I understood that the time pressure lead to mistakes that made some experiments useless. So they had to be repeated, which means more animals in total died than

I understood that the time pressure lead to mistakes that made some experiments useless. So they had to be repeated, which means more animals in total died than if the experiments had been done correctly the first time. Of course the specific animals would have been used for other experiments, but it would have affected the total number of animals bred and killed.