@Arcana https://www.nature.com/articles/243171a0damn this is cool, parthenogenesis has happened randomly in chickens
anyway yeah, milk production is often violent. it doesn't have to be but its so hard to avoid, they'd need to commit to keeping cows for life after they stop producing milk and to not taking away calves. my highly sanguine thinking is if all the calves were female (as in the case of some reptiles) they wouldn't be taken away. this sort of genetic modification is much more likely to be successful in chickens (who are sauropsids) than cows.
a much more likely and sane solution is selecting for female chickens only by centrifuging the male haploid contribution instead of killing male chicks at birth, but why keep so many male cows/roosters around if not for meat? far less males than females are needed yes, it is possible, but somewhat unnatural, and a vegetarian food production model in that regard could be very expensive or violent considering. parthenogenesis is thus the ideal but very ambitious, certainly.
its possible to coax female-female reproduction in individual cases, without germline editing, as in the case of the bimaternal mice, this is also a nice medium.