The first generation (P1) of gilts (31 exposed, 18 sham exposed) was mated after 4 month of the experiment with unexposed boars. Some of them were killed at day 100 of gestation (teratological examination I), the others produced a F1 generation of offspring (litter I). The P1 sows which produced the F1 generation were mated again after 10 month of exposure/sham exposure and were killed at day 100 of gestation (teratological examination II). The F1 gilts (29 exposed, 14 sham exposed) were mated at the age of 18 month (litter II) and again 10 month later, but then killed at day 100 of gestation (teratological examination III).
Exposure duration: 20 h/day, 7 days/week
|Exposure duration||20 h/day, 7 days/week|
|electric field strength||30 kV/m||unspecified||measured||-||-|
No significant differences occurred in malformation incidence, litter size, fetal mass or mass of fetal organs between the first offspring of the exposed and the sham exposed P1-sows (litter I + teratological examinations I). However, a greater malformation incidence was found in the second offspring of the exposed P1-sows, but no differences in litter size, fetal mass or mass of fetal organs were observed when compared to the sham exposed P1-sows(teratological examinations II). In the first offspring of the exposed F1-sows significantly more malformations were found than in the first offspring of the sham exposed F1-sows (litter II). However, no significant difference in the number of malformations was found between the second offspring of the exposed F1-sows and the second offspring of the sham exposed F1-sows (teratological examinations III).
The authors conclude that there could be an association between exposure to a 60 Hz-electric field and malformations in the offspring of swine, though a number of potentially interacting factors may be involved in the responses, too.