Effects of Euphorbia humifusa Extract on Nutrient Digestibility, Diarrhea, Serum Biomarkers, and Anti-Inflammatory Mechanisms in Preweaned Calves.

Early-life rearing of animals is critical for their lifelong productivity, health, and the quality/safety of livestock products. EHE, a feed additive with growth-promoting, antibacterial, and immunity-enhancing properties, was tested for effects on preweaned calves. Forty-eight calves (42.18 ± 0.61 kg) were randomly assigned to four groups (n = 12/group), fed milk replacer with 0 (CON), 400 (A), 800 (B), or 1200 (C) mg/d EHE for 60 d (after 6 d adaptation). Growth, nutrient digestibility, serum biomarkers, rumen fermentation, and diarrhea incidence were measured; network pharmacology was used to analyze EHE's targets. Results: Group C had 14.09% higher body weight gain (52 vs. 45 kg, p < 0.05), higher dry matter intake/digestibility, and increased acid detergent fiber digestibility vs. CON. Group C had reduced diarrhea frequency, tended to have lower rumen acetate-to-propionate ratio, and had higher early rumen volatile fatty acids (VFA). At d 66, Groups B and C had reduced serum IL-6/IL-8 (p < 0.05). Network pharmacology identified 256 anti-inflammatory targets (e.g., BCL2, IL6) involved in apoptosis/inflammatory pathways. Conclusion: 1200 mg/d EHE optimally improves calf growth, digestibility, and anti-inflammatory status.