Prevalence and Risk Factors of Bovine Viral Diarrhea in Dairy Herds of Bangladesh

A cross-sectional study conducted in Bangladesh from January 2023 to December 2024 assessed BVD prevalence and risk factors in large dairy herds. The study collected 138 bulk milk samples from 14 districts and 767 cow milk samples from positive herds, using cELISA for diagnosis. The overall herd prevalence was 72.5% (95% CI: 64.1-79.6), with a cow-level prevalence of 93.3% (95% CI: 91.3-94.9%). Prevalence within herds ranged from 81.8% to 100%. Herds with over 70 cows had 31.95 times higher odds of BVD than those with 13-23 cows. BVD prevalence was significantly higher in the third, fifth, and eighth semen sources compared to the reference source. Cows older than 8 years had 4.53 times higher odds of BVD than those aged up to 4 years. Cows with thin physical condition had 13.02 times higher odds than those with normal condition. Conversely, cows producing over 8.8 kg of milk daily had a significantly lower BVD prevalence (OR: 0.41; 95% CI: 0.17-0.98). Regular screening, using semen from BVD-free bulls, and prioritizing sur-veillance for thin cows and low milk producers are essential. Good nutrition, management, and targeted monitoring are crucial for reducing BVD transmission and improving herd productivity.