Search Results (257)

Dark cutting (DC) is a significant quality defect in beef, often linked to stress experienced by animals prior to slaughter. This study evaluated how antemortem handling affects behavior and DC incidence in Holstein (n = 101) and commercial crossbred (CC; n = 101) steers finished under the same commercial conditions in northwestern Mexico. Animal welfare and handling practices were assessed during driving, transport, lairage, stunning and bleeding, and carcass and meat traits related to DC were measured. Holsteins, originating from confined systems with high human–animal interaction, showed more backing events than CC (73 vs. 30; p = 0.03), which led operators to increase vocal encouragement (109 vs. 5; p < 0.001) and hitting (100 vs. 28; p = 0.002). Additionally, 56.4% of Holstein carcasses had L* ≤ 40 compared with 22.8% in CC (p = 0.001), whereas a greater proportion of CC carcasses exhibited ultimate pH ≥ 5.8 (46.5 vs. 20.8%; p = 0.03). Meat from Holstein steers showed lower lightness, lower redness and higher yellowness, together with a higher incidence of DC (17.8 vs. 10.9%). In conclusion, genetic background and the human–animal relationship influence responses to antemortem handling and the incidence of dark cutting. Full article

Yanhuang cattle is a specialized beef breed independently developed in China with high economic value. However, the effects of the horned/polled trait on its production performance and the underlying genetic markers are poorly understood. This study aimed to evaluate the impact of horn status and to validate candidate genetic markers for the polled trait in this breed. A total of 60 Yanhuang cattle (30 horned and 30 polled) were used for comparative analysis of growth, carcass, and meat quality traits. Additionally, blood samples from 200 individuals (100 horned and 100 polled) were collected for molecular screening of seven candidate genetic markers previously associated with polledness in cattle. The polled cattle showed significantly higher body weight from 12 months onward. Body height and hip height were significantly greater at 12, 18, and 24 months, while body length displayed significant advantages at 6, 18, 24, and 30 months. Polled cattle also outperformed in chest girth (18 months), abdominal circumference (significant at 18–30 months), and ischial end width (significant at 6–12 months). Regarding slaughter traits, polled cattle exhibited higher carcass weight, along with significantly improved slaughter and net meat rates, though no differences were observed in meat quality. At the molecular level, the P_202ID indel marker was successfully validated in the polled Yanhuang population. Our findings demonstrate that the polled trait is associated with superior production performance in Yanhuang cattle, and the P_202ID marker represents a reliable molecular tool for polled selection, providing a theoretical and technical basis for the genetic improvement and breeding of this breed. Full article

Several species of the genus Acinetobacter are nosocomial pathogens with a well-documented ability to acquire resistance to multiple antibiotics. Although Acinetobacter is one of the most abundant genera in meat processing environments, data on this genus outside of clinical environments remains limited. The objective of this study was to ascertain the prevalence, diversity and antimicrobial resistance profile of Acinetobacter spp. in 200 samples collected from food contact surfaces, non-food contact surfaces, carcasses and final meat cuts across five pork, chicken and beef processing facilities, each comprising physically connected slaughterhouses and meat processing plants. Acinetobacter spp. were detected in 80% (95% CI = 71–87%) and 70% (95% CI = 60–79%) of samples from slaughterhouses and processing plants, respectively. The facilities harboured a wide diversity of Acinetobacter species, with 27 different species identified. Acinetobacter baumannii was the species most frequently detected. Whole-genome sequencing of 18 Acinetobacter spp. isolates revealed the presence of ARGs conferring resistance to beta-lactams, tetracyclines and aminoglycosides, and disclosed phylogenetic relationships with isolates from fresh meat. Phenotypic resistance to beta-lactams, fluoroquinolones, aminoglycosides, folate pathway inhibitors and/or tetracyclines was observed in 77.8% of the sequenced isolates, with 44.4% classified as multidrug-resistant. These findings identify meat processing environments as an important reservoir of Acinetobacter spp. and highlight the need for further investigation to prevent the dissemination of antimicrobial-resistant strains. Full article

Background: Citrus components potentially suppress adipogenic differentiation and lipid accumulation, and exhibit anti-inflammatory and antioxidant effects. We hypothesized that the bioactive compounds in Citrus junos Sieb ex Tanaka (yuzu) fruit peel can alter the systemic metabolism and productivity of beef cattle. Methods: Japanese Brown (JBR) steers were fed with a diet supplemented with 2.5% yuzu peel during the last month of the finishing period. To investigate the effect of dietary yuzu supplementation (DYS) on beef and liver metabolism, we explored the metabolomic profiles of longissimus thoracis (LT, loin) muscle at 14 d postmortem using capillary electrophoresis (CE-TOF/MS) and high-performance liquid chromatography time-of-flight mass spectrometry (LC-TOF/MS). Results: The DYS treatment enhanced the beef fat score compared to that recorded in beef in the no-DYS (None) group (p = 0.050); however, the other carcass quality traits were not significantly different between the DYS and None groups. CE-TOF/MS and LC-TOF/MS revealed 242 and 107 annotated peaks, respectively, for the LT muscle. DYS significantly increased 9(S)-hydroxyoctadecadienoic acid (9-HODE, a beef flavor precursor), cyclo(-Leu-Pro), spermidine, asymmetric dimethylarginine, and 7α-hydroxycholesterol levels and reduced 2-ethylhydracrylic acid (2-EHAA), γ-tocopherol, coenzyme Q10 (CoQ10), sphingomyelin(d18:1/16:0), Cys-Gly, Tyr-Arg, and palmitoylcarnitine levels in postmortem LT muscle (p < 0.050). Concomitantly, in the fresh liver, DYS increased acetyl-CoA, 6-phosphogluconic acid, S-methylglutathione, ATP, ribulose 5-phosphate, and ADP levels and suppressed the content of thiamine, Ala-Ala, riboflavin, and ascorbate 2-sulfate (p < 0.050). Conclusion: Collectively, yuzu ingredients activated ATP production in the liver through the elevation of hepatic energy metabolism primarily in the citrate cycle and β-oxidation, and potentially altered muscle metabolism, including linoleic acid oxidation, FAD-mediated electron transport chain, and isoleucine catabolism, as demonstrated in the reduced accumulation of 2-EHAA and CoQ10 in DYS beef. Moreover, DYS likely affects the gut microbiome by enhancing the production of cyclo(-Leu-Pro), an antimicrobial dipeptide. Full article

This study aimed to evaluate the effects of various levels of intramuscular fat (IMF) and oleic acid (C18:1 cis-9) on retronasal aromas in Wagyu beef. Muscle samples were collected from 167 carcasses of Japanese Black. The chemical compositions were analyzed, and the cooked beef was evaluated by a trained sensory panel. Tenderness, juiciness, and fatty aroma were mainly related to the IMF content. Both sweet and Wagyu beef aromas were affected by the oleic acid and IMF contents. In marbled beef with low IMF content, both sweet and Wagyu beef aromas were stronger as the oleic acid composition increased (r = 0.401, 0.376); however, their relationships were weaker at the moderate IMF content (r = 0.278, 0.273). The effect of oleic acid on these aromas was hardly observed in beef with high IMF content (r = 0.030, 0.011). The oleic acid index [IMF content (%) × oleic acid composition (%)/100] could be fitted to the logarithmic curve for all the aromas determined (r = 0.526 to 0.565). These results indicated that the higher oleic acid composition could be better for the favorable aromas of Wagyu beef; however, the effect differs depending on the IMF content levels, and the phenomenon is relatively well explained by the oleic acid index. Full article

The continuous growth in both the number of phenotypic records and the range of traits included in beef cattle genetic evaluations poses substantial statistical and computational challenges for the estimation of genetic and residual (co)variance matrices required for breeding value estimation. Structural equation models (SEM), implemented using either factor analysis (FA) or recursive model (REC) structures, provide a flexible framework to model genetic and residual (co)variance matrices while yielding more parsimonious and computationally efficient parameterizations. Here, SEM was applied to estimate parameters for growth and ultrasound-measured carcass traits in beef cattle. The dataset comprised 2942 animals, and six traits were evaluated using standard multiple-trait mixed models (SMTM) and SEM. We considered FA and REC models implemented with six alternative parameterizations, in which random effects were represented as linear combinations of fewer unobservable random variables. Relative to the SMTM, both the model with two factors in the genetic covariance matrix (FA2G) and the model in which six recursive effects were constrained to zero in the residual covariance matrix (REC1) demonstrated a strong ability to capture genetic variability, as reflected by comparable heritability estimates. Correlations between estimated breeding values (EBV) for the same traits across models were consistently high, ranging from 0.94 to 1.00, indicating strong agreement among model estimates. The FA2G model was the most parsimonious in terms of the effective number of parameters ($p_D$), with 431.2 $p_D$, corresponding to a reduction of 25.3 parameters relative to the SMTM. The REC1 model also emerged as a competitive alternative for this dataset, exhibiting a lower $p_D$ (443.6) than the SMTM (456.5) and the most favorable deviance information criterion among all models evaluated (e.g., 37,868.6 for REC1 versus 37,874.7 for SMTM). Overall, these results demonstrate that mixed-effects multi-trait models for beef cattle genetic evaluation can be effectively implemented using FA or REC structures, which provide parsimonious representations of the underlying covariance patterns while maintaining high agreement in EBV. Full article

Slaughter performance is a critical economic trait that varies across breeds, yet the rumen metabolic mechanisms driving these phenotypic differences remain unclear. The study involved 30 healthy 12-month-old beef cattle, with 10 animals from each of the three breeds: Chinese Simmental (ST), Taihang Yun (TY), and Charolais (CL). The cattle were randomly assigned into three groups using a completely randomized design, and the average initial body weight was 549.78 ± 59.45 kg. A 130-day feeding trial (10-day pre-feeding period, 120-day main trial period) was conducted. By comparing the slaughter performance, relative organ weight, and rumen fluid metabolomic profiles, the study investigated breed-specific differences in meat quality and potential underlying metabolic patterns. The results showed that CL exhibited a superior carcass yield, with a significantly higher dressing percentage (62.38%, p = 0.013) and net meat percentage (56.54%, p = 0.028) than ST and TY, and a significantly lower backfat thickness (p = 0.006); ST had the highest proportion of premium cuts, relative to carcass weight (72.97%, p = 0.014), with prominent economic value, while TY had significantly higher weights of visceral organs, such as liver, kidney, small intestine and omasum, than CL (p < 0.05). Metabolomic analysis revealed that CL and ST had elevated levels of purine metabolism, nucleotide synthesis and cofactor biosynthesis compared to TY. In conclusion, CL and ST possess advantages in carcass yield supported by upregulated anabolic metabolism in the rumen, whereas TY prioritizes visceral organ development. These findings provide valuable insights into the physiological and metabolic divergences regulating the slaughter performance and regional adaptability across cattle breeds. Full article

Intramuscular fat (IMF) significantly influences meat quality, particularly flavor. The gastrointestinal microbiota can regulate lipid metabolism. The relationship between intramuscular fat metabolism, rumen microbiota, and beef quality remains unclear. This study enrolled 22 30-month-old Xinjiang Brown Beef cattle, which were randomly allocated to two groups: an intact bull group (n = 15) and a castrated bull group (n = 7). All experimental animals were housed and maintained under consistent feeding and management conditions throughout the entire experimental period. By combining in vivo ultrasonography, slaughter trials, rumen microbiome diversity analysis, and metabolomics techniques, and after adjusting for covariates including intramuscular fat (IMF) content, body weight, and backfat thickness, the present study demonstrated that castration regulates muscle lipid metabolism by reshaping the composition of the rumen microbial community, thereby exerting a cascading effect on key beef quality traits. (1) Production and meat quality: Live weight, carcass weight, eye muscle area, backfat thickness, and intramuscular fat (IMF) content were significantly higher in the YN group than in the GN group (p < 0.01). Conversely, dressing percentage, shear force value, and muscle protein content were significantly lower in the YN group than in the GN group (p < 0.01 or p < 0.05). (2) Rumen microbiota–metabolite correlation: Significant differences existed in microbial composition and community structure between groups (with significant differences in both α and β diversity). Core microbes regulated by castration exhibited distinct co-variation patterns with metabolites: genera such as Anaeroplasma showed significant positive correlations with hydroxy fatty acids, while Sharpea and others showed significant negative correlations with saturated fatty acids. (3) Microbial–metabolite axis and host phenotype correlation: Axes composed of Eubacterium uniforme and others showed significant positive correlations with IMF, while Docosapentaenoic acid (22n-3) exhibited significant negative correlations with IMF. Anaeroplasma and others showed significant positive correlations with oleic acid and others, as well as BFT, while saturated fatty acids showed significant negative correlations with BFT. (4) Covariate validation: After adjusting for covariates including body weight, backfat thickness, and IMF, castration was confirmed to significantly regulate the abundance/content of core genera such as Anaeroplasma, Eubacterium uniforme, as well as key metabolites such as hydroxy fatty acids and docosapentaenoic acid (22n-3) (p < 0.05 after adjustment), making it a core driver regulating rumen microbial composition and muscle lipid metabolism. After adjustment, the regulatory effects of IMF, body weight, and backfat thickness on the aforementioned microorganisms and metabolites were no longer significant (adjusted p > 0.05). Intramuscular fat (IMF), body weight, and backfat thickness are not independent drivers but rather indirect effects resulting from castration-induced physiological state remodeling. This study did not include feeding rate measurements, which represents a limitation. Future research should incorporate this data to further validate the conclusions. This study elucidates the interactive mechanisms between rumen microbiota and their metabolites, identifies the key pathways governing intramuscular fat (IMF) deposition, pinpoints potential regulatory targets for beef quality optimization, and clarifies the intermediate regulatory mechanisms underlying the modulation of meat quality traits by castration. Full article

Conjugated linoleic acid (CLA) is produced by bacterial biohydrogenation in the rumen of cattle, fulfills various biological functions, and is known for anti-obesity, anti-inflammation, anti-cancer, and other beneficial effects. It has numerous isomers, of which cis-9,trans-11 CLA accounts for 80% of total CLA, followed by trans-10,cis-12 CLA (t10,c12 CLA), with distinct molecular structures, oxidation efficiencies, activities, and functions. Different effects were observed, when isomers were individually supplemented in livestock nutrition. Currently, CLA is supplemented into the diets of dairy cows to improve the energy balance, and avoid negative effects of energy loss during the transition period. Furthermore, t10,c12 CLA was shown to reduce subcutaneous fat and to improve intramuscular fat (IMF) content in the carcasses of ruminants and pigs. Increasing the IMF content without increasing other fat depots and without compromising feed efficiency is an important goal in beef production. However, inconsistent and conflicting results were reported partly based on different study designs. This review aims to summarize studies on CLA supplementation in cattle, focusing on t10,c12 CLA and the effects of the dose, time, and method of supplementation on energy balance, milk yield and body composition, as well as on individual cells in vitro. This may improve our understanding of energy-saving and repartitioning effects of CLA in cattle. Full article

As one of the five major indigenous yellow cattle breeds in China, Qinchuan cattle are characterized by stable genetic performance and desirable meat quality. However, compared with imported commercial breeds, Qinchuan cattle have a relatively slow growth rate. Therefore, improving the growth rate of Qinchuan cattle has become a top priority in Qinchuan cattle breeding. The CDC10 (Septin 7) gene, an important member of the Septin family, participates in various cellular physiological processes including intracellular substance transport, cell division, cell cycle regulation, and apoptosis. Studies have repeatedly mapped the CDC10 gene to quantitative trait loci influencing growth-related traits, such as body weight and carcass weight in many beef cattle breeds. Previous study has also demonstrated the high expression of CDC10 in JB cattle with high performance for carcass weight, however, the association between CDC10 and growth-related traits in Qinchuan cattle remain unclear. Therefore, in this study, we selected five individuals each from Chinese Simmental, Mongolian cattle, Luxi cattle, and Qinchuan cattle for direct sequencing, aiming to identify mutations within the CDC10 gene of native Chinese yellow cattle. Subsequently, we performed genotyping of 367 Qinchuan cattle using the MassARRAY technology, followed by genetic diversity analysis of the identified mutations and association analysis between these sites and growth-related traits of Qinchuan cattle. This study demonstrated high expression of the CDC10 gene in Qinchuan cattle with high performance for carcass weight. Furthermore, we identified the g.61303052G>C and c.225A>G SNPs in the promoter and exon regions, respectively, as being significantly associated with multiple growth-related traits in Qinchuan cattle. The c.225A>G SNP was also found to alter the secondary structure of the CDC10 protein. These findings provide reliable molecular markers for enhancing the growth rate of Qinchuan cattle and establish a solid theoretical foundation for the development of the beef cattle industry. Full article

Bovine respiratory disease (BRD) remains one of the most consequential health and economic challenges in U.S. beef production, particularly within integrated systems where microbial, environmental, and management factors intersect. This review synthesizes contemporary epidemiological insights, emphasizing BRD’s multifactorial pathogenesis driven by dynamic host–pathogen–environment interactions involving agents such as Mannheimia haemolytica, Pasteurella multocida, and Mycoplasma bovis, alongside stressors from transportation, weaning, and commingling. BRD imposes annual losses exceeding two billion dollars through diminished feed efficiency, reduced carcass yield, increased treatment costs, and mortality. Despite progress in vaccination, biosecurity, and therapeutic interventions, BRD persists due to diagnostic subjectivity and limitations of traditional control measures. The review underscores emerging innovations, including precision livestock technologies, AI-enabled surveillance, and metabolomic biomarkers as transformative tools for early detection and targeted mitigation, while noting barriers related to cost, data harmonization, and scalability. The rising threat of antimicrobial resistance further highlights the need for stewardship frameworks that balance therapeutic effectiveness and public health priorities. Additionally, the paper analyzes policy and economic considerations, arguing for coordinated efforts among producers, veterinarians, researchers, and regulators. BRD is reframed as a systems-level challenge requiring integrated scientific, operational, and regulatory strategies to enhance resilience and sustainability across U.S. beef production. Full article

The valorization of cull sheep and the incorporation of agro-industrial by-products into animal feeding represent effective approaches to enhancing the sustainability of small ruminant production systems. This study investigated the effects of dietary inclusion of 17% partially destoned olive cake (OC) in the concentrate fed to Valle del Belice ewes on carcass characteristics, as well as on meat and salami quality. A 14-week feeding trial was conducted on 124 animals allocated to a control (CTR) and an experimental (EXP) group, balanced for parity, days in milk, and daily milk yield. At the end of the trial, five animals per group were slaughtered and their meat was processed into three types of salami: 100% sheep meat (SM), 90% sheep meat with 10% beef heifer brisket (HB), and 90% sheep meat with 10% pork backfat (PB). Meat and salami were evaluated for chemical composition, fatty acid profile, polyphenol content, antioxidant capacity, lipid oxidation, microbiological status, textural properties, and sensory characteristics. Dietary OC supplementation resulted in increased carcass weight, separable fat, intramuscular fat content, and monounsaturated fatty acids—particularly oleic acid—along with higher polyphenol levels and antioxidant activity. Salami produced from OC-fed ewes exhibited reduced weight loss during ripening, lower lipid oxidation, an improved MUFA/SFA ratio, and satisfactory sensory attributes. Microbiological analyses indicated a dominance of lactic acid bacteria and coagulase-negative staphylococci, with no pathogenic microorganisms detected. Overall, the inclusion of olive cake in the diet enhanced meat and processed product quality, supporting the valorization of olive oil by-products within circular economy frameworks. Full article

Carcass weight (CW) is a major determinant of beef yield and market value in Korea, yet the genetic basis of this trait remains largely unexplored in cattle from Jeju Island. In this study, we performed a genome-wide association study (GWAS) using both a mixed linear model (MLM) and the FarmCPU approach, followed by pathway and network analyses to identify loci and biological functions underlying CW variation. A total of 256 Jeju cattle (92 Jeju Black and 164 Jeju Black × Hanwoo crossbreds) were initially sampled. One crossbred sample failed genotyping, leaving 255 animals (92 Jeju Black and 163 crossbreds) for analysis. Animals were genotyped using the Illumina BovineSNP50 v3 BeadChip, and 39,055 high-quality single nucleotide polymorphisms (SNPs) were retained after quality control. The MLM analysis detected no genome-wide significant associations, whereas the FarmCPU analysis identified six significant loci on Bos taurus chromosomes 3, 5, 6, 10, and 13, each explaining 2.55–9.58% of the phenotypic variance. Candidate genes located near these loci included EIF2B3, HECTD3, SOX5, KLF6, PHACTR3, and two uncharacterized protein-coding genes. Functional enrichment analysis identified biologically relevant pathways including lysine degradation, tryptophan metabolism, glycerolipid metabolism, fatty acid biosynthesis, extracellular matrix–receptor interaction, and signaling cascades such as PI3K–Akt and Rap1, although most pathways were not statistically significant after FDR correction. Protein–protein interaction (PPI) network analysis using STRING highlighted modules of signaling, extracellular matrix, and metabolic genes. These clusters suggest that coordinated interactions among these pathways contribute to carcass growth and development. These findings provide new insights into the molecular basis of CW in Jeju Black and Hanwoo × Jeju Black crossbred cattle and identify candidate genes and pathways that may be useful for genomic selection and the sustainable improvement of Jeju Black cattle populations. Full article

Growth and carcass traits are key economic traits in beef cattle production, and identifying their associated genetic markers is crucial for improving breeding efficiency. Charolais cattle, as a superior beef breed, exhibit excellent performance in growth rate and meat production. The aim of this study was to utilize the preferred high-coverage whole-genome resequencing (hcWGS) as a replacement for single nucleotide polymorphism (SNP) chips to identify significant SNPs and candidate genes associated with growth (body weight, body height, cross height, body length, and chest measurement across different growth stages) and carcass traits (live backfat thickness and eye muscle area at 18 months) in 240 Charolais cattle, thereby providing guidance for beef cattle breeding. Through hcWGS (approximately 13× coverage) and quality control, 4,088,633 SNPs were identified and subsequently used for genetic analyses. Through FarmCPU-based genome-wide association studies, 196 potentially significant SNPs associated with growth traits and 29 SNPs with carcass traits were identified. Annotation analyses revealed 353 candidate genes (such as RBM33, KCTD17, PTHLH, RAC2, CHD6, TRDN, WBP1L, TLL2, CH25H, and ST13) linked to growth traits and 26 candidate genes linked to carcass traits (such as CHST11, LRRK2, RIOK2, and INTS10). Additionally, three SNPs (g.8674692C>G, g.54418624G>T, and g.71085551G>A) were validated via polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP), enabling efficient marker-assisted selection. Furthermore, eight SNPs in the Acyl-CoA oxidase 1 (ACOX1) gene were found to be associated with growth and backfat thickness traits. These findings provide valuable preliminary insights into the genetic mechanisms underlying growth and carcass traits in Charolais cattle, facilitating genome-assisted breeding. Full article

The aim of this study was to evaluate the nutritional composition of beef from five autochthonous calving breeds from Southwest Spain (Retinta, Pajuna, Marismeña, Berrenda en Colorado, and Lidia) reared under their traditional production systems. Longissimus dorsi samples were analyzed for pH, fat, moisture, ash protein content, mineral composition, fatty acid profile, and volatile compounds. Carcass weights of calves ranged from 108 to 328 kg according to the Spanish market, with significant breed differences in fat (range 2.98–8.41%), moisture (69.47–72.62%), and protein (20.98–23.82%), but not in ash (1.03–1.17%). Sodium levels were below 120 mg/100 g, allowing all breeds to be classified as low-sodium, while phosphorus values supported a high-phosphorus label. The Pajuna, Berrenda en Colorado, and Lidia breeds showed higher levels of beneficial fatty acids such as EPA, DPA, DHA, and CLA, with n-6/n-3 ratios ≤ 4, while Retinta and Marismeña presented higher ratios (6.09 and 5.23, respectively). The breeds from Southwest Spain stand out for their content in ketone, ester, and aromatic hydrocarbon volatile compounds linked to the intake of grass, forage, and food concentrate. These results highlight the favorable nutrient profiles and distinctive traits of Spanish autochthonous cattle breeds, emphasizing their value in sustainable production and conservation programs. Full article