I wonder what this is supposed to prove, other than that they can grow bovine muscle cells in a lab.
Cells grown in the lab are fed with medium containing 10% fetal bovine serum (FBS). FBS is collected from the fetuses from slaughtered cows. Within the scientific community, there is some discussion of the ethics of collecting this material. I believe that it is justified on the basis that after the mother is slaughtered, the fetus becomes unconscious and presumably does not feel the collection process. (I won’t go into details of how it is done.)
In any case, to grow up cells in the quantities necessary to commercialize vat-grown meat, it would take vast quantities of FBS. Being a limited commodity, FBS is rather expensive. Furthermore, I don’t see its availability increasing much. Any lab-grown meat would be quite expensive. Might as well save the time, effort, and money and just eat the cows.
Not saying the collection process is right.
I just want to point out that the people mostly likely finding this offensive - cruelty in how the unborn calf is treated and the possible pain it might endure - are very likely the same people that have no problem with human abortions.