Of all animals to merge with, why on EARTH would they chose a cow? I'm sure they worked it all out and have their reasons, but it seems to me like a step back in evolution rather than a step forward. Even if it was for medical treatment, I'd prefer not to have a cell with the DNA of a completely incapable animal grown into me. Besides, even if it is just 1% 'animal', there's a strong likelihood that the average human body would still reject it. Sometimes the reactions triggered by experiments such as these can be fatal, and there's no telling if one of these cells being injected into a monkey and successfully treating a condition would mean that it could work on a human. Preliminary stages of new tiers of research are the most susceptible to failure...yet the impact can be profound if it can work and is approved of. No doubt there would be major controversy, but society overall trends towards the liberal over time in terms of concepts such as these.