscle fibers. The study aim was to titrate a vasodilator ingredient, inositol-stabilized arginine silicate (ASI), as a feed additive to improve blood flow and ultimately, breast meat quality. A total of 1,260 male Ross 708 broilers were assigned to: 1) a control basal diet, or the control diet plus increasing ASI: 2) 0.025% ASI, 3) 0.05% ASI, 4) 0.10% ASI, or 5) 0.15% ASI. At d 14, 28, 42, and 49, growth performance was measured on all broilers and serum from 12 broilers/diet was analyzed for creatine kinase and myoglobin presence. On d 42 and 49, 12 broilers/diet were measured for breast width, then left breast fillets were excised, weighed, palpated for WB severity, and visually scored for degree of white striping (WS). At 1 d postmortem, 12 raw fillets/treatment underwent compression force analysis, and at 2d postmortem, the same fillets were analyzed for water-holding capacity. mRNA was isolated from 6 right breasts/diet at both d 42 and 49 for qPCR quantification of myogenic gene expression. Birds fed the lowest dose of 0.025% ASI had a 5-point/3.25% feed conversion ratio reduction compared to birds fed 0.10% ASI over wk 4 to 6 and reduced serum myoglobin at 6-wk of age compared to the control. Breasts from birds fed 0.025% ASI received 42% greater normal WB scores at d 42 compared to control fillets. At d 49, breasts from broilers fed 0.10 and 0.15% ASI received 33% normal WB scores. At d 49, 0.025% AS-fed broiler breasts showed no severe WS. Increased myogenin expression was observed in 0.05 and 0.10% ASI breast samples on d 42 and myoblast determination protein-1 expression was upregulated in breasts from birds fed 0.10% ASI on d 49 compared to the control. Therefore, a dietary inclusion of 0.025, 0.10, or 0.15% ASI was beneficial in reducing WB and WS severity and promoting muscle growth factor gene expression at age of harvest without diminishing bird growth or breast muscle yields.

Assessment of meat quality attributes of four commercial broiler strains processed at various market weights

As the demand for poultry meat continues to rise, industry production is constantly challenged with obtaining consumer needs. Integrators have answered this increasing demand by improving the growth rate of broilers allowing for increased production efficiently. The resulting broiler produces higher yields and a larger quantity of fresh poultry to satisfy consumer needs. However, this increase in efficiency has cost integrators as new quality issues continue to manifest through global production. Therefore, the objective of the current experiment was to evaluate the effect of genetic strain (standard and high yielding) and target weight on meat quality attributes such as pH, water holding capacity (WHC), and tenderness, alongside meat quality defects such as breast and tender myopathies. In the current study, 1,800 broilers from 4 commercial strains (2 high breast yielding (HY) and 2 standard yielding (SY) were raised sex separate to evaluate meat quality trends over time at 6 previously defined market weights. Birds were processed at weights ranging from 2,043 to 4,313 g in 454 g increments. HY strains produced higher breast and tender yields than those of SY strains (P < 0.05). There was an increase in breast and tender yield as target weight increased (P < 0.05) for both HY and SY strains. Differences were observed between strains for all fillet dimensions (P < 0.05); however, these measurements increased as target weight increased as expected. Woody breast (WB) had a higher severity (P < 0.05) in HY strains over SY strains, for both males and females. Differences were observed in white striping (WS; P < 0.05) for females in both strains, but no differences were observed in males. A main effect of target was noticed for both WB and WS (P < 0.05), expressing increased severity as target weight increased. Shear values were influenced more by target weight (P < 0.05), but inconsistent differences were observed between HY and SY groups. Meullenet-Owens Razor Shear (MORS) energy values increased slightly as target weights increased (P < 0.05) from 2,951 to 4,313 g in both males and females, but differences were minor and inconsistent with the smaller carcass weights. The MORS peak counts generally increased as target weight increased for both sexes. While strain had minimal effects on meat quality attributes, processing weight had a greater influence on quality, specifically muscle myopathies, WHC, and shear properties.

Breast muscle white striping and serum corticosterone reduced in broilers exposed to laser environmental enrichment

Genetic selection for breast yields and fewer days to market has inadvertent effects on broiler meat quality. Woody breast (WB) and white striping (WS) are pectoralis major myopathies prevalent in commercial broilers. Effects of voluntary exercise on these disorders, specifically, are unknown. A second-generation laser enrichment device shown to induce activity in Ross 308 and 708 birds was implemented using 1,360 Ross 708 broilers randomly assigned to laser enrichment or control for 49 d. Laser-enriched birds were exposed to 6-min laser periods 4 times daily. Seventy focal birds were gait and contact dermatitis scored weekly. Blood was collected wk 5 to 7 from 56 broilers for serum corticosterone, myoglobin, and troponin. Seventy broilers were sampled for breast muscle width, fillet dimensions, and WB and WS at wk 6 and 7. One and 2-day postmortem, fillet compression force and water-holding capacity were measured. Serum corticosterone was reduced by up to 21% in laser-enriched birds wk 5 to 7 (P < 0.01). Serum myoglobin was increased in laser-enriched broilers by 5% on wk 5 (P < 0.01) but increased in control birds wk 6 to 7 by up to 13% (P < 0.01). Serum troponin was reduced in laser-enriched broilers by 9% at wk 5 (P < 0.01). Laser exposure increased breast width and fillet weight at d 42 by 1.08 cm (P < 0.05) and 30 g (P < 0.05). At d 49, fillet height was increased 0.42 cm in laser-enriched birds (P < 0.05). Laser enrichment reduced severe WS incidence at d 42 by 24% (P < 0.05) and on d 49 by 15% (P < 0.10). Severe WB score was numerically reduced by 11% in laser enrichment on d 42 and 18% on d 49 (P > 0.05). Water-holding capacity was improved in laser-enriched breasts (P < 0.01) and expression of myostatin and insulin-like growth factor 2 were increased on d 49 (P ≤ 0.01. Laser enrichment reduced markers of stress and muscle damage while improving breast muscle quality and is therefore a potential effective enrichment for commercial broilers.

Integrated metabolomics and lipidomics evaluate the alterations of flavor precursors in chicken breast muscle with white striping symptom

White striping (WS) is the most common myopathy in the broiler chicken industry. To reveal flavor changes of WS meat objectively, flavor precursors of WS breast muscle were evaluated systematically with integrated metabolomics and lipidomics. The results showed that WS could be distinguished from normal controls by E-nose, and four volatile compounds (o-xylene, benzene, 1,3-dimethyl, 2-heptanone and 6-methyl and Acetic acid and ethyl ester) were detected as decreased compounds by gas chromatography-mass spectrometry. Lipidomic analysis showed that WS breast fillets featured increased neutral lipid (83.8%) and decreased phospholipid molecules (33.2%). Targeted metabolomic analysis indicated that 16 hydrophilic metabolites were altered. Thereinto, some water-soluble flavor precursors, such as adenosine monophosphate, GDP-fucose and L-arginine increased significantly, but fructose 1,6-bisphosphate and L-histidine significantly decreased in the WS group. These results provided a systematic evaluation of the flavor precursors profile in the WS meat of broiler chickens.

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

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

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-022-05608-9.

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.

Dietary vasodilator and vitamin C/L-arginine/choline blend improve broiler feed efficiency during finishing and reduce woody breast severity at 6 and 7 wks

Woody breast has become a considerable economic concern to the poultry industry. This myopathy presents rigid, pale breasts characterized by replacement of lean muscle protein with connective tissue, a result of hypoxia and oxidative stress in a metabolically starved muscle with inadequate circulation. Hence, the objectives were to supplement broiler diets with ingredients specifically aimed to improve circulation and oxidative status. About 1,344 male Ross 708 broilers were assigned to 1 of 4 diets: 1) a basal diet (control), 2) basal diet plus a blend of 0.2% supplemental L-arginine, 0.17% choline bitartrate, and 0.03% vitamin C (blend), 3) 0.1% vasodilator ingredient (vasodilator), or 4) 0.02% Astaxanthin ingredient (AsX). At d 14, 28, 42, and 49, performance outcomes were collected on all birds and serum from 16 broilers/diet (n = 64) was analyzed for creatine kinase and myoglobin. Once weekly beginning on d 28, a subset of 192 broilers were measured for breast width. On d 42 and 49, breast fillets from 16 broilers/diet (n = 64) were palpated for woody breast severity, weighed, and analyzed for compression force at 1-day postmortem and water-holding capacity at 2-day postmortem. mRNA was isolated from 15 breast fillets/timepoint for qPCR quantification of myogenic gene expression. Data were analyzed using Proc Mixed (SAS Version 9.4) with the fixed effect of diet. Feed conversion ratio was improved in the blend and vasodilator-fed birds d 42 to 49, each by over 2 points (P < 0.05). Breast width was increased in the control on d 42 compared to the vasodilator and AsX-fed broilers (P < 0.05). At d 42, there were 12% greater normal fillets in blend diet-fed birds and 13% more normal scores in vasodilator-fed birds at d 49 compared to the control. At d 49, myogenin expression was upregulated in the AsX diet compared to blend and control diets (P < 0.05), and muscle regulatory factor-4 expression was increased by 6.5% in the vasodilator diet compared to the blend and AsX diets (P < 0.05). Blend and vasodilator diets simultaneously improved feed efficiency in birds approaching market weight while reducing woody breast severity.

Textural and physical properties of breast fillets with myopathies (wooden breast, white striping, spaghetti meat) in Canadian fast-growing broiler chickens

The combined effects of different severities of Wooden Breast (WB), White Striping (WS), and Spaghetti Meat (SM) were examined in 300 chicken breast fillets from 10 flocks. Severity (0 = absent, 1 = mild, noticeable upon close inspection, 2 = severe), noticeably altered from normal breast fillet (NB). Results showed that any combination of myopathies and severity resulted in significantly elevated compression force, pH and peak counts measured by the shear force test. With the exception of mild WB + mild WS, all combinations resulted in significantly higher drip loss, cooking loss and lightness value. Overall, the quality of fillets was affected the least by WS, while negatively affected the most by SM. There were limited effects on fillet quality from mild WB but major deleterious effects from severe WB.

Use of image analysis to evaluate morphometric measurements of broiler breast fillets affected by the woody breast condition

The objective of this study was to investigate the relationships between morphometric measurements and woody breast (WB) severity in breast fillets using image processing as an objective detection method for WB. Breast fillets were collected and categorized as normal (NORM), mild (MILD), moderate (MOD), and severe (SEV). Compression force and energy increased as WB severity increased alongside a decrease in severity through fillet regions (P < 0.05). Length and caudal thickness were highest in SEV and MOD groups (P < 0.05), and cranial thickness increased as WB severity increased (P < 0.05). The aerial area was the smallest in NORM fillets, while the planar area increased from NORM to MOD (P < 0.05). Fillet curvatures were highest in SEV and MOD fillets (P < 0.05). All measured parameters expressed strong correlation to WB scores (P < 0.05) except width. The results from this study may provide a basis for further assessment of the potential incorporation of these measurements into vision grading systems that may allow processors to sort fillets by WB severity in commercial plants.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-022-05525-x.

Water properties and marinade uptake in broiler pectoralis major with the woody breast condition

To provide insight into the mechanisms by which the woody breast (WB) condition reduces marinade uptake, water properties of normal (NOR) and WB meat were investigated using TD-NMR. Broiler Pectoralis major was marinated with either water, 0.625% sodium tripolyphosphate, 5% NaCl, or 5% NaCl + 0.625% sodium tripolyphosphate (SP). Targeted final concentrations were 4% NaCl and 0.5% SP. WB reduced meat marinade uptake but did not affect relationships between marinade ingredients and water mobility. WB inhibited increases in extra-myofibrillar water mobility induced by marinade ingredients. Marination increased intra-myofibrillar water (Amp₂₁) regardless of marinade ingredients or muscle condition; however, WB resulted in reduced Amp₂₁. Additionally, NaCl- or phosphate-induced extra-myofibrillar water (Amp₂₂) gain in WB was greater than that in NOR. Our data suggest changes in both Amp₂₁ and Amp₂₂ are related to the difference in marinade uptake between NOR and WB meat marinated with NaCl-phosphate marinade.

Dominant changes in the breast muscle lipid profiles of broiler chickens with wooden breast syndrome revealed by lipidomics analyses

BACKGROUND

Chicken is the most consumed meat worldwide and the industry has been facing challenging myopathies. Wooden breast (WB), which is often accompanied by white striping (WS), is a serious myopathy adversely affecting meat quality of breast muscles. The underlying lipid metabolic mechanism of WB affected broilers is not fully understood.

RESULTS

A total of 150 chickens of a white-feathered, fast-growing pure line were raised and used for the selection of WB, WB + WS and control chickens. The lipids of the breast muscle, liver, and serum from different chickens were extracted and measured using ultra performance liquid chromatography (UPLC) plus Q-Exactive Orbitrap tandem mass spectrometry. In the breast, 560 lipid molecules were identified. Compared to controls, 225/225 of 560 lipid molecules (40.2%) were identified with differential abundance (DA), including 92/100 significantly increased neutral lipids and 107/98 decreased phospholipids in the WB/WB + WS groups, respectively. The content of monounsaturated fatty acids (MUFA) was significantly higher, and the polyunsaturated fatty acids (PUFA) and saturated fatty acids (SFA) were significantly lower in the affected breasts. In the liver, 434 lipid molecules were identified, and 39/61 DA lipid molecules (6.7%/14.1%) were detected in the WB and WB + WS groups, respectively. In the serum, a total of 529 lipid molecules were identified and 4/44 DA lipid molecules (0.8%/8.3%) were detected in WB and WB + WS group, respectively. Compared to controls, the content of MUFAs in the serum and breast of the WB + WS group were both significantly increased, and the content of SFAs in two tissues were both significantly decreased. Only five lipid molecules were consistently increased in both liver and serum in WB + WS group.

CONCLUSIONS

We have found for the first time that the dominant lipid profile alterations occurred in the affected breast muscle. The relative abundance of 40.2% of lipid molecules were changed and is characteristic of increased neutral lipids and decreased phospholipids in the affected breasts. Minor changes of lipid profiles in the liver and serum of the affected groups were founded. Comprehensive analysis of body lipid metabolism indicated that the abnormal lipid profile of WB breast may be independent of the liver metabolism.

Effect of combined maternal and post-hatch dietary 25-hydroxycholecalciferol supplementation on broiler chicken Pectoralis major muscle growth characteristics and satellite cell mitotic activity

Skeletal muscle growth is largely dependent on the proliferation and differentiation of muscle-specific stem cells known as satellite cells (SC). Previous work has shown that dietary inclusion of the vitamin D3 metabolite, 25-hydroxycholecalciferol (25OHD3), also called calcidiol, can promote skeletal muscle growth in post-hatch broiler chickens. Improving vitamin D status of broiler breeder hens by feeding 25OHD3 in addition to vitamin D3 has also been shown to positively impact progeny. Yet, whether combined pre- and post-hatch supplementation with 25OHD3 produces an additive or synergistic SC-mediated, skeletal muscle growth response remains unanswered. To evaluate the effect of combined maternal and post-hatch dietary 25OHD3 supplementation on the growth and SC mitotic activity of the Pectoralis major (PM) muscles in broiler chickens, a randomized complete block design experiment with the main effects of maternal diet (MDIET) and post-hatch diet (PDIET) arranged in a 2 × 2 factorial treatment structure was conducted. From 25 to 36 wk of age, broiler breeder hens were fed 1 of 2 MDIET formulated to provide 5,000 IU D3 (MCTL) or 2,240 IU of D3 + 2,760 IU of 25OHD3 per kg of feed (M25OHD3). Their male broiler chick offspring (n = 400) hatched from eggs collected from 35 to 36 wk of age were reared in raised floor pens. Broilers were fed 1 of 2 PDIET formulated to provide 5,000 IU of D3 per kg of feed (PCTL) or 2,240 IU of D3 + 2,760 IU of 25OHD3 per kg of feed (P25OHD3). Muscle was collected at days 4, 8, 15, 22, and 29 and stored until immunofluorescence analysis. Data were analyzed as a 2-way ANOVA with SAS GLIMMIX. Dietary 25OHD3 was effectively transferred from hen plasma to egg yolks (P = 0.002) and to broiler progeny plasma (days 4 to 22; P ≤ 0.044). Including 25OHD3 in either MDIET or PDIET altered PM hypertrophic growth prior to day 29 (P ≥ 0.001) and tended to reduce Wooden Breast severity (P ≤ 0.089). Mitotic SC populations were increased in PM of MCTL:P25OHD3 and M25OHD:PCTL-fed broilers at d 4 (P = 0.037). At d 8, the PM mitotic SC populations were increased 33% by P25OHD3 (P = 0.054). The results of this study reveal that combined maternal and post-hatch 25OHD3 supplementation does not produce additive or synergistic effects on SC-mediated broiler muscle growth. However, vitamin D status improvement through dietary 25OHD3 inclusion in either the maternal or post-hatch diet stimulated broiler breast muscle growth by increasing proliferating SC populations.

Factors Affecting Breast Myopathies in Broiler Chickens and Quality of Defective Meat: A Meta-Analysis

Fast-growing broiler chickens are subjected to breast myopathies such as white striping (WS), wooden breast (WB), and spaghetti meat (SM). Available studies about risk factors for myopathy occurrence often used flock data whereas a few reports evaluated chicken individual data. Thus, the present study aimed to elucidate the effect of growth and slaughter traits, besides sex and genotype on myopathy occurrence. Data were obtained from eight experimental trials, which used a total of 6,036 broiler chickens. Sex, genotype, daily weight gain, slaughter weight, and breast yield were evaluated as potential risk factors by logistic regression analyses. Then, the effects of myopathy and sex were evaluated on meat rheological traits (pH, colour, cooking losses and shear force). Based on a logistic regression, WS occurrence was associated with genotype, breast weight, and breast yield. Compared with chickens with intermediate breast weight and breast yield, higher odds of having WS were found in chickens with high breast weight (OR: 1.49) and yield (OR: 1.27), whereas lower odds were found in those with low breast weight (OR: 0.57) and yield (OR: 0.82). As for WB and SM, females had lower odds of having WB (OR: 0.55) and higher odds of showing SM (OR: 15.4) compared to males. In males, higher odds of having WB were found in chickens with a high daily weight gain (OR: 1.75) compared to those with an intermediate daily weight gain. In females, higher odds of having SM were associated to a high slaughter weight (OR: 2.10) while lower odds to a low slaughter weight (OR: 0.87). As for meat quality, only WB meat was clearly different for some technological and sensorial properties, which can play a major role also in meat processing. In conclusion, our analysis identified breast development as a potential risk factor for WS, while a high growth was the risk factor for WB and SM. A different probability of having WB or SM in females and male was found.

Improving the poor texture and technological properties of chicken wooden breast by enzymatic hydrolysis and low-frequency ultrasound

Abstract

Wooden breast (WB) is a recurrent myopathy in fast‐growing birds, which alters the appearance, functionality, and the texture of the breast muscle. The objectives of this study were (i) to evaluate the effect of a combined use of papain enzyme and ultrasound on the texture of WB chicken using response surface methodology and (ii) to assess the effect of marinating on the quality of WB chicken meat. Full factorial experimental design method was used to obtain the ideal conditions to soften the WB meat. The independent variables were the concentration of papain (0.1%–0.3%) and the time in ultrasonic bath (10–30 min); shear force (SF) was the dependent variable. The optimum results were obtained at a concentration of 0.2% papain and 20 min on ultrasound. Papain enzyme had a great influence on the texture of WB meat, reducing its hardness. However, the effect of the ultrasound time on the SF response was not observed. The marinated WB meat showed similar SF values and texture profile than those from normal (N) meat, with reduction in the parameters of protein and lipid oxidation. The use of papain without ultrasound bath proved to be an efficient means for improving the tenderness of WB breasts.

Practical Application

This study shows the efficiency of the application of two technological procedures (enzymatic treatment and ultrasound) to improve the texture profile and technological properties of chicken breasts affected by the wooden breast myopathy. The economic loss caused by the world‐wide occurrence of wooden breast is enormous, and the application of papain has been found to counteract the impaired properties of this abnormal chicken breasts. Since papain is already widely used in the food industry to tenderize meat, its application in improving the quality of WB meat is straightforward.

Influence of slaughter age on the occurrence and quality characteristics of white striping and wooden muscle abnormalities

The aim of this study was to assess the occurrence of white striping (WS), wooden breast (WB), and WS combined with WS/WB muscle abnormalities in broilers (Ross 500) at different slaughter ages (34, 41, and 48 d). In addition, the influence of these muscle abnormalities at different slaughter ages on quality characteristics (physical dimensions, pH, color index, and chemical composition) was studied. Overall occurrence of muscle abnormalities was 45%, 92%, and 100% at slaughter ages of 34, 41, and 48 d, respectively. It was found that about 39% from the occurrence of muscle abnormalities was not similar in the same bird (left and right fillets). Breast fillets affected by muscle abnormalities had significantly (p<0.05) higher weight than normal fillets. At slaughter age of 34 d, normal fillets had significantly higher L* (67.37 vs. 61.73 and 63.05, p<0.05), lower a* (3.25 vs. 4.87 and 5.18, p<0.05) and b* (4.02 vs. 5.20 and 5.99, p<0.05) than WS and WS combined with WB fillets; respectively. The changes in chemical composition due to muscle abnormalities were more significant at high slaughter age than at low slaughter age. In conclusion, the occurrence of muscle abnormalities was strongly influenced by slaughter age. Moreover, breast fillets affected by muscle abnormalities had different quality characteristics (proximate composition, color traits, and dimensions) in comparison to normal fillets.

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

The aim of this study was to evaluate possible changes in the quality of chicken breast meat containing white stripes during freezing for 12 mo. Samples of Pectoralis major muscle from male Cobb 500 broilers containing white stripes in moderate and severe degrees were used, as well as samples from a control group (normal - absence of myopathies). Part of the samples (n = 60; n = 20 for each severity degree) were analyzed on the day of collection (beginning) and the rest (n = 240) was frozen (-20°C) for up to 12 mo. At the end of each proposed freezing period (3, 6, 9, and 12 mo), color, pH, water holding capacity, cooking loss, tenderness, lipid oxidation, chemical composition, cholesterol and collagen concentrations, myofibrillary fragmentation, and sarcomere length were analyzed. Microbiological analysis of samples was performed at the beginning and after 12 mo of freezing. Myopathy linked to freezing showed results of increased meat tenderness, with reduction of crude protein and mineral matter and increase of moisture, fat, and cholesterol, without affecting the meat's collagen percentages. However, these variations with the onset of myopathy do not compromise the consumption of broiled chicken breast meat, kept frozen for up to 12 mo.

Shelf-Life Evaluation of Ingredient Combinations and Technologies for Use in Pet Food Formulations

Simple Summary

Creation of new meat-based pet food and pet treats continues to grow at a steady annual rate within the pet food industry. Poultry co-products are often overlooked due to their poor quality and low customer acceptance. However, poultry co-products pose great potential and added value to the pet food industry. Two of the most common poultry co-products (wooden breast and carcass frames) often directed towards pet food were used in a fresh pet food formulation. Due to variations in meat quality because of the wooden breast and carcass frames, a hydrocolloid was utilized to improve fresh pet food characteristics. A hydrocolloid is a type of protein that when added to meat products aids with binding and stabilization of the pet food. For the current study, the combination of sodium alginate and encapsulated calcium lactate pentahydrate (ALGIN) was used. Due to the perceived poor quality of wooden breast and carcass frames, it is plausible that the addition of hydrocolloids can combat the undesirable characteristics. Results from the current study suggest that the impact of ALGIN in poultry co-product pet food combinations does not severely alter shelf-life characteristics of a fresh pet food. However, the inclusion of varying amounts of wooden breast and ground carcass frame can impart a greater impact on shelf-life characteristics in fresh pet food by altering surface color and lipid oxidation.

Abstract

Poultry co-product chicken frames (CF) and wooden breast (WB) along with ingredient technology use may bring enhanced value to the pet food industry. Therefore, the current study focused on evaluating CF and WB combinations along with sodium alginate and encapsulated calcium lactate pentahydrate (ALGIN) inclusion within a fresh pet food formulation under simulated shelf-life conditions. Fresh chicken frames (CF) and boneless-skinless wooden breast (WB) were ground and allocated randomly to one of ten treatment combinations with either 0.5 or 1.0% added ALGIN. Ground treatments were placed into a form and fill vacuum package and stored using a reach-in refrigerated case for 21 days. Packages were evaluated for instrumental surface color, lipid oxidation, water activity, and pH on days 1, 3, 7, 14 and 21 of the display. Packages of pet food were lighter, less red, and more yellow (p < 0.05) with increasing percentages of CF regardless of ALGIN inclusion, whereas pH was greater (p < 0.05) and lipid oxidation was less (p < 0.05) with increasing percentage of WB. Water activity increased (p < 0.05) when WB and ALGIN inclusion increased. The current results suggest that the use of ALGIN in a poultry co-product pet food formulation can improve shelf-life characteristics such as surface color and lipid oxidation in fresh pet food.

Characteristics of Broiler Chicken Breast Myopathies (Spaghetti Meat, Woody Breast, White Striping) in Ontario, Canada

Spaghetti meat (SM), woody breast (WB), and white striping (WS) are myopathies affecting breast muscle of broiler chickens, and are characterized by a loss of myofibers and an increase in fibrous tissue. The conditions develop in intensive broiler chicken production systems, and cause poor meat process-ability and negative customer perception leading to monetary losses. The objectives of the present study were to describe the physical and histological characteristics of breast myopathies from commercial broiler chicken flocks in Ontario, Canada, and to assess the associations between the severity of myopathies with the physical and histological characteristics of the affected breast muscle fillets. Chicken breast fillets (n = 179) were collected over 3 visits from a processing plant and scored macroscopically to assess the severity of myopathies, following an established scoring scheme. For each fillet, the surface area, length, width, thickness, weight, and hardness (compression force) were measured. A subset of 60 fillets was evaluated microscopically. Multinomial logistic regression models were built to evaluate associations between physical parameters and macroscopic scores. The odds of SM co-occurring with severe WB (SM1WB2) were significantly associated with increased fillet thickness (OR = 1.59, 95% CI 1.31–1.94) and weight (OR = 1.06, 95% CI 1.03–1.09). Histologically, myopathies had overlapping lesions consisting of polyphasic myodegeneration, perivascular inflammatory cuffing and accumulation of fibrous tissue and fat. The pairwise correlation between macroscopic and microscopic scores was moderate (rho 0.45, P < 0.001). This is the first study to characterize breast myopathies in Canadian broiler flocks. Results show that the morphologic and microscopic changes of fillets from this cohort are similar to data from other countries, and provide database to benchmark these parameters in future studies. Our standardized categorization can be applied to broiler breast fillets in other regions of the world.

Laser Environmental Enrichment and Spirulina Algae Improve Broiler Growth Performance and Alter Myogenic Gene Expression and pectoralis major Dimensions

Sustainability in poultry production is evident in efforts to reduce inputs and a focus on bird welfare and livability. Dietary protein alternatives to traditional sources such as soybean meal aim to meet or exceed efficiency benchmarks and be cost-effective. Environmental enrichment encouraging activity may reduce the occurrence of the predominant breast muscle myopathy, woody breast (WB); interventions to minimize muscle damage and economic loss have yet to be established. The study objectives were to maintain or improve broiler performance and breast quality through environmental enrichment and partially replacing dietary soybean meal with Spirulina. Twelve hundred Ross 708 broilers were randomly assigned to enrichment (LASER; laser enrichment, or CON; no laser enrichment) and diet (algae; 2.5% Spirulina algae, or control) in a 2 × 2 factorial design for 49 days. The same 70 randomly selected birds were examined for contact dermatitis wk 1–6. Breast width was measured weekly on 200 growing broilers beginning on d22. On d42 and 49 slaughter, WB score was assigned using a tactile 0–3 scale and the right breast filet was weighed (n = 200). RNA isolated from 30 breast muscle samples each at d42 and 49 was analyzed using real-time qPCR. Laser enrichment increased body weight at all timepoints (d49: 0.148 kg, P &lt; 0.001). Feed conversion ratio was improved in LASER-enriched birds by 3 points in the starter period (P = 0.003). Breast width was increased at all timepoints in LASER-enriched birds compared to CON (d49: 0.47 cm, P &lt; 0.001). Algae inclusion increased body weight at d28 (0.059 kg, P = 0.005). At d42, 12% more LASER-enriched WB scores were 0 (normal) compared to CON, and at d49, 15% more enriched scores were 0. At d42, 5% more algae-fed broiler scores were 0 compared to control. LASER-enriched broiler breast tissue showed upregulated expression of myogenin, muscle regulatory factor 4, insulin-like growth factor 1, and myostatin compared to CON (P &lt; 0.01). Both laser enrichment and algae inclusion improved broiler performance without negatively impacting environmental or physiological outcomes. LASER enrichment decreased severity of WB score and positively shifted myogenic gene expression in the breast muscle at slaughter.

Bacitracin, Bacillus subtilis, and Eimeria spp. challenge exacerbates woody breast incidence and severity in broilers

Woody breast (WB) is a myopathy that is related to the increasing growth rate. Understanding the influence of management factors on WB formation and development is important to minimize WB. This study was conducted to define how management factors affect broiler growth performance, processing yield, and WB incidence. Ross × Ross 708 chicks were randomly assigned to a 3 (diet) × 2 (cocci challenge) × 2 (sex) factorial arrangement of treatments. The 3 dietary treatments were: control diet (corn-soybean meal basal diet), antibiotic diet (basal diet + 6.075 mg bacitracin /kg feed), and probiotic diet (basal diet + 2.2 × 10⁸ CFU Bacillus subtilis PB6/kg feed). Birds in cocci challenge treatments received 20 × live cocci vaccine on d 14. The hardness of breast muscle in live birds was determined by palpation and grouped into Normal, Slight, Moderate, and Severe categories. Across diet and sex treatments, the cocci challenge resulted in decreases in body weight (BW) on d 29 and 35 (P < 0.0001 and = 0.032) in body weight gain (BWG) from d 14 to 29 (P < 0.0001). However, an increase of BW occurred on d 35 (P = 0.032) and an increase of BWG occurred from d 29 to 35 and d 35 to 43 (P = 0.0001 and 0.002), and the cocci challenge increased WB incidence on d 29 (P = 0.043) and d 43 (P = 0.013). Across challenge and sex treatments, birds fed the antibiotic diet exhibited a higher growth rate (GR) than those fed the control or probiotic diet from d 0 to 14 (P = 0.016), but not after d 14 (P > 0.05). Across sex, the antibiotic and probiotic diets increased WB incidence for those birds that did not receive a cocci challenge on d 43 (P = 0.040). Across challenge and diet treatments, males exhibited a higher BW, BWG, and GR throughout all growth phases, and males showed a higher WB incidence on d 29, 35, and 43 (P = 0.002, P < 0.0001, and P = 0.0002, respectively). In conclusion, bacitracin and Eimeria spp. increased WB incidence, BW, and GR. However, Bacillus subtilis increased WB incidence in male broilers without affecting BW and GR.

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.

Effects of Guanidinoacetic Acid Supplementation on Productive Performance, Pectoral Myopathies, and Meat Quality of Broiler Chickens

Simple Summary

Genetic selection for rapid growth is accompanied with challenges in meat quality such as pectoral myopathies, which lead to downgrading of breast muscle and economic losses for slaughterhouses. This experiment evaluated the effects of guanidinoacetic acid supplementation at rate of 0%, 0.06%, and 0.12% on the productive performance and meat quality of broiler chickens. Result showed that wooden breast was manifested by low creatine and high ultimate pH, and more associated with heavy birds. Guanidinoacetic acid supplementation increased muscle glycogen, reduced the ultimate pH, and reduced the incidence of wooden breast severity. In conclusion, guanidinoacetic acid can be used in broiler diets to improve the productive performance without exacerbating pectoral myopathy or affecting meat quality.

Abstract

The effects of guanidinoacteic acid (GAA) supplementation on productive performance, pectoral myopathies, and meat quality of broilers were studied. Treatments consisted of corn/soybean-based diets with a GAA supplement (0%, 0.06%, and 0.12%). A total of 546 one-day-old Ross-308 males were randomly allocated to 42 floor pens with 14 replicates (13 birds/pens) for each treatment. The results showed that GAA at doses of 0.06% and 0.12% improved feed conversion, increased the percentage of normal breast, and decreased the severity of wooden breast. Breast muscle myopathy severity was positively correlated with heavy birds and negatively correlated with breast muscle creatine and glycogen. Breast muscle creatine and glycogen correlated positively with normal, less severe pectoral myopathies and meat quality. In conclusion, GAA supplementation improved broiler performance without exacerbating pectoral myopathy or affecting meat quality.

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.

In pursuit of a better broiler: carcass traits and muscle myopathies in conventional and slower-growing strains of broiler chickens

Selection for accelerated growth rate and high breast yield in broiler chickens have been associated with an increase in myopathies, including wooden breast (WB) and white striping (WS). To investigate effects of growth rate on carcass traits and incidence of myopathies, 14 strains were evaluated, encompassing 2 conventional (CONV; strains B and C: ADG0-48 > 60 g/d) and 12 slower-growing (SL) strains. The latter were categorized based on growth rate: FAST (strains F, G, I and M; ADG0-62=53-55 g/d), MOD (strains E, H, O and S; ADG0-62=50-51 g/d), and SLOW (strains D, J, K and N; ADG0-62<50 g/d). In a randomized incomplete block design, 7,216 mixed-sex birds were equally allocated into 164 pens (44 birds/pen; 30 kg/m2), with each strain represented in 8 to 12 pens over 2 to 3 production cycles. From each pen, 4 males and 4 females were processed at 2 Target Weights (TWs) based on their expected time to reach 2.1 kg BW (TW 1: 34 d for CONV; 48 d for SL strains) and 3.2 kg BW (TW 2: 48 d for CONV; 62 d for SL strains). Weights and yields for the carcass, breast, drumsticks, thighs, and wings were obtained; breast fillets were assessed to determine the presence and severity of WB and WS. At both TWs, breast yield was higher as growth rate increased (P < 0.001), with CONV having greater breast yield than other categories. Strain F had the greatest breast yield at both TWs (P < 0.001) within the FAST category. At TW 2, CONV had the greatest incidence of WB and WS (P < 0.001). However, within FAST, strain F had the greatest incidence of myopathies (P < 0.001) at both TWs, exhibiting values as high or as greater than CONV birds. The incidence of WB and WS in strains with differing growth rates but high breast meat yield suggests that the latter may play a major role in the occurrence of these myopathies.

Accumulation of lipofuscin in broiler chicken with wooden breast

Lipofuscin is one of the indicators of oxidative stress. To elucidate the role of oxidative stress in the development of wooden breast, this study investigates lipofuscin accumulation in various parts of wooden breast muscles. Sampling was performed using 46-day-old broiler chickens housed at a commercial Japanese poultry slaughterhouse. Fourteen wooden breast fillets and 13 normal breast fillets were collected in the deboning line. The samples used to measure shear force, 2-thiobarbituric acid reactive substance (TBARS), and for histological analysis were taken from the six portions of breast muscle fillets. In muscles affected by wooden breast, vacuolated muscle fibers were observed, and connective tissues appearing like perimysium were expanded with fibrosis. TBARS value and accumulation of lipofuscin were significantly higher in the wooden breast than in the normal breasts. A lot of lipofuscin granules were localized in the cytoplasm of collapsed muscle fibers of the wooden breast. The cranial portion of the wooden breast showed the highest shear force. The cranial position had a large amount of connective tissue and lipofuscin granules. The results of the present study strongly suggest that high oxidative stress, especially with a significant accumulation of lipofuscin, is associated with the development of wooden breasts.

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.