Background and Aim: The administration of hot chili pepper in cattle nutrition has been suggested to influence immune responses, antioxidant
Background and Aim: The administration of hot chili pepper in cattle nutrition has been suggested to influence immune responses, antioxidant activities, and physiological parameters. This study aimed to evaluate the effects of microencapsulated hot chili pepper (MCP) supplementation on blood metabolites, antioxidant capacity, and physiological parameters in crossbred dairy cows, contributing novel insights into metabolic and physiological adaptations under tropical production systems. Materials and Methods: Twenty-four crossbred lactating cows (Bos taurus × Bos indicus); average body weight 447.8 ± 89.6 kg; 53.54 ± 11.8 days in milk; average daily milk production 6.34 ± 1.91 L/cow/day) were randomly divided into two groups: A control group without additives and a treatment group supplemented with MCP (1,000 mg/cow/day) for 42 days. Blood samples were collected weekly for hematological analysis, biochemical evaluations, and oxidative stress biomarkers (2,2-diphenyl-1-picrylhydrazyl [DPPH], thiobarbituric acid reactive substances [TBARS], and trolox equivalent antioxidant capacity [TEAC]). Physiological measurements, including body condition score, heart rate, respiratory frequency, and urine pH, were also assessed weekly. Data were statistically analyzed using mixed-model procedures with repeated measures over time. Results: Significant interactions between treatment and time were observed for hematocrit, red blood cells, and hemoglobin (p < 0.05), indicating physiological adaptations potentially related to increased water intake. Serum albumin levels were significantly lower in MCP-supplemented cows compared to controls (p = 0.006), suggesting a modulation of lipid transport mechanisms. Temporal variations significantly affected 75% of hematological parameters and 83% of biochemical parameters. Although antioxidant parameters (DPPH, TBARS, TEAC) did not differ significantly between groups, notable temporal changes were observed (p < 0.05). Physiological parameters showed significant temporal variations but no consistent effects due to MCP supplementation. Conclusion: Supplementation of dairy cows with MCP significantly impacted hematological parameters and serum albumin levels, revealing potential metabolic adjustments involving lipid transport and hydration status. However, oxidative stress markers and physiological parameters remained largely unaffected by the supplementation. These findings support the potential regulatory role of MCP in dairy cow metabolism, emphasizing its relevance as a dietary additive in tropical livestock production systems.