The Canadian swine industry produces around 2 million tons of carbon dioxide (CO2) equivalents of methane gas per year. This corresponds to 54% of the emissions coming from manure management in Canada. A reduction in methane emissions would mean a better management of organic carbon coming from manure. Regarding dinitrogen oxide (N2O), pig manure emits annually 130 000 tons of this gas in CO2 equivalents. Reducing these nitrogen losses to the atmosphere would improve the energy efficiency of soil fertilizers. The efficiency of a floating roof to reduce nitrogen losses and the ability of a biofilter to trap and oxidize methane emitted from a slurry storage tank had been examined. This study confirmed that a covered tank emits much less ammonia than a non-covered one. This improved nitrogen conservation reduces the cost of nitrogen fertilizers. Considering annual precipitations of 600mm, a floating roof increases the storage capacity of the tank by 15%. Generally, installing a cover on an existing tank is less expensive than building a new covered tank. According to literature, hermetic covers offer an excellent odour-reducing potential. In terms of methane oxidization and its consequent decreased emission, biofiltration showed very encouraging results: a decrease in methane emissions by 80% or more with every type of filter material tested. Thus, a floating cover can altogether decrease odours and manure dilution, and increase the storage capacity of the tank and the nitrogen concentration of the pig slurry.