This is definitely a nuanced issue. I'm sure there's worse going on than what's in this experiment, and the food industry is certainly far worse. I just wish we'd say the quiet part out loud and put more effort into discovering where that line should be. The ethics section of this paper in its entirety is:

> This work did not require ethical approval. We minimized the number of animals used in the experiment and kept manipulations to a minimum.

edit: formatting