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Woody breast (WB) is one of muscle myopathy found in chicken breast, characterized with enlarged size and extremely stiff texture. The WB condition is one of the most prevalent quality issues in the modern poultry industry. WB has been shown to be heritable, but no effective detection method of WB severity in live birds exists for the selection purpose. The objective of this study was to determine potential of a non-invasive, portable digital palpation device as WB detection method that can be used for the selection to estimate the heritability of WB. The physical and functional properties of WB was also investigated in comparison with normal breast (NB). Two hundred ten breast muscles were obtained from a local processing plant one day after harvest and sorted based on WB scoring (1 for NB and 2 and 3 for WB). The samples were subjected to physical and physicochemical analyses, determining biomechanical properties (muscle tone, stiffness, elasticity, relaxation, and creep), pH, color, cooking yield, and texture (firmness and compression energy were used for raw meat and shear force and energy for cooked meat). The least squares means of the following variables were significantly different between WB and NB (p < 0.01): stiffness (603.4 vs 565.8; N/m), and elasticity (1.40 vs 1.55). However, relaxation and creep were not significantly different (p > 0.05). These results collectively showed that biomechanical properties of WB differ from NB. The degree of muscle stiffness in WB can be considered as a trait to be selected. The WB score showed strong negative correlations with cooking yield (−0.77) and cooked L*(−0.74), which means that as the breast becomes harder, the cooking yield decreases, and the color becomes darker after cooking. The WB score showed high correlations with physical and functional characteristics and exhibited strong correlations with the biomechanical properties measured by the device. Therefore, the results indicated that the digital palpation device has potential to detect the WB severity (degree of stiffness) of breast muscle.

Unique metabolites contribute to the performance of meat flavor and potential function. In this study, UHPLC-Q Exactive HF-X-based metabolomics and multivariate analysis were applied to explore the characteristic metabolites in the breast meat of Beijing-You chicken (BYC) aged 150, 300, and 450 days (D150, D300, and D450). Based on the criteria of variable importance in the projection (VIP) > 1 and p < 0.05, a total of 154 and 97 differential metabolites (DMs) were screened out compared with D450 (D450 vs. D150, D450 vs. D300), respectively. In general, the relative content of carnosine, L-L-homoglutathione, demethyloleuropein, neohesperidin dihydrochalcone, 7-chloro-2-(3,4-dimethoxyphenyl)-3,5-dihydroxy-6,8-dimethoxy-4H-chromen-4-one, glycerophospholipids, exhibited the highest abundance at D450, while balenine, anserine, L-beta-aspartyl-L-leucine, glutathione, oxidized glutathione, stearoylcarnitine, ganoderic acid alpha, oleuroside, Lysoglycerophospholipid species (LGP) presented a downward trend with age. These 210 DMs were involved in 10 significantly enriched pathways related to the synthesis and metabolism of amino acids, peptides, and glycerophospholipid, such as glutathione metabolism, histidine metabolism, glycerophospholipid metabolism, arginine biosynthesis, tyrosine metabolism, and lysine degradation. In conclusion, this work could not only facilitate a better understanding of the differences of chicken flavor and benefit properties with age, but also provide potential valuable bioactive compounds for further research. [ABSTRACT FROM AUTHOR]

Using in ovo injection method, specific nutrients and antioxidants can be provided in precise doses at certain times for maximum absorption by the embryo. The objective of this study was to examine the effect of in ovo injection of flaxseed oil on the quality and antioxidant properties as well as fatty acid profile of breast meat of day-old broilers. 20 one-day-old fertilized eggs were randomly divided into two groups of 10; one control and one FSO (flaxseed oil) which received 100 μL of flaxseed oil by injection into the allantoic sac. The amounts of fat, vitamin E, total phenol, carotenoid, TBARS (thiobarbituric acid reactive substances) value, color, texture and fatty acid profile of the chicken breast meat were measured. In ovo injection of flaxseed oil significantly increased the fat content. The mean amounts of vitamin E in control and FSO were 0.54 and 0.71 mg/100g, respectively (P

Using in ovo injection method, specific nutrients and antioxidants can be provided in precise doses at certain times for maximum absorption by the embryo. The objective of this study was to examine the effect of in ovo injection of flaxseed oil on the quality and antioxidant properties as well as fatty acid profile of breast meat of day-old broilers. 20 one-day-old fertilized eggs were randomly divided into two groups of 10; one control and one FSO (flaxseed oil) which received 100 μL of flaxseed oil by injection into the allantoic sac. The amounts of fat, vitamin E, total phenol, carotenoid, TBARS (thiobarbituric acid reactive substances) value, color, texture and fatty acid profile of the chicken breast meat were measured. In ovo injection of flaxseed oil significantly increased the fat content. The mean amounts of vitamin E in control and FSO were 0.54 and 0.71 mg/100g, respectively (P<0.05). Carotenoid content, redness and yellowness of the broilers breast meat in FSO increased in comparison to control, while TBARS value and lightness index decreased insignificantly. FSO showed lower saturated fatty acids and higher unsaturated, monounsaturated, polyunsaturated, unsaturated/saturated and n-3 fatty acids, but these differences were not significant. Based on the results of this study, in ovo injection of flaxseed oil improved oxidative stability of day-old broiler breast meat through increasing vitamin E content. [ABSTRACT FROM AUTHOR]

The effects of dietary supplementation with Rumex nervosus leaves (RNL) on fatty acid (FAs) indices, organoleptic evaluation, performance index, and feed efficiency were investigated. This study consists of five treatments. Broilers in treatments 1–4 received basal feed plus RNL at doses of 0, 1, 3, and 5 g/kg, while broilers in treatment 5 received basal feed plus the antibiotic Colimex. On day 34, FAs profile and organoleptic assessment were evaluated, and performance index and feed efficiency were determined for the entire experimental period. Results showed that FAs profile of the breast meat was affected by treatments with varying degrees (p˂0.05). The 1 g RNL resulted in the highest eicosapentaenoic acid + docosahexaenoic acid, which resulted in the highest meat lipid quality, the highest elongation index, improved organoleptic characteristics, and tended to improve performance index, feed efficiency, and nutritional index. The 5 g RNL treatment reduced total saturated fatty acids (ƩSFAs), omega-6/omega-3 ratio, especially linoleic acid/α-linolenic acid ratio, alanine aminotransferase, and increased total omega-3 fatty acids, unsaturation index, and Δ9-desaturase. In conclusion, RNL can be introduced to broiler diets, especially at an incorporation rate of 1 g, and it promotes broiler health and performance because it contains phytoconstituents that can alter the content and indices of FAs meat and improve storability and sensory quality.

The effects of dietary supplementation with Rumex nervosus leaves (RNL) on fatty acid (FAs) indices, organoleptic evaluation, performance index, and feed efficiency were investigated. This study consists of five treatments. Broilers in treatments 1–4 received basal feed plus RNL at doses of 0, 1, 3, and 5 g/kg, while broilers in treatment 5 received basal feed plus the antibiotic Colimex. On day 34, FAs profile and organoleptic assessment were evaluated, and performance index and feed efficiency were determined for the entire experimental period. Results showed that FAs profile of the breast meat was affected by treatments with varying degrees (p˂0.05). The 1 g RNL resulted in the highest eicosapentaenoic acid + docosahexaenoic acid, which resulted in the highest meat lipid quality, the highest elongation index, improved organoleptic characteristics, and tended to improve performance index, feed efficiency, and nutritional index. The 5 g RNL treatment reduced total saturated fatty acids (ƩSFAs), omega-6/omega-3 ratio, especially linoleic acid/α-linolenic acid ratio, alanine aminotransferase, and increased total omega-3 fatty acids, unsaturation index, and Δ9-desaturase. In conclusion, RNL can be introduced to broiler diets, especially at an incorporation rate of 1 g, and it promotes broiler health and performance because it contains phytoconstituents that can alter the content and indices of FAs meat and improve storability and sensory quality. Oxidative chemicals increase lipid peroxidation and decrease sensory quality of broiler meat. As antioxidants, natural RNL inhibit oxidative degradation and prevent lipid peroxidation. RNL contains phytoconstituents that increase the fatty acid content and oxidative stability of meat. Fat deposition and associated markers in breast meat differed between low and high RNL levels. RNL improved nutritional index, sensory quality, performance index, and feed efficiency. [ABSTRACT FROM AUTHOR]

Unique metabolites contribute to the performance of meat flavor and potential function. In this study, UHPLC-Q Exactive HF-X-based metabolomics and multivariate analysis were applied to explore the characteristic metabolites in the breast meat of Beijing-You chicken (BYC) aged 150, 300, and 450 days (D150, D300, and D450). Based on the criteria of variable importance in the projection (VIP) > 1 and p < 0.05, a total of 154 and 97 differential metabolites (DMs) were screened out compared with D450 (D450 vs. D150, D450 vs. D300), respectively. In general, the relative content of carnosine, L-L-homoglutathione, demethyloleuropein, neohesperidin dihydrochalcone, 7-chloro-2-(3,4-dimethoxyphenyl)-3,5-dihydroxy-6,8-dimethoxy-4H-chromen-4-one, glycerophospholipids, exhibited the highest abundance at D450, while balenine, anserine, L-beta-aspartyl-L-leucine, glutathione, oxidized glutathione, stearoylcarnitine, ganoderic acid alpha, oleuroside, Lysoglycerophospholipid species (LGP) presented a downward trend with age. These 210 DMs were involved in 10 significantly enriched pathways related to the synthesis and metabolism of amino acids, peptides, and glycerophospholipid, such as glutathione metabolism, histidine metabolism, glycerophospholipid metabolism, arginine biosynthesis, tyrosine metabolism, and lysine degradation. In conclusion, this work could not only facilitate a better understanding of the differences of chicken flavor and benefit properties with age, but also provide potential valuable bioactive compounds for further research.

ABSTRACT: Poultry meat has a high polyunsaturated fatty acids content, making it vulnerable to oxidative stress. Mitophagy participates in the regulation of oxidative stress and the nucleotide-binding and oligomerization domain (NOD)-like receptor family as well as pyrin domain-containing protein 3 (NLRP3) inflammasome activation. Lactiplantibacillus plantarum P8 (P8) is a probiotic strain with an antioxidant capacity. In the present study, we investigated the effects of P8 on oxidative stress, mitochondrial function, mitophagy, and NLRP3 inflammasome in the breast meat of oxidatively stressed broilers. Four hundred 1-day-old male broilers were assigned to a 2 × 2 factorial design with 2 P8 levels (0 or 1 × 108 cfu/g), either with or without dexamethasone (DEX) injection, for a 21-day experimental period. DEX was injected intraperitoneally once daily from d 16 to 21. The breast meat was collected on d 21. The results showed that P8 supplementation decreased malondialdehyde (MDA) levels, increased superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), and activated the Keap1-Nrf2 pathway in DEX-injected broilers. Moreover, P8 supplementation downregulated mitochondrial DNA (mtDNA) copy number and increased the expressions of peroxisome proliferator-activated receptor gamma coactivator 1α (PGC-1α), silent information regulator 1 (SIRT1), mitochondrial fusion protein 1 (Mfn1), and optic atrophy protein 1 (OPA1) in DEX-treated broilers. In addition, the decreased mitophagy level in DEX-treated broilers was elevated with P8 supplementation, as reflected by the increased gene expression of autophagy-related gene 5 (ATG5), Bcl-2-interacting protein (Becline-1), Parkin, PTEN-induced kinase 1 (PINK1), light chain 3 II (LC3II)/LC31, and the protein expression of Parkin as well as decreased p62 expression. In addition, P8 supplementation inhibited NLRP3 inflammasome activation by decreasing the transcription of NLRP3, IL-18, cysteinyl aspartate-specific proteinase-1 (Caspase-1), and the expression of NLRP3 and IL-18 in DEX-treated broilers. In conclusion, dietary P8 supplementation alleviates oxidative stress, improves mitophagy, and inhibits NLRP3 inflammasome activation in the breast meat of oxidatively stressed broilers.

Simple Summary: Age plays a critical role in meat quality and flavor formation. A clear understanding of flavor changes during development is helpful to regulate meat quality as well as flavor in production. Various compounds and metabolites are the sources of flavor precursors, which contribute most to flavor development. Beijing-You chicken, famous for its special appearance and excellent flavor, is an excellent model to study the changes in meat quality and flavor against age. Therefore, the compounds, metabolites, and meat quality in Beijing-You chicken breast meat at the ages of 90, 120, and 150 days were characterized to trace their changes against age. It was found that the meat quality and metabolites at 90 days of age were significantly different from those at the ages of 120 and 150 days, revealing that attention should be focused on the period of 90 to 120 days to study the flavor formation mechanism in Beijing-You chicken breast meat. This study provides an initial insight into the changes in compounds, metabolites, and meat quality in chicken meat around market ages. The physical properties, free amino acids, and metabolites of Beijing-You chicken (BYC) breast meat aged 90, 120, and 150 days were analyzed to investigate the flavor changes with age. The shear force and intramuscular fat increased from 90 to 120 days significantly. The contents of total free amino acids and essential amino acids decreased from 90 to 120 days significantly. No significant differences were detected between 120 and 150 days. The contents of sweet amino acids, bitter amino acids, and umami amino acids showed no significant differences between different ages. In addition, GC-MS and LC-MS were integrated for metabolite detection in breast meat. A total of 128, 142, and 88 differential metabolites were identified in the comparison groups of 120 d vs. 90 d, 150 d vs. 90 d, and 150 d vs. 120 d. Amino acids and lipids were the main differential metabolites. The pathway analysis showed that arginine biosynthesis, histidine metabolism, purine metabolism, and cysteine and methionine metabolism were the main pathways involved in flavor formation during BYC development. It was also found that the metabolites associated with flavor, such as methionine, cysteine, glucose, anserine, arachidonic acid, and glycerol 1-phosphate, were significantly affected by age. [ABSTRACT FROM AUTHOR]

The present study examined the effects of dietary supplementation with extracts of pomegranate (Punica granatum) and onion (Allium cepa), either encapsulated in cyclodextrin (POMALCD group) or in an aqueous (POMALAQ group) form, on breast meat, thigh meat, and liver composition, oxidative stability, cellular signaling pathways, and the gene expression of certain hepatic genes. The results showed that breast and thigh meat contained significantly (p < 0.05) higher moisture content in the group with the aqueous extract, compared to the control and POMALCD groups. Moreover, the protein content was significantly (p < 0.05) higher in the thigh and liver samples of the treated groups in comparison to the control. The iron-induced challenge deteriorated (p < 0.001) the lipid and protein oxidative status of the control group, whereas both supplemented groups showed considerable tolerance in all tissues. The supplementation of pomegranate and onion extracts mitigated or maintained heat shock protein (HSP) levels and elevated (p < 0.05) the Bcl-2/Bad ratio in thigh and breast meat, whereas mitogen-activated protein kinase (MAPK) activation was modulated at a lower rate. After normalization to β-actin expression, quantitative real-time PCR analysis revealed a significant (p < 0.05) induction in the expression of MTR and MSRB1 genes in the liver of the supplemented groups. No differences were observed for the TAT, SMS, and BHMT genes. In conclusion, dietary mixtures of herbal extracts with pomegranate and onion improved protein and lipid oxidative stability in meat, enhanced the hepatic energy status, and exerted ameliorative effects on stress-related proteins. The encapsulated extract of pomegranate and onion, using cyclodextrin as a carrier, appeared to reduce lipid oxidation to a greater extent than the aqueous extract. In contrast, the aqueous extract exhibited higher total antioxidant capacity (TAC) values and provided better protection against protein carbonyl formation. [ABSTRACT FROM AUTHOR]

The present study aimed to determine the incidence and coincidence of white striping (WS), woody breast (WB) and spaghetti meat (SM) in raw chicken breast meat (n = 300) collected 3-3.5 h post mortem from commercial broiler flocks (Ross 708 males, 56 days of age). The fillets were scored for the occurrence and severity of WS, WB and SM using visual and tactile methods, and the relationship between myopathies and breast weight was evaluated. A total of 88% of samples (out of 300) had either one or a combination of three myopathies, leaving only 12% without any myopathies. Approximately 29% of the fillets had only one myopathy present, with 59% of the samples demonstrating the cooccurrence of breast myopathies. In the present study, 47.7% of WB samples also exhibited WS, while the cooccurrence of WB and SM was exhibited in 14.7%. Based on binomial logistic regression, an increase in WB scores decreases the odds that the fillet may be affected by SM myopathy. No association was found between SM and fillet weight. Multinomial logistic regression showed that the weight of breast fillets was positively associated with WB1 (P = 0.011), WB2 (P < 0.001), and WB3 (P < 0.001). Furthermore, positive associations were found between WS1 and WB3 (P = 0.004) as well as between WS2 and WB3 (P < 0.001). The percentage distribution changes of each WB and WS myopathy score were used in relation to the 10 weight groups. The percentages of WB3 increased and WB0 decreased as the average fillet weight increased. Regarding linear regression, these results exhibited a positive linear relationship for both WB (R2 = 0.91, P < 0.001) and WS (R2 = 0.71, P = 0.002) myopathy with fillet weight. A high prevalence of myopathies was observed. The incidence of severe WB categories and the overall high cooccurrence rate are alarming.

Flavor is an important sensory trait of chicken meat. The free amino acid (FAA) and nucleotide (NT) components of meat are major factors affecting meat flavor during the cooking process. As a genetic approach to improve meat flavor, we performed a genome-wide association study (GWAS) to identify the potential candidate genes related to the FAA and NT components of chicken breast meat. Measurements of FAA and NT components were recorded at the age of 10 weeks from 764 and 767 birds, respectively, using a White leghorn and Yeonsan ogye crossbred F2 chicken population. For genotyping, we used 60K Illumina single-nucleotide polymorphism (SNP) chips. We found a total of nine significant SNPs for five FAA traits (arginine, glycine, lysine, threonine content, and the essential FAAs and one NT trait (inosine content), and six significant genomic regions were identified, including three regions shared among the essential FAAs, arginine, and inosine content traits. A list of potential candidate genes in significant genomic regions was detected, including the KCNRG, KCNIP4, HOXA3, THSD7B, and MMUT genes. The essential FAAs had significant gene regions the same as arginine. The genes related to arginine content were involved in nitric oxide metabolism, while the inosine content was possibly affected by insulin activity. Moreover, the threonine content could be related to methylmalonyl-CoA mutase. The genes and SNPs identified in this study might be useful markers in chicken selection and breeding for chicken meat flavor.

The present study aimed to determine the incidence and coincidence of white striping (WS), woody breast (WB) and spaghetti meat (SM) in raw chicken breast meat (n = 300) collected 3-3.5 h post mortem from commercial broiler flocks (Ross 708 males, 56 days of age). The fillets were scored for the occurrence and severity of WS, WB and SM using visual and tactile methods, and the relationship between myopathies and breast weight was evaluated. A total of 88% of samples (out of 300) had either one or a combination of three myopathies, leaving only 12% without any myopathies. Approximately 29% of the fillets had only one myopathy present, with 59% of the samples demonstrating the cooccurrence of breast myopathies. In the present study, 47.7% of WB samples also exhibited WS, while the cooccurrence of WB and SM was exhibited in 14.7%. Based on binomial logistic regression, an increase in WB scores decreases the odds that the fillet may be affected by SM myopathy. No association was found between SM and fillet weight. Multinomial logistic regression showed that the weight of breast fillets was positively associated with WB1 (P = 0.011), WB2 (P < 0.001), and WB3 (P < 0.001). Furthermore, positive associations were found between WS1 and WB3 (P = 0.004) as well as between WS2 and WB3 (P < 0.001). The percentage distribution changes of each WB and WS myopathy score were used in relation to the 10 weight groups. The percentages of WB3 increased and WB0 decreased as the average fillet weight increased. Regarding linear regression, these results exhibited a positive linear relationship for both WB (R² = 0.91, P < 0.001) and WS (R² = 0.71, P = 0.002) myopathy with fillet weight. A high prevalence of myopathies was observed. The incidence of severe WB categories and the overall high cooccurrence rate are alarming. [ABSTRACT FROM AUTHOR]

Wooden breast myopathy (WB) strongly affects the poultry industry mainly in terms of consumers rejection and economical loses, due to morphological changes in broiler muscle tissue and consequently low meat quality. The aim of this study is to evaluate the histomorphometry of muscle fibers of breast fillets of broilers with severity levels of WB myopathy. The histological evaluation considered 30 samples of the pectoralis major muscle and the level of WB myopathy (ten normal fillets, ten moderate fillets, and ten severe fillets). Fillets with a severe level of WB present low average fiber number, high average fiber diameter, low percentage of fibers with diameter of less than 20 µm, low percentage of fibers with diameter between 20 and 40 µm, and high percentage of fibers with diameter between 40 and 70 µm. Fiber cross-sectional area is greater in fillets affected by moderate and severe WB. Thus, fillets with a severe level of WB damage the muscle fiber structure and contribute more severely to the degenerative processes of breast meat.

ObjectiveThis study aimed at investigating white striping (WS) and wooden breast (WB) cases in breast meat collected from commercial broilers.MethodsA total of 183 breast samples were collected from male Ross 308 broilers slaughtered at the age of 6 weeks (n = 100) and 7 weeks (n = 83). The breasts were subjected to meat defect inspection, meat quality determination and histology evaluation.ResultsOf 183, 4 breasts from 6-week-old broilers were classified as non-defective while the others exhibited the WS lesion. Among the 6-week-old birds, the defective samples from the medium size birds (carcass weight ≤2.5 kg) showed mild to moderate WS degree with no altered meat quality. Some of the breasts from the 6-week-old birds with carcass weight above 2.5 kg exhibited WB in accompanied with the WS condition. Besides of a reduction of protein content, increases in collagen matter and pH values in the defective samples (p

Simple Summary: Performance, body composition, and processing yield are important traits in broiler production. Quantifying their association will favor making decisions and better understanding the underlying processes involved in productive and economic efficiency. This study aimed to approach this topic by modeling the relationships between these groups of variables by applying regression to data from multiple studies. The study suggests that regardless of the intervention applied and the type of broilers, the feed conversion ratio improves when the body weight gain also increases. The study's results support the use of body composition to predict the carcass conformation of broilers and their economic value. The information provided herein may particularly be of value to point out in the right direction further modeling efforts in areas related to poultry economics and sustainability. This study aims to model the relationship among performance, whole body composition, and processing yield through meta-regression. Scientific papers found in Scopus and Google Scholar were included if they reported results and variability values of an actual experiment in the three mentioned groups of variables using a single broiler genetic line. Weighted mean effect sizes were determined with a random model, the risk of bias was determined, and heterogeneity was considered an indicator of usefulness. Meta-regressions considered the effect sizes of the response variable and the percent change in one or more variables as predictors. A 78-row database was built from 14 papers, including nine factors tested on 22,256 broilers. No influencing bias was found, and the data was determined useful. Meta-regressions showed that the changes in body weight gain (BWG) are inversely related to the effects in feed conversion ratio (FCR) (p < 0.001) and that the changes in FCR and effects in protein-to-fat gain (PFG) are directly related (p < 0.001). The changes in PFG and the effects on carcass conformation or the market value of birds are directly related (p < 0.001). In conclusion, body composition predicts carcass conformation and its market value, supporting its use to predict the economic value of broilers. [ABSTRACT FROM AUTHOR]

The influence of diet enrichment with flaxseed, selenium and vitamin E, and market class on breast meat was investigated in terms of technological and sensorial quality of breast meat. A randomized complete block design with an experimental unit of n = 6000 broilers receiving a standard or enriched diet, and slaughtered at 37 (light class), 47 (medium class), or 57 (heavy class) days of life, was developed. Then, enriched and standard breast muscles from every market class were studied for their technological and sensorial traits—both at 24 h post-mortem and after one month of frozen storage—by a statistical multiple linear model. Redness and yellowness of muscles significantly (p < 0.05) increased and decreased with increasing market age. Moreover, the yellowness significantly (p < 0.05) raised after frozen storage. However, obtained data were always indicative of a normal meat color. The water holding capacity improved following fed enrichment and significantly (p < 0.05) worsened after frozen storage. For the sensory analysis, juiciness and chewing rest of meat resulted significantly (p < 0.05) improved with increasing slaughtering age and diet enrichment, as well as their mutual interaction, while they deteriorated after frozen storage. Overall, fresh and enriched muscles from heavy broilers had the best technological and sensorial traits, thus, confirming that market size and diet should be highly considered to obtain breast meat with greater consumer acceptance. [ABSTRACT FROM AUTHOR]

Background and Aim: In the post-antibiotic era, consumer demand for healthy and safe meats has prompted poultry producers to seek alternative effective feed additives. This study aimed to investigate the effects of a novel natural feed additive based on a mixture of Averrhoa bilimbi L. fruit filtrate, wheat bran, and Saccharomyces cerevisiae on the growth rate, internal organ weight, and breast meat characteristics of broilers. Materials and Methods: A total of 280 1-day-old chicks were divided into one control (CNTRL; feed without additives) and three treatment groups: NOV25, feed with 2.5 g/kg novel additive; NOV50, feed with 5.0 g/kg novel additive; and NOV100, feed with 10 g/kg novel additive. The body weight (BW), feed intake (FI), and feed conversion ratio (FCR) were measured weekly. On day 35, the chickens from each group were slaughtered, and their internal organs and breast meat samples were collected. Results: The BW of broilers in NOV100 was greater (p=0.016) than that in the other groups. The FCRs in the treatments groups were lower (p

Energy, known as the most expensive nutrient in broiler feed, is what strongly adjusts and affects the growth of broilers. Creatine has a key role in cellular energy metabolism and could be synthesised from guanidinoacetic acid (GAA) in the liver; however, its de novo synthesis is not able to adequately fulfil the demand of energy metabolism, especially in fast-growing modern broilers. So the aim of the study was to evaluate the efficiency of commercial GAA in energy-reduced broiler diets on performance and intestinal development. Overall, 11 400 day-old Ross 308 chicks were randomly allocated to six dietary treatments with ten replicates in each. Dietary treatments were designed as a 3 × 2 factorial arrangement with three levels of dietary metabolisable energy (AMEn) recommended by Aviagen for Ross 308 broilers (12.55 MJ/kg, 12.97 MJ/kg and 13.38 MJ/kg for starter, grower and finisher, respectively), 0.209 MJ/kg and 0.418 MJ/kg reduced and two levels of GAA (0.00% and 0.06%). There was no significant GAA × AMEn interaction for all performance parameters, carcass traits and jejunal morphological parameters (except for the villus width). Reduction of dietary AMEn (0.209 MJ/kg and/or 0.418 MJ/kg) caused a significant depression in body weight (BW) gain (P < 0.001) and feed conversion ratio (FCR) (P < 0.001). However, a decreasing AMEn level increased villus height (P < 0.003) and villus surface area (P < 0.03), while crypt depth and villus width were similar. The GAA improved final BW and FCR by 1.77% and 1.66%, respectively (P < 0.001). Birds fed low energy diets supplemented with GAA showed a significant improvement in the performance so that BW and FCR were the same as in the control birds; however, no such positive effects were obtained in jejunal villus development. Hence, it might be concluded that 0.06% GAA supplementation improves BW and FCR and can save at least 0.209 MJ/kg dietary AMEn in broiler diets.

This study investigated physical and sensory quality attributes of broiler chicken meat stored at -20°C. Sixty birds were allotted into 5-treatment in a completely randomized design and each treatment had (n = 12, r = 3). Treatment 1 (T1: fresh un-stored meat) and meat stored for 1, 2, 3 and 4 weeks were used as T2, T3, T4 and T5 respectively. Samples were assessed for physical attributes: cooking loss, water holding capacity (WHC), thermal shortening and thaw loss. Sensory qualities were assessed using the 9-point hedonic scale. Data were analyzed using ANOVA at a0.05. Thaw loss of breast, thigh and drumstick in T2 (breast: 6.21%; thigh: 2.30%; drumstick: 1.90%) were significantly lower than other treatments (T1 exempted). Cooking loss of breast, thigh and drumstick in T1 (breast: 14.59%; thigh: 20.85%; drumstick: 13.32%) were significantly lower compared to other treatments. WHC for breast, thigh and drumstick in T1 (breast: 79.03%; thigh: 80.10%; drumstick: 78.16%) were significantly higher than other treatments but not significantly different from T2 (breast: 76.66%; thigh: 76.46%; drumstick: 77.43). Thermal shortening of breast, thigh and drumstick in T5 (breast: 30.67%; thigh: 34.67%; drumstick: 54.67%) were significantly higher compared to other treatments. Sensory quality of breast, thigh and drumstick in terms of overall acceptability in T1 (breast:7.27; thigh: 7.10; drumstick: 7.26) had significant higher preference compared to other treatments. It was concluded that the physical and sensory attributes of broiler chicken meat had the tendency of being negatively affected by cold storage particularly when stored beyond one week. [ABSTRACT FROM AUTHOR]

Due to the increasing prevalence of growth-related myopathies and abnormalities in turkey meat, the ability to include meat quality traits in poultry breeding strategies is an issue of key importance. In the present study, genetic parameters for meat quality traits and their correlations with body weight and meat yield were estimated using a population of purebred male turkeys. Information on live body, breast, thigh, and drum weights, breast meat yield, feed conversion ratio, breast lightness (L*), redness (a*), and yellowness (b*), ultimate pH, and white striping (WS) severity score were collected on 11,986 toms from three purebred genetic lines. Heritability and genetic and partial phenotypic correlations were estimated for each trait using an animal model with genetic line, hatch week-year, and age at slaughter included as fixed effects. Heritability of ultimate pH was estimated to be 0.34 ± 0.05 and a range of 0.20 ± 0.02 to 0.23 ± 0.02 for breast meat colour (L*, a*, and b*). White striping was also estimated to be moderately heritable at 0.15 ± 0.02. Unfavorable genetic correlations were observed between body weight and meat quality traits as well as white striping, indicating that selection for increased body weight and meat yield may decrease pH and increase the incidence of pale meat with more severe white striping. The results of this analysis provide insight into the effect of current selection strategies on meat quality and emphasize the need to include meat quality traits into future selection indexes for turkeys. [ABSTRACT FROM AUTHOR]

In this study, we aimed to investigate the meat quality characteristics, bioactive compound content, and antioxidant activity during refrigerated storage of breast meat of Arbor Acres broilers (carcass weight: 1.1 kg, raised for 35 D) obtained from a conventional farm (BCF, n = 30) and an animal welfare farm (BAF, n = 30) in Korea. The BCF and BAF did not differ in their proximate composition, color, water-holding capacity, creatine, creatinine, and carnosine contents. However, the shear force value was significantly higher in BAF than in BCF (P < 0.05). The 2-thiobarbituric acid reactive substance (TBARS) levels in BCF on days 7 and 9 were significantly higher than those in BAF (P < 0.001). During storage, the total volatile basic nitrogen (VBN) content of BAF was significantly lower, except on day 1. The fatty acid composition of samples was not affected by the storage period, however, saturated fatty acid and unsaturated fatty acid contents did differ among the types of farm systems (P < 0.05). Although the creatine, creatinine, and carnosine contents in BAF and BCF did not differ significantly, the carnosine and creatinine contents decreased with the increase in storage period (P < 0.05). The anserine content of BAF was significantly higher than that of BCF throughout storage. Superoxide dismutase activity was not affected by the type of farm system but was affected by storage period. Overall, BAF showed lower pH, microorganism, TBARS, and VBN values, and higher anserine contents than BCF. These findings can serve as reference data for the evaluation of chicken meat quality of broilers raised in animal welfare farm and conventional farm.

Due to the increasing prevalence of growth-related myopathies and abnormalities in turkey meat, the ability to include meat quality traits in poultry breeding strategies is an issue of key importance. In the present study, genetic parameters for meat quality traits and their correlations with body weight and meat yield were estimated using a population of purebred male turkeys. Information on live body, breast, thigh, and drum weights, breast meat yield, feed conversion ratio, breast lightness (L*), redness (a*), and yellowness (b*), ultimate pH, and white striping (WS) severity score were collected on 11,986 toms from three purebred genetic lines. Heritability and genetic and partial phenotypic correlations were estimated for each trait using an animal model with genetic line, hatch week-year, and age at slaughter included as fixed effects. Heritability of ultimate pH was estimated to be 0.34 ± 0.05 and a range of 0.20 ± 0.02 to 0.23 ± 0.02 for breast meat colour (L*, a*, and b*). White striping was also estimated to be moderately heritable at 0.15 ± 0.02. Unfavorable genetic correlations were observed between body weight and meat quality traits as well as white striping, indicating that selection for increased body weight and meat yield may decrease pH and increase the incidence of pale meat with more severe white striping. The results of this analysis provide insight into the effect of current selection strategies on meat quality and emphasize the need to include meat quality traits into future selection indexes for turkeys.

Wing flapping and body movement can occur during the slaughter of poultry. Wing movement and flapping are driven primarily by the breast muscles (Pectoralis major and minor), and this muscle activity may have implications for meat quality. The objective of this study was to evaluate turkey post mortem activity during slaughter at a commercial poultry processing plant. Post mortem activity (during bleeding) was scored on 5,441 male turkeys, from six different genetic lines, using a 1–4 scale from none to severe wing flapping. Meat quality was measured on these birds in terms of pH (initial, ultimate, delta or change), color (L*, a*, b*), and physiochemical traits (drip loss, cooking loss, shear force). Linear mixed models were used to analyze the effect of activity (score 1–4), genetic line (A–F), and season (summer vs. autumn) on the nine meat quality traits. Post mortem activity influenced a*, drip loss, and shear force although the magnitude of the effects was small. There was an effect (P < 0.05) of genetic line on all the meat quality traits except for L*, cooking loss, and shear force. In general, larger, faster-growing lines had higher pH, but the relationship between the lines for the other traits is not as clear. Season affected all the meat quality traits, except for pHdelta, with meat having a higher pH, L*, b*, drip loss, cooking loss, and shear force in the summer. This study provides an exploratory assessment of post mortem activity in turkeys and identifies meat quality traits which are most affected while also accounting for the effects of genetic line and season. Although identified effect sizes are small, the cumulative effect on turkey meat quality may be more substantial.

Effects of the interaction between lighting programme and dietary protein content on broiler performance and meat yield were investigated. The hypothesis was that low breast meat yield from birds managed under short day lengths could be improved by increasing dietary protein content. The treatments consisted of four lighting programmes and four dietary protein levels. They were applied to sexed broilers from one day old to 35 days old. Eight light-tight rooms each contained eight pens with 50 birds, sexes separate, in each pen. Each feed x sex treatment was replicated twice in each room, with the four lighting treatments also being replicated twice. Multiple regression analysis was used to measure responses to the three factors. There was no significant interaction between dietary protein content and lighting programme in feed intake, feed conversion efficiency, bodyweight gain, carcass chemical composition and breast meat yield. Breast meat yield was linearly related to the number of hours of light, the highest yield occurring on the longest day length. Food intake was the same on the shortest day length and the longest, yet breast meat yield was greater on the 23-hour light programme. The decreased breast meat yield in broilers given short day lengths was therefore not the consequence of a shortage of dietary protein, and this hypothesis therefore had to be rejected. [ABSTRACT FROM AUTHOR]

Indigenous chicken breeds have showed slower growth rate and yield lower meat production, compared to commercial broilers. However, their meat quality is valued by modern consumers. The present study aimed at analyzing the quality traits of breast meat samples of Noi broilers, one of the famous indigenous chicken breeds in Vietnam. A total of 355 breast fillet samples were collected to evaluate quality meat traits such as pH, surface color, drip loss, and cooking loss at different time points of 3, 24, and 48 hours after slaughtering as well as to analyze chemical compositions such as dry matter, crude protein and ether extract. As result, sex and cold-storage time significant affect some of quality traits of breast meat, whereas their interaction did not associate among the observed properties. After 3 hour-storage, the pH value was determined at 5.63, then decrease to 5.56 and 5.55 after 24 and 48 hours, respectively. The color values (L* , a* , and b* ) were in the normal range reported from previous studies. Meat samples of two sexes did not vary in the cooking loss and drip loss values, whereas it was significantly different due to cold-storage time. The ether extract content of the meat was found negatively correlated with the cooking loss. The higher dry matter content of breast meat resulted in the lower drip loss value after 3h coldstorage (r=-0.12, P

Abstract Background Both selenium (Se) and probiotic Bacillus regulate the metabolism to help defense clod stress and improve the meat quality in breeding chicks. The purpose of this study was to evaluate the effect of supplemental Se and Bacillus in the form of Se-enriched Bacillus (SECB) on the growth performance, lipid parameters, breast Se and antibiotic levels, and breast meat quality of chicken in winter cold stress. Methods Five hundred 1-d-old chickens were divided into five groups randomly: Control, inorganic Se, compound Bacillus, SECB, and antibiotic. The feed duration was 56 d. Results After 28 d of treatment, chicks feed SECB or compound Bacillus had higher body weights than the control, and after 56 d, chicks given either SECB or compound Bacillus had higher body weights than the control chicks or those given inorganic Se. Adding SECB to feed significantly increased the lightness, redness, and yellowness of breast meat, improved the water-holding capacity, and reduced the shear force and cooking loss. The concentration of Se in the breast muscle very significantly increased after SECB and inorganic Se supplementation, which was opposite to the concentration of flavomycin in antibiotic supplemented chicks. The antioxidative status of plasma and breast meat was significantly improved with added compound Bacillus and SECB: the total antioxidant capacity, total superoxide dismutase, and glutathione peroxidase ability in the breast muscle significantly improved, and the malondialdehyde concentration in plasma decreased. The levels of total cholesterol plasma triglyceride and very-low-density lipoprotein cholesterol in the plasma and breast muscle was decreased compared to that of the control, while the plasma high-density lipoprotein cholesterol concentration increased. Conclusions In conclusion, SECB supplementation promoted the body growth, antioxidative status, and Se concentrations in the plasma and breast meat, and also improved the breast meat quality.

Summary: This study was conducted to evaluate the effect of whole corn inclusion before pelleting on performance, processing yield, and microbiome modulation of broilers from 1 to 42 d of age. One thousand male Ross 708 broilers were randomly distributed among 4 treatments, with 10 replicate pens per treatment and 25 broilers per pen. Treatments consisted of 4 levels of whole corn (0, 2.5, 5.0, and 7.5%) replacing ground corn. Feed intake and BW were determined at 14, 28, and 42 d, and feed conversion ratio (FCR) was calculated by considering the weight of the mortality. At 42 d, ileal and cecal contents were analyzed to determine intestinal microbiota. At 43 d, 10 birds per pen were processed for yield determination. Data were evaluated using the ANOVA procedure (PROC GLM), and means were separated using Tukey's honestly significant difference procedure. Inclusion of whole corn did not influence BW and feed intake (P > 0.05) until 42 d of age. However, broilers consuming diets with 2.5, 5.0, and 7.5% whole corn had lower FCR from 28 to 42 d of age (1.93, 1.95, and 1.94 vs. 2.00, P < 0.05) than in broilers fed with diets containing 0% whole corn. Broilers fed with diets containing 5% whole corn had higher breast meat yield (29.11 vs. 28.40%, P < 0.05) than broilers fed with 7.5% whole corn, but yields were similar to broilers fed with diets without whole corn. Diets with 7.5% whole corn showed a trend toward increased Faecalibacterium (P = 0.07) and decreased Lactobacillus (P = 0.08) in cecal microbiota compared with diets with 5% whole corn. The results of this experiment indicated that up to 5% whole corn can replace ground corn in broiler diets from 1 to 42 d.

Energy, known as the most expensive nutrient in broiler feed, is what strongly adjusts and affects the growth of broilers. Creatine has a key role in cellular energy metabolism and could be synthesised from guanidinoacetic acid (GAA) in the liver; however, its de novo synthesis is not able to adequately fulfil the demand of energy metabolism, especially in fast-growing modern broilers. So the aim of the study was to evaluate the efficiency of commercial GAA in energy-reduced broiler diets on performance and intestinal development. Overall, 11 400 day-old Ross 308 chicks were randomly allocated to six dietary treatments with ten replicates in each. Dietary treatments were designed as a 3 × 2 factorial arrangement with three levels of dietary metabolisable energy (AMEn) recommended by Aviagen for Ross 308 broilers (12.55 MJ/kg, 12.97 MJ/kg and 13.38 MJ/kg for starter, grower and finisher, respectively), 0.209 MJ/kg and 0.418 MJ/kg reduced and two levels of GAA (0.00% and 0.06%). There was no significant GAA × AMEn interaction for all performance parameters, carcass traits and jejunal morphological parameters (except for the villus width). Reduction of dietary AMEn (0.209 MJ/kg and/or 0.418 MJ/kg) caused a significant depression in body weight (BW) gain (P < 0.001) and feed conversion ratio (FCR) (P < 0.001). However, a decreasing AMEn level increased villus height (P < 0.003) and villus surface area (P < 0.03), while crypt depth and villus width were similar. The GAA improved final BW and FCR by 1.77% and 1.66%, respectively (P < 0.001). Birds fed low energy diets supplemented with GAA showed a significant improvement in the performance so that BW and FCR were the same as in the control birds; however, no such positive effects were obtained in jejunal villus development. Hence, it might be concluded that 0.06% GAA supplementation improves BW and FCR and can save at least 0.209 MJ/kg dietary AMEn in broiler diets. [ABSTRACT FROM AUTHOR]

The influence of diet enrichment with flaxseed, selenium and vitamin E, and market class on breast meat was investigated in terms of technological and sensorial quality of breast meat. A randomized complete block design with an experimental unit of n = 6000 broilers receiving a standard or enriched diet, and slaughtered at 37 (light class), 47 (medium class), or 57 (heavy class) days of life, was developed. Then, enriched and standard breast muscles from every market class were studied for their technological and sensorial traits—both at 24 h post-mortem and after one month of frozen storage—by a statistical multiple linear model. Redness and yellowness of muscles significantly (p < 0.05) increased and decreased with increasing market age. Moreover, the yellowness significantly (p < 0.05) raised after frozen storage. However, obtained data were always indicative of a normal meat color. The water holding capacity improved following fed enrichment and significantly (p < 0.05) worsened after frozen storage. For the sensory analysis, juiciness and chewing rest of meat resulted significantly (p < 0.05) improved with increasing slaughtering age and diet enrichment, as well as their mutual interaction, while they deteriorated after frozen storage. Overall, fresh and enriched muscles from heavy broilers had the best technological and sensorial traits, thus, confirming that market size and diet should be highly considered to obtain breast meat with greater consumer acceptance.

Objective This study aimed at investigating white striping (WS) and wooden breast (WB) cases in breast meat collected from commercial broilers. Methods A total of 183 breast samples were collected from male Ross 308 broilers slaughtered at the age of 6 weeks (n = 100) and 7 weeks (n = 83). The breasts were subjected to meat defect inspection, meat quality determination and histology evaluation. Results Of 183, 4 breasts from 6-week-old broilers were classified as non-defective while the others exhibited the WS lesion. Among the 6-week-old birds, the defective samples from the medium size birds (carcass weight ≤2.5 kg) showed mild to moderate WS degree with no altered meat quality. Some of the breasts from the 6-week-old birds with carcass weight above 2.5 kg exhibited WB in accompanied with the WS condition. Besides of a reduction of protein content, increases in collagen matter and pH values in the defective samples (p

Objective This study was conducted to estimate the genetic parameters and breeding values of breast meat related traits of Pekin ducks. Selection response was also determined by using ultrasound breast muscle thickness (BMT) measurements in combination with bosom breadth (BB) and keel length (KL) values. Methods The traits analyzed were breast meat weight (BMW), body weight (BW), breast meat percentage (BMP) and the three parameters of breast meat (BB, KL, and BMT). These measurements were derived from studying 15,781 Pekin ducks selected from 10 generations based on breast meat weight. Genetic parameters and breeding value were estimated for the analysis of the breeding process. Results Estimated heritability of BMW and BMP were moderate (0.23 and 0.16, respectively), and heritability of BW was high (0.48). Other traits such as BB, KL, and BMT indicated moderate heritability ranging between 0.11 and 0.28. Significant phenotypic correlations of BMW with BW and BMP were discovered (p

There is an ongoing search for novel protein sources suitable to replace soybean meal. The present study aimed to investigate the utility of cold-pressed perilla seed meal for broiler diets. Perilla meal was included at dietary levels of 0, 4, and 8 %. In the first experiment, apparent digestibility and metabolisability of nutrients were performed with 24 Cobb 500 broilers. In the second experiment, growth performance and carcass quality were investigated in 120 Cobb 500 broilers. The inclusion of perilla meal into the diet in an iso-nitrogenous way increased feed intake and metabolisability of nitrogen but decreased the digestibility of fat and fiber as well as the metabolisability of energy. The highest proportion of perilla meal enhanced the growth performance. Carcass weight and dressing percentage did not differ among groups. Proportions of total retail cuts and, among them, breast meat and thighs, were elevated by using perilla meal, especially at a level of 8 %. The proportion of abdominal fat declined with increasing levels of perilla meal. In conclusion, perilla meal turned out to be a valuable protein source in broiler nutrition. It also showed that part of the soybean meal could be replaced without risking adverse effects on growth performance and carcass quality. [ABSTRACT FROM AUTHOR]

A study was conducted to evaluate the changes in serum biochemical and lipid profile, and fatty acid composition of breast meat of broiler chickens fed supplemental grape seed extract (GSE). A total of 240 1-day-old male broiler chickens were randomly allocated to 4 groups, each consisting of 4 replicate pens having 15 birds/replicate pen. One group served as control group fed basal diets and other groups received 100, 200, and 400 ppm GSE supplemented to the basal diets. Liver weight was greater in broilers fed 200 ppm GSE compared to the other groups (P = 0.004, L = 0.024, C = 0.010). Serum AST and ALT levels decreased (P < 0.001) whereas ALP levels increased with increasing dietary GSE levels (P < 0.001). Serum albumin and total protein levels were lower in control in comparison with other groups (P < 0.001). Serum cholesterol, triglyceride, and LDL levels declined (P < 0.001) while HDL levels increased with increasing supplemental GSE levels (P < 0.001). MUFA levels were greater in breast meat of broiler chickens fed diets supplemented with 100 ppm GSE. On the other hand, PUFA (including n-3 and n-6) were greater in broiler chickens fed control diets or 400 ppm GSE supplemented diets. In general, essential fatty acids such as α-linolenic acid (n-3 C18:3), arachidonic acid (n-6 C20:4), eicosapentaenoic acid (n-3 C20:5), and docosahexaenoic acid (n-3 C22:6) were greater in breast meat of broiler chickens fed supplemental GSE (100, 200, or 400 ppm) while overall UFA concentration in breast meat remained unaffected. In conclusion, findings of this study suggest that dietary supplementation of up to 400 ppm GSE in broilers may improve serum biochemical and lipid profile. It may also improve the fatty acid composition of breast meat to varying extent despite no effect on overall UFA concentration. [ABSTRACT FROM AUTHOR]

The objective of our study was to investigate the role of three different light-color temperatures of Light-Emitting Diodes (LEDs) [Neutral (K=3300−3700); Warm (K=3000−2500) and Cool (K=5500−6000)] on the qualitative attributes of breast meat obtained from male AZ Extra Heavy Red chickens. The comparison was made with meat deriving from chickens reared in the presence of classic neon lighting (Control). The meat was analyzed for the determination of both physical and chemical properties (cooking loss, moisture, total lipids and fatty acid composition). Furthermore, meat samples subjected to cooking were also analyzed for the identification of volatile compounds produced during the process; such evaluation was performed both immediately after cooking (T0) and after 7 days (T7) of cooked-meat storage at 4 °C. Cooking-loss values were higher for samples from chickens raised with Neutral LED (p < 0.05) compared to the other groups. For the fatty acid profiles of the meat, higher values were found for monounsaturated fatty acids (MUFAs) such as C18:1, C9 and C16:1 in Cool LED compared to the Control. Regarding the volatile profile of cooked meat, compounds belonging to the families of aldehydes, alcohols, ketones, and aromatic compounds were identified. Compounds belonging to the aldehyde family, such as hexanal, increased in Cool LED samples at T0 in comparison to the Control. On the other hand, the amounts of 1-Pentanol, 1-Octanol and 2-Octen-1-ol, which belong to the alcohol family, increased at T7 in Cool LED samples compared to the Warm LED. In conclusion, LED lighting showed to be effective in inducing significant variations on chicken breast meat ready to be introduced to the market, in particular regarding fatty acid profiles and the accumulation of volatile compounds. However more in-depth evaluation is needed for the identification of modifications regarding the sensorial sphere, which could have an impact on the consumer acceptability of the product.

In the past decades, the intense selection practices carried out in order to develop fast growing and high breast-yield turkey hybrids profoundly modified the muscle physiology leading to the development of growth-related alterations and muscular abnormalities. White striations of variable thickness have been particularly observed on the ventral surface of Pectoralis major muscle belonging from heavy male turkeys since several years. However, although the effects of white striping (WS) have been extensively studied on broilers, this condition was not considered as a main quality issue by both turkey producers and meat industry. Thus, this study aimed at evaluating whether the occurrence of WS in heavy male turkeys affects the quality traits and technological properties of meat to the same extent previously observed for broilers. In two replications, 72 Pectoralis major muscles were classified as: normal (NORM), moderate WS (MOD) and severe WS (SEV) cases. The whole muscle was weighed and cut in order to assess colour, ultimate pH, water holding (drip and cooking losses) and binding (marinade uptake) capacities, NMR relaxation properties, shear force as well as proximate composition of meat. The Pectoralis major muscles affected by WS (both moderate and severe cases) exhibited a one-fifth increased weight in comparison with their NORM counterpart. However, the occurrence of WS only partially affected the proximate composition of the meat. In detail, although moisture, collagen and protein contents did not differ among the groups, if compared with NORM, higher lipid levels were found in SEV muscles, whereas MOD had intermediate values. On the other hand, both MOD and SEV exhibited lower ash content. Despite these variations in proximate composition, both water holding and binding capacities of turkey breast meat were not affected by WS. Indeed, quality traits of raw (pH, colour, cooking losses and shear force) and marinated (uptake, cooking losses and shear force) meat as well as water distribution within the muscle tissue did not differ between NORM and WS cases. Overall, if compared with broilers, WS only marginally affected quality traits of turkey breast meat. It might thus be hypothesised a diverse specie-specific physiological response to the pressure in muscle tissue induced by the selection in turkeys that, although analogously led to the occurrence of WS, results in limited effects on meat quality.

Korat chicken (KRC) is a slow-growing chicken bred in Thailand, whose meat exhibits a unique toughness. A previous study produced KRC breast meat containing high carnosine content through dietary supplementation with β-alanine or L-histidine; however, the KRC that were fed an L-histidine-supplemented diet produced meat that was significantly more tender. Herein, we performed RNA-Seq to identify candidate genes involved in the regulation of carnosine content and meat toughness. Total RNA was isolated from five female KRC breast muscles in each treatment group that KRC fed diets without supplementation, supplemented with β-alanine or L-histidine. Compared to the non-supplemented group, we identified 118 and 198 differentially expressed genes (DEGs) in the β-alanine or L-histidine supplementation groups, respectively. Genes potentially related to meat tenderness—i.e., those regulating myosin, collagen, intramuscular fat, and calpain—were upregulated (LOC107051274, ACSBG1, and CAPNS2) and downregulated (MYO7B, MYBPH, SERPINH1, and PGAM1). However, carnosine synthase gene was not identified. Functional enrichment analysis identified pathways affected by dietary supplementation, including the insulin signaling pathway (β-alanine supplementation) and the insulin resistance and adipocytokine signaling pathways (L-histidine supplementation). The FoxO signaling pathway was identified as a regulatory network for both supplementation groups. The identified genes can be used as molecular markers of meat tenderness in slow-growing chickens.

Aim: The present study was conducted to explore the effect of supplementation of Withania somnifera and synbiotics alone or in combination on the composition of broiler breast meat under heat stress conditions. Materials and Methods: A 42-day feeding trial was conducted on 360 broiler chicks randomly allotted into eight treatment groups with three replicates each under completely randomized design. The T1 group was kept as control whereas T2-T4 were supplemented with 0.5%, 1%, and 1.5% W. somnifera root powder; T5 and T6 were supplemented with 0.025% and 0.050% synbiotic and T7 and T8 were fed on diet containing 0.25% W. somnifera+0.025% synbiotic and 0.50% W. somnifera+0.05% synbiotic, respectively. Three broilers from each replicate were sacrificed at the end of the trial to estimate crude protein (CP), ether extract and ash content of the breast muscle on dry matter basis. Results: Significantly higher CP values and lower ether extract values were observed in 1.5% W. somnifera supplemented group (T4) or in group supplemented with 0.50% W. somnifera and 0.05% synbiotic (T8). The ash content of breast meat was observed non-significant in T1-T4 groups however the inclusion of synbiotics in T5-T8 groups significantly raised the ash contents. Conclusion: The study concluded that inclusion of 0.5% W. somnifera with 0.05% synbiotic substance enriches the total protein content and reduces the total lipids content of broiler breast meat under heat stress conditions.

Recently, consumers have paid an attention to animal-friendly meat. The aim of the study was to evaluate the meat quality of breast muscles in indoor and free-range chickens with respect to the stocking density of outdoor chickens (8.3 or 4.15 birds per m2) fed feed with rapeseed oil. The free-range chickens reached 96 and 97% of the final live weight of the indoor chickens and their feed : gain ratio was by 7 and 9% higher. The pasture intake had a small effect on the breast meat quality and was presumably associated with rapeseed oil in the basal diet which strongly influenced meat monounsaturated and polyunsaturated fatty acid content and reduced the effect of pasture. The free-range system and lower stocking density led to an increase in muscle fibre cross-sectional area and diameter and a higher meat shear force (P = 0.003). Concerning the meat sensory properties, the total acceptability of the meat of free-range chickens with a lower stocking density was found to be lower compared with the other groups.esults indicate a minor effect of the rearing system and free-range stocking density on chicken meat quality, and also that meat quality in experiments with free-range housing can be affected by a fat source in basal diet.

Salmonella infections represent a leading cause of foodborne illnesses; resistance to third-generation cephalosporins (TGCs), which are a first-choice antimicrobial for treating human Salmonella enteritis, has become a serious public health concern worldwide. Because the consumption of undercooked chicken meat products is a major cause of foodborne salmonellosis in Japan, we conducted three surveys at different periods between 2017 and 2022, with the cooperation of four abattoirs (two in Eastern and two in Western Japan). The first survey was conducted at abattoir A, which is located in Eastern Japan. Salmonella was detected in 84.4% of broiler flocks tested (27/32); among them, all the TGC-resistant isolates obtained from one farm (farm FA) were identified as S. Infantis. Salmonella was recovered from 62.5% of breast meat samples (20/32), with one case suggesting cross-contamination. The second survey was conducted at three other abattoirs to examine the prevalence of TGC-resistant Salmonella , in both Western (abattoirs B and C) and Eastern (abattoir D) Japan. Salmonella was detected in 90.6% of broiler flocks examined (29/32). TGC-resistant S. Infantis was isolated from 2 flocks until 2018 and not thereafter. Subsequently, isolates were identified as TGC-susceptible S. Schwarzengrund in both regions. The third survey was performed at abattoir A to elucidate whether there were changes in the phenotypes. Of the 11 broiler flocks introduced from farm FA, 10 were positive for Salmonella (90.9%); all the isolates were S. Schwarzengrund susceptible to TGC. This study shows that TGC-susceptible S. Schwarzengrund has replaced the resistant phenotypes among broiler flocks in both Eastern and Western Japan. Although chicken meat products could be cross-contaminated with Salmonella during the slaughtering process, reducing the prevalence of Salmonella in broiler flocks remains important to decrease Salmonella enteritis in humans., Competing Interests: Conflict of Interest: The authors have no conflicts of interest to declare., (©2024 Food Safety Commission, Cabinet Office, Government of Japan.)

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. [ABSTRACT FROM AUTHOR]

Dietary starch with lower rate and extent of digestion improves broiler feed efficiency, but previous results might have been confounded by non-starch components of the grains. Therefore, the objective of this research was to study the effects of starch digestion on broilers using semi-purified starch. Semi-purified wheat (WS , rapidly digested) and pea (PS , slowly digested) starch were combined to create 6 WS:PS ratios (100:0, 80:20, 60:40, 40:60, 20:80, and 0:100) in starter, grower and finisher diets. Each treatment was fed to Ross 308 male (2,124) and female (2,376) broilers housed in 72 L floor pens from 0 to 31 d of age to measure performance and meat yield relative to live weight. On day 33, the effects of diet on 8 h feed withdrawal was assessed in 20 males per treatment. Data were analyzed with ANOVA and linear and quadratic regression analyses using SAS 9.4. Significance was accepted at P  ≤ 0.050. Body weight gain declined linearly with increasing PS. Male feed intake decreased with increasing PS, but PS did not affect female feed intake. Mortality corrected gain:feed ratio was quadratically influenced by diet (estimated maximum at 25% PS). Breast meat increased linearly with PS, while fat pad and breast and thigh skin decreased linearly. Quadratic responses were found for thigh meat and whole drum (estimated maximum values at 56 and 54% PS, respectively). Males grew faster, ate more, and had higher mortality than females. They also had heavier pectoralis major, thigh bone, and whole drum, while females had heavier pectoralis minor and more breast and thigh skin. After feed withdrawal, digesta content decreased linearly with time in all sections, except for the crop and duodenum, which declined quadratically. Ileal digesta pH increased linearly with time, while crop and caecal pH decreased for 2 h before steadily increasing. Diet did not affect digestive tract emptying or digesta pH. In conclusion, dietary PS maximized feed efficiency at 25% PS and linearly improved breast meat yield, but did not affect digesta clearance after feed withdrawal. [ABSTRACT FROM AUTHOR]

The relationship between woody breast (WB) and white striping (WS) myopathies were investigated in breast fillets collected from commercial slaughter facilities that process large broilers. For the population of samples collected in this study, 94.2% of all WB fillets also exhibited WS. Of the fillets that did not exhibit WB, 54.0% exhibited WS. Of the fillets that exhibited severe WB, 27.9% had severe WS, 50.9% had moderate WS, and 21.2% had mild or no WS. Approximately 82.8% of all WS fillets also exhibited WB. Of the fillets that did not exhibit WS, 26.0% exhibited WB. Among fillets that exhibited severe WS, 40.7% had severe WB, 46.0% had moderate WB, and 13.3% had mild or no WB. The strength of the relationship between WS and WB scores decreased as average fillet weight increased. In addition to overall WB and WS scores, a subset of fillets was also evaluated for specific attributes of muscle hardness, rigidity, out-bulging shape, and the occurrence of petechial hemorrhages on the skin-side surface of the fillets. Muscle hardness, rigidity, and out-bulging shape were highly correlated to WB scores but their relationships with WS were much weaker. There was a statistically positive, but relatively weak, correlation between the occurrence of petechial hemorrhages and the WB and WS myopathies. With regards to developing WB sorting criteria and methodologies, tactile traits have a greater potential for accurately indicating the presence and severity of the WB myopathy in broiler breast meat than visually-assessed traits such as WS. [ABSTRACT FROM AUTHOR]

The present study was designed to investigate the role of three different light-emitting diode (LED) light color temperatures on the growth performance, carcass characteristics, and breast meat quality of broilers. In our experimental condition, 180 chicks were randomly distributed into four environmentally controlled rooms (three replicates/treatment). The experimental design consisted of four light sources: neon (Control), Neutral (Neutral LED; K = 3500–3700), Cool (Cool LED; K = 5500–6000), and Warm (Warm LED; K = 3000–2500). Upon reaching the commercial weight (3.30 ± 0.20 kg live weight), 30 birds from each group were randomly selected, and live and carcass weight were evaluated to determinate the carcass yield. Following the slaughtering, samples of hemibreast meat were collected from each group and analyzed for physical and chemical properties, fatty acids composition, and volatile compounds. Live weight and carcass weight were negatively influenced by the Warm LED; however, no significant differences were observed in carcass yield in any of the experimental conditions. Higher drip loss values were detected in breast meat samples obtained by broilers reared under Neutral and Cool LEDs. In regard to the meat fatty acids profiles, higher polyunsaturated fatty acids (PUFA) values were detected with the Warm LED; however, the ratio of PUFA/saturated fatty acids (SFA) did not change in any group. The evaluation of volatile profiles in cooked chicken meat led to the identification of 18 compounds belonging to the family of aldehydes, alcohols, ketones, and phenolic compounds, both at 0 (T0) and 7 (T7) d after the cooking. The results of the present study suggest that the LED represents an alternative technology that is cheaper and more sustainable than traditional light sources, since it allows economic savings for poultry farming without significant alterations on the production parameters or the quality of the product.

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.

Selenium (Se) is able to transform from inorganic to organic forms via many bacterial species. This feature is being considered for delivering more bioavailable selenium compounds such as selenocysteine and selenomethionine for human and animal diet. This study investigated the effects of bacterial selenoprotein versus inorganic Se on the carcass characteristics, breast meat selenium content, antioxidant status, and meat quality of broiler chickens. One hundred and eighty chicks were randomly allotted to five treatments of a basal diet supplemented with no Se, sodium selenite, Enterobacter cloacae Selenium (ADS1-Se), Klebsiella pneumoniae-Selenium (ADS2-Se), and Stenotrophomonas maltophilia-Selenium (ADS18-Se). The results showed that bacterial selenoprotein has the ability to deposit more Se in the breast meat compared to sodium selenite. Both Se sources reduced breast meat drip loss, cooking loss, shear force, and 2-thiobarbituric acid reactive substances (TBARS) significantly. It also increased total antioxidant (TAC) and glutathione peroxidase (GSH-Px) in comparison with the negative control. The highest activity of (GSH-Px), catalase (CAT), and superoxide dismutase (SOD) was found in bacterial selenoprotein. In conclusion, bacterial selenoprotein is more efficient than sodium selenite in increasing the breast meat Se deposition and oxidative capacity of broiler chickens. Therefore, it can be effectively used to produce Se-rich meat as a functional food.

Acute heat stress may affect the quality of broilers meat, however there are no reports considering thermal conditions commercially available in Brazil. In this way, the present work aimed to fill this gap of industrial relevance. Broilers of commercial strain (Cobb 500, n = 540) were randomly assigned to two thermal conditions: acute heat stress (AHS; 35°C; 75 – 85% relative humidity) and not-heat-stress (NS; 22ºC; 83 ± 6.6% relative humidity), for 2 hours prior to slaughter. The mortality rate for AHS broilers reached 37%, which was greater than 5.2% verified for NS. According to the mean values, the broiler chickens were not totally affected in the parameters of pH24h, lightness (L*), cooking loss, and shear force. However, the distributions of data show great variability in the values of pH24h, L* and water holding capacity (WHC) for AHS broilers. It is suggested that AHS broilers, at severe conditions which result in increased mortality, present breast meat with greater incidence of higher pH24h, and lower lightness and WHC values.

This study, performed on turkeys aged 1 to 98 days, aimed to investigate whether different dietary inclusion levels (20, 10, 2 mg kg−1) of copper nanoparticles (Cu-NP) as a substitute for copper sulphate (Cu-SUL) affect redox and immunological status of turkeys' tissues. No significant differences in the final body weights of turkeys were found across the dietary treatments. A comparison of the physiological effects of Cu-NP and Cu-SUL revealed equivocal metabolic responses including decreased superoxide dismutase (SOD) activity in the liver, increased SOD and catalase activities in breast muscles, decreased total glutathione concentrations in breast muscles, and decreased plasma IgY concentrations. An analysis of the antioxidant and immune status parameters in the blood, liver and breast meat of turkeys indicates that 10 mg/kg is the optimal inclusion level of additional Cu. Both two-fold higher and five-fold lower Cu supplementation levels have a negative influence on selected parameters of the antioxidant and immune status of birds. Lower supplementation levels of Cu-NP (2 and 10 mg/kg) exert similar physiological effects to Cu-SUL, whereas higher addition of Cu-NP (20 mg/kg) may negatively affect selected redox parameters and stimulate the synthesis of the proinflammatory cytokine IL-6. The results of the present study indicate that further research is needed to establish the actual dietary requirements for Cu in turkeys and the efficacy of nanoparticles as a new additional Cu source in turkey nutrition. [ABSTRACT FROM AUTHOR]