Innovative Gutter Modifications for Reducing Nitrogen Losses in Tie-Stall Dairy Systems

Abstract Manure from dairy cows, consisting of feces and urine, presents a significant issue for smallholder dairy farms in Indonesia. Managing feces is easier than urine as it can be collected and stored for use as organic fertilizer. However, most urine is discharged and lost to the environment. This study aims to analyze the potential reduction of nitrogen (N) losses from urine by modifying the gutter system. We modified the gutter by constructing the urine gutter which separated with the feces gutter on a smallholder dairy farm in Lembang, West Java, with five lactating cows and two dry cows. The separated urine line was directed to temporary storage and processed as liquid processed manure (POC). We calculated the amount of urine excreted per cow over 24 hours to estimate the N content in the urine. Our findings showed the average excreted urine of 15 liters per day, totalling 125 liters per farm or 3770 liters per month. By modifying the gutter system, 880 kg of urine has been captured, which equals to 23.3% of the total urine per month. With a 0.5% N content in urine, the potential N loss was 18.8 kg, and the avoided losses were 4.4 kg per month. Modifying the gutter can thus reduce N losses from urine production and support sustainability Indonesian dairy farms.