Skip to main content

Table 5 Stunning and killing of rainbow trout in the field study: overview of applied stunning methods, electrical parameters, stunning success and times

From: Is humane slaughtering of rainbow trout achieved in conventional production chains in Germany? Results of a pilot field and laboratory study

Stunning intervention.Electrical parameters Stunning successInjuries/ mis-hitsTime until exsanguinationBehavioural signs at time of slaughtering
Water conductivity [μS/cm; MIN-MAX]Voltage [V; MIN-MAX]Electric current densities [A/dm2; MIN-MAX]Stunning time (seconds or minutes)[%; (n/total number of fish)][%; (n/total number of fish)][seconds or minutes; MIN-MAX][%; (n/total number of fish)]
Stunning by percussion (n = 8 stunning interventions)
1n.a.n.a.n.a.n.a.83.0 (7/11)0.0 (0/11)60–95 s.27.0 (3/11)
2n.an.an.an.a95.0 (19/20)50.0 (4/8)15–20 s.0.0 (0/20)
3n.an.an.an.a95.0 (19/20)70.0 (7/10)15–30 min.5.0 (1/20)
4n.a.n.an.an.a.100.0 (20/20)10.0 (1/10)5–10 min.0.0 (0/20)
5n.a.n.a.n.a.n.a.100.0 (20/20)10.0 (1/10)20 s. – 5 min.0.0 (0/20)
6n.a.n.a.n.a.n.a.80.0 (16/20)50.0 (5/10)10–20 min.10.0 (2/20)
7n.a.n.a.n.a.n.a.100.0 (10/10)100.0 (10/10)2–5 min.0.0 (0/10)
8n.a.n.a.n.a.n.a.95.0 (19/20)50.0 (5/10)20–25 min.10.0 (1/10)
Summary Percussion (N = 8)n.an.an.an.a92.2 (130/141)41.8 (33/79)15 s. – 30 min.5.3 (7/131)
Electrical stunning (a: in a water bath,n = 9 stunning interventions;b: on wet electrodes outside the water, n = 1 stunning intervention)
9a45336–470.0163–0.02133 min.100.0 (10/10)10.0 (1/10)2–5 min.0.0 (0/10)
10a33433–360.0245–0.02671 min.70.0 (14/20)60.0 (6/10)60–90 s.35.0 (7/20)
11a613360.006130–45 s.100.0 (10/10)0.0 (0/10)10–120 min.0.0 (0/10)
12a604360.006430–45 s.100.0 (10/10)0.0 (0/10)10–120 min.0.0 (0/10)
13a438340.019660 s.100.0 (20/20)20.0 (2/10)20–90 min10.0 (1/10)
14a969200.12120 s.20.0 (2/10)30.0 (3/10)2–4 min.80.0 (8/10)
15a910200.11420 s.20.0 (2/10)30.0 (3/10)2–4 min.70.0 (7/10)
16a7562300.43530 s.95.0 (19/20)20.0 (2/10)2 min.10.0 (1/10)
17a7562300.43530 s.95.0 (19/20)40.0 (4/10)2 min.10.0 (1/10)
19b20953.3Not measurable2 min.95.0 (19/20)70.0 (7/10)2–5 min.10.0 (1/10)
Summary Electrical stunning (N = 10)334–96920–2300.0061–0.43520 s. – 3 min.83.3 (125/150)28.0 (28/100)1–120 min.23.6 (26/110)
Electrical stunning followed by percussion (c: electrical stunning in a water bath, n = 2;d: electrical stunning first on wet electrodes outside the water followed by electrical stunning in a water bath, n = 1)
20c57737.60.043420 s.100.0 (10/10)20.0 (2/10)20 s.0.0 (0/10)
21c82228.50.1461 min.100.0 (6/6)0.0 (0/6)60–90 s.0.0 (0/6)
22d441360.13598 min
(3 min dry,
5 min in water)
100.0 (20/20)0.0 (0/10)2–5 min.0.0 (0/10)
Summary Electrical stunning followed by percussion
(N = 3)
577–82228.5–37.60.0434–0.14620 s. – 8 min.100.0 (26/26)12.5 (2/16)20 s. – 5 min.0 (0/16)