"love between mature and consenting beings"
Human beings are animals on this earth as any other. We can barely live together with each other leaving those who have transcended race seem as paragons of our species. I think the real trailblazers are those who have transcended species but that's another discussion. I've never participated in any form of animal copulation but that weakness I share with so many other humans, again, isn't what this is about. This is simply about choice and the right of living things to coexist and be happy together. It's not something that any human or government has a right to judge or legislate against. The sooner we begin to accept the love between to mature and consenting beings then the better off we will be as a planet.
Also, I encourage you to not use loaded labels like bestiality to describe people's choice of life-style. It's not hard to to use species-neutral language but if you most then just treat everything like a human and that includes showing animals (as you would humans) proper respect.
I really hope you're a troll.
Animals cannot consent, and to top that off, a chicken is not built to accommodate a human penis.
Severe internal injury is a possibility, in addition to mental trauma. Poor chicken.
The only case where bestiality could be even remotely acceptable is if the animal is the active part (e.g. "Mr. Hands"), because, you know, an animal actively inserting its dick could probably be seen as consent. Still, it's a line that's better not crossed.