The study looked at using cow dung in household biogas digesters to make biogas in a cold region. By keeping the temperature around 35-45℃, they found that the digesters produced 8.7 m3 of biogas in 42 days. The highest daily biogas production was 0.5 m3. After 30 days, the biogas production started to decrease, meaning that the organic material in the digester was used up. To keep producing biogas, more cow dung needed to be added before 30 days.