Observations were made of a 1000-sow pig complex in Virginia, USA, to determine atmospheric ammonia loadings. Comparisons were made with similar data from the Netherlands, where ammonia release was being regulated. Results compared well with those reported from Europe. Threshold limit values did not violate the Virginia ambient air standard (25 p.p.m.), but calculated values for total annual discharge were approx. 67,500 kg/yr for the farm.