Search Results (693)

The Raramuri Criollo (RC) cattle is recognized for its adaptability, resilience, and low feeding requirements under low-input production systems. This study compared the productive and reproductive performance of purebred RC and Angus × Raramuri Criollo (AC) heifers with Hereford × Angus (HA) heifers. Experiment I evaluated post-weaning growth, feed intake, and feed efficiency in a 56 d individual feeding trial using 10 RC, 10 AC, and 8 HA heifers after a 14 d adaptation period; heifers received the experimental diet ad libitum throughout the trial. Experiment II evaluated puberty attainment and growth development of 14 RC, 17 AC, and 11 HA heifers under rangeland with limited supplementation (RLS) and 11 RC, 16 AC, and 10 HA heifers under annual irrigated pasture (AIP). Puberty attainment was determined from two consecutive serum progesterone concentrations >1 ng/mL, and body weight, average daily gain (ADG), age at puberty (AP), and body weight at puberty (BWP) were analyzed using mixed models and Kaplan–Meier survival analysis. Under individual feeding, RC and AC heifers gained 0.56 ± 0.06 and 0.32 ± 0.06 kg/d less and consumed 40.4% and 22.0% less feed than HA heifers (p < 0.05), whereas feed conversion and residual feed intake did not differ among breed groups. Heifers developed under AIP attained puberty earlier than those under RLS (median AP: 369 vs. 546 d; logrank p < 0.001). Overall, AC heifers combined the adaptive capacity of RC cattle with the productive potential of British breeds, achieving a favorable balance among growth, feed intake, feed efficiency, and reproductive development under contrasting development conditions, supporting their use in low-input beef production systems. Full article

Optimizing feeding regimes and finishing duration is essential for improving beef production efficiency and meat quality. This study evaluated the effects of two feeding regimes and three finishing durations on growth performance, nutrient digestibility, carcass traits, meat quality, blood biochemical parameters, rumen fermentation, and rumen microbiota in Black Angus bulls. A total of 552 healthy bulls with similar initial body weight were assigned to a 2 × 3 factorial design with two diets—a corn silage–rice straw–concentrate TMR (CSRC) and a rice straw–concentrate TMR (RSC)—and three finishing durations: 10, 12, and 14 months. The CSRC TMR increased average daily gain and reduced feed-to-gain ratio during early finishing (p < 0.05), whereas the RSC TMR resulted in greater final body weight and higher meat redness at 14 months (p < 0.05). Prolonged finishing decreased average daily gain, feed efficiency and nutrient digestibility (p < 0.05), but increased carcass weight, eye muscle area, backfat thickness and meat tenderness (p < 0.05). The CSRC TMR promoted higher total volatile fatty acid production (p < 0.05), an acetate-oriented fermentation pattern and greater rumen microbial alpha diversity. These findings support a stage-specific feeding regime for Black Angus bull finishing. Under the present conditions, corn silage inclusion may be used to improve early finishing efficiency, whereas rice straw–concentrate TMR may be more suitable for late finishing to balance final body weight, meat quality, and production cost. Full article

(1) Background: This study investigated the effects of fermented palm kernel cake (FPKC) on growth performance, serum indices, rumen fermentation and microbiota in growing–fattening beef cattle. (2) Methods: Forty-eight Angus cattle (504.50 ± 52.45 kg) were randomly divided into four groups (n = 12). The control group was fed a basal diet, while treatment groups were fed diets with 10%, 20% and 30% FPKC replacing corn and soybean meal concentrate. The experiment included a 14-day adaptation period and a 56-day formal experimental phase. (3) Results: Compared with the control, 20% FPKC significantly increased average daily gain and decreased the feed-to-gain ratio (p < 0.05). All FPKC groups had lower serum alanine aminotransferase (ALT) (p < 0.05). The 20% and 30% FPKC groups showed higher IgA and T-AOC, and lower MDA (p < 0.05) and highly significantly lower IL-1β. All FPKC groups had higher ruminal propionic acid (p < 0.05). In particular, 20% FPKC modified rumen microbial structure and increased the relative abundance of Succinivibrionaceae_UCG-002 (p < 0.05). (4) Conclusions: Replacing part of concentrate with 20% FPKC (9.1% inclusion in the total diet) improved growth performance, enhanced immune and antioxidant function in growing–fattening beef cattle, optimized rumen fermentation, and increased the relative abundance of beneficial bacteria including Succinivibrionaceae_UCG-002. Full article

Background: Foodborne pathogenic Escherichia coli is a major public health concern due to its frequent association with meat and meat products and its potential to harbor virulence factors and antimicrobial resistance (AMR) determinants. Objective: This study aimed to investigate the prevalence, virulence gene profiles, and AMR patterns of E. coli isolates obtained from beef and chicken meat products. Methods: A total of 200 beef and chicken meat product samples were collected from retail markets in Samsun, Türkiye. Isolation of E. coli was performed using conventional culture-based methods, and PCR targeting the uspA gene was used for molecular confirmation. The presence of virulence genes (stx1, stx2, eae, and hlyA) was investigated by PCR. Antimicrobial susceptibility testing was conducted using the disk diffusion method, and multidrug resistance (MDR) and multiple antibiotic resistance (MAR) indices were evaluated. Results: Among the 200 samples analyzed, 80 (40%) were positive for E. coli, including 38 (38%) beef and 42 (42%) chicken meat samples. A total of 185 E. coli isolates were recovered and confirmed by PCR. Virulence gene analysis showed that stx2 was the most prevalent gene (51.4%), followed by eae (37.3%), hlyA (13.0%), and stx1 (6.5%). Antimicrobial susceptibility testing demonstrated high resistance rates to tetracycline (69.7%), ampicillin (58.4%), trimethoprim–sulfamethoxazole (48.1%), streptomycin (40.5%), nalidixic acid (40.0%), chloramphenicol (40.0%), and ciprofloxacin (34.1%). In contrast, the lowest resistance rates were observed for imipenem (2.2%), amoxicillin–clavulanate (4.9%), and amikacin (7.6%). Moreover, 126 isolates (68.1%) were identified as MDR, exhibiting resistance to at least three antimicrobial agents. The MAR index ranged from 0.06 to 1.00. Conclusions: The coexistence of virulence-associated genes and high AMR rates among E. coli isolates from meat products indicates a potential public health risk. These findings highlight the importance of continuous monitoring of pathogenic and antimicrobial-resistant E. coli throughout the food production chain. Full article

This study compared the effects of air freezing (AF), immersion freezing (IF), and ultrasound-assisted immersion freezing (UIF) at different power levels on the physicochemical properties, oxidative characteristics, and the structural and functional properties of myofibrillar protein (MP) of fresh beef. The results showed that UIF treatments generally outperformed AF and IF, with UIF-400 W exhibiting the best performance in maintaining beef quality. Specifically, UIF-400 W mitigated muscle fiber damage by inhibiting ice crystal growth, significantly improved water-holding capacity and color stability, reduced shear force, and effectively delayed protein and lipid oxidation. In addition, UIF-400 W brought the rheological properties, emulsifying properties, water distribution, and gel microstructure of MP closer to those of fresh beef. These findings highlight that UIF-400 W can effectively preserve beef quality as well as the structural and functional characteristics of MP, reduce oxidative damage, and thus become a promising technology for quality improvement of beef during freezing. Full article

Madura cattle are a nationally important indigenous Indonesian beef cattle breed and a locally adapted genetic resource that supports smallholder livelihoods and beef production under tropical dryland, low-input farming conditions. As an indigenous Indonesian beef cattle breed raised predominantly by smallholder farmers in dryland and low-input systems, Madura cattle require integrated management practices that combine resource management, technical management, environmental management, and operational efficiency to improve farm performance. A quantitative survey was conducted with 400 farmers from Madura Island. Data were collected through structured interviews using a five-point Likert-scale questionnaire and analyzed using SEM-PLS by evaluating the measurement and structural models. The results show that all constructs met validity and reliability criteria. The model demonstrated adequate explanatory power, with adjusted R² values of 0.369 for Operational Efficiency and 0.522 for Farm Performance. Resource Management, Technical Management, and Environmental Management had positive and significant effects on Operational Efficiency. Operational Efficiency also had a positive and significant effect on Farm Performance and partially mediated the relationships between the three management variables and Farm Performance. These findings indicate that improving Madura cattle farming performance requires stronger resource, technical, and environmental management supported by operational efficiency as a strategic mechanism to enhance production, reproduction, and economic performance sustainably. Full article

Rumen methane emissions contribute to global warming and energy loss in cattle. The use of plants rich in secondary metabolites to mitigate methane emissions has been extensively studied, with varying outcomes. The primary aim of this meta-analysis was to assess the impact of secondary metabolites on methane production, productive performance, and ruminal fermentation in beef cattle supplemented with plant-based additives. In accordance with the PRISMA guidelines, 43 of the 578 studies were selected for analysis, employing random-effects models to estimate the raw and standardized mean differences (RStudio: metafor and ggplot, with significance thresholds of p ≤ 0.05 and p ≤ 0.1). Heterogeneity was evaluated using the I² statistic, alongside a subgroup meta-regression examining variables such as dose, additive type, additive form, and forage-to-concentrate ratio. After performing Egger’s test and trim and fill analysis, it was determined that tannins reduced methane yield (g/kg DM, adjusted SDM = −0.463), increased propionate production (%, RMD = 0.066, p = 0.001), rumen pH (adjusted SMD = 0.307), and organic matter intake (RMD = 0.066, p = 0.01). Despite phenolic compounds, flavonoids, terpenes, and terpenoids successfully modulating methane production, fermentative parameters, and nutrient intake, the limited number of comparisons and publication bias suggest caution in generalizing these results. In conclusion, supplementation with plant-based additives containing tannins offers a promising nutritional strategy for reducing enteric methane emissions while maintaining beef cattle performance. Full article

Objectives: Increasing antimicrobial resistance among foodborne pathogens, particularly extended-spectrum β-lactamase (ESBL) and plasmid-mediated AmpC β-lactamase (pAmpC) production, has become a major public health concern worldwide. This study aimed to determine the presence of Salmonella Enteritidis, Salmonella Typhimurium, and Escherichia coli O157:H7 in bovine carcasses and to evaluate their antibiotic resistance profiles together with ESBL and pAmpC resistance characteristics. Methods: A total of 300 bovine carcasses were examined for the presence of Salmonella spp. and E. coli O157:H7 using culture-based isolation methods following ISO 6579-1 and FDA guidelines, respectively. The isolates were confirmed by molecular methods, and stx1, stx2, eae, and hly were investigated in E. coli O157:H7 isolates. Antimicrobial susceptibility testing was performed according to EUCAST guidelines. ESBL and pAmpC production were determined phenotypically and subsequently characterized by molecular methods. Results: A total of 25 Salmonella spp. (32% S. Enteritidis and 68% S. Typhimurium) and 20 E. coli O157:H7 isolates were recovered from different bovine carcasses. stx2 was the most frequently detected virulence gene. Of the 31 phenotypically ESBL-positive isolates, 29 carried at least one ESBL-associated gene. The predominant ESBL gene was bla_CTX-M (79.3%), followed by bla_TEM and bla_SHV (37.9%). Among CTX-M gene groups, CTX-M-25 was the most prevalent (94.4%). Phenotypic pAmpC production was detected in 13 isolates, while 17 isolates carried at least one pAmpC-associated gene, with FOX identified as the predominant gene group. All isolates were resistant to pefloxacin, followed by gentamicin (93.3%) and cefoxitin (55.5%). Multidrug resistance was detected in 34 (75.6%) isolates. Conclusions: The detection of ESBL-producing, pAmpC-positive, and multidrug-resistant Salmonella spp. and Escherichia coli O157:H7 isolates in bovine carcasses indicates the presence of antimicrobial-resistant foodborne pathogens in the beef production chain. These findings highlight the need for continued monitoring of antimicrobial resistance and effective control measures at the slaughterhouse level. Full article

Pasture ecosystems are a key component of livestock production in arid and semi-arid regions, where forage availability and nutritive value are often associated with animal performance under grazing conditions. This study aimed to provide an exploratory assessment of pasture productivity, forage nutritive value, and beef cattle productivity across contrasting natural–climatic settings in Kazakhstan. The study was conducted under commercial production conditions on five farms representing different grazing environments during the 2024–2025 grazing seasons. Because each zone was represented by a single farm, the study should be interpreted as an observational assessment of farm-level patterns rather than as a fully replicated experimental comparison. Pasture productivity and forage chemical composition, including crude protein, fiber, and dry matter content, varied among farms and seasons. Average daily gain ranged from 316.7 to 900 g day⁻¹ depending on the study site and year of observation. Exploratory statistical analyses indicated variability among the studied systems; however, pairwise comparisons did not reveal statistically significant differences in animal productivity among farms (p > 0.05). Correlation analyses revealed moderate positive associations between average daily gain, crude protein content, and pasture yield, although these relationships were not statistically significant after adjustment for multiple comparisons. Similarly, linear models incorporating forage nutritive value indicators and study site did not identify statistically significant predictors of animal productivity within the current dataset. Overall, the results describe patterns of variation in pasture characteristics and animal productivity observed under extensive grazing conditions in continental environments. Given the observational design and limited replication at the farm level, the findings should be interpreted cautiously and regarded as preliminary. The study provides baseline information for future investigations of pasture–livestock interactions in arid and semi-arid grazing environments. Full article

Background/Objectives: This study evaluated the effects of a compound probiotic fermented feed (CPFF) containing Lactobacillus plantarum, Bacillus subtilis, yeast, and Aspergillus niger on rumen in vitro fermentation, in situ feed degradation, and growth performance in beef cattle. Methods: We established a control group (CON) and experimental groups with 2%, 4%, and 8% CPFF supplementation for in vitro fermentation. Results: The results indicated that the NH₃-N concentration in the 4% CPFF group was significantly higher than in the other groups (p < 0.001). Similarly, microbial crude protein (MCP) production was significantly greater in the 4% CPFF group compared to the CON group (p = 0.016). The molar proportions of acetate, butyrate, isobutyrate, and valerate were significantly higher in the 2% and 4% CPFF groups than in the control group (p < 0.001), while propionate levels were significantly lower (p < 0.001). After 48 h, gas production was highest in the 4% CPFF group. Based on improvements in gas production, MCP synthesis, and fermentation intensity, the 4% inclusion level was determined to be optimal for further studies. We conducted an in situ degradation trial using 4% CPFF. Results showed that at 12 h, the neutral detergent fiber (NDF) degradation rate in the 4% CPFF group was significantly higher than in the CON group at 4, 8, 12, and 48 h (p < 0.05). At 48 h, the acid detergent fiber (ADF) degradation rate in the 4% CPFF group was also significantly higher than in the CON group (p < 0.001), and this group exhibited a significant increase in crude protein (CP) degradation (p = 0.030). We analyzed rumen fluid samples from both the CON and 4% CPFF groups after in vitro fermentation using 16S rRNA sequencing and untargeted metabolomics. Microbial community analysis revealed significantly increased abundances of functional bacterial groups such as Rikenellaceae_RC9_gut_group, Christensenellaceae_R-7_group, and UCG-002 in the 4% CPFF group (p < 0.05). Differential metabolites were primarily involved in pathways related to tryptophan metabolism, and tyrosine metabolism signaling. A feeding trial was conducted by adding 4% CPFF to the diet of Angus growing cattle. The results indicated that average daily gain (ADG) (p = 0.004) and average daily feed intake (ADFI) (p = 0.001) were significantly higher in the CPFF group than in the CON group. Conclusions: In conclusion, our results demonstrate that CPFF enhances rumen fermentation activity, optimizes the microbiota and metabolic profiles of rumen fluid, and improves the average daily gain of beef cattle. This research provides a valuable theoretical basis for applying CPFF in beef cattle breeding. Full article

This study evaluated the effects of monolaurin intake per finishing feedlot cattle on growth performance, metabolic status, ruminal environment, and meat fatty acid profile. Twenty-four castrated Holstein males (379 ± 8.5 kg; 12 months old) were randomly assigned to two treatments: basal diet (control) or basal diet with α-monolaurin (treated: 0.762 g/kg dry matter intake; ≈6.63 g/animal/day) for 79 days. Feed intake, body weight, and feed efficiency were recorded, and blood and ruminal samples were collected during the trial. Ruminal fermentation parameters, protozoa counts, hematological and biochemical variables, oxidative status biomarkers, ruminal microbiota composition (16S rRNA sequencing), and Longissimus dorsi fatty acid profile were analyzed. Monolaurin feed did not affect dry matter intake or final body weight, but increased total weight gain, average daily gain, and feed efficiency (p ≤ 0.05), indicating improved nutrient utilization. Hematological and serum biochemical variables were largely unchanged, although total leukocyte counts were lower in treated cattle. Animals receiving monolaurin showed reduced reactive oxygen species and lower superoxide dismutase activity, suggesting improved oxidative balance without changes in lipid peroxidation. During the adaptation phase (day 14), treated cattle exhibited lower acetate, propionate, valerate, and total volatile fatty acid concentrations and higher protozoa counts, but these differences disappeared by day 79, indicating ruminal adaptation. Microbiota diversity was not altered overall, although specific genera differed in relative abundance between treatments. In meat, monolaurin increased lauric, linoleic, and arachidonic acids, reduced palmitic and heptadecanoic acids, decreased total saturated fatty acids, and increased polyunsaturated fatty acids (p ≤ 0.05). Overall, dietary monolaurin improved feed efficiency, modulated oxidative status, induced transient ruminal microbial adjustments, and enhanced the nutritional quality of beef lipids without compromising metabolic health. Full article

The objective of this study was to evaluate the impacts of varying inclusion levels of soybean hull pellets (SHP) with annual ryegrass baleage (BAL) on animal performance and digestive kinetics in beef cattle. In Experiment 1 (Exp. 1), 60 weaned mixed-sex beef calves were randomly assigned to one of three treatments: 0.0%, 0.5%, or 1.0% body weight (BW) SHP with ad libitum access to BAL for 48 days (d). Animal performance, including BW, dry matter intake (DMI), and average daily gain (ADG), was evaluated for the duration of the study. In Experiment 2 (Exp. 2), six ruminally cannulated beef steers received the same treatments utilized in Exp. 1. Steers were dosed with ytterbium (Yb)-labeled BAL to evaluate ruminal passage rate across three 24 d periods. All data were analyzed using SAS 9.4. In Exp. 1, total BAL intake decreased in calves supplemented with SHP, while cumulative ADG increased from 0.30 (0.0% BW SHP) to 0.54 (0.5% BW SHP) and 0.74 kg/d (1.0% BW SHP), respectively. Final BW at D47 also increased as SHP inclusion increased. In Exp. 2, ruminal retention time decreased from 38.0 h (0.0% BW SHP) to 15.1 h (1.0% BW SHP), while cecum-to-proximal colon passage rate did not differ among treatments (p = 0.06). Baleage DMI did not differ between treatments. Results suggest that SHP supplementation improved calf performance despite reduced BAL intake in Exp. 1, with the greatest cumulative ADG observed in calves supplemented with 1.0% BW SHP. In Exp. 2, 1.0% BW SHP produced the greatest effects on passage rate kinetics, while BAL DMI was unaffected by SHP supplementation. Full article

This study evaluated the effects of maternal overfeeding during mid-to-late gestation on maternal productivity, metabolic status, reproductive recovery, and calf performance in Hanwoo cattle using conventional statistics and machine learning (ML) approaches. A total of 243 pregnant cows were assigned to either a control group or an overfeeding group from gestation day 90 to parturition. The overfeeding treatment increased nutrient supply to approximately 140–145% of the control level. Maternal body weight (BW), body condition score (BCS), serum metabolites, and reproductive traits were evaluated throughout gestation and postpartum, while calf growth, morphometrics, and metabolic traits were assessed at birth and weaning. Calves were further classified into growth- or meat-quality-oriented genotypes using SNP-based profiling. Overfeeding increased maternal BW gain and BCS during gestation and reduced circulating non-esterified fatty acid concentrations, indicating improved maternal energy status. However, overfed cows showed a longer interval to postpartum estrus return. Calf birth weight was not significantly affected by maternal overfeeding, whereas calf growth and morphometric traits at weaning were more strongly influenced by parity, sex, and genotype. Machine learning models identified gestational BW, metabolic indicators, calf feed intake, and genotype as major predictors of maternal and calf outcomes, with random forest and XGBoost showing superior predictive performance compared with linear models. These findings suggest that parity- and genotype-informed nutritional management combined with ML-based prediction may support precision feeding strategies in beef cattle production systems. Full article

Beef cattle behavior provides valuable information regarding their health status. Recently, deep convolutional network-based methods have achieved considerable results in beef cattle behavior recognition. However, their robustness under low-light or dark conditions remains limited, which restricts their application in real farm environments. To address this issue, this study constructed a realistic beef cattle behavior dataset in the dark, named Dark Beef Cattle Actions, which was collected under real nighttime farm conditions. The constructed dataset contains 1097 video clips collected from 30 beef cattle and covers 6 behavioral classes, including running, feeding, drinking, grooming, mounting, and fighting. Based on this dataset, we proposed a novel neural network architecture based on spatio-temporal dark enhancement and dynamic fusion for beef cattle behavior recognition in the dark. First, a spatio-temporal dark enhancement module was designed to improve dark video quality while preserving motion features. Second, a dynamic fusion module was introduced to adaptively fuse features from different branches and obtain more discriminative representations. In addition, a joint loss was adopted to optimize both dark enhancement and action recognition. Experimental results on the constructed dataset show that the proposed method achieved a weighted-averaged precision score of 88.47%, a weighted-averaged recall score of 80.18%, an accuracy score of 83.80%, and a weighted-averaged F1-score of 84.12%. Compared with other state-of-the-art methods, the proposed method achieved competitive performance in the recognition of night-time beef cattle behavior. These findings would provide support for intelligent livestock behavior recognition and monitoring in precision farming. Full article

The use of exogenous enzymes in feedlot cattle nutrition has been investigated as a strategy to increase nutrient utilization efficiency and productive performance. The objective of this study was to evaluate the effects of including arazyme, an exogenous metalloprotease, in the diet of feedlot beef cattle on zootechnical performance, hematological parameters, serum biochemical biomarkers, ruminal fermentation, and apparent nutrient digestibility. Twelve male Holstein cattle, with an average initial body weight of 352.5 ± 20.6 kg, were distributed in a completely randomized design with two treatments: control (no additive) and basal diet with arazyme (0.67 g/kg of dry matter consumed) for 63 days. The diet was formulated with a forage/concentrate ratio of 40:60. Although the sample size was small, the inclusion of arazyme proved effective under these conditions, with animals receiving the enzyme showing greater total weight gain, higher average daily gain, and better feed conversion, without affecting dry matter intake. No significant changes were observed in hematological parameters or in most serum biochemical biomarkers, indicating an absence of adverse effects on the metabolic or hepatic health of the animals. Higher total concentrations of volatile fatty acids in the rumen, particularly acetic, propionic, and butyric acids, as well as a higher ruminal pH on day 63, may be related to the enzyme’s action. Additionally, the apparent digestibility of crude protein and neutral detergent fiber was higher. Therefore, the inclusion of arazyme in the diet of feedlot cattle may be a promising alternative for improving digestive efficiency and intensifying ruminal fermentation, potentially resulting in improved productive performance. Future research with a larger number of replicates and different doses of the additive is necessary to understand its action. Full article