Bovine viral diarrhea (BVD) is a common viral disease in cattle that causes huge economic losses in naïve herds that are introduced to bovine viral diarrhea virus (BVDV). Currently, there are no available anti-BVDV drugs due to the variety and mutability of strains; therefore, developing new anti-BVDV drugs is of great significance. The aim of this study was to investigate the anti-BVDV effects and immunomodulatory activities of Codonopsis pilosula polysaccharides (CPPs) in BVDV-infected bovine macrophage (BoMac) cells. CPPs directly inactivated BVDV particles and intervened in BVDV absorption process. The immunity suppression resulting from BVDV in BoMac cells was restored by CPPs, as was verified by phagocytosis increase, the expression up-regulation of cell surface co-stimulatory molecules (CD40, CD80, and CD86), and antigen-presenting function recovery. Furthermore, the expressions of cytokines including TNF-α, IFN-γ, IL-6, IL-18, IL-1β, Caspase-3, Bim, and Bcl-xL at the mRNA and proteins levels were modulated, and a reduction in the apoptosis rate was observed, which demonstrates that CPPs attenuated inflammation and apoptosis induced by BVDV. Collectively, our findings reveal new pharmacological properties of CPPs, which exert anti-BVDV efficacy and regulate immune injury induced by BVDV in BoMac cells, indicating that CPPs are a potential option for BVDV prevention in clinical application.

Bovine viral diarrhea virus (BVDV) constitutes a significant pathogen adversely threatening reproductive performance in the cattle industry, primarily by inducing ovarian dysfunction characterized by aberrant hormone synthesis and impaired follicular development. Although several commercial vaccines are available, they are insufficient for prevention and control BVDV infection, underscoring the necessity for the development of novel therapeutic drugs. This study aimed to investigate the antiviral activity of cryptotanshinone (CRY) against BVDV infection and its protective effects on bovine ovarian granulosa cells (BOGCs). An in vitro infection model was established by exposing BOGCs to BVDV. The results demonstrated that CRY exhibits anti-BVDV activity and alleviates detrimental effects on BOGCs through multiple mechanisms. Comparative analysis revealed that therapeutic administration of CRY constitutes the most effective mode of intervention. Furthermore, CRY promotes the secretion of estradiol (E₂) and progesterone (P₄) in BOGCs, counteracting the BVDV-induced reduction in these hormones. Moreover, CRY shows protective activity by mitigating BVDV-induced apoptosis in BOGCs. In summary, this study is the first to elucidate the inhibitory effect of CRY on BVDV and its regulatory role in BOGCs function, suggesting that CRY holds potential application value in the clinical treatment of BVDV-related reproductive disorders.

The aim of this study was to understand the status of Mycobacterium paratuberculosis infection in a large-scale dairy farm in Xi’an city and evaluate the impact via a “quarantine + elimination” model of bovine paratuberculosis on the production performance, reproductive performance, and economic benefits in said dairy farm. The paratuberculosis antibodies from 4488 dairy cow sera were detected by an ELISA kit, complemented by a comprehensive analysis of milk production parameters, health metrics, reproductive indices, and pharmaceutical expenditures (2021–2024). The results indicated that the paratuberculosis prevalence in the dairy farm gradually reduced from 6.76% (2021) to 3.58% (2024). It was also found that the paratuberculosis prevalence among dairy cows increased progressively with the increase in parity until the fifth calving, after which a significant decline was observed. The reduction in infection rates in the herd was correlated with measurable improvements in milk quality metrics, including elevated milk fat and protein content, extended shelf stability, and decreased somatic cell counts in milk. In addition, the reproductive performance of the dairy cows relatively improved with the decrease in paratuberculosis prevalence; there was a relative improvement in the reproductive performance of the dairy cows, which mainly occurred by the time of pregnancy at the first service of the cows, while the number of monthly occurrences of endometritis, diarrhea, calving intervals, and inseminations decreased. Further data correlation analysis showed that daily milk volume was positively correlated with lactase persistence (95% CI: 0.247–0.753, p = 0.001) and peaked at the day of milk production (95% CI: 0.135–0.698, p = 0.008) but was negatively correlated with parity (95% CI: −0.783–−0.315). In addition, lactation time was positively correlated with 305-day milk volume (95% CI: 0.173–0.718, p < 0.004) and peaked at the day of milk production (95% CI: 0.265–0.761) but showed the opposite trend with the milk fat rate (95% CI: −0.633–−0.018, p = 0.040) and milk protein rate (95% CI: −0.738–−0.215, p = 0.002). Furthermore, milk loss was negatively correlated with peak milk production (95% CI: −0.758–−0.258, p = 0.001). Intriguingly, the cost of medications for diarrhea exhibited a downward trend over the past three years. Taken together, these findings confirmed the necessity to reduce the incidence of Mycobacterium avium subsp. paratuberculosis in dairy cows and serve as a guide for the future successful and gradual eradication of paratuberculosis in Chinese dairy cow farms.