Bestiality, Rape, and Consent

Bestiality in the sense relevant here is sexual intercourse of humans with lower animals. Is there anything morally wrong with it? Some say that there is because lower animals cannot be consensual partners in bestial relations.  Here is one form the argument might take. 

Argument from consent against bestiality 

1) It is morally wrong to do anything to a sentient being without that being's express consent.
2) Bestiality is the initiation by a human of sexual relations with a non-human sentient being without that being's express consent.
Therefore
3) Bestiality is morally wrong.

Is (1) true? Here are some putative counterexamples.  a) Raising, killing, and eating animals for food. ('Turkey Day' is coming!) b) Killing animals (and humans) in self-defense. c) The majority of cases of punishment from the obviously legitimate and necessary disciplining of children to the obviously legitimate and necessary incarceration of some criminals to capital punishment. 

Surely (1) is false given (b) and (c). Suppose we substitute for (1)

1*) It is morally wrong to do anything to a sentient being capable of granting consent without that being's consent. 

This change blocks counterexample (c), but not (a) or (b). So (1*) is false too given (b). Because (b) is false. the following argument against rape  unsound:

1*) It is morally wrong to do anything to a sentient being capable of granting consent without that being's consent. 
4) Rape is the initiation of sexual relations by a human being with a human being capable of granting consent at the time at which the sexual relations are initiated without that being's consent.
Therefore
5) Rape is morally wrong.

Now people who are not morally obtuse 'know' that there is something deeply immoral about bestiality and rape. What then makes these actions morally wrong? My tentative conclusion at the moment is merely negative: it is that considerations of consent do not contribute to sound arguments against these actions.  

Comments

[Vlastimil]

Comment of my fb friend:

"It is morally wrong to do anything to a being with preferences, who would be capable of granting or withholding consent if they had sufficient cognitive capacity, if it harms them, if they do not consent and would not have consented under idealised circumstances. It is also morally wrong to financially support people in doing so when you can reasonably avoid it. For this reason rape, buying meat, and some but not all instances of bestiality are morally wrong.
No-one who is not vegan is in a position to criticize people who practice bestiality."

Reply welcome.

[BV]

Hi Vlastimil. Thanks for the comment.

>>"It is morally wrong to do anything to a being with preferences, who would be capable of granting or withholding consent if they had sufficient cognitive capacity, if it harms them, if they do not consent and would not have consented under idealised circumstances.<<

False! It is morally permissible to shoot a home invader who poses a credible threat to oneself or to one's family members.

>>No-one who is not vegan is in a position to criticize people who practice bestiality<<

False! See arguments above.