6a00e009947fe2883301b8d061965e970c-320wiA few weeks ago I talked about the common practice of maceration in our egg industry. This is the mass killing of male chicks—of no use to the industry since they don’t lay eggs. These baby birds are dumped into massive grinders while fully conscious, or sometimes simply thrown live into trash bags to suffocate, on the first day of their lives. 
You can read more in this blog from the US Humane Society. 
Just to remind you this is a process approved by the SPCA’s blue tick programme along with beak trimming. So if you are buying eggs with the blue tick you know the producers do this with the blessing of the SPCA which defies belief.