Key parameters of head-heart electrical stunning need to be adapted to improve stunning effectiveness and meat quality in pigs of different genetic lines.

Adjustment of key parameters of electrical stunning of pigs is necessary to better respect animal welfare and avoid impairments of meat quality. In the present study, we analysed the effect of genetic line, stunning program and genetic line × stunning program interactions on stunning effectiveness, carcass and meat quality traits in 10,338 pigs from five different genetic lines in a German slaughterhouse using electrical stunning (two-cycle method head/heart current). Genetic line, stunning program and its interaction significantly influenced stunning effectiveness and pH in the semimembranosus muscle. Backup stunning rates ranged from 1.59 to 5.01% in the five genetic lines, and were significantly decreased (2.85%) in program 1 using a current of 1.3 to 1.35 A, 800 Hz and 1 s for the head-cycle compared to program 2 (4.73%) with 1.8 A, 100 Hz and 4.5 s. We suggest to consider genetic line × stunning program interactions when adjusting officially defined stunning parameters for head-heart electrical stunning.