This has nothing to do with chickens, but it has something to do with life. Before I retired I had to sometimes referee disagreements between people. Sometimes there are just basic differences, but a whole lot of problems were solved just by getting them to agree on what they were talking about. Somebody misunderstood what someone else said or meant and got their feelings hurt. Often they were arguing the same side of a question but just didn't realize it.
Cull is one of those words that means different things to different people. To some people it means to kill. To some it means to select or sort. If you know the person you are talking to and they know what you mean, fine. Use it as you wish. But if you throw it out ot the general population, don't be surprised if someone doesn't understand what you mean.
We can sit here arguing about what a word means to you as much as you want. Some people enjoy that kind of argument. It means this! No, it means that! He said! She said! Personally,I find that stuff a waste of time.
editted to add: To me, language is a tool designed to aid communication. If it is used correctly (and I consider Webster to define "correctly") it enables us to communicate clearly. But just like any tool, if it is not used correctly, it does not do a good job.