Greenhouse gas (GHG) emissions from manure storage facilities at four different commercial farrow-to-finish swine operations under liquid manure management located in Saskatchewan, Canada, were experimentally determined during the spring-to-fall period between 2001 and 2003. These operations featured three types of manure storage facilities: uncovered concrete tank, uncovered earthen manure basin (EMB), and covered (blown chopped straw) EMB. GHG emission rates were expressed in terms of unit mass of animal producing the stored manure. On average, methane and carbon dioxide emission rates were respectively 3.75 g CO 2 equivalent day -1 kg -1 and 1.73 g CO 2 equivalent day -1 kg -1 , while nitrous oxide emission rates were negligible. The total average GHG emission rate measured in this study was 5.48 g CO 2 equivalent day -1 kg -1 . On average, GHG emissions from the uncovered EMB were the largest, while those from the covered EMB were the lowest. Emissions were maximum during the summer and at their lowest during the spring, and night emissions were larger than those that occurred during the daytime. Estimations based on the results of this study indicate that the addition of a blown chopped straw cover on an EMB can yield reductions in CO 2 and CH 4 emissions of 56 and 786 tons of CO 2 equivalent per year, respectively, for each 1,000-sow increment.