The 60% is indeed what we studied for cows here in Switzerland. It is clearly related to the amount of time they live longer (18 instead of 11 month). You can c

The 60% is indeed what we studied for cows here in Switzerland. It is clearly related to the amount of time they live longer (18 instead of 11 month). You can check the source here: http://www.eaternity.org/blog/smart-chefs-research-results http://www.eaternity.org/blog/smart-chefs-research-results