Field experiments were conducted in Brittany (western France) in 2012 to measure and compare ammonia emissions after surface application and injection of fattening and farrowing-gestating pig slurry. Experiments were conducted on wheat stubble. Ammonia emissions were measured using wind tunnels. The results showed a reduction in ammonia emissions after injection compared to broadcast spreading whatever the slurry. However, the reduction in ammonia volatilization using the injection technique was less with the farrowing/gestating slurry (65% reduction) than with the fattening slurry (97% reduction). The lesser reduction was associated with lower emissions of total ammonia nitrogen in farrowing slurry (16% of the N-NH 4 + applied) compared to the fattening slurry (74% of the N-NH 4 + applied). The lower ammonia emissions were attributed to lower dry matter content and less ammonium in the farrowing/gestating pig slurry compared to the fattening pig slurry. © 2019 Elsevier B.V.