Carcass characteristics, physicochemical traits, texture and microstructure of young and spent quails meat.

The purpose of the study was to compare young (6-wk-old) and spent (52-wk-old) Japanese quail in terms of body weight, carcass characteristics, and some meat quality traits. Whole carcasses were dissected, pectoral muscles and leg muscles were sampled for determination of basic chemical composition and L*a*b* color parameters, while m. pectoralis major was sampled for texture and microstructure traits. Age of quails had a significant effect on body weight, carcass weight, carcass yield, pectoral muscle, abdominal fat and skin with subcutaneous fat, and carcass remainders contents in eviscerated carcass. Spent quails had significantly higher intramuscular fat content in pectoral and leg muscles and protein content in breast muscle, and also lower content of water in breast and leg muscles than young quails. Slaughter age significantly affected lightness (L*) and redness (a*) of pectoral muscles, as well as texture traits (except for cohesiveness) and microstructure of m. pectoralis major, except for thickness of perimysium and endomysium. Regardless of age, quail sex had an effect on the carcass traits studied (except for leg muscle content), intramuscular fat content of pectoral and leg muscles, water content of leg muscles and yellowness of pectoral muscle. In addition, a significant effect of quail sex was found on cutting work, springiness, chewiness and marked microstructural characteristics, except for vertical fiber diameter. The interaction between age and sex was significant for most slaughter and microstructural characteristics and also WB-shear force of m. pectoralis major, and L*, b* pectoral muscles. Higher fatness of carcasses, higher intramuscular fat in meat, and poorer textural and microstructural characteristics of m. pectoralis major spent Japanese quail indicate poorer fulfillment of most consumers' requirements compared to carcasses and meat of young quails.

Relationships of quality indices with wooden breast myopathy severity in chicken breast meat under refrigerated storage.

1. This study investigated the relationships of quality indices with the severity of wooden breast (WB) myopathy in chicken breast meat under refrigerated storage. The physicochemical properties, water-holding capacity (WHC), microbial quality and fatty acid profiles of normal chicken breast meat samples (NOR samples, n = 63), moderate WB (MWB, n = 63) myopathy and severe WB (SWB, n = 63) myopathy (MWB and SWB samples, respectively) were evaluated immediately after sampling and after 4 and 8 d of refrigerated storage at 4°C.2. Total collagen, fat, saturated and monounsaturated fatty acid contents, redness and pH of the SWB and MWB samples were higher than the NOR samples. The SWB samples that were stored for 8 d had poor WHC, total viable counts (TVC) of higher than 7.0log colony-forming units, total volatile basic nitrogen (TVB-N) content of greater than 15 mg/100 g and a thiobarbituric acid - reactive substance level of higher than 1 mg/kg malondialdehyde.3. No significant difference was observed in the TVB-N content and TVC of the MWB and NOR samples during storage. Polyunsaturated fatty acid content was lower in the SWB and MWB samples than in the NOR samples. The SWB samples were tougher than the MWB and NOR samples after 8 d of refrigeration.4. In conclusion, the quality of chicken breast meat with SWB myopathy degraded considerably over time; thus, such meat should not be subjected to extended refrigeration for storage.

Genome-wide association studies of anserine and carnosine contents in the breast meat of Korean native chickens.

Histidine-containing dipeptides (HCDs), such as anserine and carnosine, are enormously beneficial to human health and contribute to the meat flavor in chickens. Meat quality traits, including flavor, are polygenic traits with medium to high heritability. Polygenic traits can be improved through a better understanding of their genetic mechanisms. Genome-wide association studies (GWAS) constitute an effective genomic tool to identify the significant single-nucleotide polymorphisms (SNPs) and potential candidate genes related to various traits of interest in chickens. This study identified potential candidate genes influencing the anserine and carnosine contents in chicken meat through GWAS. We performed GWAS of anserine and carnosine using the Illumina chicken 60K SNP chip (Illumina Inc., San Diego, CA) in 637 Korean native chicken-red-brown line (KNC-R) birds consisting of 228 males and 409 females. The contents of anserine and carnosine in breast meat of KNC-R chickens were investigated. The mean value of the anserine and carnosine are 29.12 mM/g and 10.69 mM/g respectively. The genomic heritabilities were moderate (0.24) for anserine and high (0.43) for carnosine contents. Four and nine SNPs were significantly (P < 0.05) associated with anserine and carnosine, respectively. Based on the GWAS result, the 30.6 to 31.9 Mb region on chicken chromosome 7 was commonly associated with both anserine and carnosine. Through the functional annotation analysis, we identified HNMT and HNMT-like genes as potential candidate genes associated with both anserine and carnosine. The results presented here will contribute to the ongoing improvement of meat quality to satisfy current consumer demands, which are based on healthier, better-flavored, and higher-quality chicken meat.

Water properties in intact wooden breast fillets during refrigerated storage.

The wooden breast (WB) condition notably alters moisture content and water holding capacity (WHC) in broiler breast fillets. The purpose of this study was to investigate water properties during refrigerated storage from 4 h to 168 h postmortem using time domain nuclear magnetic resonance (TD-NMR). Water properties measured included mobility (T), proportion (P), and abundance per 100 g of meat (A). Changes in meat quality indicators including compression force, color, pH, cumulative purge loss, and proximate composition were also measured. Compression force and energy of the WB fillets were higher than normal fillets (P < 0.05). Slopes of changes in lightness of the WB and normal fillets were different in skin and bone side (P < 0.05). The slope of the purge loss from the WB fillets was higher than the normal fillets (P < 0.05). Time domain nuclear magnetic resonance analysis showed 4 water populations in intact broiler fillets with transverse relaxation time (T2) constants at approximately 4 to 5 milliseconds (ms) (designated as 2b, corresponding to hydration water or bound water), 40 to 60 ms (designated as 21, corresponding to intra-myofibrillar water or immobilized water), 80 to 210 ms (designated as 22a, corresponding to extra-myofibrillar water or free water with lower mobility) and 210 to 500 ms (designated as 22b, corresponding to extra-myofibrillar water or free water with higher mobility) during early postmortem storage (between 4 h and 72 h postmortem) and only 3 populations (2b, 21, and 22a) after 72 h postmortem. There were interaction effects (P < 0.05) between storage time and WB condition for all water properties except T2b, A2b/100 g, and T22b. The linear change of T21, P21, A21/100 g, T22a, A22a/100 g, P22b, and A22b/100 g in stored WB samples were different from the normal fillets (P < 0.05). During storage, P21 and A21/100 g of the WB fillets exhibited faster linear increases than those of the normal fillets, whereas T21 and T22a of the normal fillets and A22a/100 g, P22b, and A22b/100 g of the WB fillets showed faster linear decreases (P < 0.05). Our data demonstrate that the WB condition affects changes in water properties in broiler fillets during postmortem refrigerated storage.

Impact of Wooden Breast myopathy on in vitro protein digestibility, metabolomic profile, and cell cytotoxicity of cooked chicken breast meat.

This study investigated the impacts of Wooden Breast (WB) abnormality on in vitro protein digestibility and cytotoxicity of cooked chicken breast meat. Chicken breasts without (non-WB, n = 6) or with severe WB condition (WB, n = 6) were cooked and subjected to static in vitro protein digestion. The results showed no significant differences in free-NH2, degree of hydrolysis and distribution of peptide molecular weight between non-WB and WB samples at late intestinal digestion (P5), suggesting no adverse effects of WB on protein digestibility. Based on peptidomic analysis, P5 fraction of WB showed greater content of peptides with oxidative modification than that of non-WB. Untargeted metabolomics did not find any metabolites with potential toxicity either in non-WB and WB. Hydrolyzed non-WB and WB (1.56-100 µg/mL) did not affect viability of Caco-2 and Vero cells but addition of WB samples reduced Caco-2 cell viability compared with non-WB.

Comparison of growth performance, meat quality, and blood biochemical indexes of Yangzhou goose under different feeding patterns.

The East China region is the main market for the breeding and consumption of meat geese in China, in order to provide data reference for small and medium-sized farms and farmers to choose breeding methods and growth performance. This study selected 300 Yangzhou geese as materials and determined the number of geese in each group according to different modes. The meat quality, blood biochemical indicators, and economic benefits of 4 common feeding methods (Group I: full concentrate feeding; Group II: concentrate feeding in the first stage + 3% fat addition in the later stage; Group III: concentrate feeding + pasture supplementation; Group IV: grazing feeding + concentrate) in East China were analyzed. The results are as follows: The average daily weight gain of Yangzhou geese in Group IV at 5 to 8 wk old was the highest, with the highest feed utilization rate. The body weight at 8 wk old was significantly higher than that of the group III (P < 0.05). The total mortality rate of Group I and II remained at a relatively low level, while the mortality rates of Group III and IV exceeded 17%. The SR, FECR, and FECW of female geese in Groups II, III, and IV were significantly higher than those in Control group I (P < 0.05). Different feeding methods have little effect on the quality of goose breast muscles, while in terms of leg muscles, Group II has the highest binding force, significantly higher than Group I (P < 0.05). The rate of chest muscle loss in group III was significantly higher than that in groups I and II (P < 0.05). However, the pH of leg muscles in groups I, II and III was significantly higher than that in group IV (P < 0.05). Group II has the highest protein and collagen content, and Group I has the highest fat content. Except for the significantly higher histidine content in Groups I And II compared to those in Groups III and IV (P < 0.05), there was almost no significant difference in amino acid content among the groups (P > 0.05). There was no significant difference in ALB/GLO content among the 3 groups of Groups II to IV, but they were all significantly higher than those of Group I (P < 0.05). There was no statistically significant difference in other indicators among the groups (P > 0.05). There was no significant difference in the content of Ca, Cu, Fe, P, Zn, and other elements in the muscles between the groups (P > 0.05). This study solved the problems of slow growth, poor meat performance, and low economic benefits in meat goose breeding, providing theoretical basis and data support for meat goose breeding enterprises and farmers to choose appropriate breeding modes.

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

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

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

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

Replacement of soybean oil by Hermetia illucens larvae fat in broiler diets alters the breast muscle lipidome and reduces lipid oxidation of the breast muscle during heat-processing.

Replacement of soybean oil by insect fat from Hermetia illucens (HI) has been reported to increase the proportions of saturated fatty acids (SFA) and decrease those of polyunsaturated fatty acids (PUFA) in total lipids of breast and thigh meat in broilers. Since the susceptibility of meat to oxidation is strongly dependent on its PUFA content, the present study hypothesised that replacement of soybean oil by HI larvae fat in broiler diets reduces the formation of lipid oxidation products, including oxidation products of cholesterol and phytosterols, in heat-processed breast muscle of broilers. To test this hypothesis, 100 male, 1-day-old Cobb 500 broilers were assigned to three groups and fed three different nutrient adequate diets, which varied only in the fat source (group HI-0: 0% HI larvae fat and 5% soybean oil; group HI-2.5: 2.5% HI larvae fat and 2.5% soybean oil; group HI-5.0: 5.0% HI larvae fat and 0% soybean oil), in a three-phase feeding system for 35 days. While the growth performance of the broilers was not different, the absolute and relative breast muscle weights were higher in group HI-5.0 than in group HI-0 (p < 0.05). The proportions of C12:0, C14:0, C14:1, C16:0, C16:1 and total SFA were higher and those of C18:1, C18:2 n-6, C18:3 n-3 and total PUFA were lower in breast muscle total lipids of group HI-5.0 than in groups HI-2.5 and HI-0 (p < 0.05). Lipidomic analysis of breast muscle revealed that the concentration of triacylglycerols was 46% and 53% lower in groups HI-2.5 and HI-5.0, respectively, than in group HI-0 (p < 0.05), whereas all other lipid classes detected did not differ among groups. Concentrations of thiobarbituric acid-reactive substances, 7α-hydroxycholesterol, 7ß-hydroxycholesterol and total cholesterol oxidation products in heat-processed breast muscle were lower in group HI-5.0 than in group HI-0 (p < 0.05). Concentrations of oxidation products of phytosterols in heat-processed breast muscle were generally much lower than those of cholesterol oxidation products and did not differ between the three groups of broilers. In conclusion, complete replacement of soybean oil with HI larvae fat in broiler diets strongly alters the fatty acid composition of breast muscle total lipids and reduce lipid oxidation of the breast muscle during heat-processing.

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

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

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.

Comparative analysis of amino acid content and protein synthesis-related genes expression levels in breast muscle among different duck breeds/strains.

Evidences have found important effects of breeds/strains on the content of amino acids (AAs) which is an important substrate for protein synthesis and contributes greatly to meat quality. Therefore, the objective of the present study was to compare the AAs content and protein synthesis-related genes expression levels in breast muscle of native breed (Jianchang duck (J)), hybrid strains (BH1, BH2, and MC♂ × (BGF2♂ × GF2♀)♀ (MC)), and commercial breed (Cherry Verry duck). Results showed that a total of 17 AAs (TAAs) was detected from breast muscle among 5 duck breeds/strains including 11 essential AAs (EAAs). Among these AAs, the contents of Proline, Threonine, Glutamine, Serine, Methionine, Phenylalanine, Histidine, and Cysteine were significant difference among 5 duck breeds/strains. The contents of EAAs, TAAs, and flavor AAs were higher in breast muscle of J and BH2 than those in other duck breeds/strains, and the ratio of EAAs/TAAs was higher in breast muscle of BH2. Furthermore, the expression levels of eukaryotic translation initiation factor 4E-binding protein 1, mammalian target of rapamycin, and proton-coupled amino acid transporter 1 were the highest in breast muscle of BH2, and that of solute carrier family 38 member 2 was the highest in breast muscle of J. Meanwhile, principal component analysis results showed that principal component 1 of BH1, principal component 3 of BH2, and principal component 2 of MC were positively corelated with EAAs/TAAs, and principal component 1 was positively correlated with flavor AAs and EAAs. In conclusion, compared to BH1, MC, and Cherry Verry duck, AA content was higher in breast muscle of BH2 and J, which might be associated with the higher expression levels of mammalian target of rapamycin, eukaryotic translation initiation factor 4E-binding protein 1, and proton-coupled amino acid transporter 1 in breast muscle of BH2 and solute carrier family 38 member 2 in breast muscle of J. The comparative analysis of AA content in breast muscle among different duck breeds/strains could provide an important basis for improving the nutritional value of duck meat in the breeding process.

Improved identification and classification accuracy of wooden breast by jointly using near-infrared spectroscopy and compression speed.

A uniform standard for classifying wooden breast (WB) is still being explored. The palpation method is the most common grading method in WB, but it requires a large number of people, who need professional sensory training. This study aims to verify the feasibility of near-infrared spectroscopy (NIR) and compression speed for the classification of WB. The quality characteristics of different categories of WB and normal breast (NB) show that the hardness of raw WB is significantly higher than that of NB, but no difference was observed in the shear force between NB and WB. The water holding capacity (WHC) of NB is better, and the weight, height, redness (a*) and yellowness (b*) of WB are higher than those of NB. Afterward, the NIR and compression speed were used to identify and classify WB by using Partial Least Squares Discriminant Analysis (PLSDA). The results show that the NIR can effectively distinguish between NB and WB, the total classification accuracy of modeling and prediction are 85.71% and 81.58%, respectively. Then, for WB, the compression speed was further used to achieve precise classification and the total classification accuracy of modeling and prediction from PLSDA are 80.65% and 82.14%, respectively. To a certain extent, the compression speed inspired by ergonomics can quantify and simulate the palpation method. The results clarify that WB and NB can be identified by combining the compression speed and NIR, and it can be used as an assessment tool for food classification.

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.

Effects of different breeds/strains on fatty acid composition and lipid metabolism-related genes expression in breast muscle of ducks.

Fatty acid composition contributes greatly to the nutritional value of meat, and breeds/strains are important factors affecting the composition of fatty acid. Recently, few studies have focused on the fatty acid composition in breast muscle of different duck breeds. Therefore, the objective of the present study was to compare the fatty acid composition and lipid metabolism-related genes expression in breast muscle of Jianchang duck (J), Cherry Verry duck (CV) and 3 crossbred strains (BH1, BH2 and MC♂ × (BGF2♂  × GF2♀)♀ (MBG)). Our results showed that the breast muscle of J had the highest contents of C22:1(n-9) but the lowest ratios of Æ©-omega 6 (Æ©n-6)/Æ©-omega 3 (Æ©n-3), Æ©-mono-unsaturated fatty acid (Æ©MUFA)/Æ©-saturated fatty acid (Æ©SFA) and Æ©-polyunsaturated fatty acid (Æ©PUFA)/Æ©SFA. The Æ©PUFA/Æ©SFA ratio was higher in breast muscle of MBG than in that of BH2 and CV, and the contents of C22:1(n-9), Æ©MUFA and Æ©PUFA were higher in BH1 than in BH2 and CV. Furthermore, the mRNA levels of SCD1, FADS2, ELOVL2, and ELOVL5 were significantly higher in MBG (P < 0.05), while those of FASD1 and ACACA were significantly higher in BH1 than in BH2 and CV (P < 0.05). Principal component analysis showed that fatty acids variation exhibited extensive positive loading on principal components (PCs). Correlation analysis showed that PC1 and PC3 of BH1, as well as PC1 of MBG were correlated with the mRNA levels of ACACA and FABP3, respectively. Thus, it could be concluded that the breast muscles of MBG and BH1 have better fatty acid composition, which was closely related to the increased expression levels of SCD1, FADS2, ELOVL2, and ELOVL5 genes in MBG but FADS1 and ACACA in BH1. Moreover, these results also showed that crossbreeding could optimize the composition of fatty acid in breast muscle of ducks.

Effect of synbiotics administered in ovo on microvascularization and histopathological changes in pectoral muscle and the biochemical profile of broiler chicken blood.

The aim of this study was to investigate whether injecting synbiotics to the egg air chamber on d 12 of embryo incubation will affect the processes of angiogenesis, and thus the share of histopathological changes in superficial pectoral muscle, as well as Ca and P in blood of 42-day-old broiler chickens. The eggs containing viable embryos were injected with 0.2 mL suspension of 1/physiological saline, 2/SYN1 composed of galactooligosaccharide (GOS) (trade name: Bi2tos®, Clasado Biosciences Ltd, UK) and L. salivarius or 3/SYN2 composed of RFO and L. plantarum. All birds were fed ad libitum the standard commercial feed mixtures: starter, grower, and finisher, with a constant access to water and feed. Injecting synbiotics in ovo on d 12 of the embryonal development significantly affected the blood supply to superficial breast muscle in broiler chickens. The highest density of capillaries in the muscle area under study and per muscle fiber were identified in the group of birds the egg air chamber of which was provided with synbiotic GOS+L. salivarius. Consequently, for the muscles of the birds injected with the same synbiotic there was found the highest share of normal fibers and least necrosis and splitting, as compared with the control. The conducted research confirms the relationship between the blood supply to the muscle and the occurrence of pathological changes. We have observed a positive effect of synbiotics on the microvascularization and the size of histopathological changes in the chicken muscle, which, from a practical perspective, can affect the health status and the meat quality. Blood biochemical analyses showed that the in ovo injection of synbiotics did not significantly affect the level of parameters, except for Ca and P. A significant increase in the concentration of these minerals in the blood of chickens injected with SYN1 could have a positive effect on the angiogenesis process.

Breast meat quality in males and females of fast-, medium- and slow-growing chickens fed diets of 2 protein levels.

The aim of this study was to evaluate the effects of genotype, sex, dietary protein level, and their interactions on select carcass characteristics and meat quality of fast- (Ross 308), medium- (Hubbard JA757) and slow-growing (ISA Dual) chickens (n = 2,520). The diet of the low-protein group of chickens had 6% lower CP than the commercial diet fed to the control group. When the chickens reached an average live weight of 2 kg, 10 males and 10 females of each genotype and the diet were selected for slaughter and breast meat-quality analysis. The dressing out and breast percentages were lower in the JA757 (-2.0 and -5.9%, respectively) and ISA Dual chickens (-9.9 and -14.3%, respectively) than those in the Ross 308 chickens. The ISA Dual chickens had higher abdominal fat percentage, higher DM and protein contents and lower ether extract content and shear force value in breast meat than the other genotypes. Significant interaction effects of genotype, sex, and diet were found on the color of breast skin. Among the various combinations of genotype, sex, and diet group, Ross 308 females fed the low-protein diet had the highest redness and yellowness of breast skin, highest pH45 value, and largest fibers, whereas ISA Dual females had the lowest color parameters and pH45 value, and ISA Dual males had the smallest muscle fibers. The low-protein diet was associated with decreased abdominal fat percentage and changes in meat quality parameters, including increased darkness, meat color intensity, drip loss, and muscle fiber area, in all genotypes. The results indicated greater differences in meat quality owing to genotype than to sex or dietary protein level.

Docosahexaenoic acid (22:6 n-3)-rich microalgae along with methionine supplementation in broiler chickens: effects on production performance, breast muscle quality attributes, lipid profile, and incidence of white striping and myopathy.

The effect of docosahexaenoic acid (DHA, 22:6 n-3)-rich microalgae and methionine (Met) supplementation on production performance, incidence of breast muscle white striping (WS), and pathology, lipid profile, and meat quality aspects in broiler chickens was investigated. The hypothesis tested was that feeding Met and n-3 fatty acid (FA)-rich diet enhances muscle n-3 FA content and meat quality while attenuating breast muscle WS and myopathy in broiler chickens. One hundred and forty four (n = 144) 10-day-old Cornish cross chicks were fed a corn-soybean meal-based diet containing 0% microalgae (control), 2% microalgae (diet 1), and diet 1 + 100% more National Research Council requirement of Met (diet 2) up to day 42 of growth. All diets were isocaloric and isonitrogenous. The chicks were kept in 6 pens with 8 chicks per replicate pen. Feed consumption and feed efficiency were calculated on day 21 and 42. On day 43, 3 chicks per pen (n = 18/treatment) were euthanized. The breast muscle (pectoralis major) was visually scored for muscle WS (1 = no striping, 2 = mild, 3 = severe) and was subjected to histopathology. Breast muscle lipid profile (total lipids, FA composition, cholesterol, lipid oxidation products), quality (moisture, color, drip loss, shear force, cook loss, pH), and chemical characterization (protein, minerals) were recorded. A one-way analysis of variance was carried out with diet as the main factor and significance was set at P < 0.05. The incidence of muscle WS was lower (P < 0.02) for control vs. diet 2 and a trend for reduction in WS was observed in birds fed diet 1 vs. control (P = 0.09). Histopathological changes consisted of floccular or vacuolar degeneration, fibrosis, lipidosis, interstitial inflammation, and lysis of fibers, and were minimal in diet 2 when compared to control (P < 0.05). The total lipid content was lowest in birds fed diet 1 (P < 0.05). Total n-3 and total long chain (≥20C) n-3 FA were highest in the breast muscle of diet 2 birds (P < 0.05). Muscle drip loss and shear force were highest in diet 2 (P < 0.05). Meat color (a∗, redness) was reduced (P < 0.05) and a trend for reduction in b∗ (yellowness) was observed in diet 2 (P = 0.07). No effect of diet on body weight gain, feed efficiency, breast muscle yield, pH, moisture, lipid oxidation products, cook loss, minerals (Ca, P, Mg, Na), cholesterol, or protein content was observed (P > 0.05). The results demonstrated a significant effect of DHA-rich microalgae along with Met supplementation in reducing the incidence of breast muscle striping and myopathy, while enriching meat with n-3 FA. However, inclusion of Met in microalgae-based diets could influence meat tenderness and color.

Characterization of chicken muscle disorders through metabolomics, pathway analysis, and water relaxometry: a pilot study.

Metabolite profiles of chicken breast extracts and water mobility in breasts were studied using proton nuclear magnetic resonance (1H-NMR) spectroscopy and time-domain NMR (TD-NMR) relaxometry, respectively, using normal breast (NB), and wooden breast (WB) and white striping (WS) myopathies in broilers. One thousand eight hundred sixty broilers were raised to commercial standards, receiving the same diets that were formulated as per the different growth stages. At 49 D of age, 200 animals were slaughtered following routine commercial procedures, and at 4 h postmortem, the whole breast (pectoralis major muscle) was removed and visually inspected by an experienced meat inspector who selected NB (without myopathies) and samples with the presence of WS and WB myopathies. Fifteen breasts (5 each of NB, WS, and WB) were analyzed through TD-NMR relaxometry, and samples of approximately 20 g were taken from each breast and frozen at -80°C for metabolite profiling through 1H-NMR spectroscopy. Multivariate statistical analysis was used to evaluate the effect on water relaxometry and metabolite profile in accordance with the presence and type of myopathy in the breast. 1H-NMR data showed that the metabolite profiles in WS and WB breasts were different from each other and from NB. This pilot study shows that myopathies appear to be related to hypoxia, connective tissue deposition, lower mitochondrial function, and greater oxidative stress compared with NB. The longitudinal and transverse relaxation time of the breasts determined by TD-NMR relaxometry was shorter for NB than that for WS and WB, indicating greater water mobility in breasts affected by myopathies. 1H-NMR spectroscopy can be used to differentiate the metabolism of WS, WB, and NB, and TD-NMR has the potential to be a fast, simple, and noninvasive method to distinguish NB from WB and WS. As a practical application, the metabolomic profile as per the occurrence of breast myopathies may be used for a better understanding of these issues, which opens a gap to mitigate the incidence and severity of WS and WB. In addition, the present study brings an opportunity for the development of a new and objective tool to classify the incidence of breast myopathies through TD-NMR relaxometry.

Research Note: Comparison of 3 methods used for estimating cook loss in broiler breast meat.

The objective of this study was to evaluate different methods used for estimating cook loss in broiler breast fillets (pectoralis major). Two experiments were conducted. In the first experiment, intact fillets were weighed, cooked to 75°C, and then subjected to 1 of 3 postcook handling treatments: cooling for 5 min at room temperature before reweighing (5-minute), cooling at room temperature until they reached room temperature before reweighing (RT), or cooling in ice water until they reached room temperature before reweighing (IW). In the second experiment, breast fillet portions were used to compare the effects of endpoint temperature (53°C, 57°C, 68°C, 75°C, or 90°C) on cook loss estimation by the 5-minute and RT methods. Breast fillets were collected from local chicken processing plants and trimmed to similar weight prior to cooking. Cook loss, cook loss retention, and total cook loss after 24 h in cooked fillets were measured for comparisons. Data showed that cook loss (<17%) and total loss (19.3%) estimated with the IW method were lower (P < 0.05) than those with the 5-minute and RT methods (19-21% for cook loss and 21.1-21.3% for total loss), which did not differ from each other. When the endpoint temperature was ≥75°C, no differences in cook loss estimates or moisture loss were noted between the 5 min and RT methods (after 3 h cooling). However, when the temperatures were 53°C to 75°C, cook loss estimations were significantly different (P < 0.05) between the 5 min and RT methods (more than 4%). Reduced endpoint temperature resulted in increasing differences (from less than 5% to more than 9%) in cook loss estimates. These results demonstrate that endpoint cooking temperature and postcooking sample handling methods may affect cook loss estimates in broiler breast meat.