The study was conducted at 40 household pig farms and 25 large-scale pig farms across the selected provinces and cities in the Red River Delta, Viet Nam. For household farms, the survey was conducted in four provinces and cities, namely Thai Binh, Bac Giang, Thanh Hoa and Hanoi. In each province or city, 10 household pig farms were randomly selected from the obtained list of pig farms to conduct interviews using a questionnaire form. For large-scale pig farms, the survey was conducted in three provinces, namely Hanoi (in Ung Hoa, Son Tay, Gia Lam district), Hung Yen (Van Lam district) and Thanh Hoa (Van Xuong district). In each district, five large-scale farms were selected randomly to conduct the interviews and questionnaire surveys.