Meat Quality Characteristics Research Articles

Effects of dietary Silybum marianum powder on growth performance, egg and carcass characteristics, immune response, intestinal microbial population, haemato-biochemical parameters and sensory meat quality of laying quails

The study aimed to assess the effects of different dietary Silybum marianum (SM, milk thistle) powder levels on growth performance, productivity, immunity, small intestine, haemato-biochemical parameters, meat quality, and egg and carcass characteristics of laying quails. The experimental subjects consisted of one hundred and eight 43-day-old quails divided into 3 treatments (0, 0.75, and 1.50% SM) with 4 replicates each. The egg characteristics and growth performance of the quails were evaluated. Quails were euthanized for evaluation of carcasses, microbiota, and sensory characteristics of meat. Blood samples were analyzed for haematology and biochemical profile. SM at 0.75% and 1.50% significantly (P < 0.05) increased feed intake, enhanced egg characteristics (number, weight, width, length, volume, weight of egg yolk, and eggshell thickness), jejunum and ileum length, spleen weight, lactobacillus population, sensory characteristics of meat, red blood cell (RBC), hemoglobin, erythrocytic indices, concentration of albumin, globulin and thyroid stimulating hormone (TSH). SM at 0.75% and 1.50% decreased (P < 0.05) carcass weight (abdominal fat, heart, neck, and pancreas), feed conversion ratio (FCR) based on eggs produced, percentages of heterophils and lymphocytes, concentration of lactate dehydrogenase, population of coliforms clostridia, and Escherichia coli. Aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and creatine kinase were not significantly (P > 0.05) altered by 0.75% and 1.50% SM. SM at both levels (0.75% and 1.50%) may improve growth, egg characteristics, immune response, intestinal morphology and microbiota, meat quality and erythropoiesis, and also lead to decreased cholesterol in laying quails. Economics can be improved, too. The authors recommend adding 1.0% of SM to quail diet.

The Effect of Diets Containing Different Amounts of Chasteberry Seed (Vitex Agnus Castus) On Performance, Carcass, Meat Quality and Stress Parameters of Japanese Quails

Aim of study: To investigate the effects of diets containing different amounts of chasteberry seeds (Vitex agnus- castus L.) on the growing performance, slaughter characteristics, breast meat quality characteristics and stress parameters of Japanese quails (Coturnix coturnix japonica). Area of study: Çakmar, Aydın, Türkiye. Material and methods: A total of 240 one-day-old mixed-sex Japanese quail chicks (9.38 ± 0.02 g) were divided into three treatments with four replicates of 20 birds each in a completely randomized design. The groups were fed a control diet without chasteberry seeds (CS0), a diet containing 25 g/kg chasteberry seeds (CS25), and a diet containing 50 g/kg chasteberry seeds (CS50). The experiment lasted 35 days. Main results: Body weight, body weight gain, and feed intake of the CS50 group were found to be lower than the other groups on days 0-35 (p&lt;0.05). No statistically significant difference was found in carcass and internal organ weights (p&gt;0.05). Except for breast meat water holding capacity, lightness, redness, and hue angle characteristics in females, the effects of diets containing different chasteberry seeds on the meat quality characteristics of male and female quails were not significant (p&gt;0.05). CS25 and CS50 diets caused a statistically significant increase (p&lt;0.05) in glutathione, catalase, and superoxide dismutase values and a statistically significant decrease (p&lt;0.05) in malondialdehyde values in male quail breast meat. Economically, although the lowest feed cost was obtained in the CS50 group, there was no difference in net profit between the groups. Research highlights: The addition of 25 g/kg chasteberry seeds in quail diets can be used easily without any negative effects. However, further studies are needed to determine the effects of different doses of chasteberry seeds on performance and meat quality.

Transcriptome analysis reveals the effects of Schizochytrium sp. on the meat quality attributes of Tan lambs

Schizochytrium sp., a feed additive, positively affects the quality of animal meat. In this study, the molecular mechanisms through which dietary Schizochytrium sp. affects the meat quality characteristics of Tan lambs were investigated using transcriptomic techniques. The findings demonstrate that the lambs supplemented with Schizochytrium sp. had a larger loin eye area and a higher average daily gain and intramuscular fat content (P < 0.05). They also had lower drip loss (at 24 and 48 h) and shear force (P < 0.05). Further, 745 genes were differentially expressed between lambs supplemented with Schizochytrium and the control group. Moreover, KEGG pathway analysis showed that the ECM-receptor interaction pathway, which is related to muscle generation and intramuscular fat deposition, was significantly enriched in the lambs administered a diet containing Schizochytrium sp. Herein, we identified some pivotal genes linked to muscular system development and lipid metabolism. Thus, using Schizochytrium sp. may boost the meat quality of Tan lambs by modifying the expression of genes related to hub pathways. The results supply a new basis to determine the molecular mechanisms through which Schizochytrium sp. supplementation regulates the meat quality characteristics of sheep.

RNA-Seq Reveals Pathways Responsible for Meat Quality Characteristic Differences between Two Yunnan Indigenous Chicken Breeds and Commercial Broilers.

Poultry is a source of meat that is in great demand in the world. The quality of meat is an imperative point for shoppers. To explore the genes controlling meat quality characteristics, the growth and meat quality traits and muscle transcriptome of two indigenous Yunnan chicken breeds, Wuding chickens (WDs) and Daweishan mini chickens (MCs), were compared with Cobb broilers (CBs). The growth and meat quality characteristics of these two indigenous breeds were found to differ from CB. In particular, the crude fat (CF), inosine monophosphate content, amino acid (AA), and total fatty acid (TFA) content of WDs were significantly higher than those of CBs and MCs. In addition, it was found that MC pectoralis had 420 differentially expressed genes (DEGs) relative to CBs, and WDs had 217 DEGs relative to CBs. Among them, 105 DEGs were shared. The results of 10 selected genes were also confirmed by qPCR. The differentially expressed genes were six enriched Kyoto Encyclopedia of Genes and Genomes (KEGG) biological pathways including lysosomes, phagosomes, PPAR signaling pathways, cell adhesion molecules, cytokine-cytokine receptor interaction, and phagosome sphingolipid metabolism. Interestingly, four genes (LPL, GK, SCD, and FABP7) in the PPAR signal pathway related to fatty acid (FA) metabolism were elevated in WD muscles, which may account for higher CF, inosine monophosphate content, and AA and FA contents, key factors affecting meat quality. This work laid the foundation for improving the meat quality of Yunnan indigenous chickens, especially WD. In future molecular breeding, the genes in this study can be used as molecular screening markers and applied to the molecular breeding of chicken quality characteristics.

Integrative metabolomics and transcriptomics analysis revealed specific genes and metabolites affecting meat quality of chickens under different rearing systems

Different rearing systems have varying effect on animal welfare and meat quality of poultry. Currently, there are no established standards for the rearing systems of Chinese indigenous chickens. Our study aimed to investigate the effects of different rearing systems on the meat quality, gene profiles, and metabolites of Chinese indigenous chickens (Nanchuan chicken). 10-wk-old Nanchuan chickens (n=360) were randomly divided into 3 groups (cage, net, and free-range groups), with 6 replicates per group (20 chickens per replicate). The experiment lasted for 12 wk. At 154-days-old, 36 healthy chickens (6 males and 6 females per group) were randomly selected, euthanized, and their breast muscles were collected to assess the meat quality parameters and histomorphological characteristics. Additionally, breast muscles from 18 random hens (3 males and 3 females per group) were used for metabolomics and RNA-seq analysis. The results showed that rearing systems significantly affected the meat quality and myofiber characteristics. The meat quality of breast muscles from free-range chickens was superior to that of caged chickens, characterized by more tender meat and smaller myofiber cross-sectional areas. Integrative metabolomics and transcriptomics analysis revealed that the differentially expressed genes of chicken breast muscles were primarily involved in the myofiber differentiation. Mechanically, the improved meat quality of breast muscle in free-range chickens were mainly associated with enhanced skeletal muscle differentiation facilitated by fibromodulin, increased levels of up-regulated Acetyl-L-carnitine and Propionylcarnitine level, and decreased levels of Nonanoic acid and Elaidic acid abundance (Graphical abstract). This provides a comprehensive understanding of the most effective and sustainable breeding, production, and rearing systems for Chinese indigenous chickens. It also contributes to the current knowledge of the molecular mechanisms underlying the effects of rearing systems on growth performance and meat quality of chickens.

Alleviating Heat Stress in Fattening Pigs: Low-Intensity Showers in Critical Hours Alter Body External Temperature, Feeding Pattern, Carcass Composition, and Meat Quality Characteristics.

Heat stress is a significant environmental problem that has a detrimental impact on animal welfare and production efficiency in swine farms. The current study was conducted to assess the effect of low-intensity showers, provided during critical high-temperature hours daily, on body external temperature, feeding pattern, and carcass and meat quality characteristics in fattening pigs. A total of 400 animals (200 barrows and 200 gilts) were randomly allotted in 40 pens. A shower nozzle was installed over 20 pens (half barrows and half gilts) where pigs received a low-intensity shower for 2 min in 30 min intervals from 12 to 19 h (SHO group). Another group without showers was also considered (CON). Feeder occupancy measurement, thermographic measures, and carcass and meat quality parameters were studied. In the periods with higher environmental temperatures, SHO animals showed an increase in the feeder occupancy rate compared to the CON group. A decrease in temperature was observed after the shower, regardless of the anatomical location (p < 0.005). The treatment with showers led to higher values than in the CON group of 4.72%, 3.87%, 11.8%, and 15.1% for hot carcass weight, lean meat yield, and fat thickness in Longissimus Dorsi (LD) and Gluteus Medius muscles, respectively (p < 0.01). Pork from CON showed a 14.9% higher value of drip loss, and 18.9% higher malondialdehyde concentration than SHO (p < 0.01); meanwhile, intramuscular fat content was 22.8% higher in SHO than in CON (p < 0.01). On the other hand, the CON group exhibited higher L* (2.13%) and lower a* and b* values (15.8% and 8.97%) compared to the SHO group. However, the pH20h of the CON group was significantly lower than that of the SHO group (p < 0.001), indicating a softer pH decrease. Related to fatty acids in subcutaneous outer and inner layers and intramuscular fat, the CON group showed higher ΣSFA and lower ΣMUFA and Δ9-desaturase indexes than SHO (p < 0.05). In conclusion, the amelioration of heat stress through showers at critical times should be considered an interesting tool that improves both carcass and meat quality, as well as animal welfare.

Contribution to Characterizing the Meat Quality of Protected Designation of Origin Serrana and Preta de Montesinho Kids Using the Near-Infrared Reflectance Methodology.

The aims of this study were to describe and compare the meat quality characteristics of male and female kids from the "Serrana" and "Preta de Montesinho" breeds certified as "Cabrito Transmontano" and reinforce the performance of near-infrared reflectance (NIR) spectra in predicting these quality characteristics and discriminating among breeds. Samples of Longissimus thoracis (n = 32; sixteen per breed; eight males and eight females) were used. Breed significantly affected meat quality characteristics, with only color and fatty acid (FA) (C12:0) being influenced by sex. The meat of the "Serrana" breed proved to be more tender than that of the "Preta de Montesinho". However, the meat from the "Preta de Montesinho" breed showed higher intramuscular fat content and was lighter than that from the "Serrana" breed, which favors its quality of color and juiciness. The use of NIR with the linear support vector machine regression (SVMR) classification model demonstrated its capability to quantify meat quality characteristics such as pH, CIELab color, protein, moisture, ash, fat, texture, water-holding capacity, and lipid profile. Discriminant analysis was performed by dividing the sample spectra into calibration sets (75 percent) and prediction sets (25 percent) and applying the Kennard-Stone algorithm to the spectra. This resulted in 100% correct classifications with the training data and 96.7% accuracy with the test data. The test data showed acceptable estimation models with R2 > 0.99.

Effects of dietary Allium mongolicum Regel powder supplementation on the growth performance, meat quality, antioxidant capacity and muscle fibre characteristics of fattening Angus calves under heat stress conditions

The aim of this study was to investigate the effects of dietary Allium mongolicum Regel powder (AMRP) supplementation on the growth performance, meat quality, antioxidant capacity and muscle fibre characteristics of fattening Angus calves. Growth performance data and longissimus thoracis (LT) samples were collected from four groups of fattening Angus, which were fed either a basal diet (CON) or a basal diet supplemented with an AMRP dose of 10 (LAMR), 15 (MAMR), or 20 g/animal/day AMRP (HAMR) for 120 days before slaughter. AMRP addition to the feed improved growth performance and meat quality and altered muscle fibre type. Some responses to AMRP supplementation were dose dependent, whereas others were not. Together, the results of this study demonstrated that dietary supplementation with 10 g/animal/day AMRP was the optimal dose in terms of fattening calf growth performance, while 20 g/animal/day AMRP supplementation was the optimal dose in terms of meat quality.

PSV-13 The influence of diet type on beef cattle performance and meat quality characteristics

Abstract The objective of this study was to determine what additive effect hormonal implants and inclusion of beta-agonists in the diet have on carcass quality in yearling beef steers. Hereford-cross steers [n = 21; initial body weight (BW) = 450 ± 15 kg] were assigned to one of three drylot pens based on initial BW and sire so that each pen had an equal starting BW and sires were equally represented in each pen. Each drylot pen was assigned to one of three treatments: receiving a hormonal implant (IMP), consuming a beta-agonist (BAG), or receiving both of the previous treatments (AND). All steers were fed a mixed ration consisting of 30.0% rye silage, 28.0% DDGS, 30.0% rolled corn, 10.5% soybean meal, and 1.5% mineral supplement [22.0% CP, 2.90 Mcal ME/kg dry matter (DM)]. Animals were fed daily at 0700 and 1700 h and weighed weekly at 0630 h. For the duration of the trial, animals were housed in drylot pens with ad libitum access to feed and water and had shade structures in each pen. Following a 15-d adaptation period, feed intake was recorded for 45 d. Body weight gain for each treatment group were 1.26, 1.28, and 1.48 kg/d for IMP, BAG, and AND, respectively. Animals on the AND treatment were significantly more feed efficient than the IMP treatment with F:G ratios of 5.9 kg/kg gain and 6.8 kg/kg gain, respectively. After the intake portion of the study was completed, an animal from each pen was slaughtered and evaluated for carcass quality. Hot carcass weights for diets IMP, BAG, and AND were 347.4, 352.9, and 394.8 kg, respectively. Data were analyzed as a completely random design in SAS v9.4. There was not a significant difference between the IMP treatment and the AND treatment based on assessment from Warner-Bratzler shear force, carcass yield, marbling score, and sensory assessment (P &amp;gt; 0.05); however, the BAG treatment had less marbling than the other two treatments. It was concluded that the additive effect of using both a hormonal implant and a beta-agonist can improve feed intake and feedlot performance without detrimental effects on carcass quality.

PSVI-14 Changes in zinc oxide concentration in feed and effects of probiotic addition to weaning to finishing pig diet by microbiome analysis

Abstract To analyze the implications of dietary zinc oxide (ZnO) with probiotic administration on productivity, fecal index, meat quality characteristics, odorous substances, and microbiome analysis in weaning-finishing pigs, 200 weaned piglets (3 barrows and 2 gilts) were radomly assigned (average body weight = 6.65 ± 0.66 kg) into four treatments with ten repetitions per treatment. The treatments consisted of varying ZnO content (2,500 ppm or 75 ppm) and probiotic percentages (0.1% or 0.3%), as follows: TRT1 (75 ppm ZnO), TRT2 (75 ppm ZnO with 0.3% or 0.1% probiotic), TRT3 (2,500 ppm or 75 ppm ZnO), and TRT4 (2,500 ppm or 75 ppm ZnO with 0.3% or 0.1% probiotic). In comparison with the TRT1 treatment group, the TRT2 and TRT4 treatment groups had greater (P &amp;lt; 0.05) body weight at wk 12, 18, and 22 of the trial and greater (P &amp;lt; 0.05) average daily gain at wk 12, 18, 22, and the overall period (P &amp;lt; 0.05). Additionally, pigs fed ZnO with the probiotic included a diet that reduced (P &amp;lt; 0.05) NH3 and H2S at wk 18 and 22, and CO2 at wk 22, in the TRT2 and TRT4 groups compared with the TRT1 group. However, the fecal score and meat quality exhibited no substantial change (P &amp;gt; 0.05). By incorporating probiotics into the pig diet along with ZnO supplementation, a significant (P &amp;lt; 0.05) increase in alpha diversity and beta diversity, as well as a higher relative abundance of phyla and genera of Firmicutes was found. Furthermore, based on taxonomic analysis, the dietary treatment group (TRT 4) showed a significant (P &amp;lt; 0.05) increase in beneficial bacteria (Prevotella, Lactobacillus) while simultaneously reducing (P &amp;lt; 0.05) pathogenic bacteria (Clostridium_sunsu_strico_1, Campylobacteria, Olsenella) compared with the TRT1 treatment group. An improvement in diversity and expansion of the identified taxonomic groups has been associated with healthier gut health. The results indicated that the effects of ZnO with probiotics on the improvement of performance and reduced gas emissions in pigs may be associated with the modulatory effect on the gut microbiome. In conclusion, the current study provides insights into using decreased ZnO with probiotic inclusion as a novel feeding strategy to improve pig gut health and overall performance.

Red propolis extract reduces the lipid oxidation of lamb meat

Context Brazilian red propolis stands out for its diverse composition, which includes phenolic compounds whose effects may be similar to those of synthetic feed additives. Aims The objective of this study was to evaluate the effects of red propolis extract on the carcass and meat characteristics of lambs finished under confinement conditions. Methods The meat quality characteristics of the longissimus lumborum muscle were evaluated in 35 Santa Inês lambs, with an average age of 5 months and an initial average body weight of 17.08 ± 2.36 kg (mean ± s.d.), submitted to five distinct treatments (0, 7, 14, 21, 28 mL of red propolis extract/animal.day) over 68 days. Key results The use of propolis did not affect (P &gt; 0.05) the characteristics of the carcass, as well as the chemical composition and cholesterol content. Among the physico-chemical parameters of meat, only the shear force had a quadratic effect (P &lt; 0.05). There was also an exponential effect for lipid oxidation (P &lt; 0.05), where the treatment with propolis had greater antioxidant effect. Meat with a lower content (P &lt; 0.05) of saturated fatty acids was observed in sheep that received extract. There was also an increase (P &lt; 0.05) in the content of monounsaturated acids and consequently an improvement in nutritional quality, atherogenicity and thrombogenicity indexes of desirable fatty acids. Conclusions The red propolis extract improved the lipid profile of the lamb meat. We recommend the inclusion of 7 mL red propolis extract/animal.day (or 59.50 mg total flavoloids/animal.day) in the diet of lambs finished under confinement conditions. Implications The red propolis extract proved to be a viable alternative as a natural feed additive.

A solution for fillet quality: Slaughter age's effect on protein mechanism and oxidation

Physico-chemical properties of fish flesh are reliable predictors of fillet quality and nutritional value. In our study, the age-related variations of the chemical composition, pH, water activity (aw), water holding capacity (WHC), color and texture analysis, protein thermal stability, myofibrillar fragmentation index (MFI), glycogen content, protein oxidation and protein profiles were investigated in Oncorhynchus mykiss (rainbow trout) fillet. The results revealed that protein denaturation temperatures (Tmax1 and Tmax2) decreased by 2 % and 11.6 % depending on fish age. Tmax1 and Tmax2 values in the same groups were raised 71 % at 11 months' fish and this increase was 58 % at 23 months’ fish. An age-related reduction by 66.6 % and 31.25 % was noticed for protein oxidation markers sulfhydryl groups and disulfide bonds. MFI value increased by 86.6 % connected with age.The characteristics of fish meat quality are complex and are influenced by various factors that affect the degree of freshness of the product and its acceptance in the market. Taking into account the different demands of the consumer, this study has shown that age at slaughter has an impact on final product quality and that the recommended age at slaughter, taking into account market weight, positively affects meat quality.

Dietary inclusion of defatted silkworm (Bombyx mori L.) pupa meal in broiler chickens: phase feeding effects on nutritional and sensory meat quality

The present experiment was conducted to test the effect of a 4% defatted silkworm (Bombyx mori) pupae meal (SWM) incorporation into chickens’ diets at different growth phases on meat quality characteristics and sensory traits. Ninety ROSS 308 day-old male broiler chickens were randomly assigned to three dietary groups, with five replicated pens/diet: the first group received a control (C) diet throughout the growing period of 42 days, the second group received a diet with 4% SWM (SWM1) during the starter phase (1–10 days) and the C diet up to slaughter, whereas the third group was fed the C diet during the starter phase and 4% SWM during the grower and finisher phases (SWM2). Diets were isonitrogenous and isoenergy, and birds had free access to feed and water throughout the experimental trial. At 42 days of age, 15 chickens/treatment were slaughtered at a commercial abattoir. Fatty acid (FA) and amino acid (AA) profiles and contents, as well as oxidative status, were determined in both breast and leg meat cuts. Also, a descriptive sensory analysis was performed on breast meat by trained panelists. Results highlighted that the SWM2 treatment increased the n-3 proportion and content in both breast or leg meat, thereby improving the omega-6/omega-3 (n-6/n-3) ratio in both cuts (P<0.001). However, the dietary treatment had no significant effect on the oxidative status of either breast or leg meat (P>0.05). The SWM had a limited impact on overall sensory traits of breast meat, but it did contribute to improved meat tenderness in SWM-fed chickens (P<0.01). Furthermore, SWM1 meat exhibited higher juiciness (P<0.05) and off flavor intensity (P<0.05) compared to the control meat. Overall, the present experiment indicated that defatted SWM holds promise as an alternative ingredient in chicken rations, ensuring satisfactory meat quality. Furthermore, administering SWM during the grower-finisher phase demonstrated beneficial effects on meat healthiness, ultimately enhancing n-3 fatty acids content and reducing the n-6/n-3 ratio.

Carcass characteristics and meat quality of goat kids according to the Colomer – Rocher carcass fatness and conformation classes

Classifying kid carcasses according to their fatness and conformation scores guides producers toward higher quality and income-generating production methods and determines the ideal slaughter time. This study aimed to determine the effects of Colomer–Rocher fatness and conformation classes on carcass and meat quality characteristics in goat kids. A total of 102 male kid carcasses were used in the study. Carcasses were divided into fatness (1-, 1, 1+, 2-) and conformation (P-, P, P+; O-) classes according to the Colomer–Rocher classification, and these groups were accepted as the experimental group. Hierarchical clustering analysis divided the kid carcasses into 5 clusters using certain carcass characteristics. Differences between clusters in most of the carcass characteristics were significant. The difference between the cluster groups in terms of meat colour and sensory characteristics was also significant. Fatness and conformation classes significantly affected most characteristics except kidney knob and channel fat (KKCF) percentages and carcass joints percentages. The Colomer-Rocher conformation classification was found to be more discriminatory in terms of meat quality than the fatness classification.

Broiler Spaghetti Meat Abnormalities: Muscle Characteristics and Metabolomic Profiles.

Spaghetti meat (SM) is a newly identified muscle abnormality that significantly affects modern broiler chickens, consequently exerting a substantial economic impact on the poultry industry worldwide. However, investigations into the meat quality and the underlying causative factors of SM in broilers remain limited. Therefore, this study was undertaken to systematically evaluate meat quality and muscle fiber characteristics of SM-affected meat. To elucidate the disparities between SM-affected and normal (NO) muscles in broiler chickens reared under identical conditions, we selected 18 SM-affected breast tissues and 18 NO breast tissues from 200 broiler chickens raised according to commercial standards under the same conditions for our study. The results showed that compared with the NO group, the muscle surface of the SM group lost integrity, similar to strip and paste. The brightness and yellowness values were significantly higher than those of the NO group. On the contrary, the shear force and protein were significantly lower in the SM group. Microscopic examination revealed that the muscle fibers in the SM group were lysed, necrotic, and separated from each other, with a large number of neutrophils diffusely distributed on the sarcolemma and endometrium. Thirty-five significantly different metabolites were observed in the breast muscles between both groups. Among them, the top differential metabolites-14,15-DiHETrE, isotretinoin, L-malic acid, and acetylcysteine-were mainly enriched in lipid metabolism and inflammatory pathways, including linoleic acid, arachidonic acid, phenylalanine, and histidine metabolism. Overall, these findings not only offer new insights into the meat quality and fiber traits of SM but also contribute to the understanding of potential mechanisms and nutritional regulators for SM myopathy.

Effects of Supplementing Tributyrin on Meat Quality Characteristics of Foreshank Muscle of Weaned Small-Tailed Han Sheep Lambs.

This experiment aimed to evaluate the effects of supplementing tributyrin (TB) on the meat quality characteristics of foreshank muscle of weaned lambs. A total of 30 healthy weaned Small-Tailed Han female lambs with body weights ranging from 23.4 to 31.6 kg were selected and randomly divided into five groups, and each group consisted of 6 lambs. The control group was fed a basic total mixed ration, while other groups were fed the same ration supplemented with 0.5, 1.0, 2.0, and 4.0 g/kg TB, respectively. The experiment lasted 75 d, including 15 d of adaptation. Foreshank muscle obtained at the same position from each lamb was used for chemical analysis and sensory evaluation. The results showed that supplementing TB increased the muscle contents of ether extract (p = 0.029), calcium (p = 0.030), phosphorus (p = 0.007), and intermuscular fat length (p = 0.022). Besides, TB increased the muscle pH (p = 0.001) and redness (p < 0.001) but reduced the lightness (p < 0.001), drip loss (p = 0.029), cooking loss (p < 0.001), shear force (p = 0.001), hardness (p < 0.001), cohesiveness (p < 0.001), springiness (p < 0.001), gumminess (p < 0.001), and chewiness (p < 0.001). In addition, TB increased the muscle content of inosine-5'-phosphate (p = 0.004). Most importantly, TB increased the muscle contents of essential amino acids (p < 0.001). Furthermore, TB increased the saturated fatty acids level in the muscle (p < 0.001) while decreasing the unsaturated fatty acids content (p < 0.001). In conclusion, supplementing TB could influence the meat quality of foreshank muscle of weaned lambs by modifying the amino acid and fatty acid levels.

A large-scale comparison of the meat quality characteristics of different chicken breeds in South China

Meat quality traits are essential for producing high-quality broilers, but the genetic improvement has been limited by the complexity of measurement methods and the numerous traits involved. To systematically understand the meat quality characteristics of different broiler breeds, this study collected data on slaughter performance, skin color, fat deposition, and meat quality traits of 434 broilers from 12 different breeds in South China. The results showed that there was no significant difference in the live weight and slaughter weight of various broiler breeds at their respective market ages. Commercial broiler breeds such as Xiaobai and Huangma chickens had higher breast muscle and leg muscle rates. The skin and abdominal fat of Huangma chickens cultivated in the consumer market in South China exhibited significantly higher levels of yellowness compared to other varieties. Concerning fat traits, we observed that Wenchang chickens exhibited a strong ability to fat deposition, while the younger breeds showed lower fat deposition. Additionally, there were significant positive correlations found among different traits, including traits related to weight, traits related to fat, and skin color of different parts. Hierarchical clustering analysis revealed that fast-growing and large broiler Xiaobai chickens formed a distinct cluster based on carcass characteristics, skin color, and meat quality traits. Principal component analysis (PCA) was used to extract multiple principal components as substitutes for complex meat quality indicators, establishing a chicken meat quality evaluation model to differentiate between different breeds of chickens. At the same time, we identified 46, 22, and 20 SNP loci and their adjacent genes that were significantly associated with muscle mass traits, fat deposition, and skin color through genome-wide association studies (GWAS). The above results are helpful for systematically understanding the differences and characteristics of meat quality traits among different breeds.

Changes in meat quality and muscle fiber characteristics of beef striploin (M. longissimus lumborum) with different intramuscular fat contents following freeze-thawing

Adipose (fat) tissue has different physical properties from skeletal muscle tissue, and its moisture content is relatively low; thus, freezing or freeze-thawing of meat affects its quality. However, the effect of intramuscular fat (IMF) of meat has not been comprehensively studied. The changes in the meat quality and muscle fiber characteristics of beef striploin (M. longissimus lumborum; LL) with different IMF contents (63.5 g/kg‒260.3 g/kg; n = 52) following freeze-thawing were examined. Freeze-thawing destroyed muscle fibers, and the fiber size was decreased irrespective of muscle fiber type or IMF content. However, the size of type I and IIA muscle fibers was largely altered in LL muscles with lower IMF content. Low IMF content increased the tenderness and decreased the pH of LL muscles; the effects of low IMF content on discoloration in LL muscles were less prominent. Larger IMF particles and higher density were associated with reduced thawing loss in LL muscles. IMF content reduced the lightness of frozen-thawed meat, but it did not excessively reduce water-holding capacity and pH. Thus, deterioration in meat quality can be prevented by considering the IMF content during the freezing process.

The Effects of Slaughter Age and Sex on Carcass Traits, Meat Quality, and Leg Bone Characteristics of Farmed Common Pheasants (Phasianus colchicus L.).

The aim of this study was to determine the effects of slaughter age and sex on the carcass characteristics, meat quality parameters, and leg bone dimensions of common pheasants. The study material consisted of 40 common pheasants, including 10 males and 10 females at 12 weeks of age and 10 males and 10 females at 15 weeks of age. The birds were kept on a farm in a semi-intensive system. The slaughter age had significant effects on the eviscerated carcass weight; the percentage of skin with subcutaneous fat; the wings percentage; electrical conductivity (EC24); the work required to cut the samples (cutting work); redness (a*); the intramuscular fat content in the breast meat; and the protein, intramuscular fat, water, and collagen contents in the leg meat. The sex of the pheasants had significant effects on the eviscerated carcass weight; the contents of leg muscles, skin with subcutaneous fat, and wings in the carcasses; and the electrical conductivity, thermal loss, lightness (L*), and redness (a*) of the breast muscles. It also significantly affected the protein and water contents of the pectoral and leg muscles, the intramuscular fat contents of the leg muscles, the texture traits of the pectoralis major muscle, and all femur and tibia bone dimensions. The results indicate a greater influence of sex compared to slaughter age on the pheasant traits studied. We confirmed the occurrence of a clearly marked sexual dimorphism in birds of this species. Both factors (slaughter age and gender) have significant effects on the nutritional and technological value of pheasant meat. The few studies on meat texture and the dimensions of pheasant leg bones indicate a need for continued research in this area in the future.

Identification of Characteristic Bioactive Compounds in Silkie Chickens, Their Effects on Meat Quality, and Their Gene Regulatory Network.

Silkie chicken, an important chicken breed with high medicinal and nutritional value, has a long history of being used as a dietary supplement in China. However, the compounds with health-promoting effects in Silkie chickens remain unclear. In the present study, we conducted a comprehensive analysis of metabolic and lipidomic profiles to identify the characteristic bioactive compounds in Silkie chickens, using a common chicken breed as control. The results showed that the levels of 13 metabolites including estradiol, four lipid subclasses including cardiolipin (CL), eight lipid molecules, and three fatty acids including docosahexaenoic acid (C22:6) were significantly increased in Silkie chickens, which have physiological activities such as resisting chronic diseases and improving cognition. These characteristic bioactive compounds have effects on meat quality characteristics, including improving its water-holding capacity and umami taste and increasing the content of aromatic compounds and phenols. The differentially expressed genes (DEGs) between the two chicken breeds revealed the regulatory network for these characteristic bioactive compounds. Fifteen DEGs, including HSD17B1, are involved in the synthesis of characteristic metabolites. Eleven DEGs, including ELOVL2, were involved in the synthesis and transport of characteristic lipids and fatty acids. In summary, we identified characteristic bioactive compounds in Silkie chickens, and analyzed their effects on meat quality characteristics. This study provided important insight into Silkie chicken meat as a functional food.