Nutrition has become increasingly complex. Normally, feeding programs are adopted to maximize the farm’s return over feed costs. However, certain circumstances lead to other issues such as minimizing nutrient excretion into the slurry, which is also important. Past research done at the Prairie Swine Centre and elsewhere has shown that feeding low crude protein (CP) diets can decrease the nitrogen output in manure. The use of synthetic amino acids in a low CP diet is becoming more economical, but producers still fear that growth and carcass quality may be adversely affected with the application of such a diet. Results from this study of three diets prove that low CP diets are practical for commercial productions. Growth rates were unchanged in pigs fed the low protein diet compared to those fed the control diet. Carcass quality was unchanged or improved slightly. Overall performance, and uniformity of performance was excellent. The economics of low protein and high synthetic amino acid diets is currently very favourable, saving $2 per barrow and up to $4 per gilt in this trial (based on November, 2003 prices).