Meat Quality Research Articles

Feeding broilers with the addition of an Ilex paraguariensis coproduct affects zootechnical performance and meat quality responses.

During the harvest ofIlex paraguariensis, approximately 2-5 tons per hectare of thick stems are left on the soil surface. The outer portion of these stems, referred to as the coproduct, constitutes 30% of the total residue mass. Although this coproduct has been partially characterized in terms of its phytochemical profile, its technological applications remain unexplored. The objective of this research is to evaluate whether broilers fed with feed incorporating I. paraguariensis harvest prunings will exhibit improved zootechnical performance as well as enhanced biochemical and impacts on meat quality. One-day-old Cobb 500 broilers (n = 300) were raised for 42days in the broiler shed at the experimental farm in housed in 2.0 m2 pens with a 10cm layer of poultry litter and equipped with tubular feeders and nipple drinkers. They were arranged in a completely randomized design, comprising four treatments with five replicates of 15 birds each. The treatments consisted of the following diets: a basal diet (0%; the control), feed with 1% coproduct (1% treatment), feed with 2% coproduct (2% treatment), and feed with 3% coproduct (3% treatment). Broilers were assessed for zootechnical performance, intestinal morphometry, and serum biochemical properties. Additionally, meat quality was evaluated, including centesimal composition, chlorogenic acid content, antioxidant activity, metal concentration, and fatty acid profile. Chlorogenic acid was not detected in the meat of broiler chickens. The inclusion of the coproduct impacted both zootechnical performance and meat quality, with a linear effect proportional to the concentration of the additive used in the diet; that is, the worst performance was seen in chickens that consumed 3% of the co-product. It reduced feed consumption and weight gain, lowered cholesterol and triglyceride levels in broiler blood, but increased polyunsaturated fatty acids in the meat, one effect verified for the two largest inclusions (2 and 3% of the co-product). In the intestine, greater villus height and levels of reactive oxygen species were observed in the highest dose of the additive, a group of birds in which greater activity of the enzymes creatine kinase and pyruvate kinase was also observed. In general, none of the doses tested proved to be effective in enhancing productive performance; in addition, it did not increase the concentration of chlorogenic acid in the meat, which would be our hypothesis of having a nutraceutical food.

Lactiplantibacillus plantarum improves the growth performance and meat quality of broilers by regulating the cecal microbiota and metabolites

Lactiplantibacillus plantarum improves the growth performance and meat quality of broilers by regulating the cecal microbiota and metabolites

Preliminary Research on Dietary Supplementation of Potassium Magnesium Sulphate on Transport Stress in Finishing Pigs Prior to Slaughter

Transport stress prior to slaughter frequently induces a stress response, negatively affecting meat quality. This study investigated the impact of dietary potassium magnesium sulphate (PMS) supplementation during the fattening stage on the stress response and meat quality in finishing pigs subjected to transport stress. The experiment involved two phases. Initially, 48 finishing pigs (68.00 ± 0.40 kg) were randomly allocated into two groups: a control group receiving a basal diet (CON) and a PMS-supplemented group receiving the basal diet with 0.50% PMS. Each group was housed in six pens, with four pigs per pen. After 60 days of feeding, in the second phase, two pigs from each pen were randomly selected for slaughter, with one pig subjected to a 4 h transportation stress prior to slaughter. Pigs were categorized into four treatment groups based on diet and stress: (1) control without transport stress, (2) control with transport stress, (3) PMS-supplemented without transport stress, and (4) PMS-supplemented with transport stress. Serum, jejunum, and longissimus thoracis muscle (LM) samples were collected. The results indicated that dietary PMS supplementation did not significantly affect growth performance during the fattening stage (p > 0.05). However, following transport, the PMS pigs showed a reduction in norepinephrine and cortisol concentrations (p = 0.09, p < 0.05) and a significant increase in serum glutathione peroxidase (GSH-Px) activity (p < 0.05). Furthermore, PMS supplementation significantly increased serum catalase (CAT), total antioxidant capacity (T-AOC), alkaline phosphatase (AKP) activity, and high-density lipoprotein cholesterol (HDL-C) levels (p < 0.05), while significantly reducing cholesterol (CHO) levels (p < 0.05). Transport stress adversely affected the intestinal health of finishing pigs, as evidenced by a decrease in intestinal villus height (0.05 < p < 0.1), a condition ameliorated by PMS supplementation. Additionally, transported pigs exhibited a higher drip loss24h in LM (p < 0.05), which was also alleviated through PMS supplementation. In conclusion, PMS supplementation mitigates transport stress and improves meat quality in finishing pigs.

Effects of lipoic acid on production performance, meat quality, serum biochemistry and antioxidant function in heat-stressed broilers.

This study was aim to investigate the effects of lipoic acid (ALA) on performance, meat quality, serum biochemistry and antioxidant function of broilers under heat stress (HS). Two hundred1-day-old Cobb broilers were randomly divided into four treatment groups and each treatment consisted of 4 replicates of 10 broilers each. The treatment group adopts a 2 × 2 two-factor setting, which is divided into two diets (basic diet or 250mg/kg ALA diet) and two temperatures (24 ± 1℃ or 33 ± 1℃). Starting from the 28th day of age, broilers are kept at room temperature (24 ± 1℃) or exposed to cyclic HS (33 ± 1℃ from 8:00 am to 18:00, 24 ± 1℃ from 18:00 to 8:00 am). HS significantly decreased serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), direct bilirubin (D-BIL), total antioxidant capacity (T-AOC) and total superoxide dismutase (T-SOD). However, HS increased breast meat pH, serum uric acid (UA), total cholesterol (TC) and malondialdehyde (MDA). Dietary ALA significantly decreased leg meat shear force and water loss rate, serum total bilirubin(T-BIL), UA, triglyceride (TG) and MDA of broilers. However, it increased daily gain (ADG), serum D-BIL and T-SOD. There is a significant interaction between temperature and additives. HS can destroy the balance of the oxidation-antioxidant system, and lead to damage to liver and kidney function and confusion energy metabolism. Dietary ALA improves the antioxidant capacity of broilers, reduces the level of blood lipids and liver and kidney metabolism, and increases the daily gain of heat-stressed broilers.

Effects of different environmental enrichment tools to improve behavior, welfare, and growth performance of broiler chickens.

This study was performed to evaluate the effect of various environmental enrichment (EE) tools on broiler growth, welfare, behavior, carcass, and meat quality. A total of 300 commercial broilers were randomly divided into 05 treatments. The treatments include various EE tools such as perches, balls, hanging bottles, and laser lights placed for birds and a control group. The birds kept with perches and hanging bottles had the lowest feed intake, while the birds in the control group showed the poor feed conversion ratio compared to all EE treatments. Broilers raised under different EE were more active and exhibited frequent maintenance behavior (i.e., walking, jumping, running, wing flapping and aggressiveness) than the control group which spent more time in feeding and drinking. Moreover, the birds with EE had reduced incidence of toe injuries and footpad dermatitis than those in the control group. Birds reared with perches had higher meat lightness, whereas meat from the birds in the control group had lower cooking loss and shear force. It can be concluded that the use of various EE tools improved the welfare and behavior of the birds without affecting bodyweight of the birds. Furthermore, the use of hanging bottles and placing perches reduced feed intake and improved feed conversion ratio.

Comparative Transcriptomic Analysis Provides Insight into Spatiotemporal Expression Patterns of Pivotal Genes During Critical Growth Stages in Min Pig Breed

The growth and development of animals are dynamic processes characterized by fluctuations. Min pigs, a local breed renowned for their superior meat quality, present an intriguing yet poorly understood relationship between this quality and their growth and development patterns. To elucidate this relationship, we employed a multi-faceted approach that included comparative transcriptomics, quantitative real-time PCR (qRT-PCR), selection pressure analysis of key genes, and three-dimensional protein structure simulations. Our findings revealed that 150 days (150 d) of age represented a pivotal turning point in the growth and development of Min pigs. Thirteen key genes exhibiting significant differential expression between early and late growth stages were identified. Notably, the CDK2 gene demonstrated specific high expression in the hind limb muscles and adipose tissues during the later growth stages. Comparative analysis with the African warthog revealed that while the CDK2 protein structure remained conserved, base mutations in upstream and downstream non-coding regions resulted in strong positive selection pressure on the CDK2 gene. These results suggest that CDK2 plays a crucial role in defining the spatiotemporal characteristics of meat development during the domestication of Min pigs. This study provides critical insights into the growth and development patterns of domestic pigs and offers a robust scientific foundation for improving meat quality traits through domestication.

Evaluation of the Effect of Bacteriophages and Organic Acids as a Feed Additive to Reduce Salmonella enteritidis in Challenged Chickens.

This study aimed to compare the effects of dietary supplementation of bacteriophage (BP) and acidifiers on performance, meat quality, morphology, and intestinal microbiota in chickens challenged and unchallenged with Salmonella enteritidis (SE) and also to investigate the possibility of replacing them in the diet with antibiotics. A total of 1760 male Ross (308) chicks were randomly assigned to 11 dietary treatments (8 pens/with 20 male chickens in each). Dietary treatments were as follows: SE-uninfected (negative control (NC), a basal diet without supplemention; NC+ 500 g/t BP (NBP1); NC+ 1000 g/t BP (NBP2); NC+ 300 mg/kg acidifier A (NAA); NC+ 300 mg/kg acidifier B (NAB)) and SE-infected (positive control (PC), a basal diet without supplemention; PC+ 40 mg/kg Antibiotic enrofloxacin (PA); PC+ 500 g/t BP (PBP1); PC+ 1000 g/t BP (PBP2); PC+ 3000 mg/kg acidifier A (PAA); PC+ 3000 mg/kg acidifier B (PAB)). At 13 D birds in challenged groups were orally gavaged with 1 mL bacterial suspension containing approximately 108 CFU Salmonella enterica. The results indicated that chicks challenged with SE impaired performance so that BWG and FI significantly decreased and FCR increased (p < 0.05). Diets containing a high dose of BP increased BW and improved FCR in challenged and unchallenged chickens. The quality of breast meat showed a decline in oxidation in chickens challenged with SE (p < 0.05). The inclusion of bacteriophage in the diet of chickens (1000 g/t) improved the L*, b*, and oxidation of meat. The use of bacteriophage and acidifier A in the diet significantly increased the Lactobacillus, and LAB count, especially in the challenged groups. The challenge of chickens with SE decreased the villus height and crypt depth in different parts of the small intestine (p < 0.05). The results of the present study suggested that 1000 g/t of BP probably improves chicken performance by increasing beneficial bacteria and decreasing pathogenic bacteria. Also, bacteriophage showed an improvement in the performance reduction of chickens with Salmonella infection. In addition, improved meat quality and beneficial changes in the microbiome and intestinal morphology indicate the effectiveness of BP as an alternative antibiotic growth promoter in broiler diets.

Tobacco cv. Solaris seed cake as feed for light lambs: growth performance, carcase traits and meat quality

Sixteen crossbred male lambs, housed in eight pens, were fed two isoenergetic and isonitrogenous diets: Control (CTR; n = 8) and Nicotiana tabacum cv. Solaris seed cake (SSC; n = 8). During the trial, lasted 35 days, pen dry matter (DM) concentrate consumption was calculated, individual body weight recorded, and average daily gain (ADG) calculated. Physico-chemical analyses were carried out on samples of Longissimus dorsi (LD) and Semimembranosus (SM) muscles. Animals fed Solaris seed cake showed lower (p < 0.05) ADG and slaughter body weight than CTR group. Diet did not affect the DM concentrate consumption. CTR lambs had higher cold carcase weight and yield (p < 0.01), while the proportion of commercial cuts did not differ between groups. Diet did not affect meat colour; the pH was higher (p < 0.01) for SSC group. Meat total lipid, collagen and cholesterol contents were unaffected by the diet. Fatty acid composition showed lower palmitic acid (C16:0, p < 0.05) and higher stearic acid (C18:0, p < 0.01) content in SSC compared to CTR fed lambs. The LD muscle showed lower total lipid (p < 0.01) and collagen content (p < 0.05) than SM muscle, as well as higher proportion of total SFA (p < 0.01) and lower proportion of total PUFA (p < 0.01), n-3 PUFA (p < 0.05) and n-6 PUFA (p < 0.01). Further studies are needed for a better evaluation of the potential of the innovative tobacco Solaris co-product in lambs’ diet.

Residual nitrite and nitrate in processed meats and meat analogues in the United States

Residual nitrite (NO2−) and nitrate (NO3−) have been widely studied in the past few decades for their function to improve processed meat quality and their impact on human health1, 2, 3–4. In this study we examined how the residual nitrite and nitrate (NOx−) content of major classes of processed meats products (n = 1132) produced locally from three regions (East Coast, Midwest and West Coast) and plant protein-based meat analogues (n = 53) available at retail in the United States was influenced by their composition, processing, and geographical attributes. We also conducted time-dependent depletion studies and observed different patterns of NOx− depletion and conversion during processing and storage and correlated them with product quality. Together, our results reveal a comprehensive prospective of NOx− content in processed meats and meat analogues. The NO2− in processed meats and meat analogues averaged (± standard error; minimum and maximum value in parentheses) 13.7 ± 0.62 (0.0-214.5) and 1.7 ± 0.34 (0.0–11.0), respectively, and the NO3− in processed meats and meat analogues averaged 32.6 ± 0.90 (2.0–205.9) and 7.2 ± 0.56 (4.0-25.3) ppm, respectively.

Categorization of Beef Longissimus Lumborum and Gluteus Medius Muscles Based on Metabolic Attributes Is More Informative Than Muscle pH

Muscle metabolism is generally monitored using muscle pH. However, pH does not account for all metabolic effects on meat quality. We evaluated the effectiveness of agglomerative hierarchical clustering in creating clusters of beef longissimus and gluteus medius muscles based on metabolic traits. Beef carcasses (n = 100) were selected at grading based on longissimus thoracis pH (&amp;lt; 5.6, 5.60 to 5.74, 5.75 to 5.9, and &amp;gt; 5.9). Metabolic traits characterizing oxidative and glycolytic metabolism were measured on each muscle. A subset of longissimus lumborum muscles were placed in an in vitro glycolytic system with 2 temperature decline rates to evaluate glycolytic efficiency. Gluteus medius muscles exhibited more oxidative metabolism than longissimus lumborum muscles. Metabolic traits measured in one muscle were generally positively correlated to the same trait measured in the other muscle. Clustering of metabolic traits within each muscle produced similar dendrograms. Clustering of longissimus lumborum muscles based on metabolic traits produced 4 distinct clusters (High pH, Glycolytic, Chaperone, and Soluble). Clustering of the high pH was generally, but not totally, in agreement with classifications based on pH. The remaining longissimus lumborum clusters did not differ in pH. Similar to the longissimus lumborum clusters, the gluteus medius clusters included High pH and Glycolytic clusters and a cluster with low values for protein solubility and peroxiredoxin 2 abundance. In the in vitro system, pH decline was affected by a cluster × temperature decline rate interaction (P &amp;lt; 0.05). The soluble cluster had the least extensive pH decline under the fast temperature decline but had the most rapid pH decline at the slower pH decline. These results indicate that clustering muscles based on several metabolic factors was more effective than categorizing muscles based on muscle pH. Metabolic variation identified by clustering was related to differences in the glycolytic machinery that can be differentially impacted by chilling rate.

Single-cell transcriptome reveals three types of adipocytes associated with intramuscular fat content in pigs.

Intramuscular fat is an essential component of muscle tissue, and understanding its contribution to skeletal muscle fat infiltration and meat quality, together with the underlying genetic mechanisms, is a major topic in pig husbandry. However, the composition of cell types and gene expression profiles essential for this purpose remain largely unexplored. Here, we performed single-cell transcriptome analysis on muscle tissue from adult pigs and identified 15 cell types, including three previously uncharacterized types of adipocytes: Adipocyte 1, Adipocyte 2, and Aregs. Phenotypic analysis showed their proportions correlated closely with intramuscular fat content. Based on integrated analysis of ATAC-seq with RNA-seq data, Adipocyte 1 and Aregs have gene expression profiles and transcription factor (TF) motif enrichment typical of adipocytes. On the other hand, myogenic TF motifs were enriched in marker gene promoters in Adipocyte 2, suggesting that these cells originate from muscle cells. Moreover, the marker gene promoters and lineage-specific TF expression in these three adipocyte types were conserved between pigs and humans. These findings provide deep insights towards understanding the complexity of mammalian intramuscular adipocyte types and the gene regulation underlying their organization and function.

Effects of dietary l-carnosine supplementation on the growth, intestinal microbiota, and serum metabolome of fattening lambs

Dietary l-carnosine supplementation has been shown to enhance animal performance and improve meat quality. However, the mechanisms underlying the effects of l-carnosine on the physiological functions of animals have not been fully elucidated. We investigated the effects of dietary l-carnosine supplementation on growth performance, intestinal microbiota diversity, and the serum metabolome in fattening lambs to reveal the molecular mechanism underlying the effect of l-carnosine on the growth performance of sheep. Sixty 3-month-old male crossbred lambs (Dorper ♂ × Small Tail Han ♀) with an average body weight of 30 ± 5 kg were randomly divided into two groups: a control group (group C) fed a basal diet, and an experimental group (group L) fed a basal diet supplemented with 400 mg/kg of l-carnosine. At the end of the 60-day experiment, all sheep were weighed, and fecal and blood samples were collected from 12 random sheep. The fecal microbiota was analyzed using 16S rRNA sequencing, and serum metabolites were analyzed using liquid chromatography–tandem mass spectrometry. Spearman correlation analysis was employed to assess the associations between intestinal microbiota and serum metabolite biomarkers. The results showed that weight gain and daily weight gain were significantly increased in group L compared to group C (p &amp;lt; 0.01). The dominant phyla in the intestinal microbiota (Firmicutes and Bacteroidetes) did not significantly differ between the two groups (p &amp;gt; 0.05). At the genus level, the abundances of Syntrophococcus (p &amp;lt; 0.01) and Butyricimonas (p &amp;lt; 0.001) were higher, whereas those of Escherichia-Shigella and Candidatus Saccharimonas were significantly lower in group L than in group C (p &amp;lt; 0.05). Non-targeted metabolomics identified 68 differentially abundant biomarkers (VIP &amp;gt; 1, p &amp;lt; 0.05). The content of pyridine N-oxide glucuronide was significantly downregulated (p &amp;lt; 0.01), whereas those of l-histidinol, d-apiose, and isodomedin were significantly upregulated in group L versus group C (p &amp;lt; 0.001). Holdemania and Butyricimonas were positively correlated with l-histidine, d-apiose, and l-erythrulose (p &amp;lt; 0.001), whereas Butyricimonas was negatively correlated with pyridine N-oxide glucuronide (p &amp;lt; 0.001). This study provided new insights into the effects of l-carnosine on the intestinal microbiota and nutrient metabolism in fattening sheep that will be helpful for the future application of l-carnosine in ruminants.

Effects of Free-Range Systems on Muscle Fiber Characteristics and Welfare Indicators in Geese

Recently, free-range poultry production has increased with notable benefits for animal welfare and meat quality traits. Geese, the third-most productive poultry species, have not been studied extensively. This study investigated the effects of different free-range systems on muscle fiber characteristics and welfare status (feather quality, walking ability, and behavioral changes) in Yangzhou geese. A total of 180 male geese, aged 28 days, were randomly assigned to either a long-distance pasture system (LDPS, approximately 200 m from the geese house) or a short-distance pasture system (SDPS, approximately 50 m from the geese house). The indoor system (IS) treatment was used as a control. And all geese were equipped with pedometers. Daily step counts revealed that the geese took an average of 5777 and 4520 steps in the LDPS and SDPS, respectively, whereas only 2736 steps in the IS. Although no significant differences were observed in the muscle fiber types among the three systems, free-range systems contributed to more developed muscle fibers than the IS. In addition, thicker muscle fibers in the extensor digitorum longus and gastrocnemius muscles were observed in the LDPS group than in the SDPS group. Additionally, feather cleanliness and damage were evaluated. LDPS resulted in significantly cleaner feathers on the chest, abdomen, and back than the IS. Furthermore, geese in the free-range systems had less feather damage than those in the IS. Notably, pasture systems allowed for natural behaviors, such as single-foot standing, feather pecking, and walking, regardless of grazing distance. Taken together, these results show that the muscle fibers of geese in the free-range system were more developed. Simultaneously, increasing the amount of exercise for geese will improve their welfare, which is beneficial to their health, growth, and development, and provides a technical reference for the free-range breeding system for geese.

Effects of sunflower cake in lamb diets on meat quality and its fatty acid profile.

This study aimed to evaluate the effects of sunflower cake (SFC) levels (0, 7, 14, 21, and 28% dry matter) in the diet for feedlot lambs on meat quality and its fatty acid profile. Forty crossbreed non castrated hair lambs were fed with experimental diets through 70days when they were slaughtered and a Longissimus lumborum section were evaluated for physicochemical quality and fatty acid profile. There were no effects of SFC levels (P > 0.05) on chemical composition of meat, except on moisture (P < 0.05) which was quadratically affected by SFC. The fat thickness (EG) was quadratically affected by SFC level (P < 0.05), but cooking losses, meat pH, shear force, loin eye area were not affected by SFC. The saturated fatty acids (SFA), monounsaturated fatty acids (MUFA), total of unsaturated fatty acids (TUFA) and MUFA:SFA ratio were not affected by the inclusion of SFC (P < 0.05), however, polyunsaturated fatty acids (PUFA) and PUFA:SFA ratio increased linearly (P < 0.05) while saturated hypercholesterolemic (SHC) were quadratically affected (P < 0.05). The SFC promoted a linear decrease on palmitoleic acid in the meat whereas linoleic, cis-9, trans-11 CLA and trans-10, cis-12 CLA were linearly increased (P < 0.05). Taken together, these data suggest that SFC fed up 28% on dry matter basis in lamb diets do not cause negative effects on meat quality and still promote improvement on its quality in health perspective by increasing CLA content.

Genomic signatures of selection in Brangus cattle revealing the genetic foundations of adaptability and production traits using a breed of origin approach

IntroductionThe composite breed Brangus combines the resilience and adaptability of the Bos t. indicus breed Brahman with the superior meat quality and fertility traits of the Bos t. taurus breed Angus. Its diverse genetics not only enables optimal production performance but also adaptability to hot and humid environmental conditions. From a research perspective, this makes Brangus an ideal model for identifying genomic signatures that reveal the effects of both artificial selection and natural adaptation. The aim of this study was to detect genomic signatures of selection by analyzing changes in breed origin of allele (BOA) frequencies across the genome.MethodsUsing a multi-breed Angus and Brahman herd (n = 4,516) as a reference, population structure was measured via principal component analysis and admixture analysis in two commercial Brangus herds (n = 4,720). BOA was estimated in these herds using LAMP-LD, followed by a signature of selection analysis utilizing a median-based Z-score approach and Fst analyses to detect genomic regions under selection.ResultsThe analysis revealed a genome-wide increase in Angus ancestry in both Brangus populations (71.46%, 68.7%), reflecting intense selection for traits associated with this lineage. BOA-based intra- and inter-population analyses identified significant shifts in Brahman and Angus ancestry across the genome, indicating potential selection for breed-specific genetics. Key genomic regions were identified on chromosomes 6, 8, 10, 12, 14, 17, 18, 19, 27, and 28, and were linked to traits such as fertility, growth, heat tolerance, carcass characteristics, and meat quality.DiscussionExpected genes showing signatures of selection included MC1R, responsible for black coat color, and PLAG1, integral to growth, fertility, and carcass traits, underscoring the effectiveness of this methodology. Novel genes under selection, such as CCNB2 (critical for fertility), MTCH2 (associated with meat quality and fertility) and PRLR (associated with coat length and heat tolerance), were also identified. These findings provide deeper insights into the genetic mechanisms driving adaptation and production performance in cattle and offer valuable information for strategic breeding practices aimed at optimizing the strengths of both parental breeds.

Effects of Dietary Iron Levels on the Production Performance, Nutrient Digestibility, Blood Biochemistry, and Meat and Fur Quality of Growing Rex Rabbits.

The objective of this study was to explore the effects of dietary iron (Fe) levels on the production performance, nutrient digestibility, blood biochemistry, and meat and fur quality of growing Rex rabbits. Two hundred 3-month-old Rex rabbits were randomly allocated to five groups, each with forty replicates. Rabbits were fed a basal diet supplemented with varying levels of Fe (0, 20, 40, 80, and 160 mg/kg) in the form of ferrous sulfate monohydrate. The analyzed Fe concentrations in the diets were 8.2, 25.4, 49.1, 85.6, and 178.7 mg/kg, respectively. Over a 35-day trial period, rabbits supplemented with 40 mg/kg Fe showed a markedly increased average daily feed intake, average daily gain, and fur area compared to the control group (p < 0.05). The addition of 20 and 40 mg/kg Fe markedly improved the digestibility of crude protein and nitrogen (p < 0.05). Additionally, 80 mg/kg Fe supplementation significantly increased the redness of the longissimus dorsi muscle 30 min postmortem (p < 0.05). Dietary Fe addition also significantly elevated serum concentrations of Fe and copper (p < 0.05) while decreasing the total Fe-binding capacity (p < 0.05). In conclusion, dietary Fe supplementation boosted growth performance, protein and nitrogen digestibility, Fe stores, and meat and fur quality in Rex rabbits. Specifically, 40 mg/kg Fe (diet Fe content of 49.1 mg/kg) improved growth performance, nutrient digestibility, and fur quality, while 80 mg/kg Fe (diet Fe content at 85.6 mg/kg) was optimal for enhancing meat quality.

Erucic acid promotes intramuscular fat deposition through the PPARγ-FABP4/CD36 pathway.

The regulation of intramuscular fat (IMF) accumulation plays a crucial role in determining meat quality in the beef industry. In humans, fat deposition in skeletal muscle is closely associated with insulin resistance and obesity. However, its underlying mechanisms are not fully elucidated. We previously identified erucic acid (EA) as a key metabolite that may affect IMF deposition of beef using omics strategies. By utilizing bovine intramuscular preadipocytes in vitro, the study demonstrates a dose-dependent increase in lipid storage induced by EA, along with mRNA expression levels of transporters FABP4 and CD36. At a mechanistic level, EA triggers ERK1/2 phosphorylation and enhances the expression of PPARγ, FABP4, and CD36, thereby facilitating the formation of lipid droplets within preadipocytes. In vivo experiments conducted in mice support these findings, indicating that EA stimulates fat accumulation in skeletal muscles and enhances the levels of FABP4 and CD36 proteins. These outcomes not only enhance our comprehension of the molecular mechanisms governing IMF deposition but also provide insights into potential strategies for enhancing meat quality and addressing metabolic disorders linked to fat accumulation in skeletal muscles. The findings of the study contribute to existing scholarly knowledge and lay the groundwork for future research endeavors aimed at improving meat quality and metabolic well-being.

The Role of Meat Lipids in Nutrition and Health: Balancing Benefits and Risks.

Meat lipids are determinants of the nutritional, sensory and physiological qualities of meat, encompassing triglycerides, phospholipids, cholesterol and bioactive compounds. These lipids provide essential fatty acids, including omega-3 and omega-6 polyunsaturated fatty acids, critical for metabolic regulation, inflammation control and cognitive health. However, the dual role of meat lipids as essential nutrients and potential contributors to health risks, such as cardiovascular disease and oxidative stress, necessitates a nuanced understanding. This review evaluates meat lipids' biochemical diversity, nutritional contributions and health implications, balancing their benefits and risks. It examines factors influencing lipid composition, including species, diet and processing methods, emphasising strategies such as omega-3 enrichment and antioxidant supplementation to enhance lipid quality. Advances in functional meat products, such as hybrid formulations combining plant and animal lipids, are highlighted for their potential to improve health outcomes. Emerging technologies in lipidomics provide deeper insights into lipid oxidation pathways and nutritional profiling, aiding in the development of safer, higher-quality meat products. By synthesising recent evidence, this review offers insights into dietary guidelines, optimises consumer choices and informs sustainable meat production practices aligned with public health and environmental goals.

Effects of dietary oregano essential oil supplementation on carcass traits, muscle fiber structure, oxidative stability, meat quality, and regulatory mechanisms in Holstein steers.

Dietary supplementation for beef cattle, using natural plant extracts, such as oregano essential oil (OEO), has proven effective in enhancing growth performance, beef production quantity and quality, and ensuring food safety. However, the precise mechanisms underlying these effects remain unclear. This study investigated the impact of OEO on carcass traits, muscle fiber structure, meat quality, oxidative status, flavor compounds, and gene regulatory mechanisms in the longissimus thoracis (LT) muscles of beef cattle. Eighteen steers were randomly assigned to two groups (n = 9 per group) and fed either a control diet (CK) or the same diet supplemented with 20 g of OEO per head per day for 300 days. Oregano essential oil supplementation improved the body weight, carcass weight, meat production, area and diameter of fiber, ether extract, and water-holding power of muscle. Increasing catalase (CAT), peroxidases (POD), glutathione peroxidase (GSH-Px) and by decreasing lipid droplets (LDs) reduced muscle lipid oxidation. However, the color (L*, a*, b*, C* and H°) and the flavor compounds of muscle were affected adversely by OEO. The transcriptome and metabolome indicated the OEO group enriched fat synthesis, proteo-metabolism, antioxidants, and growth significantly. Five key genes (SH2B2, CD209, LOC504773, C1QC, and HMOX) and ten downregulated metabolites (deoxyguanosine, d-melezitose, maltotriose, raffinose, melatonin, quinic acid, orotic acid, hydrocinnamic acid, 2-methylsuccinic acid, and pyridoxal 5'-phosphate) were identified as key biomarkers. These interacted to positively influence the growth, oxidative status, and meat quality of steers positively. These findings suggest that OEO, as a natural bioactive compound, can serve as an additive for beef cattle, with a daily dose of 20 g per steer improving growth and meat quality, although it may affect muscle color and flavor negatively. © 2025 Society of Chemical Industry.

The Fatty Acid Content, Health Lipid Indices, and Instrumental, Histological, and Sensory Quality of Hare Meat (Lepus europaeus Pallas).

The aim of this work was to characterize the quality of meat from hares (Lepus europaeus Pallas), namely, the fatty acid content, health lipid indices, and instrumental, histological, and sensory profiles by gender and muscle type (Longissimus dorsi/LD vs. Semimembranosus/SM). The ΣPUFA/Σ SFA was higher for males, with an average value of 1.62/1. The Σn6/n3 ratio was elevated for males, with a mean value of 5.34/1. The mean meat essential fatty acids were 41.94%, the desirable fatty acids were 77%, and the polyunsaturation index was 6.09. Moreover, the atherogenic index was 0.72, the thrombogenic index was 0.71, the hypocholesterolemic/hypercholesterolemic (h/H) fatty acids ratio was 3.30, and the nutritive value index was 1.35. After the sensory analysis, the LD muscles showed higher scores in males for overall appreciation (4.20 vs. 3.95) but higher scores in females for SM muscles (4.14 vs. 4.00). Shear force was influenced by the ratio between muscle and connective tissue, and the proportion of collagen and protein was related to the number of muscle fibers. Muscle and connective tissues are inversely proportional, and their ratio is an indicator of the textural and mechanical properties of the analyzed samples. Hare meat is an appreciated resource for consumers in terms of its sensory, instrumental, and nutritional values, and it has a higher value than that obtained from livestock species or other wild animals (more valuable proteins, lower fat content, and better health lipid indices).