First I'll answer scenario two:
For scenario two, I would definitely kill the man to save the child because it is socially acceptable to. This means I would not get in trouble by the law and I could still spread my message about animal rights without being looked down upon.
Scenario one is very difficult for me to answer. Part of me would want to kill the man for killing the animal, but the other part of me doesn't want to because the man was raised in conditions that animals are not respectable creatures. If I did kill this man, I would feel guilty because he honestly did not feel he was doing any harm because there was nothing really warning him before on why not to do it. Also, if I decided to kill this man, then I would be ostracized for this and never be taken seriously when I discuss animal rights. I also would have gone to jail and not be able to spread my message.
To be honest, I rather not have had to kill both men, but what am I to do? I want both the child and the cow to be saved, but one is socially acceptable to kill for and one is not. I really didn't want anyone to have to die. I also don't think that there would be any situation where there weren't more options for me to stop the murdering of the child and the cow.