Co-digestion of dairy cattle slurry and industrial meat-processing by-products - Effect of ultrasound and hygienization pre-treatments

► Co-digestion of ABPs and cattle slurry improved the CH4 production. ► Ultrasound and hygienization pre-treatments improved CH4 yields and biodegradation. ► Low ultrasound inputs improved CH4 yields more than the more hydrolyzing energies. ► A positive net energy yield is possibly to achieve with the studied pre-treatments.