The process of myogenesis, which involves the growth and differentiation of muscle cells, is a crucial determinant of meat yield and quality in beef cattle. Essential nutrients, such as vitamins D and A, play vital roles in the development and maintenance of various tissues, including muscle. However, limited knowledge exists regarding the specific effects of vitamins A and D in bovine muscle. Therefore, the aim of this study was to investigate the impact of vitamins A and D treatment on myogenic fusion and differentiation in bovine satellite cells (BSC). BSC were isolated from Korean native beef cattle, specifically from four female cows approximately 30 mo old. These individual cows were used as biological replicates (n = 3 or 4), and we examined the effects of varying concentrations of vitamins A (All-trans retinoic acid; 100 nM) and D (1,25-dihydroxy-vitamin D3; 1 nM, 10 nM, and 100 nM), both individually and in combination, on myoblast fusion and myogenic differentiation during the growth phase (48 h) or differentiation phase (6 d). The results were statistically analyzed using GLM procedure of SAS with Tukey’s test and t-tests or one-way ANOVA where appropriate. The findings revealed that vitamin A enhanced the myoblast fusion index, while vitamin D treatment decreased the myoblast fusion index during the growth phase. Furthermore, vitamin A treatment during the differentiation phase promoted terminal differentiation by regulating the expression of myogenic regulatory factors (Myf5, MyoD, MyoG, and Myf6) and inducing myotube hypertrophy compared to the control satellite cells (P < 0.01). In contrast, vitamin D treatment during the differentiation phase enhanced myogenic differentiation by increasing the mRNA expression of MyoG and Myf6 (P < 0.01). Moreover, the combined treatment of vitamins A and D during the growth phase increased myoblast fusion and further promoted myogenic differentiation and hypertrophy of myotubes during the differentiation phase (P < 0.01). These results suggest that vitamin A and D supplementation may have differential effects on muscle development in Korean native beef cattle during the feeding process.

The monitoring of pre-weaned calf behavior is crucial for ensuring health, welfare, and optimal growth. This study aimed to develop and validate a machine learning-based technique for the simultaneous monitoring of multiple behaviors in pre-weaned beef calves within a cow–calf contact (CCC) system using collar-mounted sensors integrating accelerometers and gyroscopes. Three complementary models were developed to classify feeding-related behaviors (natural suckling, feeding, rumination, and others), postural states (lying and standing), and coughing events. Sensor data, including tri-axial acceleration and tri-axial angular velocity, along with video recordings, were collected from 78 beef calves across two farms. The LightGBM algorithm was employed for behavior classification, and model performance was evaluated using a confusion matrix, the area under the receiver operating characteristic curve (AUC-ROC), and Pearson’s correlation coefficient (r). Model 1 achieved a high performance in recognizing natural suckling (accuracy: 99.10%; F1 score: 96.88%; AUC-ROC: 0.999; r: 0.997), rumination (accuracy: 97.36%; F1 score: 95.07%; AUC-ROC: 0.995; r: 0.990), and feeding (accuracy: 95.76%; F1 score: 91.89%; AUC-ROC: 0.990; r: 0.987). Model 2 exhibited an excellent classification of lying (accuracy: 97.98%; F1 score: 98.45%; AUC-ROC: 0.989; r: 0.982) and standing (accuracy: 97.98%; F1 score: 97.11%; AUC-ROC: 0.989; r: 0.983). Model 3 achieved a reasonable performance in recognizing coughing events (accuracy: 88.88%; F1 score: 78.61%; AUC-ROC: 0.942; r: 0.969). This study demonstrates the potential of machine learning and collar-mounted sensors for monitoring multiple behaviors in calves, providing a valuable tool for optimizing production management and early disease detection in the CCC system

This study compared the effects of two C3 forages (Italian ryegrass [RG], Timothy grass [TG]) and two C4 forages (Klein grass [KG], Bermuda grass [BG]) on growth performance, nutrient digestibility, and nitrogen (N) balance in Korean crossbred black goats to evaluate C4 warm-season forages as alternatives under changing climate conditions. Sixteen castrated goats (10 months old) were allocated to four treatments using a randomized complete block design. Diets contained 40% treatment-specific forage and 60% commercial concentrate. After adaptation periods, a 5-day metabolism trial measured performance and digestibility parameters. No significant differences occurred among treatments for growth performance or digestibility of dry matter, crude protein, neutral detergent fiber, ash, and non-fiber carbohydrate. C4 grasses showed significantly lower acid detergent fiber and ether extract digestibility than C3 grasses, with KG having the lowest ether extract digestibility. The KG group had higher N intake and absorption than the TG group, while BG showed lower urinary and total N excretion than KG. No differences existed in retained N, utilization efficiency, or biological value among groups. Both C3 and C4 forages supported comparable goat growth performance, providing a reference for utilizing different photosynthetic pathway forages under changing climatic conditions.

Our study aimed to evaluate the dualistic effect of heat stress on muscle differentiation at different temperatures, and whether vitamin E, a powerful antioxidant, could offset any negative effects, using bovine skeletal-muscle-derived cells (BSMCs) with myogenic properties. The BSMCs were extracted from the skeletal muscle of thirty-month-old Korean native cattle and subjected to myogenic differentiation under three heat exposure conditions: 37°C (control; CON), 39°C (mild heat stress; MHS), and 41°C (severe heat stress; SHS) for 24 h with or without vitamin E treatment (NE or VE). After 24 h treatments, the cells were returned to 37°C incubators and differentiated until day 6. On day 1, because of the heat exposure, the gene expression of MYOG was the highest in MHS (P = 0.047), suggesting a promotive effect of mild heat stress on myogenic differentiation, while on day 6, compared to CON and MHS, MYOD (P = 0.013) and MYOG (P = 0.029) were the lowest in SHS. Vitamin E treatment also lowered MYOG (P = 0.097), regardless of heat exposure. On day 1, HSPB1 (P = 0.001) and HSP70 (P < 0.001) were the highest in SHS, and an interaction between heat exposure and vitamin E treatment was found on day 6 (P < 0.027). BCL-2 was also the highest on day 1 in SHS (P = 0.05), and an interaction of heat exposure and vitamin E treatment was found on day 1 on BAX expression (P = 0.038). For antioxidant genes, SOD1 (P = 0.002) and GPX1 (P < 0.001) were affected by heat exposure, with the highest levels being observed in SHS, and on day 6, GPX1 was still the highest in SHS (P = 0.027). The fusion index was also affected by heat exposure, showing a decrease in SHS and an increase in MHS compared to CON (P < 0.001). Significant effects were noted from heat exposure (P < 0.001), vitamin E treatment (P < 0.001), and the interaction of heat exposure and vitamin E treatment (P = 0.002) on the protein content. Taken together, our findings provide evidence that vitamin E could ameliorate the harmful effects of heat exposure by modulating heat shock proteins and apoptosis regulators, improving the protein synthesis of BSMCs during myogenic differentiation. These results suggest that vitamin E supplementation could potentially protect muscle development in beef cattle under summer heat stress.

This study aimed to characterize behavioral differences between true estrus (TE) and false estrus (FE) in cows using neck-mounted six-axis inertial measurement unit sensors to reduce false positives in automated detection systems. A retrospective analysis was conducted on 1464 validated estrus alerts from 414 Hanwoo cows across 13 commercial farms in South Korea. Alerts were classified as TE (625 alerts) or FE (839 alerts) based on comprehensive validation criteria, including standing heat observation, artificial insemination records, ovulation confirmation, and pregnancy outcomes. Mounting activity, rumination time, and lying time were analyzed. True estrus exhibited significantly higher (p < 0.0001) total number of mounts and maximum mounting duration compared to FE over the entire observation period. Notably, the maximum number of mounts per hour was higher (p < 0.0001) in FE before alert generation but higher (p < 0.0001) in TE afterward, with FE declining rapidly. Coefficients of variation for rumination and lying time were significantly higher (p < 0.0001) in TE than in FE, indicating greater behavioral disruption. These findings revealed that secondary behavioral signs exhibit distinct quantitative and temporal patterns between TE and FE, suggesting potential criteria that could be integrated into automated detection algorithms to reduce false-positive rates.

Objective: To investigate the role of Bruton's tyrosine kinase (BTK) in pyroptosis of intestinal cells caused by endotoxin/lipopolysaccharide (LPS) in scalded mice. Methods: One hundred and twenty-eight male C57BL/6 mice aged 6-8 weeks were divided into sham injury group, scald alone group, scald+LPS group, scald+LPS+3 mg/kg LFM-A13 group, scald+LPS+10 mg/kg LFM-A13 group, and scald+LPS+30 mg/kg LFM-A13 group. There were 8 mice in sham injury group, and there were 24 mice in the other 5 groups, respectively. Mice in 5 scald groups were inflicted with 10% total body surface area full-thickness scald on the back, and mice in sham injury group were sham injured on the back. At post injury hour (PIH) 0 (immediately), mice in sham injury group and scald alone group were intraperitoneally injected with normal saline, mice in scald+LPS group were intraperitoneally injected with LPS, and mice in scald+LPS+3 mg/kg LFM-A13 group, scald+LPS+10 mg/kg LFM-A13 group, and scald+LPS+30 mg/kg LFM-A13 group were intraperitoneally injected with LPS and LFM-A13 in corresponding doses. Mice in sham injury group were sacrificed at PIH 0 to collect serum and intestinal tissue, and 8 mice in each group of 5 scald groups were sacrificed at PIH 0, 12, and 24 to collect intestinal tissue and serum at PIH 12. Immunohistochemistry was used to detect phosphorylation of BTK in intestinal tissue of mice. Western blotting was used to detect the protein expressions of phosphorylated BTK (p-BTK), cleaved cysteine aspartic acid specific protease 1 (caspase-1), and caspase-11 in intestinal tissue of mice. Enzyme-linked immunosorbent assay method was used to detect interleukin-1β (IL-1β) in serum and intestinal tissue of mice. Data were statistically analyzed with one-way analysis of variance and least significant difference test. Results: (1) There was no obvious phosphorylation of BTK in intestinal tissue of mice in 6 groups at PIH 0 and scald alone group at PIH 12 and 24. Phosphorylation of BTK in intestinal tissue of mice in scald+LPS group at PIH 12 and 24 were obviously increased compared with those in scald alone group. Phosphorylation of BTK in intestinal tissue of mice in scald+LPS+3 mg/kg LFM-A13 group, scald+LPS+10 mg/kg LFM-A13 group, and scald+LPS+30 mg/kg LFM-A13 group were obviously decreased compared with those in scald+LPS group, and the degrees of decline gradually increased with increase of dose in LFM-A13. (2) Compared with (0.130±0.010) of sham injury group and (0.120±0.040 and 0.110±0.040) of scald alone group, protein expressions of p-BTK in intestinal tissue of mice in scald+LPS group at PIH 12 and 24 were obviously increased (0.470±0.090 and 0.430±0.080, P<0.01). Compared with those in scald+LPS group, protein expressions of p-BTK in intestinal tissue of mice in scald+LPS+3 mg/kg LFM-A13 group at PIH 24, and scald+LPS+10 mg/kg LFM-A13 group and scald+LPS+30 mg/kg LFM-A13 group at PIH 12 and 24 were obviously decreased (0.280±0.060, 0.300±0.120, 0.150±0.050, 0.280±0.090, 0.140±0.040, P<0.05 or P<0.01). Compared with those in scald+LPS+3 mg/kg LFM-A13 group, protein expressions of p-BTK in intestinal tissue of mice in scald+LPS+10 mg/kg LFM-A13 group and scald+LPS+30 mg/kg LFM-A13 group at PIH 24 were obviously decreased (P<0.01). (3) Compared with those in sham injury group and scald alone group, protein expressions of cleaved caspase-1 and caspase-11 in intestinal tissue of mice in scald+LPS group were obviously increased at PIH 12 and 24 (P<0.01). Compared with those in scald+LPS group, protein expressions of cleaved caspase-1 at PIH 12 and cleaved caspase-11 at PIH 12 and 24 in intestinal tissue of mice in scald+LPS+3 mg/kg LFM-A13 group and protein expressions of cleaved caspase-1 and caspase-11 in intestinal tissue of mice in scald+LPS+10 mg/kg LFM-A13 group and scald+LPS+30 mg/kg LFM-A13 group at PIH 12 and 24 were obviously decreased (P<0.01). Compared with those in scald+LPS+3 mg/kg LFM-A13 group, protein expressions of cleaved caspase-1 and caspase-11 in intestinal tissue of mice in scald+LPS+10 mg/kg LFM-A13 group and scald+LPS+30 mg/kg LFM-A13 group at PIH 12 and 24 were obviously decreased (P<0.05 or P<0.01). (4) At PIH 12, content of IL-1β in intestinal tissue and serum of mice in scald+LPS group were obviously higher than those in sham injury group and scald alone group (P<0.01), and content of IL-1β in intestinal tissue and serum of mice in scald+LPS+30 mg/kg LFM-A13 group were obviously lower than those in scald+LPS group (P<0.01). Conclusions: Phosphorylation of BTK is related to increases of cleaved caspase-1 and caspase-11 in intestinal tissue, and IL-1β content in intestinal tissue and serum of scalded sepsis mice caused by LPS. Phosphorylation of BTK mediated intestinal cell pyroptosis of scalded mice caused by LPS. Inhibiting phosphorylation of BTK can alleviate intestinal cell pyroptosis of scalded mice, with protective effect on intestinal injury.