I don't think they were his chickens, so he might have been killing them.

If you read the memoir of poet Reinaldo Arenas, he said he would fuck chickens on his family farm as a kid, so that is probably when Bolsonaro did this as well.

You'll probably find it about as fast as me, depending on how much wading you will tolerate. I swear this used to be more available, I saw the video of him saying it! Apparently the program he said it on was called CQC and is not airing anymore, but that article is understandably more concerned with his cartoonish racism and homophobia.

I think this is it? It's not subtitled, though