Nitrogen losses from swine housings

摘要: Abstract A nitrogen budget procedure was used to estimate the loss of manure N from three swine barns with liquid systems. The determined as difference between animal plus feed inputs and outputs. Estimates ammonia were also obtained directly measurements flow rates concentrations ventilated air in two barns. Between 5% 27% excreted unaccounted for or lost after extensive monitoring periods 415 617 days. There good agreement direct methods estimating one barn. Reasons a discrepancy estimates second barn are discussed. extent generally related management system greater exposure fresh during collection storage, loss. Temperature had both indirect effects (through increased ventilation rates) on losses